CN113161480B - Phase change memory material, preparation method thereof and phase change memory - Google Patents
Phase change memory material, preparation method thereof and phase change memory Download PDFInfo
- Publication number
- CN113161480B CN113161480B CN202110316783.4A CN202110316783A CN113161480B CN 113161480 B CN113161480 B CN 113161480B CN 202110316783 A CN202110316783 A CN 202110316783A CN 113161480 B CN113161480 B CN 113161480B
- Authority
- CN
- China
- Prior art keywords
- phase change
- change memory
- memory material
- target
- phase
- 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.)
- Active
Links
- 230000008859 change Effects 0.000 title claims abstract description 237
- 230000015654 memory Effects 0.000 title claims abstract description 194
- 239000000463 material Substances 0.000 title claims abstract description 168
- 238000002360 preparation method Methods 0.000 title abstract description 15
- 239000011232 storage material Substances 0.000 claims abstract description 71
- 238000002425 crystallisation Methods 0.000 claims abstract description 54
- 230000008025 crystallization Effects 0.000 claims abstract description 54
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims abstract description 50
- 239000012782 phase change material Substances 0.000 claims abstract description 40
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract description 30
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 21
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 21
- 239000001301 oxygen Substances 0.000 claims abstract description 21
- 229910052706 scandium Inorganic materials 0.000 claims abstract description 21
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 15
- 229910052796 boron Inorganic materials 0.000 claims abstract description 14
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 claims abstract description 12
- 239000010703 silicon Substances 0.000 claims abstract description 12
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims abstract description 11
- 239000000126 substance Substances 0.000 claims description 60
- 238000004544 sputter deposition Methods 0.000 claims description 57
- 238000000034 method Methods 0.000 claims description 40
- 229910045601 alloy Inorganic materials 0.000 claims description 33
- 239000000956 alloy Substances 0.000 claims description 33
- 239000012298 atmosphere Substances 0.000 claims description 18
- 229910052755 nonmetal Inorganic materials 0.000 claims description 17
- 229910052714 tellurium Inorganic materials 0.000 claims description 17
- 229910001215 Te alloy Inorganic materials 0.000 claims description 14
- 230000008569 process Effects 0.000 claims description 12
- 239000013077 target material Substances 0.000 claims description 8
- 229910052787 antimony Inorganic materials 0.000 claims description 7
- 239000011261 inert gas Substances 0.000 claims description 6
- SIXSYDAISGFNSX-UHFFFAOYSA-N scandium atom Chemical compound [Sc] SIXSYDAISGFNSX-UHFFFAOYSA-N 0.000 claims description 5
- PORWMNRCUJJQNO-UHFFFAOYSA-N tellurium atom Chemical compound [Te] PORWMNRCUJJQNO-UHFFFAOYSA-N 0.000 claims description 5
- WATWJIUSRGPENY-UHFFFAOYSA-N antimony atom Chemical compound [Sb] WATWJIUSRGPENY-UHFFFAOYSA-N 0.000 claims description 4
- 238000005229 chemical vapour deposition Methods 0.000 claims description 4
- 238000005566 electron beam evaporation Methods 0.000 claims description 4
- 238000001451 molecular beam epitaxy Methods 0.000 claims description 4
- 238000000231 atomic layer deposition Methods 0.000 claims description 3
- 238000003860 storage Methods 0.000 abstract description 19
- 125000004429 atom Chemical group 0.000 description 25
- 239000010410 layer Substances 0.000 description 24
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 19
- 238000010586 diagram Methods 0.000 description 12
- 229910052786 argon Inorganic materials 0.000 description 10
- 239000000203 mixture Substances 0.000 description 7
- 238000004364 calculation method Methods 0.000 description 6
- 239000011247 coating layer Substances 0.000 description 5
- 239000000758 substrate Substances 0.000 description 5
- 230000009286 beneficial effect Effects 0.000 description 4
- 230000006870 function Effects 0.000 description 4
- 238000012856 packing Methods 0.000 description 4
- 229910004298 SiO 2 Inorganic materials 0.000 description 3
- 241000341910 Vesta Species 0.000 description 3
- 239000012300 argon atmosphere Substances 0.000 description 3
- 238000005314 correlation function Methods 0.000 description 3
- 238000013500 data storage Methods 0.000 description 3
- 230000003993 interaction Effects 0.000 description 3
- 230000008018 melting Effects 0.000 description 3
- 238000002844 melting Methods 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 125000004433 nitrogen atom Chemical group N* 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical group [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- UMVBXBACMIOFDO-UHFFFAOYSA-N [N].[Si] Chemical compound [N].[Si] UMVBXBACMIOFDO-UHFFFAOYSA-N 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 229910052729 chemical element Inorganic materials 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000012299 nitrogen atmosphere Substances 0.000 description 2
- 230000002035 prolonged effect Effects 0.000 description 2
- 208000037408 Device failure Diseases 0.000 description 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- OBNDGIHQAIXEAO-UHFFFAOYSA-N [O].[Si] Chemical compound [O].[Si] OBNDGIHQAIXEAO-UHFFFAOYSA-N 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000005253 cladding Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000004744 fabric Substances 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000001307 helium Substances 0.000 description 1
- 229910052734 helium Inorganic materials 0.000 description 1
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 1
- 238000004050 hot filament vapor deposition Methods 0.000 description 1
- 238000004518 low pressure chemical vapour deposition Methods 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000006911 nucleation Effects 0.000 description 1
- 238000005240 physical vapour deposition Methods 0.000 description 1
- 238000000623 plasma-assisted chemical vapour deposition Methods 0.000 description 1
- 238000010791 quenching Methods 0.000 description 1
- 230000000171 quenching effect Effects 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 230000004083 survival effect Effects 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
- 238000009827 uniform distribution Methods 0.000 description 1
Images
Classifications
-
- 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 having no potential barriers, 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 having no potential barriers, and specially adapted for rectifying, amplifying, oscillating or switching
- H10N70/011—Manufacture or treatment of multistable switching devices
- H10N70/021—Formation of switching materials, e.g. deposition of layers
-
- 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 having no potential barriers, 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
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Semiconductor Memories (AREA)
Abstract
The embodiments of the present application provideA phase change memory material is disclosed having the general formula: d x Sc y (Sb b Te c ) 1‑x‑y Wherein D represents doping elements, D is at least one of nitrogen, boron, oxygen and silicon, x represents the atomic number percentage of D, y represents the atomic number percentage of Sc, b/c represents the atomic number ratio of Sb to Te, wherein x is more than 0 and less than or equal to 40 percent, and y is more than 1 and less than or equal to 10 percent. The proper amount of doping element D is introduced, so that the crystallization temperature of the Sc-Sb-Te series material is improved, the amorphous thermal stability of the Sc-Sb-Te series material is improved, the amorphous structure density of the phase change storage material is improved, the density difference with the crystalline structure is reduced, and the phase change storage prepared from the phase change material has ultra-fast erasing operation speed, lower failure risk and longer service life. The embodiment of the application also provides a preparation method of the phase change storage material and a phase change memory.
Description
Technical Field
The application relates to the field of phase change memory materials, in particular to a phase change memory material, a preparation method thereof and a phase change memory.
Background
The phase change memory is a novel nonvolatile memory, which stores data by using a conductivity difference exhibited when a phase change memory material is changed between a crystalline state and an amorphous state, has the advantages of low power consumption, high density, small size and the like, and is considered to be one of mainstream products of future semiconductor memories. At present, the crystallization temperature of a commonly used phase change memory material in a phase change memory is not high, and the density difference between a crystalline structure and an amorphous structure of the phase change memory is large, so that the phase change memory is easy to lose efficacy, and stored data is easy to be disturbed by high temperature.
Disclosure of Invention
In view of the above, embodiments of the present application provide a Sc-Sb-Te based phase change memory material doped with at least one of nitrogen, boron, oxygen, and silicon, which has a high crystallization temperature and a small difference between the density of an amorphous structure and the density of a crystalline structure, and a phase change memory fabricated from the phase change memory material can achieve both ultra-fast erase operation speed and reliability.
In a first aspect, an embodiment of the present application provides a phase change memory material, where a chemical formula of the phase change memory material includes: d x Sc y (Sb b Te c ) 1-x-y Wherein D represents doping element, and is nitrogen, boron and oxygenAnd silicon, x represents the atomic number percentage of D, y represents the atomic number percentage of Sc, and b/c represents the atomic number ratio of Sb to Te, wherein, x is more than 0 and less than or equal to 40 percent, and y is more than 1 and less than or equal to 10 percent.
By doping the nonmetal element D in the Sc-Sb-Te series phase-change storage material in a proper amount, the doped atom D can form chemical bonds with other atoms in the system, and the formed chemical bonds are shorter and stronger in the amorphous structure of the phase-change storage material, so that the introduction of the doped atom D can ensure that the crystallization temperature of the phase-change storage material is higher, and the risk of loss or disturbance of stored data due to high-temperature interference can be reduced; the atom packing density of the amorphous structure of the phase change storage material can be improved, the density difference degree of the amorphous structure and the crystalline structure can be favorably reduced, the failure risk of the phase change storage device can be reduced, and the service life of the phase change storage device can be prolonged.
In the embodiment of the application, the chemical general formula of the phase change memory material comprises: d x Sc y (Sb 2 Te 3 ) 1-x-y ，D x Sc y (Sb 8 Te 9 ) 1-x-y ，D x Sc y (Sb 4 Te 3 ) 1-x-y ，D x Sc y (Sb 2 Te 1 ) 1-x-y Or D x Sc y (Sb 3 Te 1 ) 1-x-y 。
In the embodiment of the application, the value range of x is more than or equal to 3% and less than or equal to 10%.
In the embodiment of the application, the value range of y is more than or equal to 3% and less than or equal to 6%. When x and/or y are within the value range, the content of doping elements D and Sc is proper, and the phase change storage material can better balance the difference between the high crystallization temperature and the lower amorphous density-crystalline density.
In the present embodiment, D forms a chemical bond with at least one of Sc, sb, and Te in the phase change memory material. This is advantageous for increasing the atomic packing density of the phase change memory material.
In some embodiments of the present application, a D-Te bond is present in the phase change memory material. The D-Te bonds can better promote the crystallization speed of the phase change memory material and reduce the difference degree between the density of the amorphous structure and the density of the crystalline structure.
In the present embodiment, when the phase-change memory material is in an amorphous state, D and at least one atom of Sc, sb, and Te form a tetrahedral unit. The stability and atom stacking density of the tetrahedral structure unit are high, so that the thermal stability and density of the amorphous phase-change storage material can be further improved.
In the embodiment of the present application, the crystallization temperature of the phase change memory material is greater than or equal to 180 ℃. The crystallization temperature is higher than that of the existing ScSbTe phase-change material, and the problem that stored data are easy to lose or be disturbed due to low crystallization temperature can be solved.
In some embodiments of the present application, the crystallization temperature of the phase change memory material is 180-300 ℃.
In the embodiment of the application, the ratio of the difference between the amorphous structure density and the crystalline structure density of the phase change memory material to the crystalline structure density of the phase change memory material is less than or equal to 3%. The volume change of the phase change storage material in the phase change process is small, and a memory adopting the phase change storage material is not easy to lose effectiveness or damage due to overlarge volume change in the working process.
In the embodiment of the application, the crystallization speed of the phase change memory material is not more than 30ns. The crystallization speed of the phase-change storage material is slightly reduced compared with the crystallization speed of the phase-change material without Sc-Sb-Te due to the proper introduction of the doping elements, and is still obviously higher than the crystallization speed of the phase-change material with Ge-Sb-Te series.
In the embodiment of the application, the amorphous resistance of the phase change memory material is at least two orders of magnitude higher than the crystalline resistance of the phase change memory material. At this time, the phase change memory material has a large resistance difference between the crystalline state and the amorphous state, and is suitable for manufacturing a phase change memory to realize an erasing function.
In the embodiment of the application, the phase change memory material can be prepared by a sputtering method, an electron beam evaporation method, a molecular beam epitaxy method, a chemical vapor deposition method or an atomic layer deposition method.
In a second aspect, embodiments of the present application provide a method for preparing a phase change memory material, which can be used to prepare the phase change memory material according to the first aspect, including: co-sputtering a simple substance target and/or an alloy target of a main element and a simple substance target of a first nonmetal element to form the phase change storage material under the atmosphere of inert gas, wherein the main element comprises scandium Sc, antimony Sb and tellurium Te, and the first nonmetal element comprises at least one of boron and silicon; the atomic percent of the first non-metallic element is changed by adjusting the power of the radio frequency power supply during the co-sputtering process.
The preparation method can realize simple and convenient preparation of the phase change storage material of the first aspect. The doping element of the phase-change memory material formed at this time includes at least one of boron and silicon.
In some embodiments of the present application, the co-sputtering the elemental target and/or the alloy target of the main element and the elemental target of the first nonmetal element to form the phase-change storage material includes: co-sputtering the elemental target of the first nonmetal element, the Sc elemental target, the Sb elemental target and the Te elemental target to form the phase change storage material; co-sputtering the simple substance target of the first nonmetal element, the Sc simple substance target and the Sb-Te alloy target to form the phase change storage material; or co-sputtering the simple substance target of the first nonmetal element and the Sc-Sb-Te alloy target to form the phase change storage material.
In some embodiments of the present application, the Sb-Te alloy target comprises: sb 2 Te 3 Alloy target, sb 8 Te 9 Alloy target, sb 4 Te 3 Alloy target, sb 2 Te 1 Alloy target, sb 3 Te 1 One kind of alloy target.
In some embodiments of the present application, the above preparation method further comprises: the foregoing co-sputtering is performed under an atmosphere of nitrogen and/or oxygen. That is, the co-sputtering may be performed under an atmosphere of nitrogen and/or oxygen and the inert gas. At this time, the doping element of the phase change memory material formed includes at least one of nitrogen and oxygen in addition to at least one of boron and silicon. The atomic percentages of nitrogen and oxygen can be controlled by adjusting the flow rates and the time of introducing the nitrogen and the oxygen.
In a third aspect, an embodiment of the present application further provides a method for preparing a phase change memory material, which can be used for preparing the phase change memory material according to the first aspect, including: sputtering a target material of main elements to form the phase change storage material in the atmosphere of nitrogen and/or oxygen, wherein the main elements comprise scandium Sc, antimony Sb and tellurium Te; the atomic percentage of the host element is varied by adjusting the power of the rf power supply during sputtering.
The preparation method can realize simple and convenient preparation of the phase change storage material of the first aspect. The doping element of the phase change memory material formed at this time includes at least one of nitrogen and oxygen.
In some embodiments of the present application, the sputtering the target material of the main body element to form the phase change memory material includes: co-sputtering the Sc elementary substance target, the Sb elementary substance target and the Te elementary substance target to form the phase change storage material; co-sputtering the Sc elementary substance target and the Sb-Te alloy target to form the phase change storage material; or sputtering the Sc-Sb-Te alloy target to form the phase change storage material.
In some embodiments of the present application, the Sb-Te alloy target comprises: sb 2 Te 3 Alloy target, sb 8 Te 9 Alloy target, sb 4 Te 3 Alloy target, sb 2 Te 1 Alloy target, sb 3 Te 1 One kind of alloy target.
In a fourth aspect, an embodiment of the present application provides a phase change memory, including a phase change memory cell, where the phase change memory cell includes a bottom electrode, a top electrode, and a phase change material layer located between the bottom electrode and the top electrode, and a material of the phase change material layer includes the phase change memory material according to the first aspect of the embodiment of the present application.
In the embodiment of the application, the thickness of the phase change material layer is 20nm-300nm.
The phase change memory provided by the fourth aspect of the embodiments of the present application uses the phase change memory material with excellent performance as the phase change material layer, so that the phase change memory maintains the ultra-fast operating speed and the lower operating power consumption, and meanwhile, the thermal stability of the phase change memory is improved, the risk of device failure is reduced, and the reliability of the device is improved.
Drawings
Fig. 1 is a schematic structural diagram of a storage cluster device in an electronic device.
Fig. 2a and 2b are schematic structural diagrams of a phase change memory cell using the phase change memory material of the present application.
Fig. 3 is a superlattice model of a crystalline structure drawn by using VESTA modeling software for the N-doped ScSbTe phase change memory material in the first embodiment.
Fig. 4 is a superlattice model of an amorphous structure drawn by using VESTA modeling software for the N-doped ScSbTe phase change memory material according to the first embodiment.
Fig. 5 is a partial pair correlation function calculated by using the first principle of calculation for the N-doped ScSbTe phase change memory material in the first embodiment.
Fig. 6 shows coordination numbers of N, sc, sb, and Te elements calculated by using the first principle of calculation for the amorphous N-doped ScSbTe phase-change memory material in the first embodiment.
FIG. 7 is a first linear principle calculation of a supercell model (left diagram) of an amorphous structure of a Si-doped ScSbTe phase-change memory material in the sixth embodiment, and coordination numbers of corresponding Si, sc, sb and Te elements (right diagram).
FIG. 8 is a diagram illustrating test pulses for implementing storage in a phase change memory according to a first embodiment of the present application.
Fig. 9 shows a pulse test result of a memory cell of a phase change memory according to a first embodiment of the present application.
Detailed Description
The technical solution of the present application will be described below with reference to the drawings in the embodiments of the present application.
Fig. 1 illustrates a schematic structural diagram of a storage cluster device in an electronic device. The storage cluster apparatus, which may be used for data storage and interaction, includes a plurality of storage nodes 150, a switch fabric 160, and fans. Wherein each storage node 150 includes a CPU processor 120, a MEM memory 130, and a phase change memory 140. Phase change memory 140 includes a plurality of phase change memory cells 100. The phase change memory 140 may be used for data storage in electronic products such as mobile phones, tablet computers, notebook computers, wearable devices, and vehicle-mounted devices.
Fig. 2a and fig. 2b are schematic structural diagrams of a phase change memory cell 100 in a phase change memory 140 according to an embodiment of the present disclosure.
The phase change memory cell 100 may include a bottom electrode 10, a top electrode 30, and a phase change material layer 20 between the bottom electrode 10 and the top electrode 30. The material of the phase change material layer 20 includes a phase change memory material.
At present, the phase change memory materials used in the phase change material layer 20 of the phase change memory 140 mainly include Ge-Sb-Te systems and Sc-Sb-Te systems, the crystallization speed of the latter is 4500 times of that of the former, which can better meet the storage requirement of people for ultra-fast speed, but the crystallization temperatures of the two materials are lower, for example, the crystallization temperature of Ge-Sb-Te is about 150 ℃, the Sc-Sb-Te systems is about 170 ℃ at most, the thermal stability of the two materials at high temperature is poor, and the memory devices made of the two materials are easy to lose or disturb the survival and storage data. In addition, the density difference between the crystalline structure and the amorphous structure of the two materials is large, when the two materials are in the low-density amorphous structure, a large number of holes are generated in the phase change material layer 20, and the holes can be diffused to the connection interface between the phase change material layer 20 and the bottom electrode 10 or the top electrode 30, so that the phase change material layer 20 and the electrodes can be separated to cause the failure of the memory device, and the service life of the device is reduced. The term "crystallization speed" refers to the response time of the phase change memory material to change from the amorphous state to the crystalline state by the heat generated by the electric pulse.
In order to solve the problems that the crystallization temperature of a pure Ge-Sb-Te series or Sc-Sb-Te series phase-change storage material is not high, the density difference between an amorphous structure and a crystalline structure is too large and the like in the prior art, the embodiment of the application provides a novel phase-change storage material to solve the problems. The phase change material layer 20 may be made of a novel phase change memory material provided in the embodiments of the present application.
Specifically, the chemical general formula of the phase change memory material provided by the application is D x Sc y (Sb b Te c ) 1-x-y . Wherein Sc is a chemical element scandium, and Sb is chemicalAntimony element, te is chemical element tellurium; d represents doping elements, D is at least one of nitrogen (N), boron (B), oxygen (O) and silicon (Si), x represents the atomic number percentage of D, y represents the atomic number percentage of Sc, and B/c represents the atomic number ratio of Sb to Te. In other words, x represents the proportion of the atomic number of the doping element D to the sum of the atomic numbers of all elements in the phase-change memory material, and y represents the proportion of the atomic number of Sc to the sum of the atomic numbers of all elements in the phase-change memory material. Wherein x is more than 0 and less than or equal to 40 percent, and y is more than 1 percent and less than or equal to 10 percent.
By doping a proper amount of non-metallic element D in the Sc-Sb-Te phase-change material, the doping atoms D can form chemical bonds with Sc, sb, te and the like, and the chemical bonds formed in the amorphous structure of the obtained phase-change storage material are shorter and have stronger bond energy, so that the amorphous thermal stability and the atom stacking density of the phase-change storage material can be improved. The higher thermal stability of the amorphous state means that the crystallization temperature of the phase change memory material becomes higher (for example, the crystallization temperature can be over 180 ℃), so that the interference of the phase change characteristics caused by thermal disturbance factors is smaller, and the problem that the memory data is easy to lose or disturb due to the low crystallization temperature can be solved. The introduction of the doping atoms D enables the atom stacking density of the amorphous structure of the phase change storage material to be high, which is beneficial to reducing the density difference degree (the difference degree can be controlled below 3%) between the amorphous structure and the crystalline structure, and further can reduce the problems that the phase change storage material is easy to separate from an electrode and the phase change storage is easy to lose efficacy due to overlarge volume shrinkage difference of the phase change storage material, and the service life of the device is prolonged. In addition, the introduction of the doping element D can reduce the crystallization speed of Sc-Sb-Te to a certain extent, but the control of the atomic number percentage of D in the range of (0, 40%) can still make the crystallization speed of the phase-change memory material higher than that of the undoped Ge-Sb-Te series phase-change material.
In the embodiment of the present application, b/c represents the atomic number ratio of Sb to Te, and is generally the simplest ratio of the atomic numbers of Sb to Te. Wherein, the value range of b/c can be 0.3-4, specifically but not limited to 2/3, 8/9, 4/3, 2/1 or 3/1, etc. In other words, in some embodiments, the phase change memory materialThe chemical formula of the material can be D x Sc y (Sb 2 Te 3 ) 1-x-y ，D x Sc y (Sb 8 Te 9 ) 1-x-y ，D x Sc y (Sb 4 Te 3 ) 1-x-y ，D x Sc y (Sb 2 Te 1 ) 1-x-y Or D x Sc y (Sb 3 Te 1 ) 1-x-y . In some embodiments of the present application, 0.5. Ltoreq. B/c. Ltoreq.1.5, e.g., b/c is 2/3, 8/9, or 4/3. When b/c is 2/3, the comprehensive effect of the structural stability and the crystallization speed of the phase change memory material is better.
In the application, the value range of y is more than 1% and less than or equal to 10%. At this time, the coordination number of Sc is generally higher, and 1% -10% of Sc content can ensure that the phase change memory material still has a faster crystallization speed. In the embodiment of the application, the value range of x can be 0 < x < 35%, or 0 < x < 30%, or 0 < x < 20%, or 1% x < 20%, or 2% x < 15%. The proper amount of the doping element can improve the atom packing density of the amorphous structure of the phase-change memory material.
In some embodiments, x is in the range of 3% to 10% and y is in the range of 3% to 6%. When x and/or y are within the value range, the contents of the doping elements D and Sc are both proper, so that the phase change memory material can better give consideration to the difference degree between high crystallization temperature and low amorphous density-crystalline density.
In the application, the doping element D can be used as a nucleation center of the phase change storage material in the crystallization process, so that the crystallization speed of the phase change storage material is improved, and the atomic packing density of the phase change storage material can be improved by forming bonds with Sc, sb, te and the like. In some embodiments of the present application, the doping element D is uniformly dispersed in the phase-change memory material. The uniform distribution of the doping element D can better promote the crystallization speed of the phase-change memory material and the density of an amorphous structure.
In the present embodiment, the doping element D in the phase change memory material may form a chemical bond with at least one of Sc, sb, and Te, and is generally a covalent bond. In some embodiments of the present application, a D-Te bond is present in the phase change memory material. That is, the doping atom D forms a chemical bond with the Te atom. The D-Te bonds can better promote the crystallization speed of the phase change memory material and reduce the difference degree between the density of the amorphous structure and the density of the crystalline structure.
In the embodiment of the present application, when the phase-change memory material is in an amorphous state, the doping element D and at least one atom of Sc, sb, and Te form a tetrahedral unit. Because the stability and the atom stacking density of the tetrahedral structure unit are high, the thermal stability and the density of the amorphous phase change storage material are further improved, and the corresponding phase change memory is endowed with higher reliability of high-temperature storage data and longer service life.
In the embodiment of the application, the crystallization temperature of the phase change memory material is greater than or equal to 180 ℃. The crystallization temperature is higher than that of the existing ScSbTe phase-change material, so that the thermal stability is better, and a storage device made of the material is less prone to loss or disturbance of stored data. Illustratively, the crystallization temperature of the phase change memory material is 180, 190, 200, 210, 220, 240, 250, 260, 280, 290 ℃, or 320 ℃. In some embodiments, the phase change memory material has a crystallization temperature of 180-300 ℃. In other embodiments, the crystallization temperature is from 200 ℃ to 300 ℃. In still other embodiments, the crystallization temperature may be in the range of 220-300 ℃.
In the embodiment of the application, the amorphous structure density rho of the phase change storage material 1 And density of crystalline structure rho 2 And its crystalline structure density rho 2 Is less than or equal to 3%. That is, the density difference between the amorphous structure and the crystalline structure: (ρ) 2- ρ 1 )/ρ 2 Less than or equal to 3 percent. Therefore, the volume change of the phase change storage material in the phase change process is small, and the probability of failure or damage of the phase change storage adopting the phase change storage material due to overlarge volume change is small in the working process. Specifically, the density difference may be 2.8%, 2.5%, 2.4%, 23%, 2.2%, 2%, 1.8%, 1.5%, 1.2%, 1%, 0.8%, or 0.5%, etc. In some embodiments, the density difference is ≦ 2.5%.
In the embodiment of the present application, the crystallization speed of the phase change memory material is less than 700ps. The proper amount of the doping element D can still make the crystallization speed of the phase-change storage material far higher than that of the Ge-Sb-Te phase-change material, and can still meet the ultra-fast storage requirement of people, so that the phase-change memory adopting the phase-change storage material has faster erasing operation speed and lower operation power consumption. In some embodiments of the present application, the crystallization speed of the phase-change memory material is not more than 30ns, and in some embodiments, the crystallization speed is not more than 20ns or not more than 10ns.
The phase-change memory material may be switched between an amorphous state of high resistance and a crystalline state of low resistance by applying a pulse voltage or a pulse current to the phase-change memory material. Specifically, a pulse current (RESET pulse) with high intensity and short time is applied to the phase change memory material, so that the phase change memory material is heated to a temperature higher than the melting temperature of the phase change memory material, and a high-resistance amorphous structure is obtained after rapid quenching, so that the phase change memory device can realize erasing operation; if a pulse (SET pulse) with long time and moderate intensity is applied to the phase change memory material, the phase change memory material is heated to a temperature higher than the crystallization temperature and lower than the melting temperature of the phase change memory material, and a low-resistance crystalline structure of the phase change memory material can be obtained after the temperature is reduced, so that the writing operation is realized. In the embodiment of the present application, the amorphous resistance of the phase change memory material is at least two orders of magnitude higher than the crystalline resistance thereof. In other words, the resistance R of the amorphous structure of the phase change memory material 1 At least the resistance R of its crystalline structure 2 10 of 2 I.e. R 1 /R 2 Is more than or equal to 100 times. Thus, the phase change memory material and the phase change memory device made of the phase change memory material can play excellent erasing and writing functions.
The phase change memory material can be prepared by a sputtering method, an electron beam evaporation method, a molecular beam epitaxy method, a chemical vapor deposition method or an atomic layer deposition method. The methods can realize simple preparation of the phase change storage material. The sputtering method, the electron beam evaporation method and the molecular beam epitaxy method belong to physical vapor deposition methods. The chemical vapor deposition method may be a plasma enhanced chemical vapor deposition method, a hot filament chemical vapor deposition method, a low pressure chemical vapor deposition method, or the like.
In some embodiments of the present application, a sputtering method is used to prepare the phase change memory material. The sputtering method has higher process simplicity, is more convenient for accurately controlling the components of the material and saves the cost.
Specifically, in some embodiments of the present application, when the doping element D is B and/or Si, the phase-change storage material is formed by co-sputtering a target material of a main element and an elemental target of a first nonmetal element in an inert gas atmosphere; wherein the host elements comprise scandium Sc, antimony Sb, and tellurium Te, and the first non-metallic element comprises at least one of boron and silicon;
and changing the atomic percent of the first non-metal element by adjusting the power of a radio frequency power supply in the co-sputtering process.
In some embodiments of the present application, the target material of the main element may be a Sc elemental target, an Sb elemental target, and a Te elemental target; or Sc simple substance targets and Sb-Te alloy targets, or Sc-Sb-Te alloy targets. The elemental target of the first nonmetal element may be at least one of an elemental silicon target and an elemental boron target. In this case, the composition of the phase-change memory material can be controlled by applying different powers to each target, and the thickness of the phase-change material layer formed can be controlled by adjusting the sputtering time. The inert gas may be argon, helium, or a mixture thereof. To further simplify the operation steps, in some embodiments, at least one of elemental silicon target and elemental boron target may be co-sputtered with the Sb-Te alloy target, elemental Sc target.
Further, when the doping element D further includes N and/or O, the above co-sputtering may be performed in a nitrogen and/or oxygen atmosphere. That is, the co-sputtering may be performed under an atmosphere of nitrogen and/or oxygen and the inert gas. At this time, the doping element of the phase change memory material formed includes at least one of N and O in addition to at least one of B and Si. The atomic percentages of N and O in the phase change memory material can be controlled by adjusting the feeding flow rate, the time and the like of nitrogen and oxygen.
In other embodiments of the present application, when the doping element D is N and/or O, the phase change storage material may be formed by co-sputtering a Sc elemental target, an Sb elemental target, and a Te elemental target in a nitrogen and/or oxygen atmosphere; or formed by co-sputtering an Sb-Te alloy target and a Sc simple substance target; or formed by sputtering with Sc-Sb-Te alloy target. In this case, the content of N, O in the phase change memory material can be controlled by adjusting the flow rate and time of introduction of nitrogen and oxygen, and the bulk elements (Sc, sb, te) can be controlled by adjusting the power applied to the target.
In the phase change memory cell 100 described above, the thickness of the phase change material layer 20 made of the phase change memory material may be 20nm to 300nm. The thickness of the phase change material layer 20 may be controlled by controlling the time of the above co-sputtering. In some embodiments, the time for the co-sputtering may be 4min to 60min. In some embodiments, the thickness is 20nm to 120nm.
The phase change memory cell 100 shown in fig. 2a and 2b is a T-shaped structure, and the width of the phase change material layer 20 may be equal to the width of the top electrode 30 and greater than the width of the bottom electrode 10. In other embodiments, the phase change memory cell may also be a confined structure in which the width of the phase change material layer 20 is narrower, which may be equal to the width of the bottom electrode 10 and the width of the top electrode 30. In some embodiments, the phase change memory cell 100 further includes a substrate 101 and an insulating cladding layer 40. The bottom electrode 10, the phase change material layer 20 and the top electrode 30 are sequentially arranged on the substrate 101; the insulating coating layer 40 may only cover the periphery of the bottom electrode 10 (as shown in fig. 2 b), or other distribution modes of the insulating coating layer 40 may be selected according to the specific phase change memory cell structure, for example, only cover the periphery of the phase change material layer 20, only cover the peripheries of the phase change material layer 20 and the top electrode 30, or cover the peripheries of the bottom electrode 10, the phase change material layer 20 and the top electrode 30, etc.
In the present embodiment, the substrate 101, the bottom electrode 10, the top electrode 30, and the insulating coating layer 40 are made of the same materialThe material is not particularly limited, and any material commonly used in the art may be used. For example, the material of the substrate 101 may be Si or SiO 2 And the like. The bottom electrode 10 and the top electrode 30 are made of at least one material selected from Al, W, ti, tiN, tiW, etc. The insulating coating layer 40 is made of SiO 2 Or Si 3 N 4 And so on.
Because the phase change memory 140 adopts the phase change memory material provided by the application, which has the advantages of high crystallization temperature, high crystallization speed and small difference between the density of the amorphous structure and the density of the crystalline structure, the phase change memory improves the data retention capability, reduces the failure risk of the device and improves the reliability of the device while maintaining the ultra-fast operation speed and lower operation power consumption. In addition, when the phase change memory material is used in a phase change memory, the phase change memory material is based on a traditional phase change memory unit structure, and the process complexity is not improved.
The technical solution of the present application is further described by a plurality of specific examples.
Example one
An N-doped ScSbTe phase change storage material with a chemical general formula of N x Sc y (Sb 2 Te 3 ) 1-x-y Wherein x =4.4%, y =4.4%, by using a Sc elemental target and Sb under a high purity nitrogen atmosphere 2 Te 3 The alloy target is co-sputtered.
The N-doped ScSbTe phase change memory material in the first embodiment can be specifically prepared by the following method: sb with the atomic percent purity of not less than 99.99 percent 2 Te 3 The alloy target and the Sc elementary substance target are arranged at different target material positions in a sputtering cavity, wherein the Sc elementary substance target is arranged at an alternating current radio frequency target position, and Sb is 2 Te 3 Placing the alloy target at a direct current position; placing the base material to be plated on a sample table in a sputtering cavity, and vacuumizing to make the vacuum degree in the sputtering cavity less than 3.0 × 10 -4 Pa, then introducing high-purity argon into the sputtering cavity, introducing high-purity nitrogen with the purity of 99.999 percent at the flow rate of 2sccm, and simultaneously introducing Sb into the sputtering cavity 2 Te 3 Sputtering power is applied to the alloy target and the Sc simple substance target material to generate sputtering glow, and the air pressure in the sputtering process is controlled to be 0.5Pa-0.8Pa;and preparing the N-doped Sc-Sb-Te phase change storage material. Wherein the introduction time of the high-purity nitrogen is 10-20min, the sputtering power of the Sc elementary substance target is alternating current of 10W 2 Te 3 The sputtering power of the alloy target was DC 25W.
When the N-doped Sc-Sb-Te phase change memory material is used as a phase change material layer material in the phase change memory, the base material to be plated can be a substrate with a bottom electrode, and the phase change material layer is formed on the bottom electrode. A schematic diagram of a phase change memory cell of the resulting phase change memory may be as shown in fig. 1. Wherein, the phase change material layer 20 is made of N 0.044 Sc y (Sb 2 Te 3 ) 1-x-y The thickness is 50-100nm, the bottom electrode 10 and the top electrode 30 are made of TiW and 200nm, and the insulating coating layer 40 is made of SiO 2 。
FIGS. 3 and 4 are superlattice models of crystalline and amorphous structures drawn using VESTA modeling software for implementing an N-doped Sc-Sb-Te phase change memory material. As can be seen from fig. 3 and 4, the doped N atoms (dark-colored atoms indicated by arrows) exist in the lattice space of Sc-Sb-Te and form chemical bonds with the Sc, sb, and Te atoms. The connection of polyhedrons shows that in the amorphous structure of fig. 4, N atoms form a tetrahedral structure with other atoms; whereas the crystalline structure in figure 3 was analyzed as a cubic rock salt structure. The volume of the supercell model of the crystalline structure in FIG. 3 was found by calculation to be
The amorphous superlattice model in FIG. 4 has a volume of
The density difference of the N-doped ScSbTe phase-change storage material is only 2.4% after the two-phase change of the crystalline state and the amorphous state, and the density change is small, which shows that the volume change of the material in the phase-change process is small, thereby effectively reducing the problem that the phase-change storage device adopting the material is caused by the phase-change storage material in the working processFailure and damage caused by excessive volume change.
Fig. 5 is a partial pair correlation function calculated by using the first principle of calculation for the Sc-Sb-Te phase change memory material having an N-doping content of 4.4% in the first embodiment. Where the ordinate-pair correlation function in fig. 5 is a function used to describe the distribution of atom neighbors, its definition is the probability of finding another atom at a certain distance from a given central atom. As can be known from fig. 5, in the amorphous N-doped ScSbTe phase change material, the bond length of the chemical bond formed by N and Sc and Sb is short (i.e., the atomic distance corresponding to the abscissa is small) and the interaction is strong, and N and Te are in the first neighboring position (about
At) and a second neighbor position (about
Where) all formed chemical bonds and N and Te had a greater tendency to have stronger interactions at the second, proximal position, which also suggests a range in the first vicinity (about
And (c) N forms stronger chemical bonds with Sc and Sb. In FIG. 5, N-Sc, N-Sb, and N-Te are shown in
The peaks are close to each other, which shows that the doping of N atoms improves the atom stacking density of the whole structure, and is favorable for improving the density of the amorphous structure and reducing the density difference of the amorphous structure.
Fig. 6 shows coordination numbers of N, sc, sb, and Te atoms calculated by using the first principle of calculation for the N-doped ScSbTe phase-change memory material with an amorphous structure in the first embodiment, which are 3.37, 5.62, 3.46, and 2.48, respectively. It can be seen that the Sc element still maintains a high coordination number, and is close to coordination number 6 of an octahedron, and the amorphous structure of the material has a high similarity to the crystalline structure of the rock salt structure, which is beneficial to the rapid transition of the material from the amorphous structure to the crystalline structure, so that the memory device manufactured by using the phase change memory material of embodiment one can still have an ultra-fast operation speed.
Example two
An N-doped ScSbTe phase change storage material with a chemical general formula of N x Sc y (Sb 8 Te 9 ) 1-x-y Wherein x =4.4%, y =4.4%.
According to the preparation method of the phase change storage material, sc elementary substance targets and Sb can be adopted in the atmosphere of high-purity argon and nitrogen 8 Te 9 And co-sputtering the alloy target to obtain the N-doped ScSbTe phase change memory material with the specific composition as in the second embodiment.
EXAMPLE III
An N-doped ScSbTe phase change storage material with a chemical general formula of N x Sc y (Sb 4 Te 3 ) 1-x-y Wherein x =4.4%, y =4.4%.
According to the preparation method of the phase change storage material, sc elementary substance targets and Sb can be adopted in high-purity argon and nitrogen atmosphere 4 Te 3 And co-sputtering the alloy target to obtain the N-doped ScSbTe phase change memory material with the specific composition in the third embodiment.
Example four
An N-doped ScSbTe phase change storage material with a chemical general formula of N x Sc y (Sb 2 Te 3 ) 1-x-y Wherein x =10%, y =4.4%.
According to the preparation method of the phase change storage material, the Sc elementary substance target and the Sb can be adopted in the atmosphere of high-purity argon and nitrogen 2 Te 3 And co-sputtering the alloy target to obtain the N-doped ScSbTe phase change memory material with the specific composition as in the fourth embodiment.
EXAMPLE five
An N-doped ScSbTe phase change storage material with a chemical general formula of N x Sc y (Sb 2 Te 3 ) 1-x-y Wherein x =15%, y =4.4%.
Can be implemented according to the described phase change memoryThe preparation method of the material adopts Sc simple substance target and Sb under the atmosphere of high-purity argon and nitrogen 2 Te 3 And co-sputtering the alloy target to obtain the N-doped ScSbTe phase change memory material with the specific composition as in example five.
EXAMPLE six
The chemical general formula of the Si-doped ScSbTe phase change storage material is Si x Sc y (Sb 2 Te 3 ) 1-x-y Wherein x =4.4%, y =4.4%.
The Si-doped ScSbTe phase change memory material in the sixth embodiment can be prepared according to the method for preparing the phase change memory material described in the first embodiment, and the difference is that: without introducing high-purity nitrogen, adopting Si elementary substance target, sc elementary substance target and Sb in high-purity argon atmosphere 2 Te 3 The alloy target is obtained by co-sputtering.
Fig. 7 shows a superlattice model (left diagram) of an amorphous structure of a Si-doped ScSbTe phase-change memory material according to a sixth embodiment calculated by using a first principle, and coordination numbers of corresponding Si, sc, sb, and Te elements (right diagram). As can be seen from fig. 7, in the amorphous structure of the Si-doped ScSbTe phase-change memory material, the coordination number of Si atoms (the darkest atoms as indicated by arrows) is equal to about 4, which is close to the coordination number of tetrahedra, indicating that Si participates in the formation of more tetrahedra in the amorphous system, and increases the stability of the system, thereby increasing the crystallization temperature; meanwhile, sc still keeps a high coordination number, the coordination number of the Sc is about 5.75 and is close to the coordination number 6 of an octahedral configuration, so that the material can be ensured to be rapidly converted from an amorphous structure to a crystalline structure, and the rapid storage is favorably realized.
EXAMPLE seven
A B-doped ScSbTe phase change storage material has a chemical general formula of B x Sc y (Sb 2 Te 3 ) 1-x-y Wherein x =4.4%, y =4.4%.
According to the preparation method of the phase change storage material described in the sixth embodiment, the elemental target B, the elemental target Sc and the elemental target Sb are used in a high-purity argon atmosphere 2 Te 3 The alloy target was co-sputtered to obtain a B-doped ScSbTe phase change memory material having the specific composition as in example seven.
Example eight
An O-doped ScSbTe phase change storage material with a chemical general formula of O x Sc y (Sb 2 Te 3 ) 1-x-y Wherein x =4.4%, y =4.4%.
The O-doped ScSbTe phase-change storage material of the embodiment eight can be prepared by adopting Sc elementary substance target and Sb in high-purity oxygen atmosphere 2 Te 3 The alloy target is obtained by co-sputtering.
Example nine
An O-doped Sc-Sb-Te phase change storage material with a chemical general formula of O x Sc y (Sb 2 Te 3 ) 1-x-y Wherein x =4.4%, y =3%.
The O-doped Sc-Sb-Te phase-change storage material of the ninth embodiment can be prepared by adopting Sc elementary substance targets and Sb in the atmosphere of high-purity argon and high-purity oxygen 2 Te 3 The alloy target is obtained by co-sputtering.
Example ten
An O-doped Sc-Sb-Te phase change storage material with a chemical general formula of O x Sc y (Sb 2 Te 3 ) 1-x-y Wherein x =4.4%, y =6%.
The Sc-Sb-Te phase-change storage material doped with O in the tenth embodiment can be prepared by adopting a Sc elementary substance target and Sb in a high-purity argon and high-purity oxygen atmosphere 2 Te 3 The alloy target is obtained by co-sputtering.
EXAMPLE eleven
The silicon-nitrogen co-doped Sc-Sb-Te phase change storage material has a chemical general formula of Si x1 N x2 Sc y (Sb 2 Te 3 ) 1-x1-x2-y Wherein x1=4.4%, x2=4.4%, y =4.4%.
The silicon nitrogen co-doped Sc-Sb-Te phase change storage material of the eleventh embodiment can be prepared by adopting a Si elemental target, a Sc elemental target and Sb in the atmosphere of high-purity argon and high-purity nitrogen 2 Te 3 The alloy target is obtained by co-sputtering.
Example twelve
Silica co-dopingThe chemical formula of the miscellaneous ScSbTe phase change storage material is Si x1 O x2 Sc y (Sb 2 Te 3 ) 1-x1-x2-y Wherein x1=4.4%, x2=4.4%, y =4.4%.
The silicon-oxygen co-doped Sc-Sb-Te phase-change storage material of the twelve embodiment can be prepared by adopting Si elementary substance target, sc elementary substance target and Sb in the atmosphere of high-purity argon and high-purity oxygen 2 Te 3 The alloy target is obtained by co-sputtering.
In order to strongly support the beneficial effects brought by the technical scheme of the embodiment of the present application, the crystallization temperature, the crystallization speed, and the density difference between the amorphous structure and the crystalline structure of the phase change memory material and the undoped Sc-Sb-Te phase change material in the embodiment of the present application are tested, and the results are summarized in table 1 below.
The triggering conditions for crystallization of the phase-change materials are as follows: a write pulse (SET pulse, a specific pulse diagram is shown in fig. 8 and will be described in detail later) with a pulse width of 8ns and a pulse height of 1V is applied to each phase-change memory material, so that each amorphous material is heated to a temperature above its crystallization temperature and below its melting temperature under the action of the pulse, and the crystalline structure of the corresponding material is obtained after cooling.
TABLE 1 summary of the Properties of the various phase change memory materials
As can be known from table 1, compared with the undoped Sc-Sb-Te phase change material, the phase change memory material provided in the embodiment of the present application has a higher crystallization temperature, a smaller density difference between the amorphous structure and the crystalline structure, and a crystallization speed that is not significantly reduced is still higher than that of the existing Ge-Sb-Te phase change material. Furthermore, the memory device made of the phase-change materials has good storage reliability, long service life and fast erasing operation speed.
In addition, for further supporting the beneficial effects brought by the technical scheme of the embodiment of the present application, taking the phase change memory material in the first embodiment of the present application as an example, the phase change memory cell using the phase change memory material is subjected to a pulse test. Fig. 8 is a schematic diagram of the test pulses used, the abscissa is time, the ordinate is voltage, and the data of the specific test pulses are shown in table 2. Fig. 9 shows the results of the pulse test, in which the abscissa is the number of cycles of the test performed by the test pulse and the ordinate is the resistance value of each phase change memory material after being subjected to the electric pulse.
TABLE 2 test pulse data
Under the erasing pulse, the phase change storage material is in an amorphous structure and has larger resistance; under the write pulse, the phase change memory material is crystallized, and the resistance is smaller. Thus, the curves in fig. 9 are, from top to bottom: a high resistance amorphous state and a low resistance crystalline state. As can be seen from fig. 9, the phase change memory material provided in the embodiment of the present application has a large resistance difference between the crystalline state and the amorphous state, is clearly distinguished, and is suitable for manufacturing a phase change memory, and can better implement a data storage function.
The foregoing merely represents exemplary embodiments of the present application and the description is more specific and detailed, but is not to be construed as limiting the scope of the claims. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, and these are all within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.
Claims (18)
1. A phase change memory material, wherein a chemical formula of the phase change memory material comprises: d x Sc y (Sb b Te c ) 1-x-y Wherein D represents a doping elementD is at least one of nitrogen, boron, oxygen and silicon, x represents the atomic number percentage of D, y represents the atomic number percentage of Sc, b/c represents the atomic number ratio of Sb to Te, wherein x is more than 0 and less than or equal to 40 percent, and y is more than 1 and less than or equal to 10 percent.
2. The phase change memory material of claim 1, wherein the chemical formula of the phase change memory material comprises: d x Sc y (Sb 2 Te 3 ) 1-x-y ，D x Sc y (Sb 8 Te 9 ) 1-x-y ，D x Sc y (Sb 4 Te 3 ) 1-x-y ，D x Sc y (Sb 2 Te 1 ) 1-x-y Or D x Sc y (Sb 3 Te 1 ) 1-x-y 。
3. A phase change memory material as claimed in claim 1, characterized in that x has a value in the range 3% to 10%.
4. A phase change memory material as claimed in claim 1, characterized in that y has a value in the range 3% to 6%.
5. Phase change memory material as claimed in any of the claims 1-4, characterized in that D forms a chemical bond with at least one of Sc, sb, te in the phase change memory material.
6. A phase-change memory material according to any of claims 1 to 4, wherein D forms tetrahedral units with at least one atom of Sc, sb, te when the phase-change memory material is amorphous.
7. A phase change memory material as claimed in any one of claims 1 to 4, characterized in that the crystallization temperature of the phase change memory material is greater than or equal to 180 ℃.
8. The phase change memory material of claim 7, wherein the crystallization temperature of the phase change memory material is in a range of 180 ℃ to 300 ℃.
9. A phase change memory material as claimed in any one of claims 1 to 4, characterized in that the ratio of the difference between the density of the amorphous structure and the density of the crystalline structure of the phase change memory material to the density of the crystalline structure thereof is less than or equal to 4%.
10. Phase change memory material as claimed in any of the claims 1-4, characterized in that the crystallization speed of the phase change memory material does not exceed 30ns.
11. Phase change memory material as claimed in any of the claims 1-4, characterized in that the amorphous resistance of the phase change memory material is at least two orders of magnitude higher than its crystalline resistance.
12. A phase change memory material as claimed in any one of claims 1 to 4, comprising: the phase change storage material is prepared by adopting a sputtering method, an electron beam evaporation method, a molecular beam epitaxy method, a chemical vapor deposition method or an atomic layer deposition method.
13. A method for preparing a phase change memory material, for preparing a phase change memory material according to any of claims 1 to 12, comprising:
co-sputtering a target material of a main element and a simple substance target of a first non-metal element to form the phase change storage material under the atmosphere of inert gas, wherein the main element comprises scandium Sc, antimony Sb and tellurium Te, and the first non-metal element comprises at least one of boron and silicon;
and changing the atomic percent of the first non-metal element by adjusting the power of a radio frequency power supply in the co-sputtering process.
14. The method of claim 13, wherein the co-sputtering the target material of the main element and the single target of the first nonmetal element to form the phase-change memory material comprises:
co-sputtering the elemental target of the first nonmetal element, the Sc elemental target, the Sb elemental target and the Te elemental target to form the phase change storage material;
co-sputtering the simple substance target of the first nonmetal element, the Sc simple substance target and the Sb-Te alloy target to form the phase change storage material; or
And co-sputtering the simple substance target of the first nonmetal element and the Sc-Sb-Te alloy target to form the phase change storage material.
15. The method for preparing a phase change memory material according to claim 14, wherein the Sb-Te alloy target comprises Sb 2 Te 3 Alloy target, sb 8 Te 9 Alloy target, sb 4 Te 3 Alloy target, sb 2 Te 1 Alloy target, sb 3 Te 1 One kind of alloy target.
16. The method for preparing a phase change memory material according to any one of claims 13 to 15, further comprising: the co-sputtering is performed under an atmosphere of nitrogen and/or oxygen.
17. A phase change memory comprising a phase change memory cell, wherein the phase change memory cell comprises a bottom electrode, a top electrode, and a phase change material layer disposed between the bottom electrode and the top electrode, and the material of the phase change material layer comprises the phase change memory material according to any one of claims 1 to 12.
18. The phase change memory of claim 17, wherein the phase change material layer has a thickness of 20nm to 300nm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110316783.4A CN113161480B (en) | 2021-03-24 | 2021-03-24 | Phase change memory material, preparation method thereof and phase change memory |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110316783.4A CN113161480B (en) | 2021-03-24 | 2021-03-24 | Phase change memory material, preparation method thereof and phase change memory |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113161480A CN113161480A (en) | 2021-07-23 |
| CN113161480B true CN113161480B (en) | 2022-11-25 |
Family
ID=76884710
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110316783.4A Active CN113161480B (en) | 2021-03-24 | 2021-03-24 | Phase change memory material, preparation method thereof and phase change memory |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113161480B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113921709B (en) * | 2021-09-30 | 2024-05-14 | 华中科技大学 | Phase change memory unit |
| CN115101666A (en) * | 2022-01-30 | 2022-09-23 | 华为技术有限公司 | Phase change material, phase change memory chip, memory device and electronic device |
| CN114744109A (en) * | 2022-03-30 | 2022-07-12 | 华中科技大学 | Sb-Te phase change material doped with tetrahedral structure compound and phase change memory |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102610745A (en) * | 2011-01-19 | 2012-07-25 | 中国科学院上海微系统与信息技术研究所 | Si-Sb-Te based sulfur group compound phase-change material for phase change memory |
| CN110098322A (en) * | 2018-01-30 | 2019-08-06 | 中国科学院上海微系统与信息技术研究所 | C adulterates Sc-Sb-Te phase-change storage material, phase-changing memory unit and preparation method thereof |
| US10680175B1 (en) * | 2018-12-21 | 2020-06-09 | Intel Corporation | Memory structures having improved write endurance |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106611814B (en) * | 2015-10-23 | 2020-05-05 | 中国科学院上海微系统与信息技术研究所 | Phase change material for phase change memory and preparation method thereof |
| CN111902955A (en) * | 2018-05-31 | 2020-11-06 | 英特尔公司 | Phase change memory structure and device |
| CN110148668B (en) * | 2019-05-31 | 2022-05-17 | 中国科学院上海微系统与信息技术研究所 | Al-Sc-Sb-Te phase-change material, phase-change memory unit and preparation method thereof |
| CN110911557A (en) * | 2019-10-30 | 2020-03-24 | 华中科技大学 | Doped Ge-Sb phase change material, phase change memory and preparation method thereof |
| CN111244271B (en) * | 2020-01-19 | 2021-12-21 | 中国科学院上海微系统与信息技术研究所 | Phase change material, phase change memory unit and preparation method thereof |
-
2021
- 2021-03-24 CN CN202110316783.4A patent/CN113161480B/en active Active
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102610745A (en) * | 2011-01-19 | 2012-07-25 | 中国科学院上海微系统与信息技术研究所 | Si-Sb-Te based sulfur group compound phase-change material for phase change memory |
| CN110098322A (en) * | 2018-01-30 | 2019-08-06 | 中国科学院上海微系统与信息技术研究所 | C adulterates Sc-Sb-Te phase-change storage material, phase-changing memory unit and preparation method thereof |
| US10680175B1 (en) * | 2018-12-21 | 2020-06-09 | Intel Corporation | Memory structures having improved write endurance |
Non-Patent Citations (1)
| Title |
|---|
| Getasew M. Zewdie 等.Chemical Design Principles for Cache-Type Sc−Sb−Te Phase-Change.《Chemistry of Materials》.2019, * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113161480A (en) | 2021-07-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN113161480B (en) | Phase change memory material, preparation method thereof and phase change memory | |
| US8462545B2 (en) | Semiconductor phase change memory using multiple phase change layers | |
| US8603854B2 (en) | Preparation method for resistance switchable conductive filler for ReRAM | |
| US20150207070A1 (en) | Antimony-Rich High-speed Phase-change Material Used In Phase-Change Memory, Preparing Method, And Application Thereof | |
| US8920684B2 (en) | Al-Sb-Te phase change material used for phase change memory and fabrication method thereof | |
| CN108075039B (en) | Nano composite ZnO-ZnSb phase change storage thin film material and preparation method thereof | |
| US20180301627A1 (en) | Materials and components in phase change memory devices | |
| CN102820427A (en) | Zn-doped Ge2Sb2Te5 phase-change storage film material and preparation method thereof | |
| CN110911557A (en) | Doped Ge-Sb phase change material, phase change memory and preparation method thereof | |
| JP2018511164A (en) | Materials and components in phase change memory devices | |
| CN112687359B (en) | Screening and matching method for insulating heat-insulating material and nanocrystalline metal material in nano current channel layer | |
| Ding et al. | Graphite microislands prepared for reliability improvement of amorphous carbon based resistive switching memory | |
| Rao et al. | Programming voltage reduction in phase change memory cells with tungsten trioxide bottom heating layer/electrode | |
| US8379440B2 (en) | Metallic-glass-based phase-change memory | |
| WO2022198623A1 (en) | Sb2te3 phase-change material based on oxygen doping, phase-change memory, and preparation method | |
| CN102534479B (en) | Microcrystalline Si-SbxTe1-x composite phase change material and preparation method thereof | |
| CN102610745B (en) | Si-Sb-Te based sulfur group compound phase-change material for phase change memory | |
| CN106384783A (en) | ZnO-doped Ge2SbTe5 phase-change storage thin film material and preparation method therefor | |
| CN113921709A (en) | Phase change memory unit | |
| CN104810475A (en) | Nanometer composite TiO2-Sb2Te phase change storage membrane material and preparation method thereof | |
| CN107369760B (en) | Phase change film for phase change memory and preparation method thereof | |
| Bhatt et al. | Reduction of write current with improved thermal stability in GeSe2 doped Sb2Te3 films for Phase Change Memory applications | |
| Yin et al. | Ultra-multiple and reproducible resistance levels based on intrinsic crystallization properties of Ge1Sb4Te7 film | |
| CN114744109A (en) | Sb-Te phase change material doped with tetrahedral structure compound and phase change memory | |
| CN117956889A (en) | HfN-Ge-Sb-Te phase change material and low-power consumption phase change memory |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |