US20010033985A1 - Electrostatic printing of a metallic toner applied to solid phase crystallization and silicidation - Google Patents
Electrostatic printing of a metallic toner applied to solid phase crystallization and silicidation Download PDFInfo
- Publication number
- US20010033985A1 US20010033985A1 US09/757,306 US75730601A US2001033985A1 US 20010033985 A1 US20010033985 A1 US 20010033985A1 US 75730601 A US75730601 A US 75730601A US 2001033985 A1 US2001033985 A1 US 2001033985A1
- Authority
- US
- United States
- Prior art keywords
- photo
- toner
- metal
- sensitive surface
- silicon
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000002425 crystallisation Methods 0.000 title claims description 36
- 230000008025 crystallization Effects 0.000 title claims description 36
- 239000007790 solid phase Substances 0.000 title description 2
- 229910052751 metal Inorganic materials 0.000 claims abstract description 82
- 239000002184 metal Substances 0.000 claims abstract description 81
- 239000000463 material Substances 0.000 claims abstract description 52
- 239000004065 semiconductor Substances 0.000 claims abstract description 40
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims abstract description 39
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 39
- 239000010703 silicon Substances 0.000 claims abstract description 39
- 229910021332 silicide Inorganic materials 0.000 claims abstract description 26
- 229910021420 polycrystalline silicon Inorganic materials 0.000 claims abstract description 22
- 238000000137 annealing Methods 0.000 claims abstract description 21
- 229910052763 palladium Inorganic materials 0.000 claims abstract description 14
- 229910052697 platinum Inorganic materials 0.000 claims abstract description 10
- 229910052759 nickel Inorganic materials 0.000 claims abstract description 9
- 229910052804 chromium Inorganic materials 0.000 claims abstract description 8
- -1 such as Substances 0.000 claims abstract description 8
- 238000000034 method Methods 0.000 claims description 74
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 claims description 31
- 239000000758 substrate Substances 0.000 claims description 21
- 239000002923 metal particle Substances 0.000 claims description 20
- 229910021417 amorphous silicon Inorganic materials 0.000 claims description 18
- 150000001875 compounds Chemical class 0.000 claims description 18
- 239000011521 glass Substances 0.000 claims description 18
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims description 18
- 230000015572 biosynthetic process Effects 0.000 claims description 17
- FVBUAEGBCNSCDD-UHFFFAOYSA-N silicide(4-) Chemical compound [Si-4] FVBUAEGBCNSCDD-UHFFFAOYSA-N 0.000 claims description 17
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 16
- 230000001464 adherent effect Effects 0.000 claims description 16
- 230000005684 electric field Effects 0.000 claims description 15
- 239000000203 mixture Substances 0.000 claims description 10
- 239000011651 chromium Substances 0.000 claims description 9
- 239000010409 thin film Substances 0.000 claims description 9
- 238000000354 decomposition reaction Methods 0.000 claims description 8
- 239000004033 plastic Substances 0.000 claims description 8
- 229920003023 plastic Polymers 0.000 claims description 8
- 229910052709 silver Inorganic materials 0.000 claims description 7
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 claims description 6
- 239000012530 fluid Substances 0.000 claims description 6
- 230000003287 optical effect Effects 0.000 claims description 6
- 239000004332 silver Substances 0.000 claims description 6
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 claims description 5
- BUGBHKTXTAQXES-UHFFFAOYSA-N Selenium Chemical compound [Se] BUGBHKTXTAQXES-UHFFFAOYSA-N 0.000 claims description 5
- WBFMCDAQUDITAS-UHFFFAOYSA-N arsenic triselenide Chemical compound [Se]=[As][Se][As]=[Se] WBFMCDAQUDITAS-UHFFFAOYSA-N 0.000 claims description 5
- 229920005989 resin Polymers 0.000 claims description 5
- 239000011347 resin Substances 0.000 claims description 5
- 229910052711 selenium Inorganic materials 0.000 claims description 5
- 239000011669 selenium Substances 0.000 claims description 5
- 239000004593 Epoxy Substances 0.000 claims description 4
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 4
- 239000004642 Polyimide Substances 0.000 claims description 4
- 125000002091 cationic group Chemical group 0.000 claims description 4
- 229910052732 germanium Inorganic materials 0.000 claims description 4
- GNPVGFCGXDBREM-UHFFFAOYSA-N germanium atom Chemical compound [Ge] GNPVGFCGXDBREM-UHFFFAOYSA-N 0.000 claims description 4
- 229920001721 polyimide Polymers 0.000 claims description 4
- 230000000717 retained effect Effects 0.000 claims description 4
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 claims description 3
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 claims description 3
- 150000004696 coordination complex Chemical class 0.000 claims description 3
- 150000002736 metal compounds Chemical class 0.000 claims description 3
- 150000002902 organometallic compounds Chemical class 0.000 claims description 3
- 108091008695 photoreceptors Proteins 0.000 claims description 3
- 108020003175 receptors Proteins 0.000 claims description 3
- 239000011135 tin Substances 0.000 claims description 3
- 229910052718 tin Inorganic materials 0.000 claims description 3
- 229910052726 zirconium Inorganic materials 0.000 claims description 3
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 claims description 2
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 claims description 2
- 229910000577 Silicon-germanium Inorganic materials 0.000 claims description 2
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims description 2
- LEVVHYCKPQWKOP-UHFFFAOYSA-N [Si].[Ge] Chemical compound [Si].[Ge] LEVVHYCKPQWKOP-UHFFFAOYSA-N 0.000 claims description 2
- 229910052782 aluminium Inorganic materials 0.000 claims description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 2
- UHYPYGJEEGLRJD-UHFFFAOYSA-N cadmium(2+);selenium(2-) Chemical compound [Se-2].[Cd+2] UHYPYGJEEGLRJD-UHFFFAOYSA-N 0.000 claims description 2
- 229910017052 cobalt Inorganic materials 0.000 claims description 2
- 239000010941 cobalt Substances 0.000 claims description 2
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 claims description 2
- 229910052735 hafnium Inorganic materials 0.000 claims description 2
- VBJZVLUMGGDVMO-UHFFFAOYSA-N hafnium atom Chemical compound [Hf] VBJZVLUMGGDVMO-UHFFFAOYSA-N 0.000 claims description 2
- WPYVAWXEWQSOGY-UHFFFAOYSA-N indium antimonide Chemical compound [Sb]#[In] WPYVAWXEWQSOGY-UHFFFAOYSA-N 0.000 claims description 2
- 229910052742 iron Inorganic materials 0.000 claims description 2
- 229910052749 magnesium Inorganic materials 0.000 claims description 2
- 239000011777 magnesium Substances 0.000 claims description 2
- 229910052750 molybdenum Inorganic materials 0.000 claims description 2
- 239000011733 molybdenum Substances 0.000 claims description 2
- 229910052758 niobium Inorganic materials 0.000 claims description 2
- 239000010955 niobium Substances 0.000 claims description 2
- GUCVJGMIXFAOAE-UHFFFAOYSA-N niobium atom Chemical compound [Nb] GUCVJGMIXFAOAE-UHFFFAOYSA-N 0.000 claims description 2
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 claims description 2
- 229910010271 silicon carbide Inorganic materials 0.000 claims description 2
- 229910052715 tantalum Inorganic materials 0.000 claims description 2
- GUVRBAGPIYLISA-UHFFFAOYSA-N tantalum atom Chemical compound [Ta] GUVRBAGPIYLISA-UHFFFAOYSA-N 0.000 claims description 2
- 229910052719 titanium Inorganic materials 0.000 claims description 2
- 239000010936 titanium Substances 0.000 claims description 2
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 claims description 2
- 229910052721 tungsten Inorganic materials 0.000 claims description 2
- 239000010937 tungsten Substances 0.000 claims description 2
- 239000003054 catalyst Substances 0.000 abstract description 21
- 238000006243 chemical reaction Methods 0.000 abstract description 4
- 238000012986 modification Methods 0.000 abstract description 3
- 230000004048 modification Effects 0.000 abstract description 3
- 239000010408 film Substances 0.000 description 29
- 239000002245 particle Substances 0.000 description 24
- 230000008569 process Effects 0.000 description 24
- 238000000151 deposition Methods 0.000 description 10
- 239000007788 liquid Substances 0.000 description 10
- 230000008021 deposition Effects 0.000 description 8
- 229920000642 polymer Polymers 0.000 description 7
- 239000003381 stabilizer Substances 0.000 description 7
- 150000002739 metals Chemical class 0.000 description 6
- 239000002243 precursor Substances 0.000 description 6
- 238000012545 processing Methods 0.000 description 6
- 230000003197 catalytic effect Effects 0.000 description 5
- GMSCBRSQMRDRCD-UHFFFAOYSA-N dodecyl 2-methylprop-2-enoate Chemical compound CCCCCCCCCCCCOC(=O)C(C)=C GMSCBRSQMRDRCD-UHFFFAOYSA-N 0.000 description 5
- 238000004519 manufacturing process Methods 0.000 description 5
- 239000000178 monomer Substances 0.000 description 5
- MUJIDPITZJWBSW-UHFFFAOYSA-N palladium(2+) Chemical compound [Pd+2] MUJIDPITZJWBSW-UHFFFAOYSA-N 0.000 description 5
- 235000012431 wafers Nutrition 0.000 description 5
- 239000003795 chemical substances by application Substances 0.000 description 4
- 239000006185 dispersion Substances 0.000 description 4
- 238000012674 dispersion polymerization Methods 0.000 description 4
- 150000002430 hydrocarbons Chemical class 0.000 description 4
- 239000003999 initiator Substances 0.000 description 4
- 238000003801 milling Methods 0.000 description 4
- 239000000047 product Substances 0.000 description 4
- 238000010956 selective crystallization Methods 0.000 description 4
- 229920002818 (Hydroxyethyl)methacrylate Polymers 0.000 description 3
- CNPVJWYWYZMPDS-UHFFFAOYSA-N 2-methyldecane Chemical compound CCCCCCCCC(C)C CNPVJWYWYZMPDS-UHFFFAOYSA-N 0.000 description 3
- 239000004215 Carbon black (E152) Substances 0.000 description 3
- JIGUQPWFLRLWPJ-UHFFFAOYSA-N Ethyl acrylate Chemical compound CCOC(=O)C=C JIGUQPWFLRLWPJ-UHFFFAOYSA-N 0.000 description 3
- WOBHKFSMXKNTIM-UHFFFAOYSA-N Hydroxyethyl methacrylate Chemical compound CC(=C)C(=O)OCCO WOBHKFSMXKNTIM-UHFFFAOYSA-N 0.000 description 3
- 230000002776 aggregation Effects 0.000 description 3
- 238000004220 aggregation Methods 0.000 description 3
- 238000000576 coating method Methods 0.000 description 3
- 230000006870 function Effects 0.000 description 3
- 229930195733 hydrocarbon Natural products 0.000 description 3
- 238000005224 laser annealing Methods 0.000 description 3
- 238000000059 patterning Methods 0.000 description 3
- PNJWIWWMYCMZRO-UHFFFAOYSA-N pent‐4‐en‐2‐one Natural products CC(=O)CC=C PNJWIWWMYCMZRO-UHFFFAOYSA-N 0.000 description 3
- 238000004151 rapid thermal annealing Methods 0.000 description 3
- 238000012546 transfer Methods 0.000 description 3
- OZAIFHULBGXAKX-UHFFFAOYSA-N 2-(2-cyanopropan-2-yldiazenyl)-2-methylpropanenitrile Chemical compound N#CC(C)(C)N=NC(C)(C)C#N OZAIFHULBGXAKX-UHFFFAOYSA-N 0.000 description 2
- OBETXYAYXDNJHR-UHFFFAOYSA-N 2-Ethylhexanoic acid Chemical compound CCCCC(CC)C(O)=O OBETXYAYXDNJHR-UHFFFAOYSA-N 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- VVQNEPGJFQJSBK-UHFFFAOYSA-N Methyl methacrylate Chemical compound COC(=O)C(C)=C VVQNEPGJFQJSBK-UHFFFAOYSA-N 0.000 description 2
- 230000009471 action Effects 0.000 description 2
- 229910045601 alloy Inorganic materials 0.000 description 2
- 239000000956 alloy Substances 0.000 description 2
- 150000001412 amines Chemical class 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 239000011230 binding agent Substances 0.000 description 2
- SHZIWNPUGXLXDT-UHFFFAOYSA-N caproic acid ethyl ester Natural products CCCCCC(=O)OCC SHZIWNPUGXLXDT-UHFFFAOYSA-N 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 239000011248 coating agent Substances 0.000 description 2
- 238000001246 colloidal dispersion Methods 0.000 description 2
- 239000007771 core particle Substances 0.000 description 2
- 238000004132 cross linking Methods 0.000 description 2
- VOZRXNHHFUQHIL-UHFFFAOYSA-N glycidyl methacrylate Chemical compound CC(=C)C(=O)OCC1CO1 VOZRXNHHFUQHIL-UHFFFAOYSA-N 0.000 description 2
- 229910052737 gold Inorganic materials 0.000 description 2
- 239000010931 gold Substances 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 239000011159 matrix material Substances 0.000 description 2
- 229910021421 monocrystalline silicon Inorganic materials 0.000 description 2
- 238000000206 photolithography Methods 0.000 description 2
- 238000006116 polymerization reaction Methods 0.000 description 2
- 229920005591 polysilicon Polymers 0.000 description 2
- 239000011164 primary particle Substances 0.000 description 2
- 125000006850 spacer group Chemical group 0.000 description 2
- 230000006641 stabilisation Effects 0.000 description 2
- 238000011105 stabilization Methods 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- RIOQSEWOXXDEQQ-UHFFFAOYSA-N triphenylphosphine Chemical compound C1=CC=CC=C1P(C=1C=CC=CC=1)C1=CC=CC=C1 RIOQSEWOXXDEQQ-UHFFFAOYSA-N 0.000 description 2
- 239000004342 Benzoyl peroxide Substances 0.000 description 1
- OMPJBNCRMGITSC-UHFFFAOYSA-N Benzoylperoxide Chemical compound C=1C=CC=CC=1C(=O)OOC(=O)C1=CC=CC=C1 OMPJBNCRMGITSC-UHFFFAOYSA-N 0.000 description 1
- BDAGIHXWWSANSR-UHFFFAOYSA-M Formate Chemical compound [O-]C=O BDAGIHXWWSANSR-UHFFFAOYSA-M 0.000 description 1
- CERQOIWHTDAKMF-UHFFFAOYSA-N Methacrylic acid Chemical compound CC(=C)C(O)=O CERQOIWHTDAKMF-UHFFFAOYSA-N 0.000 description 1
- BLRPTPMANUNPDV-UHFFFAOYSA-N Silane Chemical compound [SiH4] BLRPTPMANUNPDV-UHFFFAOYSA-N 0.000 description 1
- 229910008814 WSi2 Inorganic materials 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- NIXOWILDQLNWCW-UHFFFAOYSA-N acrylic acid group Chemical group C(C=C)(=O)O NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 238000003491 array Methods 0.000 description 1
- 238000000498 ball milling Methods 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- 239000011324 bead Substances 0.000 description 1
- WPYMKLBDIGXBTP-UHFFFAOYSA-N benzoic acid Chemical compound OC(=O)C1=CC=CC=C1 WPYMKLBDIGXBTP-UHFFFAOYSA-N 0.000 description 1
- 235000019400 benzoyl peroxide Nutrition 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- BGTFCAQCKWKTRL-YDEUACAXSA-N chembl1095986 Chemical group C1[C@@H](N)[C@@H](O)[C@H](C)O[C@H]1O[C@@H]([C@H]1C(N[C@H](C2=CC(O)=CC(O[C@@H]3[C@H]([C@@H](O)[C@H](O)[C@@H](CO)O3)O)=C2C=2C(O)=CC=C(C=2)[C@@H](NC(=O)[C@@H]2NC(=O)[C@@H]3C=4C=C(C(=C(O)C=4)C)OC=4C(O)=CC=C(C=4)[C@@H](N)C(=O)N[C@@H](C(=O)N3)[C@H](O)C=3C=CC(O4)=CC=3)C(=O)N1)C(O)=O)=O)C(C=C1)=CC=C1OC1=C(O[C@@H]3[C@H]([C@H](O)[C@@H](O)[C@H](CO[C@@H]5[C@H]([C@@H](O)[C@H](O)[C@@H](C)O5)O)O3)O[C@@H]3[C@H]([C@@H](O)[C@H](O)[C@@H](CO)O3)O[C@@H]3[C@H]([C@H](O)[C@@H](CO)O3)O)C4=CC2=C1 BGTFCAQCKWKTRL-YDEUACAXSA-N 0.000 description 1
- 239000004020 conductor Substances 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 229920001577 copolymer Polymers 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 239000003085 diluting agent Substances 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000007772 electroless plating Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000011888 foil Substances 0.000 description 1
- 238000009472 formulation Methods 0.000 description 1
- 239000012634 fragment Substances 0.000 description 1
- VZCYOOQTPOCHFL-OWOJBTEDSA-L fumarate(2-) Chemical compound [O-]C(=O)\C=C\C([O-])=O VZCYOOQTPOCHFL-OWOJBTEDSA-L 0.000 description 1
- 230000009477 glass transition Effects 0.000 description 1
- 125000003055 glycidyl group Chemical group C(C1CO1)* 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 125000005842 heteroatom Chemical group 0.000 description 1
- 238000000265 homogenisation Methods 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 125000004435 hydrogen atom Chemical class [H]* 0.000 description 1
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 1
- 238000003384 imaging method Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000010348 incorporation Methods 0.000 description 1
- 230000001939 inductive effect Effects 0.000 description 1
- 239000004615 ingredient Substances 0.000 description 1
- 239000012948 isocyanate Substances 0.000 description 1
- 150000002513 isocyanates Chemical class 0.000 description 1
- YDNLNVZZTACNJX-UHFFFAOYSA-N isocyanatomethylbenzene Chemical compound O=C=NCC1=CC=CC=C1 YDNLNVZZTACNJX-UHFFFAOYSA-N 0.000 description 1
- 238000005499 laser crystallization Methods 0.000 description 1
- 239000004973 liquid crystal related substance Substances 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- 230000000873 masking effect Effects 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 239000003863 metallic catalyst Substances 0.000 description 1
- 239000013528 metallic particle Substances 0.000 description 1
- 238000004377 microelectronic Methods 0.000 description 1
- HZPNKQREYVVATQ-UHFFFAOYSA-L nickel(2+);diformate Chemical compound [Ni+2].[O-]C=O.[O-]C=O HZPNKQREYVVATQ-UHFFFAOYSA-L 0.000 description 1
- 229910000510 noble metal Inorganic materials 0.000 description 1
- QIQXTHQIDYTFRH-UHFFFAOYSA-N octadecanoic acid Chemical compound CCCCCCCCCCCCCCCCCC(O)=O QIQXTHQIDYTFRH-UHFFFAOYSA-N 0.000 description 1
- 150000002924 oxiranes Chemical class 0.000 description 1
- APGNMHZUERWZME-UHFFFAOYSA-L palladium(2+);3,3,5,5-tetramethylhexanoate Chemical compound [Pd+2].CC(C)(C)CC(C)(C)CC([O-])=O.CC(C)(C)CC(C)(C)CC([O-])=O APGNMHZUERWZME-UHFFFAOYSA-L 0.000 description 1
- ZVSLRJWQDNRUDU-UHFFFAOYSA-L palladium(2+);propanoate Chemical compound [Pd+2].CCC([O-])=O.CCC([O-])=O ZVSLRJWQDNRUDU-UHFFFAOYSA-L 0.000 description 1
- LXNAVEXFUKBNMK-UHFFFAOYSA-N palladium(II) acetate Substances [Pd].CC(O)=O.CC(O)=O LXNAVEXFUKBNMK-UHFFFAOYSA-N 0.000 description 1
- YJVFFLUZDVXJQI-UHFFFAOYSA-L palladium(ii) acetate Chemical compound [Pd+2].CC([O-])=O.CC([O-])=O YJVFFLUZDVXJQI-UHFFFAOYSA-L 0.000 description 1
- 238000010951 particle size reduction Methods 0.000 description 1
- 229920002120 photoresistant polymer Polymers 0.000 description 1
- 238000000623 plasma-assisted chemical vapour deposition Methods 0.000 description 1
- 229920006267 polyester film Polymers 0.000 description 1
- 239000004814 polyurethane Substances 0.000 description 1
- 229920002635 polyurethane Polymers 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 238000010526 radical polymerization reaction Methods 0.000 description 1
- 150000003254 radicals Chemical class 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 239000003870 refractory metal Substances 0.000 description 1
- 239000004576 sand Substances 0.000 description 1
- 229910000077 silane Inorganic materials 0.000 description 1
- 239000010944 silver (metal) Substances 0.000 description 1
- RQZVTOHLJOBKCW-UHFFFAOYSA-M silver;7,7-dimethyloctanoate Chemical compound [Ag+].CC(C)(C)CCCCCC([O-])=O RQZVTOHLJOBKCW-UHFFFAOYSA-M 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 239000012798 spherical particle Substances 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- VZCYOOQTPOCHFL-UHFFFAOYSA-N trans-butenedioic acid Natural products OC(=O)C=CC(O)=O VZCYOOQTPOCHFL-UHFFFAOYSA-N 0.000 description 1
- 238000011282 treatment Methods 0.000 description 1
- 238000007738 vacuum evaporation Methods 0.000 description 1
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/02104—Forming layers
- H01L21/02365—Forming inorganic semiconducting materials on a substrate
- H01L21/02518—Deposited layers
- H01L21/02521—Materials
- H01L21/02524—Group 14 semiconducting materials
- H01L21/02532—Silicon, silicon germanium, germanium
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/02104—Forming layers
- H01L21/02365—Forming inorganic semiconducting materials on a substrate
- H01L21/02518—Deposited layers
- H01L21/02587—Structure
- H01L21/0259—Microstructure
- H01L21/02592—Microstructure amorphous
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/02104—Forming layers
- H01L21/02365—Forming inorganic semiconducting materials on a substrate
- H01L21/02656—Special treatments
- H01L21/02664—Aftertreatments
- H01L21/02667—Crystallisation or recrystallisation of non-monocrystalline semiconductor materials, e.g. regrowth
- H01L21/02672—Crystallisation or recrystallisation of non-monocrystalline semiconductor materials, e.g. regrowth using crystallisation enhancing elements
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
- H01L27/02—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier
- H01L27/12—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier the substrate being other than a semiconductor body, e.g. an insulating body
- H01L27/1214—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier the substrate being other than a semiconductor body, e.g. an insulating body comprising a plurality of TFTs formed on a non-semiconducting substrate, e.g. driving circuits for AMLCDs
- H01L27/1259—Multistep manufacturing methods
- H01L27/127—Multistep manufacturing methods with a particular formation, treatment or patterning of the active layer specially adapted to the circuit arrangement
- H01L27/1274—Multistep manufacturing methods with a particular formation, treatment or patterning of the active layer specially adapted to the circuit arrangement using crystallisation of amorphous semiconductor or recrystallisation of crystalline semiconductor
- H01L27/1277—Multistep manufacturing methods with a particular formation, treatment or patterning of the active layer specially adapted to the circuit arrangement using crystallisation of amorphous semiconductor or recrystallisation of crystalline semiconductor using a crystallisation promoting species, e.g. local introduction of Ni catalyst
Definitions
- This invention relates to a method and apparatus for crystallizing amorphous films into polycrystalline films and, more particularly, to an electrostatic printing method and apparatus for selective deposition of catalyst metals to achieving such selective crystallization.
- This invention also relates to a method and apparatus for forming metal silicide regions on amorphous/poly-Si films or Si wafers and, more particularly, to an electrostatic printing method and apparatus for selective deposition of metals of the metal silicides to achieving such selective silicidation.
- AMLCD active matrix liquid crystal display
- Transistors made from amorphous silicon exhibit low performance characteristics (compared to those made from single crystal silicon), with low carrier mobility being a determining property.
- researchers have recognized that converting amorphous silicon to poly crystalline silicon (poly-Si) will enhance performance considerably, even to a significant fraction of the performance of single crystal silicon, the material from which all integrated circuits are made.
- Poly-Si films can be deposited, deposited and recrystallized, or deposited in the amorphous ( ⁇ -Si) form and then crystallized into poly-Si films.
- the first two are solid phase crystallization techniques, while the third is a liquid phase crystallization technique.
- RTP rapid thermal process
- laser annealing techniques have the potential for effecting low temperature crystallization, laser crystallization suffers from the need to raster the laser beam; raising throughput issues. Laser annealing also exhibits other difficulties, e.g. reproducibility, uniformity and peel-off.
- the most commonly used methods for producing large grain poly-Si films are furnace annealing of ⁇ -Si films at temperatures of at least 600° C., with very long processing times (16-30 hours or longer for ⁇ -Si films) or the RTP approach (e.g., 700° C./5 mins).
- Liu et al. also report in the '826 patent that ⁇ -Si can be selectively crystallized by depositing the nucleating site performing material in a pattern thereon and subsequently subjecting the patternized surface to an anneal procedure. Because the nucleating site forming material is a metal, the treated surface of the subsequently crystallized silicon is not optimal for structures. As a result, additional processing steps are required to allow untreated surfaces to become boundaries for devices to be grown.
- Ohtani et al. in U.S. Pat. Nos. 5,585,291, 5,612,250, 5,643,826, 5,543,352, and 5,654,203 describe a solution method for applying a catalyst metal to enhance subsequent ⁇ -Si crystallization.
- catalysts can be used to reduce the time-temperature thermal budget needed for crystallization of semiconductor materials.
- catalytic agents like palladium or nickel can be deposited by various techniques like vacuum evaporation or from solution and such catalytic agents can substantially impact the thermal budget.
- the crystallization time may be shortened to as low as 4 minutes at 550° C. by such metal treatments.
- silicidation Besides selective area crystallization of an amorphous film, another microelectronic fabrication process of interest involving the selective area application of a metal on an amorphous or polycrystalline Si film or a Si wafer is selective area silicidation.
- a wide range of noble and refractory metals form compounds with Si called silicides.
- silicidation requires annealing of the related metal layer in contact with Si. Minimum annealing temperature depends on the silicide to be formed and varies from 400 to 1000° C. Silicides exhibit conductivities close to metals (0.1-0.01 S/cm) and in certain applications are preferable to metals where a better chemical stability or lattice match is desired.
- silicides include; electrical interconnects, Schottky contacts to form Schottky barrier diodes, gate electrodes in transistors, and source and drain contacts in transistors.
- silicidation requires a thicker layer of metal be deposited. This is because, in crystallization, the catalyst layer (which may be pure metal, or a metal containing material) deposited acts as the catalyst or seed layer and does not need to be thicker than a few tens of ⁇ .
- the silicide layer is required to be at least hundreds of ⁇ . Hence, a metal layer of similar thickness (hundreds of ⁇ ) is needed which is to be consumed during silicidation process.
- fabrication of silicide structures or patterns on a Si surface requires the metal layer to be patterned. Conventionally, this procedure is also performed by photolithography and requires a number of steps increasing the processing cost.
- the process of the invention is simple, low cost and is much like a copy machine and enables the printing of a toner for the purpose of selective area crystallization or silicidation, preferably on a silicon layer that resides on a low cost substrate. Glass, plastics and metal foils covered by an insulating layer can be used. The patterning and image registration can be performed to high accuracy using the process of the present invention.
- the process sequence may be modified by applying the catalyst-containing or metal containing toner to the substrate prior to semiconductor film deposition and annealing of the semiconductor film.
- the semiconductor film can be a material other than Si, e.g., carbon, germanium and alloys thereof.
- the present invention is directed to a method for applying metallic toner onto an amorphous semiconductor layer with the objective of selective area crystallization, the method comprising the steps of: (a) exposing a photo-sensitive surface to cause exposed areas of the surface to crosslink and exhibit an increase in resistivity in comparison with unexposed areas of the photo-sensitive surface; (b) charging the photo-sensitive surface, the exposed areas of the photo-sensitive surface retaining a charge longer than the unexposed areas; (c) applying a toner to the photo-sensitive surface, the toner attracted by retained charge on the exposed areas; (d) juxtaposing the photo-sensitive surface toned in step (c) to a layer of amorphous semiconductor and applying an electric field therebetween to cause the toner that is adherent to the photo-sensitive surface to migrate to the amorphous semiconductor layer; and (e) annealing the toned amorphous semiconductor layer to enable formation of polycrystalline semiconductor only in areas where the toner is adherent.
- step (d) further comprises exposing a photo-sensitive
- the photo-sensitive surface comprises a material such as epoxy cationic, acrylic free radical, and photosensitive polyimide.
- the toner contains a metal (a) chemically, wherein the toner is a compound or solution of the metal; (b) physically, wherein the metal is contained in the toner as metal particles; or (c) both.
- the metal contained in the toner is in a form selected from the group consisting of metal complex, pure metal particle, coated metal, and organometallic compound.
- the toner is a material selected from the group consisting of: a resin with metal particles, an organosol with metal particles, a metallo-organic decomposition compound, and a metallo-organic decomposition compound with metal particles.
- the metal or the metal particle is comprised of a metal selected from the group consisting of: palladium, silver, tin, nickel, platinum, chromium and mixtures thereof.
- the amorphous semiconductor layer comprises a material such as silicon, germanium, silicon-germanium, silicon-carbide, cadmium selenide, and indium antimonide.
- the amorphous semiconductor layer is disposed on a substrate, which comprises at least one material, such as silicon, metal, glass, or plastic.
- the present invention is also directed to a method for applying metallic toner onto an amorphous semiconductor layer with the objective or selective area crystallization, the method comprising the steps of: (a) charging a photo-sensitive surface; (b) exposing the photo-sensitive surface to an optical image or a digitally addressed beam to produce a latent image of charges on the photo-sensitive surface; (c) applying a toner to the photo-sensitive surface, the toner attracted to the charged areas of the photo-sensitive surface; (d) juxtaposing the photo-sensitive surface toned in step (c) to a layer of amorphous semiconductor and applying an electric field therebetween to cause the toner that is adherent to the photo-sensitive surface to migrate to the amorphous semiconductor layer; and (e) annealing the toned amorphous semiconductor layer to enable formation of polycrystalline semiconductor only in areas where the toner is adherent.
- the photo-sensitive surface comprises a material such as organic photoreceptor surface, arsenic triselenide, selenium, and silicon.
- the exposing of the photo-sensitive surface in step (b) is to an optical image or digitally addressed beam, such as, a LED or laser.
- the present invention is further directed to a method for the formation of silicide on a silicon surface comprising the steps of: (a) exposing a photo-sensitive surface to cause exposed areas of the surface to crosslink and exhibit an increase in resistivity in comparison with unexposed areas of the photo-sensitive surface; (b) charging the photo-sensitive surface, the exposed areas of the photo-sensitive surface retaining a charge longer than the unexposed areas; (c) applying a toner to the photo-sensitive surface, the toner attracted by retained charge on the exposed areas; (d) juxtaposing the photo-sensitive layer surface toned in step (c) to a silicon surface and applying an electric field therebetween to cause the toner that is adherent to the photo-sensitive surface to migrate to the silicon surface; and (e) annealing the toned silicon surface thereby enabling formation of silicide only in areas where the toner is adherent.
- step (d) further comprises interposing a nonconductive fluid between the photo-sensitive surface and the silicon
- the photo-sensitive surface comprises a material such as epoxy cationic, acrylic free radical, and photosensitive polyimide.
- the silicon surface for the above method can be amorphous, polycrystalline, or single crystalline.
- the photo-sensitive surface comprises a material such as organic photoreceptor surface, arsenic triselenide, selenium, and silicon.
- the toner contains a metal as detailed above.
- the metal or metal particle is a metal of the desired metal-silicide including: aluminum, cobalt, chromium, hafnium, iron, magnesium, molybdenum, nickel, niobium, palladium, platinum, tantalum, titanium, tungsten, zirconium and mixtures thereof.
- the silicon surface is an amorphous or polycrystalline silicon thin film disposed on a substrate.
- the substrate comprises at least one material, such as, silicon, metal, glass, or plastic.
- the present invention is still further directed to a method for the formation of silicide on a silicon surface comprising the steps of: (a) charging a photosensitive surface; (b) exposing the photosensitive surface to an optical image or a digitally addressed beam to produce a latent image of charges on the photosensitive surface; (c) applying a toner to the photosensitive surface, the toner attracted to the charged areas of the photosensitive surface; (d) juxtaposing the photo-sensitive layer surface toned in step (c) to a silicon surface and applying an electric field therebetween to cause the toner that is adherent to the photo-sensitive surface to migrate to the silicon surface; and (e) annealing the toned silicon surface thereby enabling formation of silicide only in areas where the toner is adherent.
- the photo-sensitive surface comprises a material selected from the group consisting of: organic receptor surface, arsenic triselenide, selenium, and silicon.
- the exposing of the photo-sensitive surface in step (b) is to an optical image or digitally addressed beam, such as, a LED or laser.
- This invention utilizes electrophotography to apply a crystallization catalyst to an amorphous semiconductor layer.
- the catalyst is subsequently employed to convert areas of the amorphous semiconductor layer to discrete, defined polycrystalline regions.
- This invention also utilizes electrophotography to apply a metal or metal containing material to a Si surface.
- the metal or metal containing material is subsequently employed to convert areas of the Si surface to discrete, defined metal-silicide regions.
- FIG. 1 illustrates a first step in the process of the invention wherein a photosensitive plate material is selectively cross-linked by application of actinic energy.
- FIG. 2 illustrates a second step in the process of the invention wherein a photosensitive plate material is electrostatically charged.
- FIG. 3 illustrates a third step in the process of the invention wherein catalyst-containing or metal containing toner is applied to the charged photosensitive plate material.
- FIG. 4 illustrates a fourth step in the process of the invention wherein the catalyst-containing toner is transferred from the charged photosensitive plate material to an amorphous semiconductor layer (or to a Si surface) by action of an applied electric field.
- FIGS. 5 a , 5 b illustrate an alternate fourth step in the process of the invention wherein the metal-containing toner is transferred from the charged photosensitive plate material to a substrate, followed by deposition thereon of a Si or other semiconductor layer and then followed by an anneal operation to achieve selective crystallization or silicidation of the Si layers that are in contact with the toner.
- a catalytic liquid toner is electrostatically printed on an amorphous silicon layer (or a substrate that is to support such a layer) in an image-wise fashion. After the liquid toner is dried, the amorphous silicon layer is heated, preferably using rapid thermal annealing, to approximately 550° C. for about 2 minutes to complete the polycrystalline conversion process.
- the toner used during the printing action is a dispersion of resin particles which contains a modest amount of metallic catalyst, such as palladium, silver, tin, nickel, platinum or chromium.
- a metal containing toner is electrostatically printed on a Si surface (Si wafer, amorphous/poly-Si layer).
- Si wafer Si wafer, amorphous/poly-Si layer.
- the conversion temperature depends on the type of silicide. For example, Pd 2 Si forms at ⁇ 400° C., while WSi 2 forms at ⁇ 1000° C.
- the printing step initially forms latent images on a photo-sensitive receptor plate or drum. Images can be created either electrophotographically, as in a Xerox-graphic copier, or digitally as in a laser printer.
- the latent images are developed by application of a liquid toner. The toner is then transferred to the Si surface. After the toner is dried, the patterning process is complete. The printed Si surface is now heat processed to complete the crystallization or silicidation process.
- the remaining unprinted Si regions are unconverted to poly-Si or metal silicide (in crystallization and silicidation, respectively) and need not be removed, a significant process saving step unless required by demands such as stress control or light transmission.
- FIG. 1 shows the first step in the electrostatic printing process of the invention, i.e., the making of the printing plate.
- a photosensitive surface such as a photopolymer material 10 , preferably in a dry film form, is laminated to a grounded substrate 12 .
- Photopolymer 10 exhibits the characteristics of photoresists that are used for photolithography applications (e.g., etch resistance).
- a preferred photopolymer is Dynachem 5038, available from the Dynachem Corporation, Tustin Calif.
- Another photopolymer that is acceptable is Riston 4615, a product of the Dupont Corporation, Wilmington, Del.
- Photopolymer 10 should have the characteristic of crosslinking in areas exposed to actinic energy. As shown in FIG. 1, photopolymer 10 is exposed through a photo tool to actinic radiation in the 300 to 400 nm range or the near ultra violet region of the spectrum. Exposure levels are typically from 50 to 500 millijoules per cm 2 . Such exposure causes areas 14 to crosslink and at this stage, the plate making step is complete. To achieve selective image-wise charging, a modulated laser beam may be swept across the surface of photosensitive material 10 in the manner of a laser printer. A similar result can be achieved through use of a line of modulated laser diodes that are moved over the surface of photosensitive material 10 .
- Photosensitive material 10 is now sensitized by charging it, for example with a corona unit, as shown in FIG. 2. A positive charge is shown as being applied but the photosensitive material 10 can accept either positive or negative charge.
- each sphere 16 comprises a metal catalyst particle encompassed by a polymeric shell. Details of the method of manufacture of toner particles 16 are given below.
- the plate including photosensitive material 10 is placed close to a Si surface 20 .
- the Si surface is that of a Si film 20 coated on a glass substrate 22 .
- a conductive layer 24 is disposed on the opposite face of glass plate 22 and is connected to a voltage supply 26 .
- the region between photosensitive material 10 and amorphous silicon layer 20 is filled with a nonconductive fluid, e.g., Isopar G, a product of the Exxon Corporation.
- the mechanical gap between amorphous silicon layer 20 and photoconductor 10 is preferably of the order of 50 to 150 microns.
- toner particles 16 are transferred across the fluid filled mechanical gap to amorphous silicon layer 20 by means of an electric field that is created when a transfer voltage is applied to conductor 24 by voltage supply 26 .
- the transfer voltage is typically in the range of 500 to 2000 volts, with a polarity opposite to that of the toner particles. Accordingly, the toner particles are attracted to Si surface 20 by the electric field and remain restricted to areas in alignment with those on photoconductor 10 .
- the toner “imaged” amorphous silicon layer 20 is now removed and dried before being furnace treated or subjected to a rapid thermal anneal process to produce Poly-Si where the toner was imaged.
- the selective crystallization of amorphous silicon layer 10 occurs as described by Liu et al. in U.S. Pat. No. 5,147,826 or Fonash et al. in U.S. Pat. No. 5,275,851, both described above and incorporated by reference herein.
- 20 represents the Si surface (Si wafer, amorphous/poly-Si film) on which a silicide pattern is to be defined.
- the toner transfer prior to annealing takes place the same way as described above for the crystallization case.
- FIG. 5 a illustrates an alternate fourth step in the process of the invention wherein the catalyst-containing toner is transferred from charged photosensitive plate material 10 to substrate 22 , followed by deposition thereon of amorphous semiconductor layer 20 (FIG. 5 b ). Then an anneal operation is performed to achieve selective crystallization of the amorphous semiconductor layer portions that are in contact with the toner.
- Samples of amorphous silicon layers were prepared by RF-PECVD from hydrogen diluted silane at 250° C. on Corning 7059 glass. These amorphous Si layers were then imaged in the following manner:
- amorphous Si layer was subjected to a rapid thermal anneal (RTA) process at 550-600° C. for 5 to 10 minutes at Penn State University. Poly silicon features were demonstrated in the areas covered with the palladium toner.
- RTA rapid thermal anneal
- An organosol toner was selected for use with the present invention.
- a preferred organosol is similar to organosol compositions reported in U.S. Pat. No. 3,900,412 (G. Kosel).
- This patent discloses a class of liquid toners that make use of self-stable organosols as polymeric binders to promote self-fixing of a developed latent image.
- Self-stable organosols are colloidal (0.1-1 micron diameter) particles of polymeric binder which are typically synthesized by nonaqueous dispersion polymerization in a low dielectric hydrocarbon solvent.
- the organosol particles are sterically-stabilized with respect to aggregation by the use of a physically-adsorbed or chemically-grafted soluble polymer. Details of the mechanism of such steric stabilization are provided by Napper in “Polymeric Stabilization of Colloidal Dispersions”, (Academic Press: New York, 1983). Procedures for effecting the synthesis of self-stable organosols, generally involving nonaqueous dispersion polymerization, are known to those skilled in the art and are described in detail in “Dispersion Polymerization in Organic Media”, K. E. J. Barrett ed., (John Wiley: New York, 1975).
- nonaqueous dispersion polymerization is a free radical polymerization carried out when one or more ethylenically-unsaturated (typically acrylic) monomers, soluble in a hydrocarbon medium, are polymerized in the presence of a preformed amphipathic polymer.
- the preformed amphipathic polymer commonly referred to as the stabilizer, has two distinct functional blocks, one essentially insoluble in the hydrocarbon medium, the other freely soluble.
- the amphipathic polymer then either adsorbs onto or covalently bonds to the core, which continues to grow as a discrete particle. The particles continue to grow until monomer is depleted.
- the adsorbed amphipathic polymer “shell” acts to sterically-stabilize the growing core particles with respect to aggregation.
- the resulting core/shell polymer particles comprise a self-stable, nonaqueous colloidal dispersion (organosol) comprised of distinct spherical particles in the size (diameter) range 0.1-1 microns.
- the composition of the insoluble organosol core is preferentially manipulated such that the organosol exhibits an effective glass transition temperature (T g ) of less than the development temperature (typically 23° C.), thus causing a toner composition containing the organosol as a major component to undergo rapid film formation (rapid self fixing) in printing or imaging processes that are carried out at temperatures greater than the core T g .
- Rapid self fixing is a liquid toner performance requirement to avoid printing defects (such as smearing or loss of image resolution) in high speed printing.
- the use of low T g resins to promote rapid self fixing of printed or toned images is known in the art, as exemplified by “Film Formation” (Z. W. Wicks, Federation of Societies for Coatings Technologies, 1986, p. 8).
- the resulting organosols can be subsequently converted to a liquid toner by incorporation of the metal catalyst and charge director, followed by high shear homogenization, ball-milling, attritor milling, high energy bead (sand) milling or other means known in the art for effecting particle size reduction in a dispersion.
- the input of mechanical energy to the dispersion during milling acts to break down aggregated particles into primary particles (0.05-1.0 micron diameter) and to “shred” the organosol into fragments which adhere to the newly-created metal catalyst surface, thereby acting to sterically-stabilize the metal particles with respect to aggregation.
- the charge director may be physically or chemically adsorbed onto the metal surface, the organosol or both. The result is a sterically-stabilized, charged, nonaqueous metal catalyst dispersion in the size range 0.1-2.0 microns, with typical toner particle diameters between 0.1-0.5 microns.
- each particular organosol in terms of the ratio of the total weight of monomers comprising the organosol core relative to the total weight of graft stabilizer comprising the organosol shell. This ratio is referred to as the core/shell ratio of the organosol.
- the compositional details of each particular organosol by ratioing the weight percentages of monomers used to create the shell and the core.
- the preferred organosol can be designated LMA/HEMA-TMI//MMA/EA(97/3-4.7//25/75%w/w), and comprises a shell composed of a graft stabilizer precursor which is a copolymer consisting of 97 weight percent lauryl methacrylate (LMA) and 3 weight percent hydroxyethylmethacrylate (HEMA), to which is covalently bonded a grafting site consisting of 4.7 weight percent TMI (dimethyl-m-isopropanol benzylisocyanate, from CYTEC Industries) based upon the total weight of the graft stabilizer precursor.
- LMA lauryl methacrylate
- HEMA hydroxyethylmethacrylate
- This graft stabilizer is subsequently covalently bonded to an organosol core which is comprised of 25 weight percent methyl methacrylate (MMA) and 75 weight percent ethyl acrylate (EA).
- MMA methyl methacrylate
- EA ethyl acrylate
- the preferred organosol makes use of an LMA/HEMA graft stabilizer precursor which is similar to the LMA/GMA (glycidyl methacrylate—precursor described in Example IV of U.S. Pat. No. 3,900,412; however, the grafting site was changed to permit grafting via formation of a polyurethane linkage between a hydroxyl group and an isocyanate, as opposed to grafting via formation of an epoxide linkage between glycidyl methacrylate and methacrylic acid.
- the grafting site was changed in order to take advantage of raw materials already available.
- the polymerization of the preferred organosol was carried out in ISOPAR L (the carrier liquid selected for use in fabricating toners) using azobisisobutyronitrile (AZDN from Elf-Atochem) as the free radical initiator.
- AZDN azobisisobutyronitrile
- the AZDN initiator was selected to provide a higher effective initiator concentration and lower initiator half-life relative to benzoyl peroxide, thereby limiting the molecular weight of the graft stabilizer to values below 500,000 Daltons.
- This toner was milled for 1.5 hours@2000 RPM using 1-2 mm stainless steel shot.
- the mean particle size was 0.333 microns. It appears that milling was effective at reducing the palladium powder to primary particles.
- MOD compounds are pure synthetic metallo-organic compounds, which decompose cleanly at low temperature to precipitate the metal as the metallic element.
- the organic moiety is bonded to the metal through a heteroatom providing a weak link that provides for easy decomposition at low temperature.
- the organic constituents evolve out as CO 2 and H 2 O or other hydrocarbon fragments leaving a well-bonded metallic trace on the surface, where the MOD compound was applied. Therefore, use of a MOD compound toner in the invention described here excludes the need for metallic particles.
- the function of the MOD compound is two-fold; (1) electrographic (charging), similar to organosol, and (2) to contain the metal; the catalyst for crystallization of an amorphous semiconductor layer (e.g., Pd, Ni, Cr, Pt) or the essential ingredient for converting a Si surface to a certain metal-silicide.
- the MOD compound functions electrographically by serving as the charge control agent bound to the particle which forms acid/base couples with the charge director dissolved in the diluent liquid.
- Use of a MOD toner is advantageous for the following reasons. First, the metal is contained chemically in the toner solution, and therefore the distribution of metal is very uniform (in the molecular scale).
- MOD compounds containing catalyst metals for crystallization are palladium(II) acetate (Pd(Oac) 2 ), palladium(II) formate, palladium(II) propionate, palladium(II) fumarate, palladium(II) stearate, palladium(II) benzoate, diacetatobis (triphenylphosphine) palladium(II), (U.S. Pat. No. 5,332,646), palladium neodecanoate (U.S. Pat. No. 4,262,040), and nickel formate Ni(HCO 2 ) 2 (U.S. Pat. No. 3,897,285).
- palladium(II) acetate Pd(Oac) 2
- palladium(II) formate palladium(II) propionate
- palladium(II) fumarate palladium(II) stearate
- MOD compounds which contain catalyst metals for crystallization are produced by Engelhard Co., NJ, and are sold under the catalog names 52D (Cr), A6051 (Cr), 58A (Ni), A2985 (Pd), A1121 (Pt), A6054A (Pt), M603B (Pt).
- the toner may also be composed of metal particles coated with a MOD compound coating.
- the MOD coating need not even contain the same metal as the particle to be coated.
- 50 nm Pd particles could have a thin layer of silver neodeconoate as a charge control agent. Once printed and dried, the Pd particle would have trace levels of silver on it. Then, in crystallization, the primary catalytic function is performed by the palladium particle, with the silver, inert to further processing.
- annealing can be carried out by variety of means, e.g., furnace annealing, rapid thermal annealing, inductive heating, microwave heating, etc.
- the processed material can be a material other than Si, e.g., carbon, germanium and alloys thereof. In case of a thin film material, it may reside on various substrates, e.g., silicon, metal, glass or plastics.
- the toner can generally contain the catalyst (for crystallization, e.g., Pd, Ni, Pt, Cr) or metal (for silicidation, i.e., metal of desired silicide) either chemically (the toner is a compound or solution of the metal) or physically (the metal is contained in the toner in terms of particles) or both. Accordingly, the present invention is intended to embrace all such alternatives, modifications and variances which fall within the scope of the appended claims.
- the catalyst for crystallization, e.g., Pd, Ni, Pt, Cr
- metal for silicidation, i.e., metal of desired silicide
Abstract
Description
- This Application claims benefit from U.S. Ser. No. 09/340,009 filed Jun. 25, 1999 and U.S. Provisional Patent Application Ser. No. 60/090,663, filed Jun. 25, 1998.
- This invention relates to a method and apparatus for crystallizing amorphous films into polycrystalline films and, more particularly, to an electrostatic printing method and apparatus for selective deposition of catalyst metals to achieving such selective crystallization. This invention also relates to a method and apparatus for forming metal silicide regions on amorphous/poly-Si films or Si wafers and, more particularly, to an electrostatic printing method and apparatus for selective deposition of metals of the metal silicides to achieving such selective silicidation.
- Large area amorphous silicon layers are widely used to make the transistors used for flat panel display devices. Indeed the most widely used flat panel display, i.e., the active matrix liquid crystal display (AMLCD), derives its name from an active matrix of transistors that are arranged in both the X and Y directions. A transistor made from amorphous silicon is placed at each picture element (pixel) in each color for a color display (red, green, and blue).
- Transistors made from amorphous silicon exhibit low performance characteristics (compared to those made from single crystal silicon), with low carrier mobility being a determining property. Researchers have recognized that converting amorphous silicon to poly crystalline silicon (poly-Si) will enhance performance considerably, even to a significant fraction of the performance of single crystal silicon, the material from which all integrated circuits are made.
- Studies of poly-Si thin film transistors have concentrated on methods for reducing their fabrication costs, either by reducing the transistors' processing time or by lowering the processing temperatures. The latter effect is important since it allows the usage of less expensive substrates for the transistor arrays, e.g., glass, plastic, etc . . . . For instance, Czubatyj et al. in “Low-Temperature Polycrystalline TFT on 7057 Glass”, IEEE Electron Device Letters, Vol. 10, pages 349-351, 1989, demonstrates that polysilicon thin film transistors can be fabricated on 7059 glass substrates using relatively low temperature furnace annealing for crystallization. However, the crystallization process takes longer than 75 hours and is therefore not practically applicable.
- Poly-Si films can be deposited, deposited and recrystallized, or deposited in the amorphous (α-Si) form and then crystallized into poly-Si films. There are three principal crystallization processes: furnace annealing, rapid thermal process (RTP) and laser annealing. The first two are solid phase crystallization techniques, while the third is a liquid phase crystallization technique. Although reported laser annealing techniques have the potential for effecting low temperature crystallization, laser crystallization suffers from the need to raster the laser beam; raising throughput issues. Laser annealing also exhibits other difficulties, e.g. reproducibility, uniformity and peel-off. The most commonly used methods for producing large grain poly-Si films are furnace annealing of α-Si films at temperatures of at least 600° C., with very long processing times (16-30 hours or longer for α-Si films) or the RTP approach (e.g., 700° C./5 mins).
- In “Low Thermal Budget Poly-Silicon Thin Film Transistors on Glass”, Japanese Journal of Applied Physics, Vol. 30, pages L269-L271, 1991, it was demonstrated that thin film transistors can be fabricated on poly-Si films made by the crystallization of pre-cursor α-Si films. Those polycrystalline films were obtained by a rapid thermal annealing of the precursor films for five minutes at 700° C. on Corning 7059 glass substrates.
- In U.S. Pat. No. 5,147,826 to Liu et al., it was shown that a thermal anneal procedure at 700° C. (for converting α-Si to poly-Si) can be reduced to a range of from 550° C. to 650° C. This improvement is accomplished by depositing a thin discontinuous film of a nucleating site forming material over an already deposited layer of α-Si. The α-Si film is then rapidly thermally annealed, with the nucleating site forming material enabling crystallization of the underlying α-Si at temperatures lower than theretofore reported.
- Liu et al. also report in the '826 patent that α-Si can be selectively crystallized by depositing the nucleating site performing material in a pattern thereon and subsequently subjecting the patternized surface to an anneal procedure. Because the nucleating site forming material is a metal, the treated surface of the subsequently crystallized silicon is not optimal for structures. As a result, additional processing steps are required to allow untreated surfaces to become boundaries for devices to be grown.
- In U.S. Pat. No. 5,275,826 of Fonash et al., a fabrication process for polycrystalline silicon thin film transistors is described that commences with a deposition of an ultra-thin nucleating-site forming layer onto the surface of an insulating substrate (e.g., 7059 glass, plastic). Next, an α-Si film is deposited thereover and the combined films are annealed at temperatures that do not exceed 600° C. By patterning the deposition of the nucleating site forming material on the glass substrate, the subsequently deposited α-Si film can be selectively crystallized only in areas in contact with the nucleating-site forming material.
- Ohtani et al. in U.S. Pat. Nos. 5,585,291, 5,612,250, 5,643,826, 5,543,352, and 5,654,203 describe a solution method for applying a catalyst metal to enhance subsequent α-Si crystallization.
- The aforesaid thus clearly indicates that catalysts can be used to reduce the time-temperature thermal budget needed for crystallization of semiconductor materials. For example, catalytic agents like palladium or nickel can be deposited by various techniques like vacuum evaporation or from solution and such catalytic agents can substantially impact the thermal budget. The crystallization time may be shortened to as low as 4 minutes at 550° C. by such metal treatments.
- Each of the above-cited references has employed some form of photolithographic masking to achieve selective deposition of the catalytic metal on selected parts of a substrate. Such procedures require a number of steps and add to the cost of the ultimate product made thereby.
- Accordingly, it is an object of this invention to provide an improved method and apparatus for applying a crystallization catalyst onto an amorphous semiconductor film.
- Besides selective area crystallization of an amorphous film, another microelectronic fabrication process of interest involving the selective area application of a metal on an amorphous or polycrystalline Si film or a Si wafer is selective area silicidation. A wide range of noble and refractory metals form compounds with Si called silicides. As in the case of metal-induced crystallization, silicidation requires annealing of the related metal layer in contact with Si. Minimum annealing temperature depends on the silicide to be formed and varies from 400 to 1000° C. Silicides exhibit conductivities close to metals (0.1-0.01 S/cm) and in certain applications are preferable to metals where a better chemical stability or lattice match is desired. Applications of silicides include; electrical interconnects, Schottky contacts to form Schottky barrier diodes, gate electrodes in transistors, and source and drain contacts in transistors. As different from metal-induced crystallization, silicidation requires a thicker layer of metal be deposited. This is because, in crystallization, the catalyst layer (which may be pure metal, or a metal containing material) deposited acts as the catalyst or seed layer and does not need to be thicker than a few tens of Å. On the other hand, in applications of silicides as stated above, the silicide layer is required to be at least hundreds of Å. Hence, a metal layer of similar thickness (hundreds of Å) is needed which is to be consumed during silicidation process. As in the case of selective area crystallization, fabrication of silicide structures or patterns on a Si surface requires the metal layer to be patterned. Conventionally, this procedure is also performed by photolithography and requires a number of steps increasing the processing cost.
- Accordingly, it is also an object of this invention to provide an improved method and apparatus for applying a metal onto a Si surface (Si wafer, amorphous/poly-Si film) with the purpose of obtaining silicide regions.
- The process of the invention is simple, low cost and is much like a copy machine and enables the printing of a toner for the purpose of selective area crystallization or silicidation, preferably on a silicon layer that resides on a low cost substrate. Glass, plastics and metal foils covered by an insulating layer can be used. The patterning and image registration can be performed to high accuracy using the process of the present invention.
- In the case of crystallization or silicidation of thin films according to the present invention, the process sequence may be modified by applying the catalyst-containing or metal containing toner to the substrate prior to semiconductor film deposition and annealing of the semiconductor film. The semiconductor film can be a material other than Si, e.g., carbon, germanium and alloys thereof.
- The present invention is directed to a method for applying metallic toner onto an amorphous semiconductor layer with the objective of selective area crystallization, the method comprising the steps of: (a) exposing a photo-sensitive surface to cause exposed areas of the surface to crosslink and exhibit an increase in resistivity in comparison with unexposed areas of the photo-sensitive surface; (b) charging the photo-sensitive surface, the exposed areas of the photo-sensitive surface retaining a charge longer than the unexposed areas; (c) applying a toner to the photo-sensitive surface, the toner attracted by retained charge on the exposed areas; (d) juxtaposing the photo-sensitive surface toned in step (c) to a layer of amorphous semiconductor and applying an electric field therebetween to cause the toner that is adherent to the photo-sensitive surface to migrate to the amorphous semiconductor layer; and (e) annealing the toned amorphous semiconductor layer to enable formation of polycrystalline semiconductor only in areas where the toner is adherent. In another embodiment of the invention, step (d) further comprises interposing a nonconductive fluid between the photo-sensitive surface and the silicon surface prior to applying the electric field.
- In one embodiment of the invention, the photo-sensitive surface comprises a material such as epoxy cationic, acrylic free radical, and photosensitive polyimide.
- In another embodiment of the invention, the toner contains a metal (a) chemically, wherein the toner is a compound or solution of the metal; (b) physically, wherein the metal is contained in the toner as metal particles; or (c) both. Preferably, the metal contained in the toner is in a form selected from the group consisting of metal complex, pure metal particle, coated metal, and organometallic compound. More preferably, the toner is a material selected from the group consisting of: a resin with metal particles, an organosol with metal particles, a metallo-organic decomposition compound, and a metallo-organic decomposition compound with metal particles. The metal or the metal particle is comprised of a metal selected from the group consisting of: palladium, silver, tin, nickel, platinum, chromium and mixtures thereof.
- In a further embodiment of the invention, the amorphous semiconductor layer comprises a material such as silicon, germanium, silicon-germanium, silicon-carbide, cadmium selenide, and indium antimonide. Preferably, the amorphous semiconductor layer is disposed on a substrate, which comprises at least one material, such as silicon, metal, glass, or plastic.
- The present invention is also directed to a method for applying metallic toner onto an amorphous semiconductor layer with the objective or selective area crystallization, the method comprising the steps of: (a) charging a photo-sensitive surface; (b) exposing the photo-sensitive surface to an optical image or a digitally addressed beam to produce a latent image of charges on the photo-sensitive surface; (c) applying a toner to the photo-sensitive surface, the toner attracted to the charged areas of the photo-sensitive surface; (d) juxtaposing the photo-sensitive surface toned in step (c) to a layer of amorphous semiconductor and applying an electric field therebetween to cause the toner that is adherent to the photo-sensitive surface to migrate to the amorphous semiconductor layer; and (e) annealing the toned amorphous semiconductor layer to enable formation of polycrystalline semiconductor only in areas where the toner is adherent. In an embodiment of the invention, the photo-sensitive surface comprises a material such as organic photoreceptor surface, arsenic triselenide, selenium, and silicon. In another embodiment of the invention, the exposing of the photo-sensitive surface in step (b) is to an optical image or digitally addressed beam, such as, a LED or laser.
- The present invention is further directed to a method for the formation of silicide on a silicon surface comprising the steps of: (a) exposing a photo-sensitive surface to cause exposed areas of the surface to crosslink and exhibit an increase in resistivity in comparison with unexposed areas of the photo-sensitive surface; (b) charging the photo-sensitive surface, the exposed areas of the photo-sensitive surface retaining a charge longer than the unexposed areas; (c) applying a toner to the photo-sensitive surface, the toner attracted by retained charge on the exposed areas; (d) juxtaposing the photo-sensitive layer surface toned in step (c) to a silicon surface and applying an electric field therebetween to cause the toner that is adherent to the photo-sensitive surface to migrate to the silicon surface; and (e) annealing the toned silicon surface thereby enabling formation of silicide only in areas where the toner is adherent. In accordance with still another embodiment of the invention, step (d) further comprises interposing a nonconductive fluid between the photo-sensitive surface and the silicon surface prior to applying the electric field.
- In one embodiment of the above invention, the photo-sensitive surface comprises a material such as epoxy cationic, acrylic free radical, and photosensitive polyimide. The silicon surface for the above method can be amorphous, polycrystalline, or single crystalline. In an embodiment of the invention, the photo-sensitive surface comprises a material such as organic photoreceptor surface, arsenic triselenide, selenium, and silicon.
- In an embodiment of the invention, the toner contains a metal as detailed above. Preferably, the metal or metal particle is a metal of the desired metal-silicide including: aluminum, cobalt, chromium, hafnium, iron, magnesium, molybdenum, nickel, niobium, palladium, platinum, tantalum, titanium, tungsten, zirconium and mixtures thereof.
- In another embodiment of the invention, the silicon surface is an amorphous or polycrystalline silicon thin film disposed on a substrate. Preferably, the substrate comprises at least one material, such as, silicon, metal, glass, or plastic.
- The present invention is still further directed to a method for the formation of silicide on a silicon surface comprising the steps of: (a) charging a photosensitive surface; (b) exposing the photosensitive surface to an optical image or a digitally addressed beam to produce a latent image of charges on the photosensitive surface; (c) applying a toner to the photosensitive surface, the toner attracted to the charged areas of the photosensitive surface; (d) juxtaposing the photo-sensitive layer surface toned in step (c) to a silicon surface and applying an electric field therebetween to cause the toner that is adherent to the photo-sensitive surface to migrate to the silicon surface; and (e) annealing the toned silicon surface thereby enabling formation of silicide only in areas where the toner is adherent. In an embodiment of the invention, the photo-sensitive surface comprises a material selected from the group consisting of: organic receptor surface, arsenic triselenide, selenium, and silicon. In one embodiment of the invention, the exposing of the photo-sensitive surface in step (b) is to an optical image or digitally addressed beam, such as, a LED or laser.
- This invention utilizes electrophotography to apply a crystallization catalyst to an amorphous semiconductor layer. The catalyst is subsequently employed to convert areas of the amorphous semiconductor layer to discrete, defined polycrystalline regions.
- This invention also utilizes electrophotography to apply a metal or metal containing material to a Si surface. The metal or metal containing material is subsequently employed to convert areas of the Si surface to discrete, defined metal-silicide regions.
- FIG. 1 illustrates a first step in the process of the invention wherein a photosensitive plate material is selectively cross-linked by application of actinic energy.
- FIG. 2 illustrates a second step in the process of the invention wherein a photosensitive plate material is electrostatically charged.
- FIG. 3 illustrates a third step in the process of the invention wherein catalyst-containing or metal containing toner is applied to the charged photosensitive plate material.
- FIG. 4 illustrates a fourth step in the process of the invention wherein the catalyst-containing toner is transferred from the charged photosensitive plate material to an amorphous semiconductor layer (or to a Si surface) by action of an applied electric field.
- FIGS. 5a, 5 b illustrate an alternate fourth step in the process of the invention wherein the metal-containing toner is transferred from the charged photosensitive plate material to a substrate, followed by deposition thereon of a Si or other semiconductor layer and then followed by an anneal operation to achieve selective crystallization or silicidation of the Si layers that are in contact with the toner.
- In application to selective area crystallization a catalytic liquid toner is electrostatically printed on an amorphous silicon layer (or a substrate that is to support such a layer) in an image-wise fashion. After the liquid toner is dried, the amorphous silicon layer is heated, preferably using rapid thermal annealing, to approximately 550° C. for about 2 minutes to complete the polycrystalline conversion process. The toner used during the printing action is a dispersion of resin particles which contains a modest amount of metallic catalyst, such as palladium, silver, tin, nickel, platinum or chromium.
- In application to selective area silicidation, a metal containing toner is electrostatically printed on a Si surface (Si wafer, amorphous/poly-Si layer). Upon annealing, the Si regions in contact with the metal toner are converted to metal-silicide. The conversion temperature depends on the type of silicide. For example, Pd2Si forms at ˜400° C., while WSi2 forms at ˜1000° C.
- The printing step initially forms latent images on a photo-sensitive receptor plate or drum. Images can be created either electrophotographically, as in a Xerox-graphic copier, or digitally as in a laser printer. The latent images are developed by application of a liquid toner. The toner is then transferred to the Si surface. After the toner is dried, the patterning process is complete. The printed Si surface is now heat processed to complete the crystallization or silicidation process.
- The remaining unprinted Si regions are unconverted to poly-Si or metal silicide (in crystallization and silicidation, respectively) and need not be removed, a significant process saving step unless required by demands such as stress control or light transmission.
- FIG. 1 shows the first step in the electrostatic printing process of the invention, i.e., the making of the printing plate. A photosensitive surface such as a
photopolymer material 10, preferably in a dry film form, is laminated to a groundedsubstrate 12.Photopolymer 10 exhibits the characteristics of photoresists that are used for photolithography applications (e.g., etch resistance). A preferred photopolymer is Dynachem 5038, available from the Dynachem Corporation, Tustin Calif. Another photopolymer that is acceptable is Riston 4615, a product of the Dupont Corporation, Wilmington, Del. - Photopolymer10 should have the characteristic of crosslinking in areas exposed to actinic energy. As shown in FIG. 1,
photopolymer 10 is exposed through a photo tool to actinic radiation in the 300 to 400 nm range or the near ultra violet region of the spectrum. Exposure levels are typically from 50 to 500 millijoules per cm2. Such exposure causesareas 14 to crosslink and at this stage, the plate making step is complete. To achieve selective image-wise charging, a modulated laser beam may be swept across the surface ofphotosensitive material 10 in the manner of a laser printer. A similar result can be achieved through use of a line of modulated laser diodes that are moved over the surface ofphotosensitive material 10. Further, it is to be understood that while the foregoing description will consider use of a flat plate photopolymer, that the invention can be carried out using a flexible photopolymer that is imaged by either a swept modulated laser beam or a line of modulated laser diodes. -
Photosensitive material 10 is now sensitized by charging it, for example with a corona unit, as shown in FIG. 2. A positive charge is shown as being applied but thephotosensitive material 10 can accept either positive or negative charge. - Where
photosensitive material 10 is exposed, the resulting crosslinking raises the electrical resistivity of the material by 4 to 6 orders of magnitude. This enablesphotosensitive material 10 to retain its charge in the crosslinked areas after the charging step, while unexposed regions quickly discharge. - In FIG. 3, the previously charged areas of
photosensitive material 10 are “toned” with liquid toner particles as indicated by the negatively chargedspheres 16. Eachsphere 16 comprises a metal catalyst particle encompassed by a polymeric shell. Details of the method of manufacture oftoner particles 16 are given below. - Next, as shown in FIG. 4, the plate including
photosensitive material 10 is placed close to aSi surface 20. Here, in particular, the Si surface is that of aSi film 20 coated on aglass substrate 22. Aconductive layer 24 is disposed on the opposite face ofglass plate 22 and is connected to avoltage supply 26. The region betweenphotosensitive material 10 andamorphous silicon layer 20 is filled with a nonconductive fluid, e.g., Isopar G, a product of the Exxon Corporation. The mechanical gap betweenamorphous silicon layer 20 andphotoconductor 10 is preferably of the order of 50 to 150 microns. Thereafter,toner particles 16 are transferred across the fluid filled mechanical gap toamorphous silicon layer 20 by means of an electric field that is created when a transfer voltage is applied toconductor 24 byvoltage supply 26. The transfer voltage is typically in the range of 500 to 2000 volts, with a polarity opposite to that of the toner particles. Accordingly, the toner particles are attracted toSi surface 20 by the electric field and remain restricted to areas in alignment with those onphotoconductor 10. - In the case of crystallization, the toner “imaged”
amorphous silicon layer 20 is now removed and dried before being furnace treated or subjected to a rapid thermal anneal process to produce Poly-Si where the toner was imaged. The selective crystallization ofamorphous silicon layer 10 occurs as described by Liu et al. in U.S. Pat. No. 5,147,826 or Fonash et al. in U.S. Pat. No. 5,275,851, both described above and incorporated by reference herein. In the case of silicidation, 20 represents the Si surface (Si wafer, amorphous/poly-Si film) on which a silicide pattern is to be defined. In this case, the toner transfer prior to annealing takes place the same way as described above for the crystallization case. - FIG. 5a illustrates an alternate fourth step in the process of the invention wherein the catalyst-containing toner is transferred from charged
photosensitive plate material 10 tosubstrate 22, followed by deposition thereon of amorphous semiconductor layer 20 (FIG. 5b). Then an anneal operation is performed to achieve selective crystallization of the amorphous semiconductor layer portions that are in contact with the toner. - Samples of amorphous silicon layers were prepared by RF-PECVD from hydrogen diluted silane at 250° C. on Corning 7059 glass. These amorphous Si layers were then imaged in the following manner:
- 1.) An electrostatic printing plate ESP-4 from the Electrox Corporation; Newark, N.J. was charged to approximately −1000 v by means of a corona charge.
- 2.) The plate was developed with palladium toner (Electrox EPT1-b) by ordinary means.
- 3.) Using 125 micron thick polyester film spacer strips, the Si coated glass was spaced away from the ESP-4 plate by a mechanical gap of 125 micron filled with Isopar G (Exxon).
- 4.) With a voltage of −1500 v applied to the amorphous silicon, the palladium toner particles transferred across the gap in an orderly, image wise fashion to the amorphous silicon.
- 5.) The toned silicon coated Corning 7059 glass was lifted off the ESP-4 plate and spacers and the excess Isopar G liquid was dried.
- 6.) The amorphous Si layer was subjected to a rapid thermal anneal (RTA) process at 550-600° C. for 5 to 10 minutes at Penn State University. Poly silicon features were demonstrated in the areas covered with the palladium toner.
- An organosol toner was selected for use with the present invention. A preferred organosol is similar to organosol compositions reported in U.S. Pat. No. 3,900,412 (G. Kosel). This patent discloses a class of liquid toners that make use of self-stable organosols as polymeric binders to promote self-fixing of a developed latent image. Self-stable organosols are colloidal (0.1-1 micron diameter) particles of polymeric binder which are typically synthesized by nonaqueous dispersion polymerization in a low dielectric hydrocarbon solvent. The organosol particles are sterically-stabilized with respect to aggregation by the use of a physically-adsorbed or chemically-grafted soluble polymer. Details of the mechanism of such steric stabilization are provided by Napper in “Polymeric Stabilization of Colloidal Dispersions”, (Academic Press: New York, 1983). Procedures for effecting the synthesis of self-stable organosols, generally involving nonaqueous dispersion polymerization, are known to those skilled in the art and are described in detail in “Dispersion Polymerization in Organic Media”, K. E. J. Barrett ed., (John Wiley: New York, 1975).
- In simplified terms, nonaqueous dispersion polymerization is a free radical polymerization carried out when one or more ethylenically-unsaturated (typically acrylic) monomers, soluble in a hydrocarbon medium, are polymerized in the presence of a preformed amphipathic polymer. The preformed amphipathic polymer, commonly referred to as the stabilizer, has two distinct functional blocks, one essentially insoluble in the hydrocarbon medium, the other freely soluble. When the polymerization proceeds to a fractional conversion of monomer corresponding to a critical molecular weight, the solubility limit is exceeded and the polymer precipitates from solution, forming a core particle. The amphipathic polymer then either adsorbs onto or covalently bonds to the core, which continues to grow as a discrete particle. The particles continue to grow until monomer is depleted. The adsorbed amphipathic polymer “shell” acts to sterically-stabilize the growing core particles with respect to aggregation. The resulting core/shell polymer particles comprise a self-stable, nonaqueous colloidal dispersion (organosol) comprised of distinct spherical particles in the size (diameter) range 0.1-1 microns.
- The composition of the insoluble organosol core is preferentially manipulated such that the organosol exhibits an effective glass transition temperature (Tg) of less than the development temperature (typically 23° C.), thus causing a toner composition containing the organosol as a major component to undergo rapid film formation (rapid self fixing) in printing or imaging processes that are carried out at temperatures greater than the core Tg. Rapid self fixing is a liquid toner performance requirement to avoid printing defects (such as smearing or loss of image resolution) in high speed printing. The use of low Tg resins to promote rapid self fixing of printed or toned images is known in the art, as exemplified by “Film Formation” (Z. W. Wicks, Federation of Societies for Coatings Technologies, 1986, p. 8).
- The resulting organosols can be subsequently converted to a liquid toner by incorporation of the metal catalyst and charge director, followed by high shear homogenization, ball-milling, attritor milling, high energy bead (sand) milling or other means known in the art for effecting particle size reduction in a dispersion. The input of mechanical energy to the dispersion during milling acts to break down aggregated particles into primary particles (0.05-1.0 micron diameter) and to “shred” the organosol into fragments which adhere to the newly-created metal catalyst surface, thereby acting to sterically-stabilize the metal particles with respect to aggregation. The charge director may be physically or chemically adsorbed onto the metal surface, the organosol or both. The result is a sterically-stabilized, charged, nonaqueous metal catalyst dispersion in the size range 0.1-2.0 microns, with typical toner particle diameters between 0.1-0.5 microns.
- In summarizing the properties of organosol formulations, it is convenient to denote the composition of each particular organosol in terms of the ratio of the total weight of monomers comprising the organosol core relative to the total weight of graft stabilizer comprising the organosol shell. This ratio is referred to as the core/shell ratio of the organosol. In addition, it will be useful to summarize the compositional details of each particular organosol by ratioing the weight percentages of monomers used to create the shell and the core. For example, the preferred organosol can be designated LMA/HEMA-TMI//MMA/EA(97/3-4.7//25/75%w/w), and comprises a shell composed of a graft stabilizer precursor which is a copolymer consisting of 97 weight percent lauryl methacrylate (LMA) and 3 weight percent hydroxyethylmethacrylate (HEMA), to which is covalently bonded a grafting site consisting of 4.7 weight percent TMI (dimethyl-m-isopropanol benzylisocyanate, from CYTEC Industries) based upon the total weight of the graft stabilizer precursor. This graft stabilizer is subsequently covalently bonded to an organosol core which is comprised of 25 weight percent methyl methacrylate (MMA) and 75 weight percent ethyl acrylate (EA). The weight ratio of core to shell in the preferred organosol is adjusted to 4.
- The preferred organosol makes use of an LMA/HEMA graft stabilizer precursor which is similar to the LMA/GMA (glycidyl methacrylate—precursor described in Example IV of U.S. Pat. No. 3,900,412; however, the grafting site was changed to permit grafting via formation of a polyurethane linkage between a hydroxyl group and an isocyanate, as opposed to grafting via formation of an epoxide linkage between glycidyl methacrylate and methacrylic acid. The grafting site was changed in order to take advantage of raw materials already available. In addition, the polymerization of the preferred organosol was carried out in ISOPAR L (the carrier liquid selected for use in fabricating toners) using azobisisobutyronitrile (AZDN from Elf-Atochem) as the free radical initiator. The AZDN initiator was selected to provide a higher effective initiator concentration and lower initiator half-life relative to benzoyl peroxide, thereby limiting the molecular weight of the graft stabilizer to values below 500,000 Daltons.
- The actual process for making the toner is as follows. Aldrich Chemical Company sells a number of palladium powders, one of which (Product #32666-6) is certified 99.9 percent by weight sub-micron with a number mean diameter of 0.33 micron. A 5 gram sample of this material was acquired and prepared 120 g of the following electroless plating toner was formulated.
Preferred Organosol: 17 g #32666-6 Colloidal Pd: 2 g Zirconium HEX-CEM (12%) 1 g ISOPAR L: 100 g - This toner was milled for 1.5 hours@2000 RPM using 1-2 mm stainless steel shot. The mean particle size was 0.333 microns. It appears that milling was effective at reducing the palladium powder to primary particles.
- An alternate group of materials to serve as metal-containing toners are metallo-organic decomposition (MOD) compounds. MOD compounds are pure synthetic metallo-organic compounds, which decompose cleanly at low temperature to precipitate the metal as the metallic element. The organic moiety is bonded to the metal through a heteroatom providing a weak link that provides for easy decomposition at low temperature. Hence, once heated to 125° C. or higher, (preferably 125° C. to 250° C.) the organic constituents evolve out as CO2 and H2O or other hydrocarbon fragments leaving a well-bonded metallic trace on the surface, where the MOD compound was applied. Therefore, use of a MOD compound toner in the invention described here excludes the need for metallic particles. In other words, the function of the MOD compound is two-fold; (1) electrographic (charging), similar to organosol, and (2) to contain the metal; the catalyst for crystallization of an amorphous semiconductor layer (e.g., Pd, Ni, Cr, Pt) or the essential ingredient for converting a Si surface to a certain metal-silicide. The MOD compound functions electrographically by serving as the charge control agent bound to the particle which forms acid/base couples with the charge director dissolved in the diluent liquid. Use of a MOD toner is advantageous for the following reasons. First, the metal is contained chemically in the toner solution, and therefore the distribution of metal is very uniform (in the molecular scale). On the other hand, when metal is included in toner in terms of particles, the resolution of the metal print will be limited by the particle size as well as how good the metal particles are distributed. Second, since MOD reduces to a pure metal upon low temperature annealing, there won't be an organic residue blocking the diffusion of metal to semiconductor surface during crystallization or silicidation. For these reasons, the reproducibility is improved significantly. Examples of several MOD compounds are; silver neodecanoate, gold amine 2-ethylhexanoate, platinum amine 2-ethyl hexanoate which are listed in the U.S. Pat. No. 6,036,889, and can be used to print the noble metals Ag, Au, and Pt, respectively. MOD compounds containing catalyst metals for crystallization (also applicable to silicidation) are palladium(II) acetate (Pd(Oac)2), palladium(II) formate, palladium(II) propionate, palladium(II) fumarate, palladium(II) stearate, palladium(II) benzoate, diacetatobis (triphenylphosphine) palladium(II), (U.S. Pat. No. 5,332,646), palladium neodecanoate (U.S. Pat. No. 4,262,040), and nickel formate Ni(HCO2)2 (U.S. Pat. No. 3,897,285). Also, several MOD compounds, which contain catalyst metals for crystallization are produced by Engelhard Co., NJ, and are sold under the catalog names 52D (Cr), A6051 (Cr), 58A (Ni), A2985 (Pd), A1121 (Pt), A6054A (Pt), M603B (Pt).
- The toner may also be composed of metal particles coated with a MOD compound coating. In this case, the MOD coating need not even contain the same metal as the particle to be coated. For instance, 50 nm Pd particles could have a thin layer of silver neodeconoate as a charge control agent. Once printed and dried, the Pd particle would have trace levels of silver on it. Then, in crystallization, the primary catalytic function is performed by the palladium particle, with the silver, inert to further processing.
- It should be understood that the foregoing description is only illustrative of the invention. Various alternatives and modifications can be devised by those skilled in the art without departing from the invention. In particular, annealing can be carried out by variety of means, e.g., furnace annealing, rapid thermal annealing, inductive heating, microwave heating, etc. Furthermore, the processed material can be a material other than Si, e.g., carbon, germanium and alloys thereof. In case of a thin film material, it may reside on various substrates, e.g., silicon, metal, glass or plastics. The toner can generally contain the catalyst (for crystallization, e.g., Pd, Ni, Pt, Cr) or metal (for silicidation, i.e., metal of desired silicide) either chemically (the toner is a compound or solution of the metal) or physically (the metal is contained in the toner in terms of particles) or both. Accordingly, the present invention is intended to embrace all such alternatives, modifications and variances which fall within the scope of the appended claims.
Claims (22)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US09/757,306 US6361912B2 (en) | 1998-06-25 | 2001-01-08 | Electrostatic printing of a metallic toner applied to solid phase crystallization and silicidation |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US9066398P | 1998-06-25 | 1998-06-25 | |
US09/757,306 US6361912B2 (en) | 1998-06-25 | 2001-01-08 | Electrostatic printing of a metallic toner applied to solid phase crystallization and silicidation |
Publications (2)
Publication Number | Publication Date |
---|---|
US20010033985A1 true US20010033985A1 (en) | 2001-10-25 |
US6361912B2 US6361912B2 (en) | 2002-03-26 |
Family
ID=22223748
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/340,009 Expired - Lifetime US6171740B1 (en) | 1998-06-25 | 1999-06-25 | Electrostatic printing of a metallic toner to produce a polycrystalline semiconductor from an amorphous semiconductor |
US09/757,306 Expired - Lifetime US6361912B2 (en) | 1998-06-25 | 2001-01-08 | Electrostatic printing of a metallic toner applied to solid phase crystallization and silicidation |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/340,009 Expired - Lifetime US6171740B1 (en) | 1998-06-25 | 1999-06-25 | Electrostatic printing of a metallic toner to produce a polycrystalline semiconductor from an amorphous semiconductor |
Country Status (3)
Country | Link |
---|---|
US (2) | US6171740B1 (en) |
AU (1) | AU5085099A (en) |
WO (1) | WO1999067813A1 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2014019571A1 (en) * | 2012-07-18 | 2014-02-06 | 2H.System | Method for producing protective layers containing silicides and/or oxidized silicides on substrates |
US9899124B2 (en) | 2012-07-23 | 2018-02-20 | Hewlett-Packard Indigo B.V. | Electrostatic ink compositions |
Families Citing this family (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6171740B1 (en) * | 1998-06-25 | 2001-01-09 | The Penn State Research Foundation | Electrostatic printing of a metallic toner to produce a polycrystalline semiconductor from an amorphous semiconductor |
US6771895B2 (en) * | 1999-01-06 | 2004-08-03 | Mattson Technology, Inc. | Heating device for heating semiconductor wafers in thermal processing chambers |
WO2001038089A1 (en) * | 1999-11-23 | 2001-05-31 | Electrox Corporation | A durable electrostatic printing plate and method of making the same |
US6524758B2 (en) * | 1999-12-20 | 2003-02-25 | Electrox Corporation | Method of manufacture of printed wiring boards and flexible circuitry |
US6824603B1 (en) * | 2000-04-20 | 2004-11-30 | Parelec, Inc. | Composition and method for printing resistors, capacitors and inductors |
US6953716B2 (en) * | 2000-05-01 | 2005-10-11 | The Hong Kong University Of Science And Technology | Polysilicon material and semiconductor devices formed therefrom |
US6875674B2 (en) * | 2000-07-10 | 2005-04-05 | Semiconductor Energy Laboratory Co., Ltd. | Method of manufacturing a semiconductor device with fluorine concentration |
WO2002071465A1 (en) * | 2001-03-02 | 2002-09-12 | Electrox Corp. | Process for the manufacture of large area arrays of discrete components |
JP4359207B2 (en) * | 2004-08-30 | 2009-11-04 | シャープ株式会社 | Method for producing fine particle-containing body |
US7244540B2 (en) * | 2004-10-28 | 2007-07-17 | Samsung Electronics Company | Liquid toners comprising amphipathic copolymeric binder having insoluble components in the shell portion thereof |
US7638252B2 (en) * | 2005-01-28 | 2009-12-29 | Hewlett-Packard Development Company, L.P. | Electrophotographic printing of electronic devices |
Family Cites Families (23)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3900412A (en) | 1970-01-30 | 1975-08-19 | Hunt Chem Corp Philip A | Liquid toners with an amphipathic graft type polymeric molecule |
US3897285A (en) | 1973-09-10 | 1975-07-29 | Allied Chem | Pyrotechnic formulation with free oxygen consumption |
US4262040A (en) | 1978-08-30 | 1981-04-14 | Engelhard Minerals & Chemicals Corporation | Decoration for ceramics having the appearance of gold |
US5011758A (en) * | 1988-02-25 | 1991-04-30 | Olin Hunt Specialty Products Inc. | Use of a liquid electrophotographic toner with an overcoated permanent master in electrostatic transfer |
US5147826A (en) | 1990-08-06 | 1992-09-15 | The Pennsylvania Research Corporation | Low temperature crystallization and pattering of amorphous silicon films |
US5102756A (en) * | 1990-12-31 | 1992-04-07 | Xerox Corporation | Camera speed printing plate with in situ mask |
US5332646A (en) | 1992-10-21 | 1994-07-26 | Minnesota Mining And Manufacturing Company | Method of making a colloidal palladium and/or platinum metal dispersion |
US5275826A (en) | 1992-11-13 | 1994-01-04 | Purdue Research Foundation | Fluidized intestinal submucosa and its use as an injectable tissue graft |
US5843225A (en) * | 1993-02-03 | 1998-12-01 | Semiconductor Energy Laboratory Co., Ltd. | Process for fabricating semiconductor and process for fabricating semiconductor device |
US5985741A (en) * | 1993-02-15 | 1999-11-16 | Semiconductor Energy Laboratory Co., Ltd. | Semiconductor device and method of fabricating the same |
US5275851A (en) * | 1993-03-03 | 1994-01-04 | The Penn State Research Foundation | Low temperature crystallization and patterning of amorphous silicon films on electrically insulating substrates |
TW264575B (en) | 1993-10-29 | 1995-12-01 | Handotai Energy Kenkyusho Kk | |
US5624873A (en) * | 1993-11-12 | 1997-04-29 | The Penn State Research Foundation | Enhanced crystallization of amorphous films |
US5612250A (en) | 1993-12-01 | 1997-03-18 | Semiconductor Energy Laboratory Co., Ltd. | Method for manufacturing a semiconductor device using a catalyst |
JP3562590B2 (en) | 1993-12-01 | 2004-09-08 | 株式会社半導体エネルギー研究所 | Semiconductor device manufacturing method |
JP2860869B2 (en) | 1993-12-02 | 1999-02-24 | 株式会社半導体エネルギー研究所 | Semiconductor device and manufacturing method thereof |
US5654203A (en) | 1993-12-02 | 1997-08-05 | Semiconductor Energy Laboratory, Co., Ltd. | Method for manufacturing a thin film transistor using catalyst elements to promote crystallization |
JP3221473B2 (en) * | 1994-02-03 | 2001-10-22 | 株式会社半導体エネルギー研究所 | Method for manufacturing semiconductor device |
JPH07333954A (en) * | 1994-06-07 | 1995-12-22 | Konica Corp | Image forming method |
JP4083821B2 (en) * | 1994-09-15 | 2008-04-30 | 株式会社半導体エネルギー研究所 | Method for manufacturing semiconductor device |
US5882722A (en) | 1995-07-12 | 1999-03-16 | Partnerships Limited, Inc. | Electrical conductors formed from mixtures of metal powders and metallo-organic decompositions compounds |
US6171740B1 (en) * | 1998-06-25 | 2001-01-09 | The Penn State Research Foundation | Electrostatic printing of a metallic toner to produce a polycrystalline semiconductor from an amorphous semiconductor |
US6153348A (en) | 1998-08-07 | 2000-11-28 | Parelec Llc | Electrostatic printing of conductors on photoresists and liquid metallic toners therefor |
-
1999
- 1999-06-25 US US09/340,009 patent/US6171740B1/en not_active Expired - Lifetime
- 1999-06-25 WO PCT/US1999/014407 patent/WO1999067813A1/en active Application Filing
- 1999-06-25 AU AU50850/99A patent/AU5085099A/en not_active Abandoned
-
2001
- 2001-01-08 US US09/757,306 patent/US6361912B2/en not_active Expired - Lifetime
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2014019571A1 (en) * | 2012-07-18 | 2014-02-06 | 2H.System | Method for producing protective layers containing silicides and/or oxidized silicides on substrates |
US9899124B2 (en) | 2012-07-23 | 2018-02-20 | Hewlett-Packard Indigo B.V. | Electrostatic ink compositions |
Also Published As
Publication number | Publication date |
---|---|
WO1999067813A1 (en) | 1999-12-29 |
AU5085099A (en) | 2000-01-10 |
US6171740B1 (en) | 2001-01-09 |
US6361912B2 (en) | 2002-03-26 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US6361912B2 (en) | Electrostatic printing of a metallic toner applied to solid phase crystallization and silicidation | |
EP2567995B1 (en) | Resin composition for printing plate | |
US20110275018A1 (en) | Circuit architecture on an organic base and related manufacturing method | |
US7807326B2 (en) | Printing semiconducting components | |
JP3239960B2 (en) | Infrared or red light-sensitive particle moving image forming member | |
US10777681B2 (en) | Multi-layer photoresist | |
JPS6220541B2 (en) | ||
KR101639073B1 (en) | Colored Composition for Forming Red Pixel, Color Filter and Color Liquid Crystal Display Device | |
WO1991019023A2 (en) | Electrophoretically deposited particle coatings and structures made therefrom | |
DE102017122398A1 (en) | WET CONTROL IN EUV LITHOGRAPHY | |
US6472666B2 (en) | Two-dimensional image detector and fabrication method of the same | |
US7094627B2 (en) | Process for the manufacture of large area arrays of discrete components | |
JPH0895081A (en) | Information recording method | |
TW502449B (en) | Thin film transistor, liquid crystal display and manufacturing method thereof | |
US6579652B1 (en) | Durable electrostatic printing plate and method of making the same | |
US7541137B2 (en) | Resist resolution using anisotropic acid diffusion | |
EP0543672B1 (en) | Electrophotographic method and photosensitive material used therefor | |
DE102021101198A1 (en) | METHOD OF MANUFACTURING A SEMICONDUCTOR DEVICE | |
King | Trends in polycrystalline-silicon thin-film transistor technologies for AMLCDs | |
JPS632054A (en) | Electrophotographic sensitive body and electrophotography | |
JP3248638B2 (en) | Electrophotographic photoreceptor | |
CN117311091A (en) | Photo-induced quantum dot photoetching patterning method with controllable reaction sites and application thereof | |
JPS60102640A (en) | Photosensitive body | |
JPH0619169A (en) | Photosensitive body and image forming method using the same | |
DE3120305A1 (en) | Electrophotographic photoreceptor |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: PENN STATE RESEARCH FOUNDATION, THE, PENNSYLVANIA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:FONASH, STEPHEN J.;REEL/FRAME:011784/0001 Effective date: 20010122 Owner name: PENN STATE RESEARCH FOUNDATION, THE, PENNSYLVANIA Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:DETIG, ROBERT H.;REEL/FRAME:011784/0006 Effective date: 20010119 |
|
STCF | Information on status: patent grant |
Free format text: PATENTED CASE |
|
FPAY | Fee payment |
Year of fee payment: 4 |
|
FEPP | Fee payment procedure |
Free format text: PAT HOLDER CLAIMS SMALL ENTITY STATUS, ENTITY STATUS SET TO SMALL (ORIGINAL EVENT CODE: LTOS); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
FEPP | Fee payment procedure |
Free format text: PAT HOLDER NO LONGER CLAIMS SMALL ENTITY STATUS, ENTITY STATUS SET TO UNDISCOUNTED (ORIGINAL EVENT CODE: STOL); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
FPAY | Fee payment |
Year of fee payment: 8 |
|
FPAY | Fee payment |
Year of fee payment: 12 |