Use of high-k dielectric materials in modified ONO structure for ...

9

44 through the tunnel oxide 42 from the channel region 18 of the enhancement transistor. A voltage potential is applied to the floating gate electrode 44 by the overlying control gate electrode 46, which is capacitively coupled to the floating gate electrode 44 through the intervening modified ONO structure 26. The floating gate flash device 40 is programmed by applying a high positive voltage to the control gate electrode 46 and a lower positive voltage to the drain region 14, which transfers electrons from the channel region 18 to the floating gate electrode 44. The electrons are stored as a charge 34 in the floating gate electrode 44, as shown in FIG. 2.

It will be recognized that for proper operation of the floating gate flash device 40, the modified ONO structure interpoly dielectric layer 26 must provide effective dielectric separation between the control gate electrode 46 and the floating gate electrode 44. Any reduction in the electrical thickness of the layer 30 results in a reduction of the overall electrical thickness or the equivalent oxide thickness of the interpoly dielectric layer.

In accordance with the invention, charge leakage within the modified ONO structure 26 is minimized by forming a physically thick high-K layer 30 having a low equivalent oxide thickness. The reduced charge leakage and improved two-bit EEPROM performance obtained by the present invention can be better understood following a description of a fabrication process for the modified ONO structure carried out in accordance with the invention.

The following description of the present invention follows with reference to FIGS. 3-6. FIG. 7 is a schematic flow diagram showing the steps of the process of the present invention. The following description of the process refers to FIGS. 3-6 sequentially and with reference to FIG. 7 generally. The present invention can be carried out in a cluster tool.

In the first step of the present invention, shown schematically in FIG. 7 as Step S701, a semiconductor substrate is provided. The semiconductor substrate may be any appropriately selected semiconductor substrate known in the art. In one embodiment, the semiconductor substrate is a bulk silicon substrate. In one embodiment, the semiconductor substrate is a silicon-on-insulator semiconductor substrate. In another embodiment, the semiconductor substrate is a p-doped silicon substrate. Suitable semiconductor substrates include, for example, bulk silicon semiconductor substrates, silicon-on-insulator (SOI) semiconductor substrates, siliconon-sapphire (SOS) semiconductor substrates, and semiconductor substrates formed of other materials known in the art. The present invention is not limited to any particular type of semiconductor substrate.

In a floating gate flash device, the semiconductor device provided in the first step of the method comprises not only a silicon substrate 16 but also a tunnel oxide layer 42 and a floating gate electrode 44 which have been formed on the silicon substrate 16. The tunnel oxide layer 42 and the floating gate electrode 46 may be formed appropriately by any process and from any material known in the art. In an embodiment in which the floating gate electrode 44 is formed of polysilicon, it has a silicon surface as described herein. Thus, the following description is applicable generally to a floating gate flash device, as well as to the two-bit EEPROM described above.

Referring to FIG. 3, in the second step of the present invention, shown schematically in FIG. 7 as Step S702, a first oxide layer 28 is formed on an upper silicon surface 36 of the semiconductor substrate 16. In one embodiment, the

10

upper silicon surface is the upper surface of a polysilicon floating gate electrode. In one embodiment, the semiconductor substrate 16 is a single crystal silicon substrate. The substrate 16 may comprise other elements of a semiconduc5 tor device.

In one embodiment, the silicon surface 36 previously has been processed to remove contaminants and native oxide. A suitable pre-clean procedure includes cleaning the silicon surface 36 with a dilute solution of hydrofluoric acid or any 1° standard cleaning procedure used in the semiconductor industry, including in-situ cleaning methods used in cluster tools.

As noted above, in an embodiment in which the semiconductor device includes a two-bit EEPROM device, the 15 first oxide layer 28 may be referred to as the tunnel oxide layer 28, whereas in a floating gate flash device, the first oxide layer 28 may be referred to as a bottom oxide layer 28. The first oxide layer 28 may be formed by either a growth 2Q (e.g., oxidation of the silicon surface) or a deposition process.

In one embodiment, the first oxide layer 28 is formed by a deposition process. In one embodiment, the first oxide layer 28 is formed by an RTCVD process. In one

25 embodiment, the RTCVD deposition is carried out in the same RTCVD chamber as that in which the other steps of the present process are carried out. In one embodiment, the RTCVD chamber is part of a single-wafer cluster tool. The first oxide can also be formed by depositing the oxide in a

30 batch furnace by an LPCVD process.

In one embodiment, the first oxide layer 28 is formed by rapid thermal oxidation (RTO) or by in-situ steam generation (ISSG) oxidation of the silicon surface 36 of the semiconductor substrate 16. The ISSG oxidation of the

35 silicon surface 36 may be carried out, for example, in a rapid thermal process (RTP) apparatus. The RTP apparatus may be any such apparatus known in the art. In one embodiment, the RTP apparatus is part of a single-wafer cluster tool.

In one embodiment, the ISSG oxidation of the silicon

40 surface 36 is carried out by placing the wafer in the RTP chamber and flowing a mixture of oxygen-containing gas and hydrogen-containing gas to the chamber at suitable flow rates and pressure. The temperature of the RTP chamber can be in the range from about 700° C. to about 150° C. The flow

45 rates and temperature may be suitably selected to provide rapid oxidation of the silicon surface 36, to form an oxide layer of desired thickness.

For the ISSG process described above, any of the commercially available RTP systems can be utilized.

In one embodiment, the hydrogen-containing gas is hydrogen gas, H2. In another embodiment, the hydrogencontaining gas is methane, CH4. In one embodiment, methane is disfavored due to the possible incorporation of carbon

55 into the silicon surface 36. In another embodiment, the hydrogen-containing gas may be ammonia, NH3, but this may be disfavored since it may result in incorporation of nitrogen into the tunnel oxide being formed in the ISSG oxidation.

60 In one embodiment, the oxygen-containing gas is oxygen gas, 02. In another embodiment, the oxygen-containing gas is hitrous oxide, N20.

When the hydrogen-containing gas is hydrogen and the oxygen containing gas is oxygen, in one embodiment, the

65 ratio of hydrogen to oxygen is about 2:1, i.e., a substantially stoichiometric ratio. In one embodiment, an increased amount of oxygen is provided, in order to more rapidly drive

the ISSG oxidation to completion. Thus, in one embodiment, the ratio of oxygen to hydrogen is in the range from greater than about 2:1 to about 5:1. In another embodiment, the ratio of oxygen to hydrogen is in the range from greater than about 2:1 to about 3:1. 5

In one embodiment, the absolute pressure in the RTP chamber is in the range from about 50 Torr to about 500 Torr. In another embodiment, the absolute pressure in the RTP chamber is in the range from about 100 Torr to about 300 Torr, and in another embodiment, from about 100 Torr to 1° about 200 Torr, and in another, at about 150 Torr.

With the flows of oxygen-containing gas and hydrogencontaining gas provided to the chamber at a suitable flow rate and pressure and the silicon surface 36 at a temperature of about 500° C, additional heat is applied to the silicon 15 surface 36 to bring it to a temperature in the range of about 700° C. to about 1150° C. In one embodiment, the temperature is in the range from about 900° C. to about 1100° C. When the surface reaches a suitable temperature, it provides an ignition source for reaction of the hydrogen-containing 20 gas and oxygen-containing gas to form water steam, i.e., in-situ generated steam, or ISSG. In one embodiment, as a result of the use of tungsten halogen lights in a light pipe assembly, the ISSG reaction takes place substantially at the surface of the silicon surface 36, since only the surface of the 25 wafer is substantially heated to the foregoing temperatures, as noted above. Formation of the in-situ generated steam at the silicon surface 36 allows greater control over the ISSG oxidation than is available with either other forms of steam oxidation or other oxidations, such as dry oxygen oxidation, 30 or fluorine-enhanced oxidation.

The ISSG oxidation of the silicon surface 36 may continue for a period in the range from about 1 second to about 500 seconds. In one embodiment, the ISSG oxidation of the silicon surface 36 continues for a period from about 10 to about 120 seconds.

Following completion of the ISSG oxidation reaction, the gas flows of oxygen-containing gas and hydrogencontaining gas are stopped, the temperature of the wafer is 4Q reduced, and the chamber is purged with an inert gas, such as nitrogen or argon. In an embodiment in which the ISSG oxidation is carried out in an RTP apparatus which is part of a cluster tool, the wafer need not be fully cooled or removed from the chamber prior to subsequent processing steps. 4J

In one embodiment, the ISSG oxidation is a single-step process. In one embodiment, the silicon surface 36 is directly oxidized under ISSG conditions in a single step, without employing an initial oxidation to form an initial oxide layer, followed by a second oxidation to complete the 50 formation of the oxide layer.

In an alternate embodiment, the first oxide layer 28 may be formed by thermally oxidizing the silicon surface 36 at an elevated temperature in the presence of dry molecular oxygen. In one embodiment, the thermal oxidation is carried out 55 at a temperature in the range of about 800° C. to about 1100° C. The thermal oxidation process may be carried out in either a batch-type thermal oxidation furnace, or alternatively, in a single-wafer oxidation apparatus. In one embodiment, the thermal oxidation is carried out in the same 60 RTP apparatus as that in which the other steps of the present process are carried out. In one embodiment, the RTP chamber is part of a single-wafer cluster tool.

In one embodiment, the first oxide layer 28 has a thickness in the range from about 10 to about 150 angstroms (A), 65 and in another embodiment, the silicon oxide layer 28 has a thickness in the range from about 20 to about 100 A.

35

In the third step of the present invention, shown schematically in FIG. 7 as Step S703, a layer 30 comprising a high-K dielectric material is formed on the first oxide layer 28. As shown in FIG. 4, after forming the first oxide layer 28, the high-K dielectric material-comprising layer 30 is deposited on the first oxide layer 28. In one embodiment, the layer 30 comprises both a high-K dielectric material and a standard-K dielectric material. In one embodiment, the layer 30 comprises a composite dielectric material, which comprises a composite or a reaction product of two or more dielectric materials, at least one of which is a high-K dielectric material. In one embodiment, the composite dielectric material of which the layer 30 is formed is a mid-K dielectric material, which is a composite of a high-K dielectric material and a standard-K dielectric material. Thus, in one embodiment, the high-K dielectric material completely replaces the nitride layer of a conventional ONO structure. In another embodiment, the high-K dielectric material is, in essence, added to or combined with, the nitride layer of a conventional ONO structure. In another embodiment, the layer includes a composite dielectric material which replaces the nitride layer of a conventional ONO structure.

In another embodiment, the high-K dielectric material layer is sandwiched between two nitride layers, the lower of which is deposited on the first oxide layer 28. In another embodiment, a nitride layer is deposited on the first oxide layer 28 followed by deposition of a high-K dielectric material layer on the nitride layer. In another embodiment, the nitride layer is deposited on a high-K dielectric material layer which has been formed on the first oxide layer 28. In another embodiment, alternating sub-layers of nitride and high-K dielectric material are deposited on the first oxide layer 28.

In one embodiment, the high-K dielectric materialcomprising layer 30 is formed by means of a rapid-thermalchemical-vapor-deposition (RTCVD) process. In one embodiment, the RTCVD process is carried out at a temperature of about 400° C. to about 800° C. The high-K dielectric material may be formed by reacting a suitable metal-containing gas, e.g., hafnium tetra-t-butoxide with a suitable oxygen-containing gas, e.g., oxygen (02) or nitrous oxide (N20).

In one embodiment, the high-K dielectric material includes at least one of hafnium oxide (Hf02), zirconium oxide (Zr02), tantalum oxide (Ta205), barium titanate (BaTi03), titanium dioxide (Ti02), cerium oxide (Ce02), lanthanum oxide (La203), lanthanum aluminum oxide (LaA103), lead titanate (PbTi03), silicon titanate (SiTi03), lead zirconate (PbZro3), tungsten oxide (W03), yttrium oxide (Y203), bismuth silicon oxide (Bi4Si2012), barium strontium titanate (BST) (Ba^SrJTiO^, PMN (PbMg^Nb^ *03), PZT (PbZrJV^), PZN (PbZnJSTb^O^), and PST (PbSc^Taj^O^. In addition to the foregoing high-K dielectrics, other high-K dielectric materials, for example, ferroelectric high-K dielectric materials such as lead lanthanum titanate, strontium bismuth tantalate, bismuth titanate and barium zirconium titanate may be suitably used in the present invention. Other high-K dielectric materials known in the art, including, for example binary and ternary oxides having K values of about 20 or higher, also may be used in the present invention.

In one embodiment, the high-K material is a high-K material other than tantalum oxide (Ta205). Tantalum oxide has been found, in some embodiments, to exhibit an undesirably high leakage current. Tantalum oxide has been found, in some embodiments, to not provide the benefits of low leakage current, or to include other deleterious 13

characteristics, such as poor thermal stability and undesirable reactions with silicon and polysilicon.

In one embodiment, the silicon nitride of an interpoly dielectric layer in a floating gate flash device is replaced with aluminum nitride. Aluminum nitride has a K value of about 5 9. As such it is within the range defined for standard-K dielectric materials. However, the K value for aluminum nitride is greater than the K value for silicon nitride, and as such may be used as the replacement material for the silicon nitride layer for the modified ONO structure of the present 1Q invention.

In one embodiment, the high-K dielectric material may be deposited by chemical vapor deposition (CVD). The CVD method may be any appropriate CVD method known in the art for deposition of a high-K material. For example, the CVD method may be ALD (ALCVD), PECVD, RTCVD, 15 MOCVD or MLD.

Thus, for example, in an embodiment in which hafnium oxide is the high-K dielectric material, the hafnium may be supplied in the form of a hafnium-containing vapor or gas such as hafnium tetra-t-butoxide, and the oxygen is supplied 20 in gaseous form as oxygen, 02 or nitrous oxide, N20. When a suitable thickness of hafnium oxide has been deposited, the flow of the hafnium-containing vapor or gas and oxygencontaining gas are stopped.

As noted above, in an embodiment in which a plurality of 25 high-K materials are deposited, alternating sub-layers of each high-K dielectric material may be deposited, or a composite dielectric material which comprises at least one high-K dielectric material may be deposited. Thus, a first high-K dielectric material precursor may be provided either 30 simultaneously with or sequentially with a second dielectric precursor material. The second dielectric precursor material may be either a standard-K dielectric precursor or a high-K dielectric precursor. The process of alternating sub-layer deposition may be continued until a suitable, selected num- 35 ber of sub-layers of desired composition and thickness has been deposited.

In one embodiment, a silicon containing gas, such as SiH4, may be provided together with or alternating with the high-K precursor vapor, during the step of forming the 40 high-K dielectric material sub-layers, in an embodiment in which a composite dielectric material comprising both a high-K dielectric material and a standard-K dielectric material is to be produced.

In one embodiment, a nitrogen-containing gas, such as 45 ammonia (NH3) may be provided along with the siliconcontaining gas, oxygen-containing gas and high-K precursor.

In one embodiment, the process is carried out for a period of time and at gas flow rates sufficient to form a high-K 50 dielectric material-comprising layer 30 having a thickness of about 25 A to about 300 A. In another embodiment, the process is carried out for a period of time and at gas flow rates sufficient to form a high-K dielectric materialcomprising layer having a thickness of about 50 A to about 55 200 A, and in another embodiment, the process is carried out for a period of time and at gas flow rates sufficient to form a high-K dielectric material-comprising layer having a thickness of about 50 A to about 100 A.

In one embodiment, high-K dielectric material precursor 60 is introduced in the CVD apparatus at a flow rate of about 1 standard liter per minute (slpm) and either oxygen or nitrous oxide is introduced at a flow rate of about 1 slpm. Suitable flow rates of any other gases or vapors provided to the CVD apparatus may be determined by those of skill in 65 the art, based on the composition of the layer 30 which is desired.

14

In one embodiment, the CVD is ALCVD, atomic layer chemical vapor deposition. ALCVD may be used to deposit a dielectric material in layers as thin as a molecular monolayer. Formation of such monolayers allows formation of a nano-laminate structure of any selected dielectric materials. The nano-laminate structure provides for deposition of a plurality of different high-K dielectric materials as sublayers or nano-layers. The sub-layers may be deposited with single dielectric materials or with a plurality of simultaneously formed dielectric materials. The nano-laminates may thus form a composite high-K dielectric material layer. Alternatively, sequentially deposited, different dielectric materials may be annealed subsequently to form a composite dielectric material which comprises the elements of the sequentially deposited, different dielectric materials. The conditions of deposition may be suitably selected to provide a nano-laminate or composite high-K dielectric material layer having a controlled physical thickness, composition and K value.

Thus, for example, ALCVD or MOCVD may be used in combination with RTCVD to deposit alternating monolayers of hafnium oxide and silicon nitride (respectively), in a partial replacement of the ONO nitride with a high-K dielectric material. The alternating layers may be retained, or the structure may be annealed to cause reaction or combination of the elements to form a composite dielectric material which would include the elements Hf/Si/O/N. Depending on the relative amounts of hafnium oxide and silicon nitride deposited, the composite dielectric material may have a formula such as HfSi302N4. Of course, it will be recognized that while the composite material includes the elements of the individual dielectric materials deposited, the exact stoichiometry may vary widely from this example.

As another example, a plurality of high-K dielectric materials may be deposited to replace the N of the ONO structure in forming the modified ONO structure, either simultaneously or in sequentially deposited sub-layers of selected thickness. A combination of high-K dielectric materials may be selected in order to obtain a desired characteristic such as charge retention, K value, physical thickness, equivalent oxide thickness, or a selected combination of these or other features. The use of ALCVD, with its capability of depositing a molecular monolayer of selected dielectric materials provides a wide range of possible structures for the modified ONO structure.

In an embodiment in which the CVD is a RTCVD, the RTCVD process is carried out in three steps including an initial temperature ramp, a deposition step, and cool-down step. In one embodiment, the total reaction time is about 1-3 minutes. In another embodiment, the silicon nitride deposition step is completed in about 2 minutes.

In another embodiment, the high-K dielectric material layer 30 may be formed by means of a low-pressurechemical-vapor-deposition (LPCVD) process. In this alternative embodiment, the high-K dielectric material can be formed in a batch deposition apparatus. In one embodiment, the LPCVD process is carried out at an absolute pressure of about 200 to about 500 millitorr (mtorr), at temperatures of about 400° C. to about 800° C. using a high-K dielectric material precursor and either oxygen or nitrous oxide.

Suitable high-K precursor materials are known in the art. For example, for hafnium oxide, hafnium tetra-t-butoxide has been mentioned above. For zirconium oxide, a suitable precursor is zirconium tetra-t-butoxide.

In the fourth step of the present invention, shown schematically in FIG. 7 as Step S704, a top oxide layer 32 is 15

formed on the high-K dielectric material layer 30 by RTCVD or LPCVD of a second silicon oxide layer on the upper surface of the high-K dielectric material layer 30. As shown in FIG. 5, after depositing the high-K dielectric material-comprising layer 30, the second silicon oxide layer 32, also referred to as a top oxide layer, is formed on the high-K dielectric material-comprising layer 30. In accordance with the invention, the top oxide layer 32 may be formed by any appropriate method known in the art.

In one embodiment, an important feature of the invention includes the sequential formation of the high-K dielectric material layer 30 and the top oxide layer 32 (the top oxide) in the absence of exposure of the high-K dielectric material layer 30 to ambient atmosphere. Following the deposition of the high-K dielectric material layer 30 onto the first oxide layer 28, the top oxide layer 32 is formed by RTCVD in a single wafer cluster tool, without the necessity of being transferred to a separate oxide deposition chamber, which would entail either maintenance of vacuum conditions without exposing the substrate to ambient atmosphere, or application of a positive-pressure inert gas atmosphere during wafer transfer. Thus, the present invention provides distinct process and economic advantages in formation of a modified ONO structure.

As shown in FIG. 6, following formation of the modified ONO structure 26 in accordance with the present invention, shown schematically in FIG. 7 as Step S705, a layer forming a gate electrode 24, in the case of the two-bit EEPROM, is formed on the top oxide layer 32. In the case of the floating gate flash device, a control gate electrode 46 is formed on the top oxide layer 32. The stacked-gate structures shown in FIGS. 1 and 2 are completed by depositing a layer of gate forming material overlying the top oxide layer 32. A lithographic patterning and etching process may then be carried out to define the gate electrode 24 (or control gate electrode 46) and the modified ONO structure 26. Those skilled in the art will recognize that various gate-forming materials can be used to fabricate the gate electrode 24. For example, the gate electrode 24 and the control gate electrode 46 can be formed with polycrystalline silicon, amorphous silicon, a refractory metal silicide, a metal, and the like.

Following formation of the gate electrode 24, or the control gate electrode 46, as appropriate, and the modified ONO structure 26, fabrication of the semiconductor device continues, as indicated in the final step of FIG. 7.

For example, fabrication of the semiconductor device may include annealing the device in order to densify the silicon dioxide and/or high-K dielectric material layers and/or to further form the composite dielectric material of the layer 30.

FIG. 8 shows an embodiment of the present invention in which the semiconductor device has been annealed to form a composite dielectric material of the combined layers 28,30 and 32. In this embodiment, a non-volatile memory cell 50 (here a floating gate memory cell) is formed which includes a) a substrate 16 including a source region 12, a drain region 14, and a channel region 18 positioned therebetween; b) a floating gate 44 positioned above the channel region 18 and separated from the channel region 18 by a tunnel dielectric film 42; and c) a control gate 46 positioned above the floating gate 44 and separated from the floating gate 44 by an interpoly dielectric layer 26. In this embodiment, the interpoly dielectric layer 26 includes a single layer 48 adjacent to both the floating gate 42 and the control gate 46. In this embodiment, the single layer 48 is a dielectric material which is a metal silicate, a metal aluminate or a

16

metal mixed-aluminate/silicate. Thus, for example, using hafnium as the exemplary metal, the dielectric material forming the layer 48 may be hafnium silicate (HfSi04), hafnium aluminate (HfAl205) or a hafnium mixed5 aluminate/silicate, Hf02/Si02/Al203, which may have a formula such as Hf2Si2Al2011.

Suitable metals for the metal silicate, metal aluminate or metal mixed-aluminate/silicate include, for example, hafnium, zirconium, yttrium, cerium, tantalum, titanium,

10 lanthanum, tungsten, bismuth, barium, strontium, scandium, niobium or lead, or mixtures thereof. Other metals which, when combined with silicon dioxide or aluminum oxide, or a mixture thereof, yield a material having a K value greater than about 10 may be suitable. The metal silicate, metal

15 aluminate or metal mixed-aluminate/silicate substantially should not react with silicon (or polysilicon) at temperatures up to about 600-800° C.

There has been disclosed in accordance with the invention 2Q a process for fabricating an ONO floating-gate electrode in both a MIRRORBITTM two-bit EEPROM device and a floating gate flash device, both of which provide the advantages set forth above (as appropriate). As noted above, the process of the invention is also applicable to other semicon25 ductor devices which include an ONO structure.

Although the invention has been described and illustrated with reference to specific illustrative embodiments thereof, it is not intended that the invention be limited to those illustrative embodiments. Those skilled in the art will rec

30 ognize that variations and modifications can be made without departing from the spirit of the invention. For example, the thicknesses of the individual layers making up the modified ONO structure can be varied from that described herein. It is therefore intended to include within the inven

35 tion all such variations and modifications that fall within the scope of the appended claims and equivalents thereof.

INDUSTRIAL APPLICABILITY

40 Thus, in accordance with the present invention, a semiconductor device including a modified ONO structure is provided with improved properties. The present invention can be carried out in a cluster tool. The present invention provides advantages such as (1) formation of a cleaner

45 interface between layers of the modified ONO structure, resulting in fewer interface states that could provide charge leakage paths; (2) use of a high-K dielectric material, which allows formation of a physically thicker interpoly dielectric layer or charge storage layer having a lower equivalent oxide

50 thickness; (3) a process for scaling down the electrical thickness of ONO structures for flash memory devices; and (4) an efficient process which may be carried out in a single device, such as a cluster tool. Thus, the present invention provides an advance in interpoly dielectric fabrication

55 technology, ensures proper dielectric separation of the control gate electrode from the floating gate electrode in floating gate flash devices and ensures proper charge storage and isolation in modified ONO structures used in MIRRORBITTM two-bit EEPROM devices, while at the same time

60 providing distinct process and economic advantages. The present invention helps in scaling down the electrical thickness of ONO structures for both MIRRORBITTM two-bit EEPROM and floating gate flash memory devices. Although described in terms of, and particularly applicable to, two-bit

65 EEPROM devices, the present invention is broadly applicable to fabrication of any semiconductor device including a modified ONO structure.

What is claimed is:

1. A semiconductor device comprising a modified ONO structure, wherein the modified ONO structure comprises

a bottom oxide layer;

a layer comprising a composite dielectric material on the 5 bottom oxide layer, wherein the composite dielectric material comprises elements of at least one high-K dielectric material; and

a top oxide layer on the layer comprising a composite dielectric material. 10

2. The semiconductor device of claim 1, wherein the high-K dielectric material comprises at least one of hafnium oxide (Hf02), zirconium oxide (Zr02), barium titanate (BaTi03), titanium dioxide (Ti02), cerium oxide (Ce02), lanthanum oxide (La203), lanthanum aluminum oxide (LaA103), lead titanate (PbTi03), strontium titanate (SrTi03), lead zirconate (PbZr03), tungsten oxide (W03), yttrium oxide (Y203), bismuth silicon oxide (Bi4Si2012), barium strontium titanate (BST) (Ba-^Sr^TiO^, PMN (PbMg^Nb^O,), PZT (PbZr^Ti^^), PZN (PbZn^Nb,^), and PST (PbScJVA)- 20

3. The semiconductor device of claim 1, wherein the modified ONO structure is a memory cell in a SONOS type cell modified to incorporate the composite dielectric material in the nitride layer of the ONO structure.

4. The semiconductor device of claim 1, wherein the 25 modified ONO structure is a memory cell in a two-bit EEPROM modified to incorporate the composite dielectric material in the nitride layer of the ONO structure.

5. A non-volatile memory cell comprising:

a) a substrate comprising a source region, a drain region, 30 and a channel region positioned therebetween;

b) a floating gate positioned above the channel region and separated from the channel region by a tunnel dielectric film; and

c) a control gate positioned above the floating gate and 35 separated from the floating gate by an interpoly dielectric layer, the interpoly dielectric layer comprising a bottom silicon dioxide layer adjacent to the floating gate, a top silicon dioxide layer adjacent to the control gate, and a center layer comprising a high-K dielectric 40 material and positioned between the bottom silicon dioxide layer and the top silicon dioxide layer, with the proviso that when the center layer comprises tantalum oxide (Ta203), the center layer further comprises at least one additional dielectric material. 45

6. The non-volatile memory cell of claim 5, wherein the high-K dielectric material comprises at least one of hafnium oxide (Hf02), zirconium oxide (Zr02), tantalum oxide (Ta205), barium titanate (BaTi03), titanium dioxide (Ti02), cerium oxide (Ce02), lanthanum oxide (La203), lanthanum 50 aluminum oxide (LaA103), lead titanate (PbTi03), strontium titanate (SrTi03), lead zirconate (PbZr03), tungsten oxide (W03), yttrium oxide (Y203), bismuth silicon oxide (Bi4Si2012), barium strontium titanate (BST) (Ba^Sr^TiO^, PMN (PbMg^Nb^O^, PZT 55 (PbZrJi^O,), PZN (PbZn^Nb,.^), and PST (PbScJV^).

7. The non-volatile memory cell of claim 5, wherein the center layer comprises a composite dielectric material including elements of the high-K dielectric material and at 60 least one additional dielectric material.

8. The non-volatile memory cell of claim 7, wherein the at least one additional dielectric material comprises aluminum nitride.

9. A non-volatile memory cell comprising: 65 a) a substrate comprising a source region, a drain region,

and a channel region positioned therebetween;

b) a charge storage layer comprising a modified ONO structure, having a bottom silicon dioxide layer adjacent the channel region, a top silicon dioxide layer, and a center charge storage layer comprising a high-K dielectric material and positioned between the bottom silicon oxide layer and the top silicon dioxide layer; and

c) a gate capacitively coupled to the channel region through the charge storage layer.

10. The non-volatile memory cell of claim 9, wherein the high-K dielectric material comprises at least one of hafnium oxide (Hf02), zirconium oxide (Zr02), tantalum oxide (Ta205), barium titanate (BaTi03), titanium dioxide (Ti02), cerium oxide (Ce02), lanthanum oxide (La203), lanthanum aluminum oxide (LaA103), lead titanate (PbTi03), strontium titanate (SrTi03), lead zirconate (PbZr03), tungsten oxide (W03), yttrium oxide (Y203), bismuth silicon oxide (Bi4Si2012), barium strontium titanate (BST) (Ba^Sr^TiO^, PMN (PbMg^Nb^O^, PZT (PbZr^Ti^O,), PZN (PbZn^Nb,.^), and PST (PbScJV^).

11. The non-volatile memory cell of claim 9, wherein the charge storage layer comprises a composite dielectric material including elements of the high-K dielectric material and at least one additional dielectric material.

12. The non-volatile memory cell of claim 9, wherein the memory cell is a SONOS type cell modified to incorporate the high-K dielectric material in the center charge storage layer.

13. The non-volatile memory cell of claim 9, wherein the memory cell is a two-bit EEPROM cell modified to incorporate the high-K dielectric material in the center charge storage layer.

14. A non-volatile memory cell comprising:

a) a substrate comprising a source region, a drain region, and a channel region positioned therebetween;

b) a floating gate positioned above the channel region and separated from the channel region by a tunnel dielectric film; and

c) a control gate positioned above the floating gate and separated from the floating gate by an interpoly dielectric layer, the interpoly dielectric layer comprising a single layer adjacent to both the floating gate and the control gate, the single layer comprising a dielectric material, wherein the dielectric material is a metal silicate, a metal aluminate or a metal mixed-aluminatesilicate.

15. The non-volatile memory cell of claim 14, wherein the dielectric material is a metal silicate and the metal is hafnium, zirconium, yttrium, cerium, tantalum, titanium, lanthanum, tungsten, bismuth, barium, strontium, scandium, niobium or lead, or mixtures thereof.

16. The non-volatile memory cell of claim 14, wherein the dielectric material is a metal aluminate or a metal mixedaluminate-silicate and the metal is hafnium, zirconium, yttrium, cerium, tantalum, titanium, lanthanum, tungsten, bismuth, barium, strontium, scandium, niobium or lead, or mixtures thereof.