US20050269667A1 - Process for manufacturing integrated resistor and phase-change memory element including this resistor - Google Patents

Process for manufacturing integrated resistor and phase-change memory element including this resistor Download PDF

Info

Publication number
US20050269667A1
US20050269667A1 US11/201,790 US20179005A US2005269667A1 US 20050269667 A1 US20050269667 A1 US 20050269667A1 US 20179005 A US20179005 A US 20179005A US 2005269667 A1 US2005269667 A1 US 2005269667A1
Authority
US
United States
Prior art keywords
forming
resistivity
conductive material
resistive element
species
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.)
Abandoned
Application number
US11/201,790
Inventor
Romina Zonca
Maria Marangon
Giorgio De Santi
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
STMicroelectronics SRL
Ovonyx Inc
Original Assignee
STMicroelectronics SRL
Ovonyx Inc
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by STMicroelectronics SRL, Ovonyx Inc filed Critical STMicroelectronics SRL
Priority to US11/201,790 priority Critical patent/US20050269667A1/en
Publication of US20050269667A1 publication Critical patent/US20050269667A1/en
Abandoned legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11C—STATIC STORES
    • G11C13/00—Digital stores characterised by the use of storage elements not covered by groups G11C11/00, G11C23/00, or G11C25/00
    • G11C13/0002—Digital stores characterised by the use of storage elements not covered by groups G11C11/00, G11C23/00, or G11C25/00 using resistive RAM [RRAM] elements
    • G11C13/0021—Auxiliary circuits
    • G11C13/0069—Writing or programming circuits or methods
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11C—STATIC STORES
    • G11C13/00—Digital stores characterised by the use of storage elements not covered by groups G11C11/00, G11C23/00, or G11C25/00
    • G11C13/0002—Digital stores characterised by the use of storage elements not covered by groups G11C11/00, G11C23/00, or G11C25/00 using resistive RAM [RRAM] elements
    • G11C13/0004—Digital stores characterised by the use of storage elements not covered by groups G11C11/00, G11C23/00, or G11C25/00 using resistive RAM [RRAM] elements comprising amorphous/crystalline phase transition cells
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N70/00—Solid-state devices without a potential-jump barrier or surface barrier, and specially adapted for rectifying, amplifying, oscillating or switching
    • H10N70/011—Manufacture or treatment of multistable switching devices
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N70/00—Solid-state devices without a potential-jump barrier or surface barrier, and specially adapted for rectifying, amplifying, oscillating or switching
    • H10N70/20—Multistable switching devices, e.g. memristors
    • H10N70/231—Multistable switching devices, e.g. memristors based on solid-state phase change, e.g. between amorphous and crystalline phases, Ovshinsky effect
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N70/00—Solid-state devices without a potential-jump barrier or surface barrier, and specially adapted for rectifying, amplifying, oscillating or switching
    • H10N70/801—Constructional details of multistable switching devices
    • H10N70/821—Device geometry
    • H10N70/826—Device geometry adapted for essentially vertical current flow, e.g. sandwich or pillar type devices
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N70/00—Solid-state devices without a potential-jump barrier or surface barrier, and specially adapted for rectifying, amplifying, oscillating or switching
    • H10N70/801—Constructional details of multistable switching devices
    • H10N70/841—Electrodes
    • H10N70/8413—Electrodes adapted for resistive heating
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N70/00—Solid-state devices without a potential-jump barrier or surface barrier, and specially adapted for rectifying, amplifying, oscillating or switching
    • H10N70/801—Constructional details of multistable switching devices
    • H10N70/881—Switching materials
    • H10N70/882—Compounds of sulfur, selenium or tellurium, e.g. chalcogenides
    • H10N70/8828—Tellurides, e.g. GeSbTe
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11C—STATIC STORES
    • G11C13/00—Digital stores characterised by the use of storage elements not covered by groups G11C11/00, G11C23/00, or G11C25/00
    • G11C13/0002—Digital stores characterised by the use of storage elements not covered by groups G11C11/00, G11C23/00, or G11C25/00 using resistive RAM [RRAM] elements
    • G11C13/0021—Auxiliary circuits
    • G11C13/0069—Writing or programming circuits or methods
    • G11C2013/008—Write by generating heat in the surroundings of the memory material, e.g. thermowrite
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11C—STATIC STORES
    • G11C2213/00—Indexing scheme relating to G11C13/00 for features not covered by this group
    • G11C2213/50—Resistive cell structure aspects
    • G11C2213/52—Structure characterized by the electrode material, shape, etc.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Semiconductor Memories (AREA)

Abstract

A vertical-current-flow resistive element includes a monolithic region having a first portion and a second portion arranged on top of one another and formed from a single material. The first portion has a first resistivity, and the second portion has a second resistivity, lower than the first resistivity. To this aim, a monolithic region with a uniform resistivity and a height greater than at least one of the other dimensions is first formed; then the resistivity of the first portion is increased by introducing, from the top, species that form a prevalently covalent bond with the conductive material of the monolithic region, so that the concentration of said species becomes higher in the first portion than in the second portion. Preferably, the conductive material is a binary or ternary alloy, chosen from among TiAl, TiSi, TiSi2, Ta, WSi, and the increase in resistivity is obtained by nitridation.

Description

    BACKGROUND OF THE INVENTION
  • 1. Field of the Invention
  • The present invention relates to an integrated resistor, a phase-change memory element including this resistor, and a process for the fabrication thereof.
  • 2. Description of the Related Art
  • As is known, phase-change memory elements, or PCM elements, exploit the characteristics of a class of materials able to change between two phases having distinct electrical characteristics. For example, these materials may change from an amorphous, disorderly phase to a crystalline or polycrystalline, orderly phase, and the two phases are associated to considerably different values of resistivity.
  • At present, alloys of elements of group VI of the periodic table, such as Te or Se, referred to as chalcogenides or chalcogenic materials, can advantageously be used in phase-change cells. The chalcogenide that currently offers the most promise is formed by a Ge, Sb and Te alloy (Ge2Sb2Te5) and is widely used for storing information in overwritable disks.
  • In chalcogenides, the resistivity varies by two or more orders of magnitude when the material passes from the amorphous phase (more resistive) to the crystalline phase (more conductive) and vice versa. The characteristics of the chalcogenides in the two phases are shown in FIG. 1. As may be noted, at a given read voltage, here designated by Vr, there is a resistance variation of more than 10.
  • Phase change may be obtained by locally increasing the temperature, as shown in FIG. 2. Below 150° C. both phases are stable. Above 200° C. (nucleation start temperature, designated by Tx), fast nucleation of the crystallites takes place, and, if the material is kept at the crystallization temperature for a sufficient length of time (time t2), it changes its phase and becomes polycrystalline. To bring the chalcogenide back into the amorphous state, it is necessary to raise the temperature above the melting temperature Tm (approximately 600° C.) and then to cool the chalcogenide off rapidly (time t1).
  • From the electrical standpoint, it is possible to reach both the critical temperatures, namely crystallization and melting temperature, by causing a current to flow through a resistive element which heats the chalcogenic material by Joule effect.
  • The basic structure of a phase-change memory element 1 which operates according to the principles described above is shown in FIG. 3 and comprises a resistive element 2 (heater) and a programmable element 3. The programmable element 3 is made of a chalcogenide and is normally in the polycrystalline state in order to enable a good flow of current. One part of the programmable element 3 is in direct contact with the resistive element 2 and forms the area involved in the phase change, hereinafter referred to as phase-change portion 4.
  • If an electric current having an appropriate value is made to pass through the resistive element 2, it is possible to heat the phase-change portion 4 selectively up to the crystallization temperature or to the melting temperature and to cause phase change. In particular, if a current I is made to pass through a resistive element 2 having resistance R, the heat generated is equal to I2R.
  • At present, the resistive element 2 is obtained by deposition—using PVD (Physical Vapor Deposition), Reactive PVD and CVD (Chemical Vapor Deposition)—of materials having a resistivity of between a few hundred μΩcm and a few ten mΩcm. The material thus obtained has a substantially homogeneous resistance in all directions.
  • The memory element described above is disadvantageous since it has a high dissipation on account of the high resistance of the resistive element, even if the portion useful for generating the phase change heat for the memory element 1 is only one part of its volume. A high level of dissipation may, in fact, be harmful for the materials and components integrated in the chip. The problems associated with dissipation of the entire resistive element moreover impose design constraints on the values of resistivity that can be used for the resistive element, as well as on the programming currents and voltages, giving rise to high levels of consumption.
    • BRIEF SUMMARY OF THE INVENTION
  • An embodiment of the present invention provides a resistive element that overcomes the described disadvantages.
  • The resistive element is a vertical-current-flow resistive element that includes a monolithic region having a first portion and a second portion arranged on top of one another. The monolithic region is formed by a single material and has a height greater than at least one other dimension. The first portion has a first resistivity and the second portion has a second resistivity lower than the first resistivity.
    • BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
  • For a better understanding of the present invention, a preferred embodiment thereof is now described, purely by way of non-limiting example, with reference to the attached drawings, wherein:
  • FIG. 1 shows the current-versus-voltage characteristic of a phase-change material;
  • FIG. 2 shows the temperature-versus-current plot of a phase-change material;
  • FIG. 3 shows the basic structure of a PCM element;
  • FIG. 4 is a cross-section of a resistive element according to the invention;
  • FIG. 5 presents a concentration plot of ions designed to increase the resistivity of the resistive element of FIG. 4; and
  • FIGS. 6, 7 and 8 are top plan views of the resistive element of FIG. 4, according to three different embodiments.
    • DETAILED DESCRIPTION OF THE INVENTION
  • FIG. 4 shows a PCM memory element 10 comprising a bottom electrode 11, of electrically conductive material; an insulating layer 16, arranged on top of the bottom electrode 11; a resistive element 12, which extends vertically inside the insulating layer 16 and is in contact with the bottom electrode 11; a polycrystalline layer 13, which extends on top of the insulating layer 16 and has a portion (hereinafter referred to as phase-change portion 14) in contact with the resistive element 12; and a top electrode 15, of conductive material, which extends on top of the polycrystalline layer 13.
  • The resistive element 12, of overall height H, is of the vertical-current-flow type and has a height or thickness H in the Z direction much greater than at least one of the other dimensions (width in the X direction and depth in the Y direction). In particular, the resistive element 12 may be column-shaped, with a depth (in the Y direction) comparable to the width in the X direction, as shown in the schematic top plan view of FIG. 6, or else wall-shaped, having a depth much greater than the width in the X direction, as shown in the schematic plan view of FIG. 7, or yet again may have a closed shape, such as the annular shown in the schematic top plan view of FIG. 8.
  • The resistive element 12 is formed by a monolithic region made of a material selected among TiAlN, TiSiN, TiSi2N, TaN, WSiN and has a first portion 12 a, having high resistivity, and a second portion 12 b, of lower resistivity, arranged on top of one another. In the example illustrated, the first portion 12 a is arranged at the top, and the second portion 12 b is arranged at the bottom. The resistivity of the resistive element 12 may vary gradually, or else sharply, between the first portion 12 a and the second portion 12 b.
  • The resistive element 12 of FIG. 4 is obtained starting from a material having an intrinsically medium-to-low resistivity, such as TiAl, TiSi, TiSi2, Ta, WSi, or another binary or ternary alloy with similar characteristics, and is subsequently treated so as to increase the resistivity of the first portion 12 a with respect to the second portion 12 b.
  • Preferably, the starting material of the resistive element 12 is enriched with nitrogen ions or nitrogen radicals, so as to increase local resistivity. For example, the enrichment may be achieved by plasma implantation or nitridation. Possibly, afterwards the resistive element 12 may be subjected to a thermal process whereby the introduced nitrogen forms amorphous, temperature-stable clusters.
  • As is known, nitrogen contributes to forming covalent bonds, rather than metallic bonds, and consequently determines a decrease in the electrons present in the conduction band, and thus increases the value of resistivity of the material into which it has been introduced.
  • FIG. 5 shows the distribution of the nitrogen-ion content in the vertical direction (Z axis) inside the resistive element 12, after nitridation. In the example illustrated, in the first portion 12A (the top one) there is a concentration of nitrogen ions which to a first approximation is constant and has a higher value, corresponding to a high resistivity, whereas in the second portion 12 b (the bottom one) the concentration of nitrogen ions is smaller and decreases almost down to zero in proximity of the interface with the bottom electrode 11. For example, the first portion 12 a has a resistivity of approximately 10 mΩcm, whilst in the second portion 12 b the resistivity is reduced to approximately 1 mΩcm. The profile of the nitrogen concentration, and hence of the resistivity, can in any case be engineered according to the particular requirements.
  • As indicated in FIG. 4 by the arrows 20, the current flows in a vertical direction (Z direction), i.e., parallel to the height of the resistive element 12, in contrast to barrier regions, made of similar alloys, wherein normally the thickness of the layer is much smaller than its width, and the current flows in a direction transverse to the larger dimension (width). In barrier regions, moreover, the resistivity is approximately uniform in the direction of the flow of current.
  • The resistive element 12 of FIG. 4 is obtained as described hereinafter. After depositing and patterning the bottom electrode 11, on top of the substrate (not shown) the insulating layer 16 is deposited and planarized, so as to have, at the end, a height H. The insulating layer 16 is then etched to form an opening where the resistive element 12 is to be made.
  • Next, the starting material of the resistive element 12, for example TiAl, TiSi, TiSi2, Ta, or WSi, is deposited, and the excess material is removed from the surface of the insulating layer 16, for example by etch-back or CMP (Chemical Mechanical Polishing).
  • The resistive element 12 is then nitridated, for instance by an N implantation or a nitrogen-plasma implantation (“Remote Plasma Nitridation” or “Decoupled Plasma Nitridation”), or, in general, using any process that generates reactive nitrogen species (nitrogen ions or nitrogen radicals). The processes enable engineering of the nitrogen profile in the Z direction (as shown, for example, in FIG. 5), thus enabling modulation of the resistivity of the resistive element 12. Preferably, the nitridation step is carried out without the use of masks.
  • Next, the polycrystalline layer 13 and the layer intended to form the top electrode 15 are deposited and are then defined so as to form a strip that extends perpendicular (at least locally) to the resistive element 12. In practice, the width direction of the resistive element 12 is parallel to the direction of extension of the strip in the area of mutual contact.
  • The advantages of the resistive element described are illustrated hereinafter. First, modulation of the resistivity in the vertical direction enables minimization of the heat dissipation and of the voltage drop in the portion distant from the phase-change region 14 (second portion 12 b in contact with the bottom electrode 11) and maximization of the same quantities in the first portion (i.e., the one in contact with the phase-change region 14), where it is important to have a good generation of heat in order to control phase change of the phase-change region 14. Thus a high local dissipation of heat is obtained in contact with the phase-change region 14 and a low dissipation elsewhere, with a consequent reduction in the risks of damage to the materials and components integrated in the chip.
  • The optimization of the resistivity profile moreover enables the use of programming voltages and currents lower than those required for a uniform resistive element. Consequently, it is possible to achieve better performance of the device, reduce energy consumption, and simplify the design of the components intended to generate and transport said currents and voltages.
  • Finally, it is clear that numerous modifications and variations may be made to the resistive element described and illustrated herein, all falling within the scope of the invention, as defined in the attached claims. For example, using a heavy implantation, it is possible to nitride preferentially the deep portion of the resistive element 12, obtaining a nitrogen and resistivity profile opposite to the one of FIG. 5. In addition, by engineering the nitridation technique, it is possible to modify the concentration profile so as to obtain, instead of a gradual reduction of the resistivity in the second portion, a sharp reduction of the resistivity, or else so as to obtain a portion of reduced thickness with a high resistivity, or yet again a profile with gradual variation of the resistivity throughout the height of the resistive element. In addition, one could use a material other than nitrogen to adjust the resistivity profile of the resistive element 12.
  • All of the above U.S. patents, U.S. patent application publications, U.S. patent applications, foreign patents, foreign patent applications and non-patent publications referred to in this specification and/or listed in the Application Data Sheet, are incorporated herein by reference, in their entirety.

Claims (23)

1. A method of making a vertical-current-flow resistive element, comprising:
forming a monolithic region of a single material having a height greater than at least one other dimension, the forming including:
forming first and second portions of the monolithic region arranged on top of one another, by forming said first portion with a first resistivity and said second portion with a second resistivity lower than said first resistivity.
2. The method according to claim 1, wherein forming said first portion includes adding to the monolithic region a first concentration of species forming a prevalently covalent bond with said single material, and forming said second portion includes adding to the monolithic region a second concentration of said species, lower than said first concentration, wherein said single material is conductive.
3. The method according to claim 2, wherein said species have a decreasing concentration starting from said first portion towards said second portion.
4. The method according to claim 2, wherein said single material is a binary or ternary alloy.
5. The method according to claim 4, wherein said conductive material is chosen from among TiAl, TiSi, TiSi2, Ta, and WSi.
6. The method according to claim 2, wherein said species comprise nitrogen.
7. The method according to claim 1, wherein said first portion has an approximately constant resistivity.
8. The method according to claim 1, wherein said second portion has a gradually decreasing resistivity starting from said first portion.
9. The method according to claim 1, further comprising:
forming a top electrode of conductive material in electrical contact with said first portion; and
forming a bottom electrode of conductive material in direct electrical contact with said second portion.
10. The method according to claim 1, wherein said monolithic region has a shape chosen from among a column shape, having a height, a width and a depth, wherein the height is greater than the width and the depth; a wall shape, having a height, a width and a depth, wherein the depth and the height are greater than the width: and a closed shape having a height, a width and a perimeter, wherein the height and the perimeter are greater than the width.
11. A process for manufacturing a vertical-current-flow resistive element, comprising:
forming a monolithic region of conductive material having a uniform resistivity and having a first portion and a second portion arranged on top of one another; and
increasing the resistivity of said first portion so that said first portion has a greater resistivity than said second portion.
12. The process according to claim 11, wherein said step of increasing the resistivity comprises enriching said first portion with species that form a prevalently covalent bond with said conductive material.
13. The process according to claim 12, wherein said step of enriching comprises implanting or introducing said species from plasma.
14. The process according to claim 12, wherein said species comprise nitrogen.
15. The process according to claim 11, wherein said conductive material is a binary or ternary alloy.
16. The process according to claim 11, wherein said conductive material is chosen from among TiAl, TiSi, TiSi2, Ta, and WSi.
17. The process according to claim 11, further comprising the steps of forming a bottom electrode of conductive material in direct electrical contact with said second portion and forming a top electrode of conductive material in electrical contact with said first portion.
18. A method of making a phase-change memory element, comprising:
forming a programmable element of chalcogenic material; and
forming a resistive element having a first end in direct electrical contact with said programmable element, the resistive element including a monolithic region having a first portion and a second portion arranged on top of one another, the first portion having a first resistivity and said second portion having a second resistivity lower than said first resistivity.
19. The method of claim 18, wherein forming the resistive element includes forming the monolithic region of a conductive material; forming the first portion by adding to the monolithic region a first concentration of a species covalently bonded with the conductive material; and forming the second portion by adding to the monolithic region a second concentration of the species covalently bonded with the conductive material, the first concentration being greater than the second concentration.
20. The method of claim 19, wherein the conductive material is chosen from among TiAl, TiSi, TiSi2, Ta, and WSi and the species include nitrogen.
21. The method of claim 18 wherein the step of forming the resistive element includes:
forming the monolithic region of conductive material having a uniform resistivity; and
increasing the resistivity of the first portion so that the first portion has a greater resistivity than the second portion.
22. The method of claim 18, further comprising:
forming a conductive electrode;
forming an insulating layer on the electrode; and
forming an opening that extends through the insulating layer and exposes a portion of the electrode, wherein forming the resistive element includes forming the monolithic region in the opening and in contact with the electrode.
23. The method of claim 22 wherein forming the resistive element includes depositing a conductive material in the opening, removing an excess portion of the conductive material from a surface of the insulating layer, and nitridating the conductive material in the opening without using a mask.
US11/201,790 2002-01-17 2005-08-11 Process for manufacturing integrated resistor and phase-change memory element including this resistor Abandoned US20050269667A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US11/201,790 US20050269667A1 (en) 2002-01-17 2005-08-11 Process for manufacturing integrated resistor and phase-change memory element including this resistor

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
EP02425013A EP1331675B1 (en) 2002-01-17 2002-01-17 Integrated resistive element, phase-change memory element including said resistive element, and method of manufacture thereof
EP02425013.6 2002-01-17
US10/345,129 US6946673B2 (en) 2002-01-17 2003-01-14 Integrated resistor, phase-change memory element including this resistor, and process for the fabrication thereof
US11/201,790 US20050269667A1 (en) 2002-01-17 2005-08-11 Process for manufacturing integrated resistor and phase-change memory element including this resistor

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
US10/345,129 Division US6946673B2 (en) 2002-01-17 2003-01-14 Integrated resistor, phase-change memory element including this resistor, and process for the fabrication thereof

Publications (1)

Publication Number Publication Date
US20050269667A1 true US20050269667A1 (en) 2005-12-08

Family

ID=8185827

Family Applications (2)

Application Number Title Priority Date Filing Date
US10/345,129 Expired - Lifetime US6946673B2 (en) 2002-01-17 2003-01-14 Integrated resistor, phase-change memory element including this resistor, and process for the fabrication thereof
US11/201,790 Abandoned US20050269667A1 (en) 2002-01-17 2005-08-11 Process for manufacturing integrated resistor and phase-change memory element including this resistor

Family Applications Before (1)

Application Number Title Priority Date Filing Date
US10/345,129 Expired - Lifetime US6946673B2 (en) 2002-01-17 2003-01-14 Integrated resistor, phase-change memory element including this resistor, and process for the fabrication thereof

Country Status (3)

Country Link
US (2) US6946673B2 (en)
EP (1) EP1331675B1 (en)
DE (1) DE60220245D1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20160240478A1 (en) * 2015-02-16 2016-08-18 Globalfoundries Inc. Modified tungsten silicon

Families Citing this family (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7115138B2 (en) * 2002-09-04 2006-10-03 Boston Scientific Scimed, Inc. Sheath tip
EP1576670B1 (en) 2002-12-19 2007-02-21 Koninklijke Philips Electronics N.V. Electric device with phase change material and parallel heater
US20040251988A1 (en) * 2003-06-16 2004-12-16 Manish Sharma Adjustable phase change material resistor
US7009694B2 (en) * 2004-05-28 2006-03-07 International Business Machines Corporation Indirect switching and sensing of phase change memory cells
TW200633193A (en) 2004-12-02 2006-09-16 Koninkl Philips Electronics Nv Non-volatile memory
EP1677371A1 (en) * 2004-12-30 2006-07-05 STMicroelectronics S.r.l. Dual resistance heater for phase change devices and manufacturing method thereof
DE102005001460B4 (en) 2005-01-12 2010-01-14 Qimonda Ag Storage device and manufacturing method
JP2006210718A (en) * 2005-01-28 2006-08-10 Renesas Technology Corp Semiconductor device and manufacturing method therefor
US7973384B2 (en) * 2005-11-02 2011-07-05 Qimonda Ag Phase change memory cell including multiple phase change material portions
JP2008053494A (en) * 2006-08-25 2008-03-06 Elpida Memory Inc Semiconductor device and manufacturing method thereof
US7511984B2 (en) 2006-08-30 2009-03-31 Micron Technology, Inc. Phase change memory
US8003972B2 (en) * 2006-08-30 2011-08-23 Micron Technology, Inc. Bottom electrode geometry for phase change memory
KR100873890B1 (en) 2006-11-17 2008-12-15 삼성전자주식회사 Phase-change memory unit, method of forming the phase-change memory unit, phase-change memory device having the phase-change memory unit and method of manufacturing the phase-change memory device
TWI346382B (en) * 2007-03-30 2011-08-01 Nanya Technology Corp Phase change memory devices and fabrication methods thereof
CN101330126B (en) * 2007-06-19 2010-12-01 财团法人工业技术研究院 Phase variation storage unit structure and method for manufacturing the same
KR100881055B1 (en) 2007-06-20 2009-01-30 삼성전자주식회사 Phase-change memory unit, method of forming the phase-change memory unit, phase-change memory device having the phase-change memory unit and method of manufacturing the phase-change memory device
US8975727B2 (en) 2012-02-28 2015-03-10 Intermolecular, Inc. Memory cell having an integrated two-terminal current limiting resistor
US8563366B2 (en) 2012-02-28 2013-10-22 Intermolecular Inc. Memory device having an integrated two-terminal current limiting resistor
US9178152B2 (en) 2013-12-23 2015-11-03 Intermolecular, Inc. Metal organic chemical vapor deposition of embedded resistors for ReRAM cells
US9269902B2 (en) 2013-12-26 2016-02-23 Intermolecular, Inc. Embedded resistors for resistive random access memory cells
US9425390B2 (en) 2014-10-16 2016-08-23 Micron Technology, Inc. Select device for memory cell applications
WO2018056963A1 (en) * 2016-09-21 2018-03-29 Intel Corporation Conductive bridge random access memory (cbram) devices with graded conductivity electrolyte layer
WO2018063320A1 (en) * 2016-09-30 2018-04-05 Intel Corporation Conductive bridge random access memory (cbram) devices with low thermal conductivity electrolyte sublayer

Citations (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3271591A (en) * 1963-09-20 1966-09-06 Energy Conversion Devices Inc Symmetrical current controlling device
US4181913A (en) * 1977-05-31 1980-01-01 Xerox Corporation Resistive electrode amorphous semiconductor negative resistance device
US5166758A (en) * 1991-01-18 1992-11-24 Energy Conversion Devices, Inc. Electrically erasable phase change memory
US5687112A (en) * 1996-04-19 1997-11-11 Energy Conversion Devices, Inc. Multibit single cell memory element having tapered contact
US5714768A (en) * 1995-10-24 1998-02-03 Energy Conversion Devices, Inc. Second-layer phase change memory array on top of a logic device
US5933365A (en) * 1997-06-19 1999-08-03 Energy Conversion Devices, Inc. Memory element with energy control mechanism
US6064079A (en) * 1997-07-14 2000-05-16 Kabushiki Kaisha Toshiba Gallium nitride-based compound semiconductor device
US6121127A (en) * 1996-06-14 2000-09-19 Toyoda Gosei Co., Ltd. Methods and devices related to electrodes for p-type group III nitride compound semiconductors
US20020038872A1 (en) * 2000-09-29 2002-04-04 Lowrey Tyler A. Compositionally modified resistive electrode
US20020096512A1 (en) * 2000-11-29 2002-07-25 Abbott Richard C. Resistive heaters and uses thereof
US20030151116A1 (en) * 2001-01-12 2003-08-14 International Business Machines Corporation Semiconductor device incorporating elements formed of refractory metal-silicon-nitrogen and method for fabrication
US6617192B1 (en) * 1997-10-01 2003-09-09 Ovonyx, Inc. Electrically programmable memory element with multi-regioned contact
US20040115372A1 (en) * 2002-12-13 2004-06-17 Tyler Lowrey Vertical elevated pore phase change memory
US20040175920A1 (en) * 1998-09-03 2004-09-09 Derderian Garo J. Interface and method of forming an interface for a silicon contact
US6791102B2 (en) * 2002-12-13 2004-09-14 Intel Corporation Phase change memory

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2002009206A1 (en) * 2000-07-22 2002-01-31 Ovonyx, Inc. Electrically programmable memory element

Patent Citations (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3271591A (en) * 1963-09-20 1966-09-06 Energy Conversion Devices Inc Symmetrical current controlling device
US4181913A (en) * 1977-05-31 1980-01-01 Xerox Corporation Resistive electrode amorphous semiconductor negative resistance device
US5166758A (en) * 1991-01-18 1992-11-24 Energy Conversion Devices, Inc. Electrically erasable phase change memory
US5714768A (en) * 1995-10-24 1998-02-03 Energy Conversion Devices, Inc. Second-layer phase change memory array on top of a logic device
US5687112A (en) * 1996-04-19 1997-11-11 Energy Conversion Devices, Inc. Multibit single cell memory element having tapered contact
US6121127A (en) * 1996-06-14 2000-09-19 Toyoda Gosei Co., Ltd. Methods and devices related to electrodes for p-type group III nitride compound semiconductors
US5933365A (en) * 1997-06-19 1999-08-03 Energy Conversion Devices, Inc. Memory element with energy control mechanism
US6064079A (en) * 1997-07-14 2000-05-16 Kabushiki Kaisha Toshiba Gallium nitride-based compound semiconductor device
US6617192B1 (en) * 1997-10-01 2003-09-09 Ovonyx, Inc. Electrically programmable memory element with multi-regioned contact
US20040175920A1 (en) * 1998-09-03 2004-09-09 Derderian Garo J. Interface and method of forming an interface for a silicon contact
US20020038872A1 (en) * 2000-09-29 2002-04-04 Lowrey Tyler A. Compositionally modified resistive electrode
US20020096512A1 (en) * 2000-11-29 2002-07-25 Abbott Richard C. Resistive heaters and uses thereof
US20030151116A1 (en) * 2001-01-12 2003-08-14 International Business Machines Corporation Semiconductor device incorporating elements formed of refractory metal-silicon-nitrogen and method for fabrication
US20040115372A1 (en) * 2002-12-13 2004-06-17 Tyler Lowrey Vertical elevated pore phase change memory
US6791102B2 (en) * 2002-12-13 2004-09-14 Intel Corporation Phase change memory

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20160240478A1 (en) * 2015-02-16 2016-08-18 Globalfoundries Inc. Modified tungsten silicon
US10192822B2 (en) * 2015-02-16 2019-01-29 Globalfoundries Inc. Modified tungsten silicon

Also Published As

Publication number Publication date
US6946673B2 (en) 2005-09-20
DE60220245D1 (en) 2007-07-05
EP1331675B1 (en) 2007-05-23
EP1331675A1 (en) 2003-07-30
EP1331675A9 (en) 2004-01-28
US20030161195A1 (en) 2003-08-28

Similar Documents

Publication Publication Date Title
US20050269667A1 (en) Process for manufacturing integrated resistor and phase-change memory element including this resistor
US8344348B2 (en) Memory device
US20080210923A1 (en) Semiconductor device and method of manufacturing the same
US9000408B2 (en) Memory device with low reset current
US7042001B2 (en) Phase change memory devices including memory elements having variable cross-sectional areas
US7569844B2 (en) Memory cell sidewall contacting side electrode
US6545287B2 (en) Using selective deposition to form phase-change memory cells
KR100486306B1 (en) Phase-change memory device having self-heater structure
CN101197423B (en) Method for making a self-converged memory material element for memory cell
US7973301B2 (en) Low power phase change memory cell with large read signal
EP1667244B1 (en) Method of fabricating phase change memory device having phase change material layer containing phase change nano particles
US9105842B2 (en) Method for manufacturing a carbon-based memory element and memory element
US7879645B2 (en) Fill-in etching free pore device
US7470922B2 (en) Increasing adherence of dielectrics to phase change materials
US20080073637A1 (en) Phase-Change Material Layer and Phase-Change Memory Device Including the Phase-Change Material Layer
US9343676B2 (en) Heating phase change material
US8189374B2 (en) Memory device including an electrode having an outer portion with greater resistivity
KR20160113517A (en) Graphene inserted phase change memory device and fabricating the same
US20060273297A1 (en) Phase change memory cell having ring contacts
US8772906B2 (en) Thermally insulated phase change material cells
US8440501B2 (en) Memory device

Legal Events

Date Code Title Description
STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION