US20070120104A1 - Phase change material and non-volatile memory device using the same - Google Patents

Phase change material and non-volatile memory device using the same Download PDF

Info

Publication number
US20070120104A1
US20070120104A1 US11/290,713 US29071305A US2007120104A1 US 20070120104 A1 US20070120104 A1 US 20070120104A1 US 29071305 A US29071305 A US 29071305A US 2007120104 A1 US2007120104 A1 US 2007120104A1
Authority
US
United States
Prior art keywords
te
phase change
ge
sb
memory cell
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
Application number
US11/290,713
Other versions
US7233054B1 (en
Inventor
Dong Ho Ahn
Tae-Yon Lee
Ki Bum Kim
Byung-Ki Cheong
Dae-Hwan Kang
Jeung-Hyun Jeong
In Ho Kim
Taek Sung Lee
Won Mok Kim
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.)
Seoul National University R&DB Foundation
SK Hynix Inc
Original Assignee
Korea Advanced Institute of Science and Technology KAIST
Seoul National University University-Industry Foundation
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 Korea Advanced Institute of Science and Technology KAIST, Seoul National University University-Industry Foundation filed Critical Korea Advanced Institute of Science and Technology KAIST
Assigned to SEOUL NATIONAL UNIVERSITY INDUSTRY FOUNDATION, KOREA INSTITUTE OF SCIENCE AND TECHNOLOGY reassignment SEOUL NATIONAL UNIVERSITY INDUSTRY FOUNDATION ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: AHN, DONG HO, CHEONG, BYUNG-KI, JEONG, JEUNG-HYUN, KANG, DAE-HWAN, KIM, IN HO, KIM, KI BUM, KIM, WON MOK, LEE, TAEK SUNG, LEE, TAE-YON
Priority to US11/290,713 priority Critical patent/US7233054B1/en
Publication of US20070120104A1 publication Critical patent/US20070120104A1/en
Publication of US7233054B1 publication Critical patent/US7233054B1/en
Application granted granted Critical
Assigned to SEOUL NATIONAL UNIVERSITY R&DB FOUNDATION reassignment SEOUL NATIONAL UNIVERSITY R&DB FOUNDATION ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: SEOUL NATIONAL UNIVERSITY INDUSTRY FOUNDATION
Assigned to SK Hynix Inc. reassignment SK Hynix Inc. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: KOREA INSTITUTE OF SCIENCE AND TECHNOLOGY, SEOUL NATIONAL UNIVERSITY R&D FOUNDATION
Application status is Active legal-status Critical
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H01L45/00Solid state devices adapted for rectifying, amplifying, oscillating or switching without a potential-jump barrier or surface barrier, e.g. dielectric triodes; Ovshinsky-effect devices; Processes or apparatus peculiar to the manufacture or treatment thereof or of parts thereof
    • H01L45/04Bistable or multistable switching devices, e.g. for resistance switching non-volatile memory
    • H01L45/06Bistable or multistable switching devices, e.g. for resistance switching non-volatile memory based on solid-state phase change, e.g. between amorphous and crystalline phases, Ovshinsky effect
    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H01L45/00Solid state devices adapted for rectifying, amplifying, oscillating or switching without a potential-jump barrier or surface barrier, e.g. dielectric triodes; Ovshinsky-effect devices; Processes or apparatus peculiar to the manufacture or treatment thereof or of parts thereof
    • H01L45/04Bistable or multistable switching devices, e.g. for resistance switching non-volatile memory
    • H01L45/12Details
    • H01L45/122Device geometry
    • H01L45/1233Device geometry adapted for essentially vertical current flow, e.g. sandwich or pillar type devices
    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H01L45/00Solid state devices adapted for rectifying, amplifying, oscillating or switching without a potential-jump barrier or surface barrier, e.g. dielectric triodes; Ovshinsky-effect devices; Processes or apparatus peculiar to the manufacture or treatment thereof or of parts thereof
    • H01L45/04Bistable or multistable switching devices, e.g. for resistance switching non-volatile memory
    • H01L45/12Details
    • H01L45/1253Electrodes
    • H01L45/126Electrodes adapted for resistive heating
    • HELECTRICITY
    • H01BASIC ELECTRIC ELEMENTS
    • H01LSEMICONDUCTOR DEVICES; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H01L45/00Solid state devices adapted for rectifying, amplifying, oscillating or switching without a potential-jump barrier or surface barrier, e.g. dielectric triodes; Ovshinsky-effect devices; Processes or apparatus peculiar to the manufacture or treatment thereof or of parts thereof
    • H01L45/04Bistable or multistable switching devices, e.g. for resistance switching non-volatile memory
    • H01L45/14Selection of switching materials
    • H01L45/141Compounds of sulfur, selenium or tellurium, e.g. chalcogenides
    • H01L45/144Tellurides, e.g. GeSbTe

Abstract

The present invention provides a phase change memory cell comprising (GeASbBTeC)1−x(RaSbTeC)x solid solution, the solid solution being formed from a Ge—Sb—Te based alloy and a ternary metal alloy R—S—Te sharing same crystal structure as the Ge—Sb—Te based alloy. A nonvolatile phase change memory cell in accordance with the present invention provides many advantages such as high speed, high data retention, and multi-bit operation.

Description

    FIELD OF THE INVENTION
  • The present invention relates to a non-volatile memory device using a phase change material.
  • BACKGROUND OF THE INVENTION
  • In recent years, there has been a renewal of interest in phase change random access memory (PCRAM) as a promising candidate for next generation nonvolatile memory device because of many advantages such as non-volatility, fast operation property, process simplicity and possibility of multi-bit operation.
  • Traditionally, PCRAM employs a chalcogenide-based phase change material such as a stoichiometric Ge—Sb—Te alloy like Ge2Sb2Te5. A Ge—Sb—Te based alloy is capable of storing information in a binary form by electrically switching between the amorphous and crystalline states in a reversible manner.
  • Despite its merits as nonvolatile phase change memory material, however, a Ge—Sb—Te based alloy is disadvantageous as it tends to yield slow writing speed. For instance, it takes about 100 ns for the completion of the phase change from the amorphous (high resistance) to the crystalline (low resistance) states when a Ge—Sb—Te based alloy is employed. It takes ordinarily less than 100 ns in the reverse direction. On the other hand, conventional DRAM (dynamic random access memory), SRAM (static random access memory) and MRAM (magnetic random access memory) show the writing time of ˜50 ns, ˜8 ns and ˜10 ns, respectively. Therefore, efforts should be made if PCRAM is to be used for high speed applications.
  • In addition, there is a stability problem associated with thermal interference between adjacent memory cells.
  • To store information in a binary form, memory cell exploits the difference in electrical resistance between crystalline and amorphous states. Specifically, in order to write ‘1’ state (reset state) in a single cell, an electric voltage or current pulse is applied between the top and bottom electrodes contacting a phase change material, which induces direct or indirect heating on the phase change material for melting thereof. Upon termination of the electric pulse, the molten phase change material is quenched to an amorphous state, thereby writing the state ‘1’ in a single cell.
  • With density of PCRAM growing higher, binary data stored in amorphous memory cells may be corrupted with ease by unintended crystallization as a result of the heat generated in an adjoining memory cell which undergoes melting during a reset process thereof.
  • Nitrogen or silicon may be added to a Ge—Sb—Te based alloy for raising the crystallization temperature thereof. However, the addition of impurities may slow the crystallization process (B. J. Kuh et al, EPCOS 2005).
  • Further, integrating the memory device by sizing down the cell area is inherently bound by the limits of photolithographic techniques. In U.S. Pat. No. 5,414,271, it is disclosed that data can be stored in multi-bit forms by controlling the ratio between the amorphous and crystalline states in a single cell unit. However, it is extremely hard to control the dispersion between these two states.
  • Accordingly, it is imperative to find a way for storing multi-bit information in a single cell unit.
  • SUMMARY OF THE INVENTION
  • It is, therefore, an object of the present invention to provide a non-volatile phase change memory cell devoid of at least one of the aforementioned problems, and a memory device using the same.
  • In accordance with the present invention, there is provided a non-volatile phase change memory cell comprising a compound having the formula (GeASbBTeC)1−X(RaSbTeC)X, wherein Ge is germanium; Sb is antimony; Te is tellurium; R is an element selected from the elements belonging to the IVB group in the periodic table; S is an element selected from the elements belonging to the VB group in the periodic table; A, B, C, a, b and c are atomic mole ratios; x is a mole fraction in the range of 0 to 1; RaSbTeC has same crystal structure as GeASbBTeC; and at least one element of R and S has a higher atomic number and thus a smaller diatomic bond strength than that of the corresponding element in the GeSb portion of Ge—Sb—Te.
  • BRIEF DESCRIPTION OF THE DRAWINGS
  • The above and other objects and features of the present invention will become apparent from the following description of preferred embodiments given in conjunction with the accompanying drawings, in which:
  • FIG. 1 describes a schematic diagram of a phase change memory cell including a material in accordance with the present invention;
  • FIG. 2 shows a planar view of 70 nm contact pore by SEM;
  • FIG. 3 illustrates sectional SEM picture of a phase change memory cell including a material in accordance with the present invention;
  • FIGS. 4 a, 4 b and 4 c offer DC I-V characteristics of (Ge1Sb2Te4)0.8(R1S2Te4)0.2, (Ge1Sb2Te4)0.9(R1S2Te4)0.1 and Ge1Sb2Te4, respectively;
  • FIGS. 5 a, 5 b and 5 c delineate resistances of memory cells having (Ge1Sb2Te4)0.8(R1S2Te4)0.2, (Ge1Sb2Te4)0.9(R1S2Te4)0.1 and Ge1Sb2Te4, respectively;
  • FIG. 6 demonstrates relationship between SET pulse voltage characteristics and SET pulse width; and
  • FIG. 7 outlines change in sheet resistance with respect to the temperature of heat treatment.
  • DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
  • The preferred embodiment of the present invention will now be explained.
  • A phase change memory cell according to the present invention comprises a ternary alloy of R—S—Te which forms a homogeneous pseudo-binary solid solution with a Ge—Sb—Te alloy.
  • Specifically, the phase change memory cell of the present invention comprises a composition having the formula (GeASbBTeC)1−x(RaSbTeC)X, wherein Ge is germanium; Sb is antimony; Te is tellurium; R is an element selected from the elements belonging to the IVB group in the periodic table; S is an element selected from the elements belonging to the VB group in the periodic table; A, B, C, a, b and c are atomic mole ratios; x is a mole fraction in the range of 0 to 1; RaSbTeC has the same crystal structure as GeASbBTeC; and at least one element of R and S has a higher atomic number and thus a smaller diatomic bond strength than that of the corresponding element in the GeSb portion of Ge—Sb—Te.
  • In one embodiment, the Ge—Sb—Te alloy may be a stoichiometric compound alloy of Ge, Sb and Te, preferably selected from the group of Ge4Sb1Te5, Ge2Sb2Te5, Ge1Sb2Te4, and Ge1Sb4Te7. Therefore, it is prefera that a combination of A, B and C is selected from the group consisting of (4, 1, 5), (2, 2, 5), (1, 2, 4) and (1, 4, 7), the combination being limited to the sequence expressed in parenthesis in that order.
  • In one embodiment, the R—S—Te ternary alloy is stoichiometrically equivalent to the Ge—Sb—Te alloy.
  • A stoichiometric compound alloy tends to have fast kinetics of an amorphous to crystalline transformation for the following reasons: the alloy tends to have a high atomic mobility effected by its large thermodynamic driving force of an amorphous to crystalline transformation; the alloy tends to crystallize into a single phase, requiring only short-range atomic reconfiguration with no need of long-range atomic diffusion indispensable to phase separation. Therefore, it is preferable that R—S—Te alloy has the same stoichiometric composition as the compound Ge—Sb—Te alloy so that an amorphous to crystalline transformation in a solid solution of R—S—Te and Ge—Sb—Te alloys would proceed rapidly likewise.
  • In addition, R and S are elements belonging to the IVB and VB group in the periodic table, respectively, and the diatomic bond strength of at least one of R and S is smaller than that of the corresponding element of the Ge—Sb—Te portion. J. H. Coombs, et al. [J. AppI. Phys., 78, 4918(1995)] studied crystallization kinetics of Ge—Sb—Te alloys in which a part of Ge is replaced with Sn, or a part of Te is replaced with Sulfur or Se.
  • According to these studies, the nucleation kinetics increases when a part of Ge is replaced with Sn whose single bond energy is smaller than that of Ge, whereas the nucleation kinetics decreases when a part of Te is replaced with Sulfur or Se whose single bond energy is larger than that of Te. From these studies, it is apparent that the diatomic bond strength of each constituent element plays an important role in crystallization kinetics.
  • Therefore, in order to increase the crystallization kinetics, it is preferred that at least one of R and S has a higher atomic number and thus a smaller diatomic bond strength than that of a corresponding element in the GeSb portion of Ge—Sb—Te alloy. Thus, R is preferably Sn or Pb, and S is preferably Bi.
  • When the crystalline phases of both RaSbTeC and Ge—Sb—Te alloys have the same space group symmetry with slightly different lattice parameters, a pseudo-binary solid solution can form with a complete solubility between two alloys. Table 1 shows a list of the preferable RaSbTeC alloys for each of the stoichiometric compound Ge—Sb—Te alloys. TABLE 1 Space Group Sym. (Pearson Lattice Parameters Compound Symbol) (nm) Ge4Sb1Te5 Fm-3m a = 0.6 (cF8) 1Pb4Bi1Te5(Pb39Bi9Te52) 0.6415 2Sn4Bi1Te5(Sn38Bi12Te50) 0.63 Ge2Sb2Te5 P-3ml a = 0.42 c = 1.70 (hP9) Pb2Bi2Te5 0.446 1.75 Ge1Sb2Te4 R-3m a = 0.421 c = 4.06 (hR7) Ge1Bi2Te4 0.428 3.92 Pb1Bi2Te4 0.416 3.92 Sn1Bi2Te4 0.4411 4.15 Sn1Sb2Te4 0.4294 4.16 Ge1Sb4Te7 P-3ml a = 0.421 c = 2.37 (hP12) Ge1Bi4Te7 0.4352 2.39 3Pb1Bi4Te7 0.446 2.36 4Sn1Bi4Te7(Sn12Bi38Te50) 0.4395 2.44
    Note:

    1(Bi2Te3)x(PbTe)1−x, a = 0.64564-0.64151 nm for x = 0-0.1,

    2Bi1−xSnxTe1, a = 0.6300-0.6316 nm for x = 0.75-1,

    3three other crystal structures are also known,

    4Bi1−xSnxTe1, a = 0.4448-0.4395 nm, c = 2.427-2.436 nm for x = 0-0.25; Sn1Bi4Te7 itself has the symmetry of R-3m(hR7).
  • According to the present invention, the atomic mole ratios may deviate from the aforementioned values to the extent that a solid solution of R—S—Te and Ge—Sb—Te alloys can form a single crystalline phase, or multiple phases with a predominant crystalline phase of preferably equal to or more than 90% in volume.
  • R—S—Te alloy sharing the same crystal structure as Ge—Sb—Te alloy not only accelerates the crystallization of Ge—Sb—Te based alloy through forming a complete solid solution alloy therewith but also changes the basic concept of a binary phase change memory element which has amorphous and crystalline face-centered-cubic (fcc) states.
  • For instance, cell resistance does not return to that of an original crystalline state (1st SET value) but rather drops further to the 2nd SET value when an electric pulse is applied to the (Ge1Sb2Te4)0.8(R1S2Te4)0.2 film in a virgin amorphous state. It was also discovered that the cell resistance changes reversibly between 1st SET and 2nd SET since then.
  • Accordingly, data can be stored in different forms of crystalline phases. Transition of cell resistance from low conducting crystalline state (fcc) to high conducting crystalline hexagonal state and vice-versa is very abrupt and fast, and also each cell resistance value corresponds the resistivity of each phase. The mechanism is suggested by Dong-ho Ahn et al. (IEEE electron device letters, Vol. 26, No. 5), which is incorporated herein by reference.
  • Present inventors also discovered that three phases of amorphous, fcc and hexagonal crystalline states may be accessible for data storage if the amount of R—S—Te based alloy introduced is reduced to, e.g., (Ge1Sb2Te4)0.9(R1S2Te4)0.1.
  • Specific aspects of the present invention are further illustrated through the following Examples, without limiting the scope thereof.
  • EXAMPLE 1
  • An off-set type phase change memory cell as shown in FIG. 1 was prepared according to the following procedures. 200 nm-thick SiO2 film was deposited on silicon substrate. Ti/TiN film, as a bottom electrode, was deposited thereon at a thickness of 100 nm, respectively. Next, 100 nm-thick SiO2 was formed thereon. As shown in SEM picture of FIG. 2, a contact hole of 70 nm was formed by electron beam lithography.
  • Next, as a phase change material, solid solution of (Ge1Sb2Te4)0.8(Sn1Bi2Te4)0.2 was deposited in the contact hole by PVD (physical vapor deposition) at a thickness of 100 nm. As top electrodes, 100 nm-thick TiN and 500 nm-thick Al films were sequentially deposited on the phase change material.
  • FIG. 1 describes a schematic diagram of an off-set type phase change memory cell including a material in accordance with the present invention. Transistor part for cell addressing is not shown in FIG. 1.
  • FIG. 3 illustrates sectional SEM picture of a phase change memory cell including a material in accordance with the present invention.
  • EXAMPLE 2
  • Procedures in Example 1 were repeated except that a solid solution of (Ge1Sb2Te4)0.9(Sn1Bi2Te4)0.1 was used instead of (Ge1Sb2Te4)0.8(Sn1Bi2Te4)0.2.
  • COMPARATIVE EXAMPLE
  • Procedures in Example 1 were repeated except that Ge1Sb2Te4 alloy was employed as a phase change material instead of the solid solution.
  • Evaluation of DC I-V Characteristics, Resistance and Operational Speed
  • DC I-V characteristics were measured with Agilent 4156C for the samples prepared in Examples 1, 2 and Comparative Example as shown in FIGS. 4 a, 4 b and 4 c, respectively.
  • In FIGS. 4 a to 4 c, typical DC I-V curve of the crystalline-amorphous states was observed when only Ge1Sb2Te4 was employed (FIG. 4 c). For the sample employing (Ge1Sb2Te4)0.8(Sn1Bi2Te4)0.2 as the phase change material (Example 1), DC I-V curve revealed just the features of fcc and hexagonal crystalline states without negative resistance characteristics of amorphous state (FIG. 4 a).
  • On the other hand, all three phases of amorphous, fcc and hexagonal crystalline states were present as shown in the curve of FIG. 4 b when (Ge1Sb2Te4)0.9(Sn1Bi2Te4)0.1 was employed as the phase change material (Example 2).
  • Further, resistances of the samples were measured with Agilent 4156C, results being shown in FIGS. 5 a, 5 b and 5 c.
  • As shown in FIG. 5 c, the resistances of the amorphous and fcc states of Comparative Example were each 106 ohm and 104 ohm, showing two orders of magnitude difference.
  • On the other hand, the resistances of the fcc and hexagonal crystalline states of Example 1 were each 103 ohm and 102 ohm as shown in FIG. 5 a. The resistance gap of sample from Example 1, i.e. (Ge1Sb2Te4)0.8(Sn1Bi2Te4)0.2, was smaller than Comparative Example where pure Ge1Sb2Te4 was employed. However, it still has one order of magnitude, which is large enough to provide distinguishable binary memory states.
  • As shown in FIG. 5 b, resistances of the amorphous, fcc and hexagonal crystalline states of Example 2 were 108, 104 and 102 ohms, respectively. Accordingly, all three states of Example 2 were distinguishable by two or four orders of magnitude.
  • FIG. 6 demonstrates relationship between SET pulse voltage characteristics and SET pulse width as measured with Agilent 81110A.
  • SET pulse width in FIG. 6 is equivalent to the speed of the set operation of the device. The duration for the phase change of Comparative Example was shown to be 100 ns or more while that of Example 2 was shown to be 20 ns between its amorphous and fcc states. Duration of fcc-hexagonal phase change of Example 1 was 70 ns.
  • FIG. 7 outlines change in sheet resistance with respect to the temperature of heat treatment as measured with Agilent 4156C. Sheet resistance drops at phase change temperature. By this standard, phase change temperatures of Examples 1, 2 and Comparative Example were determined to be 210, 230 and 110° C., respectively.
  • Test results of Examples are summarized in Table 2 below. TABLE 2 Resistance after Speed of phase Phase change phase change change temperature A* fcc hex A→fcc fcc→hex A→fcc fcc→hex Example 1 ˜103 ˜102 70 ns 210° C. Example 2 ˜108 ˜104 ˜102  20 ns 70 ns 230° C. Comparative Example ˜106 ˜104 100 ns ˜10 μs  110° C. Above 300° C.
    *A and hex indicate amorphous and crystalline hexagonal states of Sn1Bi2Te4, respectively.
  • In summary, considerable advantages can be expected by employing solid solution of (GeASbBTeC)1−x(RaSbTec)x in a memory cell in accordance with the present invention.
  • For instance, the cell of Example 1 is stable against data corruption since the phase change temperature is higher than that in a conventional cell by as much as 100° C.
  • If the cell of Example 2 is employed, multi-bit information storage is enabled with three discrete phases available in a single cell unit. Both cells in Examples 1 and 2 present fast recording/deleting of data.
  • While the invention has been shown and described with respect to the preferred embodiment, it will be understood by those skilled in the art that various changes and modification may be made without departing from the spirit and scope of the invention as defined in the following claims.

Claims (9)

1. A non-volatile phase change memory cell comprising a compound having the following formula:

(GeASbBTec)1−x(RaSbTec)x
wherein, Ge is germanium; Sb is antimony; Te is tellurium; R is an element selected from the elements belonging to the IVB group in the periodic table; S is an element selected from the elements belonging to the VB group in the periodic table; A, B, C, and a, b and c are atomic mole ratios satisfying the condition that the R—S—Te alloy part is stoichiometrically equivalent to the Ge—Sb—Te alloy part; x is a mole fraction in the range of 0 to 1; RaSbTec has the same crystal structure as GeASbBTeC; and at least one element of R and S has a higher atomic number and a smaller diatomic bond strength than that of the corresponding element in the GeSb portion of Ge—Sb—Te.
2. The non-volatile phase change memory cell of claim 1, wherein R is Sn or Pb and S is Bi.
3. The non-volatile phase change memory cell of claim 1, wherein a first combination of A, S and C and a second combination of a, b and c are the same with each other, and selected from the group consisting of (4, 1, 5), (2, 2, 5), (1, 2, 4) and (1, 4, 7), the combination being limited to the sequence expressed in parenthesis in that order.
4. The non-volatile phase change memory cell of claim 3, wherein both the first and the second combinations are (1, 2, 4).
5. The non-volatile phase change memory cell of claim 4, wherein X is around 0.2.
6. The non-volatile phase change memory cell of claim 4, wherein X is around 0.1.
7. The non-volatile phase change memory cell of claim 1, wherein the compound presents two crystalline phases of a face-centered-cubic (fcc) and a hexagonal states.
8. The non-volatile phase change memory cell of claim 1, wherein the compound presents three phases of an amorphous, a crystalline face-centered cubic (fcc) and a crystalline hexagonal state.
9. A memory device comprising the phase change memory cell of claim 1.
US11/290,713 2005-11-29 2005-11-29 Phase change material and non-volatile memory device using the same Active US7233054B1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US11/290,713 US7233054B1 (en) 2005-11-29 2005-11-29 Phase change material and non-volatile memory device using the same

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US11/290,713 US7233054B1 (en) 2005-11-29 2005-11-29 Phase change material and non-volatile memory device using the same

Publications (2)

Publication Number Publication Date
US20070120104A1 true US20070120104A1 (en) 2007-05-31
US7233054B1 US7233054B1 (en) 2007-06-19

Family

ID=38086567

Family Applications (1)

Application Number Title Priority Date Filing Date
US11/290,713 Active US7233054B1 (en) 2005-11-29 2005-11-29 Phase change material and non-volatile memory device using the same

Country Status (1)

Country Link
US (1) US7233054B1 (en)

Cited By (56)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070187801A1 (en) * 2006-02-10 2007-08-16 Yoshiaki Asao Semiconductor device
US20070224770A1 (en) * 2006-03-25 2007-09-27 Makoto Nagashima Systems and methods for fabricating self-aligned memory cell
US20080061341A1 (en) * 2006-09-11 2008-03-13 Macronix International Co., Ltd. Memory Device Having Wide Area Phase Change Element and Small Electrode Contact Area
US20080142775A1 (en) * 2006-12-19 2008-06-19 International Business Machines Corporation Programmable via structure and method of fabricating same
US20080191186A1 (en) * 2007-02-14 2008-08-14 Macronix International Co., Ltd. Phase change memory cell with filled sidewall memory element and method for fabricating the same
US20090098716A1 (en) * 2006-12-06 2009-04-16 Macronix International Co., Ltd. Method for making a self-converged memory material element for memory cell
US20090101879A1 (en) * 2007-10-22 2009-04-23 Macronix International Co., Ltd. Method for Making Self Aligning Pillar Memory Cell Device
US20100048020A1 (en) * 2008-08-19 2010-02-25 International Business Machines Corporation Nanoscale Electrodes for Phase Change Memory Devices
US7688619B2 (en) 2005-11-28 2010-03-30 Macronix International Co., Ltd. Phase change memory cell and manufacturing method
US7719913B2 (en) 2008-09-12 2010-05-18 Macronix International Co., Ltd. Sensing circuit for PCRAM applications
US7786461B2 (en) 2007-04-03 2010-08-31 Macronix International Co., Ltd. Memory structure with reduced-size memory element between memory material portions
US7785920B2 (en) 2006-07-12 2010-08-31 Macronix International Co., Ltd. Method for making a pillar-type phase change memory element
US7786460B2 (en) 2005-11-15 2010-08-31 Macronix International Co., Ltd. Phase change memory device and manufacturing method
US20100264396A1 (en) * 2009-04-20 2010-10-21 Macronix International Co., Ltd. Ring-shaped electrode and manufacturing method for same
US20100295009A1 (en) * 2009-05-22 2010-11-25 Macronix International Co., Ltd. Phase Change Memory Cells Having Vertical Channel Access Transistor and Memory Plane
US7869270B2 (en) 2008-12-29 2011-01-11 Macronix International Co., Ltd. Set algorithm for phase change memory cell
US7894254B2 (en) 2009-07-15 2011-02-22 Macronix International Co., Ltd. Refresh circuitry for phase change memory
US7903447B2 (en) 2006-12-13 2011-03-08 Macronix International Co., Ltd. Method, apparatus and computer program product for read before programming process on programmable resistive memory cell
US7903457B2 (en) 2008-08-19 2011-03-08 Macronix International Co., Ltd. Multiple phase change materials in an integrated circuit for system on a chip application
US7910906B2 (en) 2006-10-04 2011-03-22 Macronix International Co., Ltd. Memory cell device with circumferentially-extending memory element
US7932506B2 (en) 2008-07-22 2011-04-26 Macronix International Co., Ltd. Fully self-aligned pore-type memory cell having diode access device
US7933139B2 (en) 2009-05-15 2011-04-26 Macronix International Co., Ltd. One-transistor, one-resistor, one-capacitor phase change memory
US7968876B2 (en) 2009-05-22 2011-06-28 Macronix International Co., Ltd. Phase change memory cell having vertical channel access transistor
US7978509B2 (en) 2007-08-02 2011-07-12 Macronix International Co., Ltd. Phase change memory with dual word lines and source lines and method of operating same
US7993962B2 (en) 2005-11-15 2011-08-09 Macronix International Co., Ltd. I-shaped phase change memory cell
US8030635B2 (en) 2009-01-13 2011-10-04 Macronix International Co., Ltd. Polysilicon plug bipolar transistor for phase change memory
US8036014B2 (en) 2008-11-06 2011-10-11 Macronix International Co., Ltd. Phase change memory program method without over-reset
US8064247B2 (en) 2009-01-14 2011-11-22 Macronix International Co., Ltd. Rewritable memory device based on segregation/re-absorption
US8064248B2 (en) 2009-09-17 2011-11-22 Macronix International Co., Ltd. 2T2R-1T1R mix mode phase change memory array
US8077505B2 (en) 2008-05-07 2011-12-13 Macronix International Co., Ltd. Bipolar switching of phase change device
US8089137B2 (en) 2009-01-07 2012-01-03 Macronix International Co., Ltd. Integrated circuit memory with single crystal silicon on silicide driver and manufacturing method
US8097871B2 (en) 2009-04-30 2012-01-17 Macronix International Co., Ltd. Low operational current phase change memory structures
US8107283B2 (en) 2009-01-12 2012-01-31 Macronix International Co., Ltd. Method for setting PCRAM devices
US8110430B2 (en) 2005-11-21 2012-02-07 Macronix International Co., Ltd. Vacuum jacket for phase change memory element
US8110822B2 (en) 2009-07-15 2012-02-07 Macronix International Co., Ltd. Thermal protect PCRAM structure and methods for making
US8134857B2 (en) 2008-06-27 2012-03-13 Macronix International Co., Ltd. Methods for high speed reading operation of phase change memory and device employing same
US8173987B2 (en) 2009-04-27 2012-05-08 Macronix International Co., Ltd. Integrated circuit 3D phase change memory array and manufacturing method
US8178387B2 (en) 2009-10-23 2012-05-15 Macronix International Co., Ltd. Methods for reducing recrystallization time for a phase change material
US8178405B2 (en) 2006-12-28 2012-05-15 Macronix International Co., Ltd. Resistor random access memory cell device
US8198619B2 (en) 2009-07-15 2012-06-12 Macronix International Co., Ltd. Phase change memory cell structure
US8238149B2 (en) 2009-06-25 2012-08-07 Macronix International Co., Ltd. Methods and apparatus for reducing defect bits in phase change memory
US8310864B2 (en) 2010-06-15 2012-11-13 Macronix International Co., Ltd. Self-aligned bit line under word line memory array
US8324605B2 (en) 2008-10-02 2012-12-04 Macronix International Co., Ltd. Dielectric mesh isolated phase change structure for phase change memory
US8363463B2 (en) 2009-06-25 2013-01-29 Macronix International Co., Ltd. Phase change memory having one or more non-constant doping profiles
US8367513B2 (en) 2006-07-14 2013-02-05 4D-S Pty Ltd. Systems and methods for fabricating self-aligned memory cell
US8395935B2 (en) 2010-10-06 2013-03-12 Macronix International Co., Ltd. Cross-point self-aligned reduced cell size phase change memory
US8406033B2 (en) 2009-06-22 2013-03-26 Macronix International Co., Ltd. Memory device and method for sensing and fixing margin cells
US20130112933A1 (en) * 2010-05-21 2013-05-09 Advanced Technology Materials, Inc. Germanium antimony telluride materials and devices incorporating same
US8467238B2 (en) 2010-11-15 2013-06-18 Macronix International Co., Ltd. Dynamic pulse operation for phase change memory
US8497705B2 (en) 2010-11-09 2013-07-30 Macronix International Co., Ltd. Phase change device for interconnection of programmable logic device
US8729521B2 (en) 2010-05-12 2014-05-20 Macronix International Co., Ltd. Self aligned fin-type programmable memory cell
US8809829B2 (en) 2009-06-15 2014-08-19 Macronix International Co., Ltd. Phase change memory having stabilized microstructure and manufacturing method
US8933536B2 (en) 2009-01-22 2015-01-13 Macronix International Co., Ltd. Polysilicon pillar bipolar transistor with self-aligned memory element
US9559113B2 (en) 2014-05-01 2017-01-31 Macronix International Co., Ltd. SSL/GSL gate oxide in 3D vertical channel NAND
US9640757B2 (en) 2012-10-30 2017-05-02 Entegris, Inc. Double self-aligned phase change memory device structure
US9672906B2 (en) 2015-06-19 2017-06-06 Macronix International Co., Ltd. Phase change memory with inter-granular switching

Families Citing this family (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080286446A1 (en) * 2005-01-28 2008-11-20 Smuruthi Kamepalli Seed-Assisted MOCVD Growth of Threshold Switching and Phase-Change Materials
US7514705B2 (en) * 2006-04-25 2009-04-07 International Business Machines Corporation Phase change memory cell with limited switchable volume
US7790529B2 (en) 2007-05-08 2010-09-07 Micron Technology, Inc. Methods of forming memory arrays and semiconductor constructions
US7848138B2 (en) * 2007-06-01 2010-12-07 Intel Corporation Biasing a phase change memory device
US20090072218A1 (en) * 2007-09-18 2009-03-19 Semyon Savransky Higher threshold voltage phase change memory
KR101394263B1 (en) * 2008-02-19 2014-05-14 삼성전자주식회사 A nonvolatile memory device and formign method of forming the same
US7491573B1 (en) * 2008-03-13 2009-02-17 International Business Machines Corporation Phase change materials for applications that require fast switching and high endurance
US7813167B2 (en) * 2008-03-21 2010-10-12 Micron Technology, Inc. Memory cell
US8412985B1 (en) 2009-06-30 2013-04-02 Micron Technology, Inc. Hardwired remapped memory
US8495467B1 (en) 2009-06-30 2013-07-23 Micron Technology, Inc. Switchable on-die memory error correcting engine
US8412987B2 (en) * 2009-06-30 2013-04-02 Micron Technology, Inc. Non-volatile memory to store memory remap information
US8467239B2 (en) 2010-12-02 2013-06-18 Intel Corporation Reversible low-energy data storage in phase change memory
US8971089B2 (en) 2012-06-27 2015-03-03 Intel Corporation Low power phase change memory cell
KR20150017066A (en) 2013-08-06 2015-02-16 삼성전자주식회사 Phase-change material layer and method of manufacturing the same

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060091374A1 (en) * 2004-11-04 2006-05-04 Yoon Sung M Multibit phase change memory device and method of driving the same

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060091374A1 (en) * 2004-11-04 2006-05-04 Yoon Sung M Multibit phase change memory device and method of driving the same

Cited By (83)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8008114B2 (en) 2005-11-15 2011-08-30 Macronix International Co., Ltd. Phase change memory device and manufacturing method
US7786460B2 (en) 2005-11-15 2010-08-31 Macronix International Co., Ltd. Phase change memory device and manufacturing method
US7993962B2 (en) 2005-11-15 2011-08-09 Macronix International Co., Ltd. I-shaped phase change memory cell
US8110430B2 (en) 2005-11-21 2012-02-07 Macronix International Co., Ltd. Vacuum jacket for phase change memory element
US7929340B2 (en) 2005-11-28 2011-04-19 Macronix International Co., Ltd. Phase change memory cell and manufacturing method
US7688619B2 (en) 2005-11-28 2010-03-30 Macronix International Co., Ltd. Phase change memory cell and manufacturing method
US20070187801A1 (en) * 2006-02-10 2007-08-16 Yoshiaki Asao Semiconductor device
US20070224770A1 (en) * 2006-03-25 2007-09-27 Makoto Nagashima Systems and methods for fabricating self-aligned memory cell
US8395199B2 (en) * 2006-03-25 2013-03-12 4D-S Pty Ltd. Systems and methods for fabricating self-aligned memory cell
US7785920B2 (en) 2006-07-12 2010-08-31 Macronix International Co., Ltd. Method for making a pillar-type phase change memory element
US8367513B2 (en) 2006-07-14 2013-02-05 4D-S Pty Ltd. Systems and methods for fabricating self-aligned memory cell
US7772581B2 (en) * 2006-09-11 2010-08-10 Macronix International Co., Ltd. Memory device having wide area phase change element and small electrode contact area
US7964437B2 (en) 2006-09-11 2011-06-21 Macronix International Co., Ltd. Memory device having wide area phase change element and small electrode contact area
US20100261329A1 (en) * 2006-09-11 2010-10-14 Macronix International Co., Ltd. Memory device having wide area phase change element and small electrode contact area
US20080061341A1 (en) * 2006-09-11 2008-03-13 Macronix International Co., Ltd. Memory Device Having Wide Area Phase Change Element and Small Electrode Contact Area
US7910906B2 (en) 2006-10-04 2011-03-22 Macronix International Co., Ltd. Memory cell device with circumferentially-extending memory element
US7749854B2 (en) 2006-12-06 2010-07-06 Macronix International Co., Ltd. Method for making a self-converged memory material element for memory cell
US20090098716A1 (en) * 2006-12-06 2009-04-16 Macronix International Co., Ltd. Method for making a self-converged memory material element for memory cell
US7903447B2 (en) 2006-12-13 2011-03-08 Macronix International Co., Ltd. Method, apparatus and computer program product for read before programming process on programmable resistive memory cell
US7652278B2 (en) * 2006-12-19 2010-01-26 International Business Machines Corporation Programmable via structure and method of fabricating same
US20080142775A1 (en) * 2006-12-19 2008-06-19 International Business Machines Corporation Programmable via structure and method of fabricating same
US8178405B2 (en) 2006-12-28 2012-05-15 Macronix International Co., Ltd. Resistor random access memory cell device
US7884343B2 (en) * 2007-02-14 2011-02-08 Macronix International Co., Ltd. Phase change memory cell with filled sidewall memory element and method for fabricating the same
US20110133150A1 (en) * 2007-02-14 2011-06-09 Macronix International Co., Ltd. Phase Change Memory Cell with Filled Sidewall Memory Element and Method for Fabricating the Same
US8263960B2 (en) * 2007-02-14 2012-09-11 Macronix International Co., Ltd. Phase change memory cell with filled sidewall memory element and method for fabricating the same
US20080191186A1 (en) * 2007-02-14 2008-08-14 Macronix International Co., Ltd. Phase change memory cell with filled sidewall memory element and method for fabricating the same
US7786461B2 (en) 2007-04-03 2010-08-31 Macronix International Co., Ltd. Memory structure with reduced-size memory element between memory material portions
US7875493B2 (en) 2007-04-03 2011-01-25 Macronix International Co., Ltd. Memory structure with reduced-size memory element between memory material portions
US7978509B2 (en) 2007-08-02 2011-07-12 Macronix International Co., Ltd. Phase change memory with dual word lines and source lines and method of operating same
US7919766B2 (en) 2007-10-22 2011-04-05 Macronix International Co., Ltd. Method for making self aligning pillar memory cell device
US8222071B2 (en) 2007-10-22 2012-07-17 Macronix International Co., Ltd. Method for making self aligning pillar memory cell device
US20090101879A1 (en) * 2007-10-22 2009-04-23 Macronix International Co., Ltd. Method for Making Self Aligning Pillar Memory Cell Device
US8077505B2 (en) 2008-05-07 2011-12-13 Macronix International Co., Ltd. Bipolar switching of phase change device
US8134857B2 (en) 2008-06-27 2012-03-13 Macronix International Co., Ltd. Methods for high speed reading operation of phase change memory and device employing same
US7932506B2 (en) 2008-07-22 2011-04-26 Macronix International Co., Ltd. Fully self-aligned pore-type memory cell having diode access device
US8119528B2 (en) 2008-08-19 2012-02-21 International Business Machines Corporation Nanoscale electrodes for phase change memory devices
US20100048020A1 (en) * 2008-08-19 2010-02-25 International Business Machines Corporation Nanoscale Electrodes for Phase Change Memory Devices
US7903457B2 (en) 2008-08-19 2011-03-08 Macronix International Co., Ltd. Multiple phase change materials in an integrated circuit for system on a chip application
US8315088B2 (en) 2008-08-19 2012-11-20 Macronix International Co., Ltd. Multiple phase change materials in an integrated circuit for system on a chip application
US7719913B2 (en) 2008-09-12 2010-05-18 Macronix International Co., Ltd. Sensing circuit for PCRAM applications
US8324605B2 (en) 2008-10-02 2012-12-04 Macronix International Co., Ltd. Dielectric mesh isolated phase change structure for phase change memory
US8036014B2 (en) 2008-11-06 2011-10-11 Macronix International Co., Ltd. Phase change memory program method without over-reset
US8094488B2 (en) 2008-12-29 2012-01-10 Macronix International Co., Ltd. Set algorithm for phase change memory cell
US7869270B2 (en) 2008-12-29 2011-01-11 Macronix International Co., Ltd. Set algorithm for phase change memory cell
US8089137B2 (en) 2009-01-07 2012-01-03 Macronix International Co., Ltd. Integrated circuit memory with single crystal silicon on silicide driver and manufacturing method
US8107283B2 (en) 2009-01-12 2012-01-31 Macronix International Co., Ltd. Method for setting PCRAM devices
US8237144B2 (en) 2009-01-13 2012-08-07 Macronix International Co., Ltd. Polysilicon plug bipolar transistor for phase change memory
US8030635B2 (en) 2009-01-13 2011-10-04 Macronix International Co., Ltd. Polysilicon plug bipolar transistor for phase change memory
US8064247B2 (en) 2009-01-14 2011-11-22 Macronix International Co., Ltd. Rewritable memory device based on segregation/re-absorption
US8933536B2 (en) 2009-01-22 2015-01-13 Macronix International Co., Ltd. Polysilicon pillar bipolar transistor with self-aligned memory element
US20100264396A1 (en) * 2009-04-20 2010-10-21 Macronix International Co., Ltd. Ring-shaped electrode and manufacturing method for same
US8084760B2 (en) 2009-04-20 2011-12-27 Macronix International Co., Ltd. Ring-shaped electrode and manufacturing method for same
US8173987B2 (en) 2009-04-27 2012-05-08 Macronix International Co., Ltd. Integrated circuit 3D phase change memory array and manufacturing method
US8097871B2 (en) 2009-04-30 2012-01-17 Macronix International Co., Ltd. Low operational current phase change memory structures
US8916845B2 (en) 2009-04-30 2014-12-23 Macronix International Co., Ltd. Low operational current phase change memory structures
US7933139B2 (en) 2009-05-15 2011-04-26 Macronix International Co., Ltd. One-transistor, one-resistor, one-capacitor phase change memory
US7968876B2 (en) 2009-05-22 2011-06-28 Macronix International Co., Ltd. Phase change memory cell having vertical channel access transistor
US8624236B2 (en) 2009-05-22 2014-01-07 Macronix International Co., Ltd. Phase change memory cell having vertical channel access transistor
US8350316B2 (en) 2009-05-22 2013-01-08 Macronix International Co., Ltd. Phase change memory cells having vertical channel access transistor and memory plane
US20100295009A1 (en) * 2009-05-22 2010-11-25 Macronix International Co., Ltd. Phase Change Memory Cells Having Vertical Channel Access Transistor and Memory Plane
US8313979B2 (en) 2009-05-22 2012-11-20 Macronix International Co., Ltd. Phase change memory cell having vertical channel access transistor
US8809829B2 (en) 2009-06-15 2014-08-19 Macronix International Co., Ltd. Phase change memory having stabilized microstructure and manufacturing method
US8406033B2 (en) 2009-06-22 2013-03-26 Macronix International Co., Ltd. Memory device and method for sensing and fixing margin cells
US8238149B2 (en) 2009-06-25 2012-08-07 Macronix International Co., Ltd. Methods and apparatus for reducing defect bits in phase change memory
US8363463B2 (en) 2009-06-25 2013-01-29 Macronix International Co., Ltd. Phase change memory having one or more non-constant doping profiles
US8779408B2 (en) 2009-07-15 2014-07-15 Macronix International Co., Ltd. Phase change memory cell structure
US7894254B2 (en) 2009-07-15 2011-02-22 Macronix International Co., Ltd. Refresh circuitry for phase change memory
US8110822B2 (en) 2009-07-15 2012-02-07 Macronix International Co., Ltd. Thermal protect PCRAM structure and methods for making
US8228721B2 (en) 2009-07-15 2012-07-24 Macronix International Co., Ltd. Refresh circuitry for phase change memory
US8198619B2 (en) 2009-07-15 2012-06-12 Macronix International Co., Ltd. Phase change memory cell structure
US8064248B2 (en) 2009-09-17 2011-11-22 Macronix International Co., Ltd. 2T2R-1T1R mix mode phase change memory array
US8178387B2 (en) 2009-10-23 2012-05-15 Macronix International Co., Ltd. Methods for reducing recrystallization time for a phase change material
US8729521B2 (en) 2010-05-12 2014-05-20 Macronix International Co., Ltd. Self aligned fin-type programmable memory cell
US8853047B2 (en) 2010-05-12 2014-10-07 Macronix International Co., Ltd. Self aligned fin-type programmable memory cell
US20130112933A1 (en) * 2010-05-21 2013-05-09 Advanced Technology Materials, Inc. Germanium antimony telluride materials and devices incorporating same
US9190609B2 (en) * 2010-05-21 2015-11-17 Entegris, Inc. Germanium antimony telluride materials and devices incorporating same
US8310864B2 (en) 2010-06-15 2012-11-13 Macronix International Co., Ltd. Self-aligned bit line under word line memory array
US8395935B2 (en) 2010-10-06 2013-03-12 Macronix International Co., Ltd. Cross-point self-aligned reduced cell size phase change memory
US8497705B2 (en) 2010-11-09 2013-07-30 Macronix International Co., Ltd. Phase change device for interconnection of programmable logic device
US8467238B2 (en) 2010-11-15 2013-06-18 Macronix International Co., Ltd. Dynamic pulse operation for phase change memory
US9640757B2 (en) 2012-10-30 2017-05-02 Entegris, Inc. Double self-aligned phase change memory device structure
US9559113B2 (en) 2014-05-01 2017-01-31 Macronix International Co., Ltd. SSL/GSL gate oxide in 3D vertical channel NAND
US9672906B2 (en) 2015-06-19 2017-06-06 Macronix International Co., Ltd. Phase change memory with inter-granular switching

Also Published As

Publication number Publication date
US7233054B1 (en) 2007-06-19

Similar Documents

Publication Publication Date Title
Lacaita Phase change memories: State-of-the-art, challenges and perspectives
US7956358B2 (en) I-shaped phase change memory cell with thermal isolation
US7829876B2 (en) Vacuum cell thermal isolation for a phase change memory device
Hosoi et al. High speed unipolar switching resistance RAM (RRAM) technology
US7932506B2 (en) Fully self-aligned pore-type memory cell having diode access device
US6967865B2 (en) Low-current and high-speed phase-change memory devices and methods of driving the same
US5406509A (en) Electrically erasable, directly overwritable, multibit single cell memory elements and arrays fabricated therefrom
US7697316B2 (en) Multi-level cell resistance random access memory with metal oxides
US7728172B2 (en) Precursor, thin layer prepared including the precursor, method of preparing the thin layer and phase-change memory device
US8223565B2 (en) Resistance change memory with current control and voltage control during a write operation, and write method of the same
US7436695B2 (en) Resistive memory including bipolar transistor access devices
US7639523B2 (en) Stabilized resistive switching memory
US6888155B2 (en) Stoichiometry for chalcogenide glasses useful for memory devices and method of formation
CN101369597B (en) Multi-level memory cell having phase change element and asymmetrical thermal boundary
US7531825B2 (en) Method for forming self-aligned thermal isolation cell for a variable resistance memory array
KR100379322B1 (en) An electrically erasable, direct overwritable multi-bit single cell memory device and an array fabricated therefrom
US7476917B2 (en) Phase-changeable memory devices including nitrogen and/or silicon dopants
US5359205A (en) Electrically erasable memory elements characterized by reduced current and improved thermal stability
DE102008016522B4 (en) Phase change memory cell with phase change memory material with limited resistance, method for producing a deratigen memory cell and integrated circuit with corresponding memory cell
US6872963B2 (en) Programmable resistance memory element with layered memory material
US5534712A (en) Electrically erasable memory elements characterized by reduced current and improved thermal stability
US20080285330A1 (en) Methods of operating a bistable resistance random access memory with multiple memory layers and multilevel memory states
EP0601068B1 (en) Electrically erasable, directly overwritable, multibit single cell memory elements and arrays fabricated therefrom
CN100481389C (en) Programmable resistive RAM and manufacturing method thereof
JP4933687B2 (en) Composite memory material comprising a mixture of phase change memory material and dielectric material

Legal Events

Date Code Title Description
AS Assignment

Owner name: SEOUL NATIONAL UNIVERSITY INDUSTRY FOUNDATION, KOR

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:AHN, DONG HO;LEE, TAE-YON;KIM, KI BUM;AND OTHERS;REEL/FRAME:017938/0843

Effective date: 20051117

Owner name: KOREA INSTITUTE OF SCIENCE AND TECHNOLOGY, KOREA,

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:AHN, DONG HO;LEE, TAE-YON;KIM, KI BUM;AND OTHERS;REEL/FRAME:017938/0843

Effective date: 20051117

STCF Information on status: patent grant

Free format text: PATENTED CASE

FPAY Fee payment

Year of fee payment: 4

FPAY Fee payment

Year of fee payment: 8

AS Assignment

Owner name: SEOUL NATIONAL UNIVERSITY R&DB FOUNDATION, KOREA,

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:SEOUL NATIONAL UNIVERSITY INDUSTRY FOUNDATION;REEL/FRAME:037671/0587

Effective date: 20160129

AS Assignment

Owner name: SK HYNIX INC., KOREA, REPUBLIC OF

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:KOREA INSTITUTE OF SCIENCE AND TECHNOLOGY;SEOUL NATIONAL UNIVERSITY R&D FOUNDATION;REEL/FRAME:038116/0874

Effective date: 20151230

MAFP Maintenance fee payment

Free format text: PAYMENT OF MAINTENANCE FEE, 12TH YEAR, LARGE ENTITY (ORIGINAL EVENT CODE: M1553); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY

Year of fee payment: 12