WO2023184668A1 - Lattice matching-based compound-doped ge-sb-te phase change material and phase change memory - Google Patents

Lattice matching-based compound-doped ge-sb-te phase change material and phase change memory Download PDF

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WO2023184668A1
WO2023184668A1 PCT/CN2022/093092 CN2022093092W WO2023184668A1 WO 2023184668 A1 WO2023184668 A1 WO 2023184668A1 CN 2022093092 W CN2022093092 W CN 2022093092W WO 2023184668 A1 WO2023184668 A1 WO 2023184668A1
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phase change
change material
compound
doped
centered cubic
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程晓敏
曾运韬
缪向水
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华中科技大学
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    • H—ELECTRICITY
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    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N70/00—Solid-state devices without a potential-jump barrier or surface barrier, and specially adapted for rectifying, amplifying, oscillating or switching
    • H10N70/801—Constructional details of multistable switching devices
    • H10N70/881—Switching materials
    • H10N70/882—Compounds of sulfur, selenium or tellurium, e.g. chalcogenides
    • H10N70/8828—Tellurides, e.g. GeSbTe
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    • C23C14/06—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the coating material
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    • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
    • C23C14/22—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the process of coating
    • C23C14/24—Vacuum evaporation
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    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
    • C23C14/22—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the process of coating
    • C23C14/34—Sputtering
    • C23C14/35—Sputtering by application of a magnetic field, e.g. magnetron sputtering
    • C23C14/352—Sputtering by application of a magnetic field, e.g. magnetron sputtering using more than one target
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
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    • C23C16/00—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes
    • C23C16/22—Chemical coating by decomposition of gaseous compounds, without leaving reaction products of surface material in the coating, i.e. chemical vapour deposition [CVD] processes characterised by the deposition of inorganic material, other than metallic material
    • C23C16/30—Deposition of compounds, mixtures or solid solutions, e.g. borides, carbides, nitrides
    • C23C16/305—Sulfides, selenides, or tellurides
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N70/00—Solid-state devices without a potential-jump barrier or surface barrier, and specially adapted for rectifying, amplifying, oscillating or switching
    • H10N70/011—Manufacture or treatment of multistable switching devices
    • H10N70/021—Formation of the switching material, e.g. layer deposition
    • H10N70/026—Formation of the switching material, e.g. layer deposition by physical vapor deposition, e.g. sputtering

Definitions

  • the invention belongs to the field of micro-nano electronic technology, and more specifically, relates to a compound-doped Ge-Sb-Te phase change material and a phase change memory based on lattice matching.
  • Phase change memory is considered by the International Semiconductor Industry Association to be the most likely to replace flash memory and dynamic memory and become the mainstream memory in the future due to its advantages such as high integration, fast response speed, long cycle life and low power consumption.
  • phase change memory The basic principle of phase change memory is to use an electrical pulse signal to act on the memory unit, causing the phase change material to undergo a reversible phase change between the amorphous state and the crystalline state to achieve the storage of "0" and "1".
  • a narrow pulse width, high amplitude electrical pulse is applied to the unit to perform a RESET operation.
  • the crystalline phase change memory material melts and quickly cools and transforms into an amorphous disordered state, thereby achieving a transition from a low resistance state "0" to a high resistance state. Fast resistive change of state "1".
  • a wide pulse width, low amplitude electrical pulse is applied to the phase change unit to perform a SET operation.
  • the amorphous phase change memory material undergoes an annealing-like process to crystallize, returns to a low resistance state, and realizes "1" erasing and writing. Return "0".
  • Optimizing the performance of phase change materials is the key to improving the performance of phase change memory, and the microstructure of phase change materials determines their macroscopic properties. Research has found that the reliability and cyclic erasing and erasing characteristics of phase change memory are mainly related to the internal atomic migration mechanism of phase change materials during repeated heating and cooling processes.
  • the data retention time of phase change memory is mainly determined by the amorphous stability of the phase change material.
  • the erasing and writing speed of phase change memory is mainly determined by the crystallization speed of phase change materials.
  • Phase change materials are mainly sulfur series compound materials, among which compounds composed of three elements: Ge, Sb, and Te are the most common.
  • the Ge-Sb-Te system is a phase change material that has received widespread attention in recent years. It combines the advantages of the Sb-Te system and the Ge-Te system.
  • the cycle performance of phase change memory devices based on the Ge-Sb-Te system is poor.
  • the phase change speed cannot meet the requirements of applications such as memory-level memory. Therefore, the cycle performance and erasing and writing speed of phase change memory devices based on the Ge-Sb-Te system need to be further improved.
  • the main performance optimization method for Ge-Sb-Te system phase change materials is doping.
  • the existing doping mechanism for improving the performance of the Ge-Sb-Te system is mainly to dope single elements (such as N, Sc, Al, Ti, etc.) with one or several elements in the Ge-Sb-Te system.
  • the key is to locally control the crystallization process of the Ge-Sb-Te system and improve the amorphous stability of the Ge-Sb-Te system material and the performance of the device.
  • This doping method has a simple process, but the doped single element will generally combine with a certain element in the base phase change material to form a bond, changing the original composition of the phase change material and destroying the lattice structure of the phase change material. While the high resistance stability of the device is improved, the crystallization speed will be sacrificed to a certain extent, making it difficult to achieve an overall improvement in device performance.
  • the purpose of the present invention is to provide compound-doped Ge-Sb-Te phase change materials and phase change memories based on lattice matching.
  • the crystallization process can be accelerated. to ensure the integrity of the lattice structure of the phase change material, thereby improving the cycle performance of the device, reducing the grain size, preventing the atomic migration of phase change elements, improving the stability of the device, and ultimately improving the overall performance of the device in an all-round way.
  • the present invention provides a compound-doped Ge-Sb-Te phase change material based on lattice matching, whose chemical formula is (MA) x (Ge-Sb-Te) 1-x , where MA is The high-melting-point compound with face-centered cubic structure has a melting point higher than that of the Ge-Sb-Te phase change material, with a melting point greater than 900K.
  • the high-melting-point compound MA with face-centered cubic structure matches the lattice of the Ge-Sb-Te system, and x represents the face center
  • the number of cubic structure compound molecules accounts for the percentage of the total number of molecules, 0 ⁇ x ⁇ 10%, and the MA includes one or more of SrS, CaSe, CaS, ScN, ScBi, TiN and HfN.
  • MA a high-melting compound with a face-centered cubic structure, forms a stable nucleation point in the phase change layer of the Ge-Sb-Te system. It is used as a crystallization template for the Ge-Sb-Te system during the crystallization process, which can accelerate the Ge- Crystallization of Sb-Te system.
  • the M element and A element in the face-centered cubic structure high melting point compound MA are independent of each other and the elements in the Ge-Sb-Te system phase change material, without bonding, substitution and gap doping, thus ensuring
  • the phase change material has a complete lattice structure, which can ultimately improve the device's cycle performance.
  • the high melting point compound MA with a face-centered cubic structure is evenly distributed in the amorphous form at the grain boundaries of the crystalline Ge-Sb-Te system phase change material, and can be used to reduce the stress of the Ge-Sb-Te system phase change material.
  • the grain size hinders the atomic migration of phase change elements, which ultimately improves device reliability.
  • the Ge-Sb-Te system phase change material includes one or more of Ge 2 Sb 2 Te 5 , Ge 1 Sb 2 Te 4 and Ge 1 Sb 4 Te 7 .
  • a phase change memory of phase change material which includes a bottom electrode, an isolation layer, a phase change memory material thin film layer and a top electrode stacked in sequence, wherein the phase change memory material thin film layer
  • the Ge-Sb-Te phase change material is doped with compounds based on lattice matching as described above.
  • compound MA forms a stable nucleation point in the phase change layer of the Ge-Sb-Te system, providing amorphous Ge-Sb-Te It provides a template for the crystallization of the system and accelerates the crystallization of the amorphous Ge-Sb-Te system; the chemical bond energy of the compound MA is large, and it hardly bonds with the elements in the Ge-Sb-Te system material in the thin film material, and only forms M-A, M-M and A-A bonds do not undergo substitution or interstitial doping, ensuring the integrity of the lattice structure of the Ge-Sb-Te system phase change material and improving the cycle performance of the device; in addition, the compound MA is evenly distributed in Ge-Sb- in an amorphous form The grain boundaries of the Te system effectively reduce the grain size, hinder the atomic migration of phase change elements, improve the reliability of the device, and thereby improve the
  • Figure 1 is a schematic diagram of the atomic structure of the doped cubic structure compound stably existing in the Ge-Sb-Te matrix material in the present invention.
  • Figure 2 is a flow chart for preparing a phase change memory based on a Ge-Sb-Te system phase change material doped with a stable face-centered cubic structure compound based on lattice matching provided in Embodiment 2 of the present invention.
  • Figure 3 is an R-V test chart of two different devices in Example 4 and Comparative Example 1 under a fixed pulse width of 8ns.
  • Figure 4 is a cycle characteristic test chart of the phase change memory device based on TiN-Ge 1 Sb 4 Te 7 under a fixed pulse width of 20 ns in Example 4.
  • Figure 5 is a cycle characteristic test chart of the phase change memory device based on pure Ge 1 Sb 4 Te 7 in Comparative Example 1 under a fixed pulse width of 20 ns.
  • Figure 6 is a schematic diagram of the structural position of atoms in the Ge-Sb-Te system phase change material model doped with a stable face-centered cubic structure compound based on lattice matching using first principles simulation at a temperature of 600K after 60ps.
  • the application of the present invention relates to an information memory, and in particular to a new type of fast and high cycle performance Ge-Sb-Te system phase change material and phase change memory doped with a stable face-centered cubic structure compound based on lattice matching. It involves the use of a lattice-matched stable face-centered cubic structure compound doping process, using the compound structure to regulate the Ge-Sb-Te system phase change material.
  • phase change layer forms a stable nucleation point, and its face-centered cubic structure matched with the lattice of the Ge-Sb-Te system provides a reliable crystallization template, accelerating the crystallization of Ge-Sb-Te; stable face-centered The elements in the cubic structure compound hardly bond with the elements in the Ge-Sb-Te system phase change material, so no substitution or interstitial doping occurs, ensuring the integrity of the lattice structure of the phase change material, thereby improving the cycle performance of the device; In addition, stable face-centered cubic structure compounds are easily distributed in the amorphous form at the grain boundaries of crystalline phase change materials, reducing the size of the crystal grains, preventing the atomic migration of phase change elements, improving the stability of the device, and ultimately ensuring the overall safety of the device. Comprehensively improve the overall performance of the device.
  • Figure 1 is a schematic diagram of the atomic structure of the doped cubic structure compound stably existing in the Ge-Sb-Te matrix material in the present invention. It can be seen from the figure that the cubic structure compound forms a stable nucleation point, which interacts with the Ge-Sb-Te system
  • the lattice-matched face-centered cubic structure provides a reliable crystallization template and accelerates Ge-Sb-Te crystallization.
  • the present invention introduces the lattice-matched stable face-centered cubic structure compound MA into the Ge-Sb-Te system phase change material to obtain a phase change material.
  • the thickness of the (MA) x (Ge-Sb-Te) 1-x phase change film material is 10 nm to 300 nm.
  • the phase change memory unit sequentially includes a bottom electrode, an isolation layer, a phase change material film layer, and a top electrode.
  • the phase change material film layer is made of the above-mentioned Ge-Sb-Te phase change material doped with a stable face-centered cubic structure compound based on lattice matching, which is filled in a small hole with a diameter of 250 nm and a depth of 100 nm. middle.
  • the bottom electrode material is TiN.
  • the material of the isolation layer is SiO 2 .
  • the top electrode material is metal Pt.
  • the present invention can also provide a method for preparing a Ge-Sb-Te system phase change material doped with a lattice-matched stable face-centered cubic structure compound for a phase change memory.
  • the preparation method includes magnetron sputtering, chemical vapor phase Deposition, atomic layer deposition, electroplating, electron beam evaporation, etc.
  • the magnetron sputtering method is the most flexible. It can use Ge-Sb-Te system target and MA target to co-sputter. This method can prepare the lattice-matched stable face-centered cubic of the present invention according to the proportion of the general chemical formula. Ge-Sb-Te system phase change material doped with structural compounds.
  • the lattice-matched stable face-centered cubic structure compound-doped Ge-Sb-Te system phase-change memory material and device preparation process of the present invention are mature and easy to achieve compatibility with existing microelectronic process technology.
  • the doped lattice-matched stable face-centered cubic structure compound structure is used to regulate the Ge-Sb-Te system phase change material, forming a stable nucleation point in the Ge-Sb-Te system phase change layer, which interacts with the Ge-Sb
  • the lattice-matched face-centered cubic structure of the -Te system provides a reliable crystallization template and accelerates the crystallization of Ge-Sb-Te; the elements in the stable face-centered cubic structure compound have almost no interaction with the Ge-Sb-Te system phase change material
  • the elements in the material form bonds, so no substitution or interstitial doping occurs, ensuring the integrity of the lattice structure of the phase change material, thereby improving the cycle performance of the device.
  • stable face-centered cubic structure compounds are easily distributed in the amorphous form at the grain boundaries of crystalline phase change materials, reducing the grain size, preventing the atomic migration of phase change elements, improving the stability of the device, thereby improving Ge -Comprehensive performance of Sb-Te system phase change memory.
  • SrS-Ge 2 Sb 2 Te 5 phase change memory thin film material is produced by magnetron sputtering method. During preparation, high-purity argon was introduced as the sputtering gas, and the sputtering pressure was 0.5Pa.
  • the Ge 2 Sb 2 Te 5 target used a DC power supply with a power supply of 30W; the SrS target used an AC power supply with a power supply of 60W.
  • the specific preparation process includes the following steps:
  • the baffle After the pre-sputtering is completed, open the baffle. When the sputtering time is 6 minutes, the thickness of the prepared film is about 100nm.
  • SrS-doped Ge 2 Sb 2 Te 5 phase change film material is used as the phase change layer material to prepare a memory device, wherein the SrS doped Ge 2 Sb 2 Te 5 phase change layer is produced by magnetron sputtering.
  • high-purity argon was introduced as the sputtering gas, and the sputtering pressure was 0.5Pa.
  • the Ge 2 Sb 2 Te 5 target used a DC power supply with a power supply of 30W; the SrS target used an AC power supply with a power supply of 60W.
  • Figure 2 is a flow chart for the preparation of a phase change memory based on the Ge-Sb-Te system phase change material doped with a stable face-centered cubic structure compound based on lattice matching provided in Embodiment 2 of the present invention.
  • the specific preparation process includes the following step:
  • the thickness of the phase change layer prepared is about 100nm.
  • TiN-Ge 1 Sb 4 Te 7 phase change memory thin film material is produced by magnetron sputtering method.
  • high-purity argon gas was introduced as the sputtering gas, the sputtering pressure was 0.5Pa, and the Ge 1 Sb 4 Te 7 target used a DC power supply with a power supply of 30W.
  • the TiN target uses a DC power supply with a power supply of 20W.
  • the specific preparation process includes the following steps:
  • the baffle After the pre-sputtering is completed, open the baffle. When the sputtering time is 6 minutes, the thickness of the prepared film is about 100nm.
  • TiN-doped Ge 1 Sb 4 Te 7 phase change film material is used as the phase change layer material to prepare a memory device, in which the TiN-doped Ge 1 Sb 4 Te 7 phase change layer is produced by magnetron sputtering.
  • high-purity argon was introduced as the sputtering gas, and the sputtering pressure was 0.5Pa.
  • the Ge 1 Sb 4 Te 7 target used a DC power supply with a power supply of 30W; the TiN target used a DC power supply with a power supply of 20W.
  • the specific preparation process includes the following steps:
  • the thickness of the phase change layer prepared is about 100nm.
  • pure Ge 1 Sb 4 Te 7 phase change film material is used as the phase change layer material to prepare a memory device.
  • the pure Ge 1 Sb 4 Te 7 phase change layer is produced by magnetron sputtering.
  • high-purity argon gas was introduced as the sputtering gas, the sputtering pressure was 0.5Pa, and the Ge 1 Sb 4 Te 7 target used a DC power supply with a power supply of 30W.
  • the specific preparation process includes the following steps:
  • the thickness of the phase change layer prepared is about 100nm.
  • the TiN-Ge 1 Sb 4 Te 7 phase change memory device and the pure Ge 1 Sb 4 Te 7 phase change memory device in the above Example 4 and Comparative Example 1 were respectively tested for electrical characteristics.
  • Figure 3 is an RV test chart of two different devices in Example 4 and Comparative Example 1 under a fixed pulse width of 8ns, which reflects the SET speed performance of the device.
  • the phase change memory can successfully SET from the high resistance state to the low resistance state under an 8ns pulse width; while the phase change memory device based on pure Ge 1 Sb 4 Te 7 cannot successfully SET the device even if the pulse amplitude is increased to 2.4V.
  • Figures 4 and 5 are cycle characteristic test charts of two different devices in Example 4 and Comparative Example 1 under a fixed pulse width of 20 ns.
  • the maximum cycle number of the phase change memory device based on TiN-Ge 1 Sb 4 Te 7 in Figure 4 is close to E9 times, while the maximum cycle number of the phase change memory device based on pure Ge 1 Sb 4 Te 7 in Figure 5 is 3.5E6 times. It has been verified that doping with stable face-centered cubic structure compounds can improve the cycle performance of Ge-Sb-Te system phase change memory devices.
  • FIG. 6 is a schematic diagram of the structural position after 60ps of simulating the movement of atoms at a temperature of 600K in the Ge-Sb-Te system phase change material model doped with a stable face-centered cubic structure compound based on lattice matching using first principles. It can be found The incorporated TiN still maintains a stable compound state in the Ge 1 Sb 4 Te 7 system, providing a stable structurally matched nucleation point for the system.
  • SrS and TiN were selected as the high melting point compound MA with a face-centered cubic structure
  • Ge 2 Sb 2 Te 5 and Ge 1 Sb 4 Te 7 were selected as the Ge-Sb-Te system phase change material.
  • Ge-Sb The -Te system phase change material can also choose Ge 1 Sb 2 Te 4
  • the high melting point compound MA with a face-centered cubic structure can also choose one or more of CaSe, CaS, ScN, ScBi and HfN, such as CaSe-Ge 1 Sb 2 Te 4 , CaS-Ge 2 Sb 2 Te 5 , ScN-Ge 1 Sb 4 Te 7 , ScBi-Ge 2 Sb 2 Te 5 and HfN-Ge 2 Sb 2 Te 5 , etc.
  • the present invention is doped with a stable face-centered cubic structure compound based on lattice matching.
  • the doped lattice-matched stable face-centered cubic structure compound structure is used to regulate the Ge-Sb-Te system phase change material, and the Ge-Sb-Te system phase change layer is formed Stable nucleation point, its face-centered cubic structure that matches the lattice of the Ge-Sb-Te system provides a reliable crystallization template and accelerates crystallization; the elements in the stable face-centered cubic structure compound have almost no interaction with Ge-Sb
  • the elements in the -Te system phase change materials form bonds, so no substitution or interstitial doping occurs, ensuring the integrity of the lattice structure of the phase change material, thus improving the cycle performance of the device; in addition, stable face-centered cubic structure compounds are easy to be
  • the crystal forms are distributed at the grain boundaries of crystalline phase change materials, reducing the grain size, preventing the atomic migration of phase change elements, improving the stability of the device, and ultimately improving the overall performance of the device in an all-round way.

Abstract

The present invention relates to the technical field of micro- and nano-electronics, and provides a lattice matching-based compound-doped Ge-Sb-Te phase change material and a phase change memory. The chemical formula of the phase change material is (MA)x(Ge-Sb-Te)1-x, wherein MA is a high-melting-point compound having a face-centered cubic structure, the melting point of the MA is greater than 900 K, the high-melting-point compound MA having the face-centered cubic structure is in lattice matching with a Ge-Sb-Te system, x represents the percentage of the number of molecules of the compound having the face-centered cubic structure in the total number of molecules, 0<x<10%, and the MA comprises one or more of SrS, CaSe, CaS, ScN, ScBi, TiN, and HfN. The present invention further provides a phase change memory comprising the phase change material. According to the phase change material of the present invention, the erasing speed and the cycle performance of the phase change memory can be improved at the same time, the stability of a device is improved, and finally the comprehensive performance of the device is comprehensively improved.

Description

基于晶格匹配的化合物掺杂Ge-Sb-Te相变材料和相变存储器Compound-doped Ge-Sb-Te phase change materials and phase change memories based on lattice matching 【技术领域】【Technical field】
本发明属于微纳米电子技术领域，更具体地，涉及一种基于晶格匹配的化合物掺杂Ge-Sb-Te相变材料和相变存储器。The invention belongs to the field of micro-nano electronic technology, and more specifically, relates to a compound-doped Ge-Sb-Te phase change material and a phase change memory based on lattice matching.
【背景技术】【Background technique】
在当今电子技术以及信息产业飞速发展的时代，随着数据的爆炸式增长，人们对非易失性存储器的性能要求也越来越高。相变存储器(PCM)凭借其集成度高、响应速度快、循环寿命长和低功耗等优点被国际半导体工业协会认为最有可能取代闪存和动态存储器而成为未来主流存储器。In today's era of rapid development of electronic technology and information industry, with the explosive growth of data, people have higher and higher performance requirements for non-volatile memory. Phase change memory (PCM) is considered by the International Semiconductor Industry Association to be the most likely to replace flash memory and dynamic memory and become the mainstream memory in the future due to its advantages such as high integration, fast response speed, long cycle life and low power consumption.
相变存储器的基本原理是用电脉冲信号作用于存储单元上，使相变材料在非晶态与晶态之间发生可逆相变来实现“0”和“1”的存储。在单元上施加一个窄脉宽、高幅值的电脉冲对其进行RESET操作，晶态相变存储材料熔化快冷转变为非晶无序态，从而实现从低阻态“0”到高阻态“1”的快速阻变。反之，在相变单元上施加一个宽脉宽、低幅值的电脉冲对其进行SET操作，非晶态相变存储材料经历一个类退火过程结晶，返回低阻态，实现“1”擦写回“0”。The basic principle of phase change memory is to use an electrical pulse signal to act on the memory unit, causing the phase change material to undergo a reversible phase change between the amorphous state and the crystalline state to achieve the storage of "0" and "1". A narrow pulse width, high amplitude electrical pulse is applied to the unit to perform a RESET operation. The crystalline phase change memory material melts and quickly cools and transforms into an amorphous disordered state, thereby achieving a transition from a low resistance state "0" to a high resistance state. Fast resistive change of state "1". On the contrary, a wide pulse width, low amplitude electrical pulse is applied to the phase change unit to perform a SET operation. The amorphous phase change memory material undergoes an annealing-like process to crystallize, returns to a low resistance state, and realizes "1" erasing and writing. Return "0".
相变材料性能的优化是提升相变存储器性能的关键，而相变材料的微观结构决定着其宏观特性。研究发现，相变存储器的可靠性和循环擦写特性主要与相变材料在反复升温降温过程中的内部原子迁移机制有关。相变存储器的数据保持时间主要由相变材料的非晶稳定性决定。相变存储器的擦写速度主要由相变材料的晶化速度决定。Optimizing the performance of phase change materials is the key to improving the performance of phase change memory, and the microstructure of phase change materials determines their macroscopic properties. Research has found that the reliability and cyclic erasing and erasing characteristics of phase change memory are mainly related to the internal atomic migration mechanism of phase change materials during repeated heating and cooling processes. The data retention time of phase change memory is mainly determined by the amorphous stability of the phase change material. The erasing and writing speed of phase change memory is mainly determined by the crystallization speed of phase change materials.
相变材料主要为硫系化合物材料，其中，又以Ge、Sb、Te三种元素组成的化合物最为常见。Ge-Sb-Te体系是近年来受到广泛关注的相变材料，其结合了Sb-Te体系和Ge-Te体系的优点，但是，基于Ge-Sb-Te体系的相变存 储器件循环性能较差并且相变速度不能满足内存级存储器等方面的应用，因此，基于Ge-Sb-Te体系的相变存储器件的循环性能以及擦写速度需要进一步提升。Phase change materials are mainly sulfur series compound materials, among which compounds composed of three elements: Ge, Sb, and Te are the most common. The Ge-Sb-Te system is a phase change material that has received widespread attention in recent years. It combines the advantages of the Sb-Te system and the Ge-Te system. However, the cycle performance of phase change memory devices based on the Ge-Sb-Te system is poor. Moreover, the phase change speed cannot meet the requirements of applications such as memory-level memory. Therefore, the cycle performance and erasing and writing speed of phase change memory devices based on the Ge-Sb-Te system need to be further improved.
目前，对Ge-Sb-Te体系相变材料的主要性能优化手段是掺杂。通过在Ge-Sb-Te体系相变材料中引入其他元素形成不同的微观结构，改变相变材料的局域特性从而改善相变存储器件的性能。已有的Ge-Sb-Te体系掺杂对其性能的改善机制主要是，掺杂单元素(如N、Sc、Al、Ti等)与Ge-Sb-Te体系中一种或几种元素成键，局域调控Ge-Sb-Te体系的晶化过程，提高Ge-Sb-Te体系材料的非晶稳定性及器件的性能。这种掺杂方式，工艺简单，但是掺入的单元素一般会和基底相变材料中的某一元素结合成键，改变相变材料的原始组分并破坏相变材料的晶格结构，在器件高阻稳定性得到改善的同时会一定程度上牺牲晶化速度，很难实现器件性能的全面提升。At present, the main performance optimization method for Ge-Sb-Te system phase change materials is doping. By introducing other elements into the Ge-Sb-Te system phase change material to form different microstructures, the local characteristics of the phase change material are changed to improve the performance of the phase change memory device. The existing doping mechanism for improving the performance of the Ge-Sb-Te system is mainly to dope single elements (such as N, Sc, Al, Ti, etc.) with one or several elements in the Ge-Sb-Te system. The key is to locally control the crystallization process of the Ge-Sb-Te system and improve the amorphous stability of the Ge-Sb-Te system material and the performance of the device. This doping method has a simple process, but the doped single element will generally combine with a certain element in the base phase change material to form a bond, changing the original composition of the phase change material and destroying the lattice structure of the phase change material. While the high resistance stability of the device is improved, the crystallization speed will be sacrificed to a certain extent, making it difficult to achieve an overall improvement in device performance.
因此，需要开发一种新型的Ge-Sb-Te体系改性方法，以实现对其微观结构的精确、灵敏、简单地调控，从而全面提升器件性能，使其能作为商业化的相变存储材料应用。Therefore, it is necessary to develop a new method of modifying the Ge-Sb-Te system to achieve precise, sensitive and simple control of its microstructure, thereby comprehensively improving device performance and enabling it to be used as a commercial phase change memory material. application.
【发明内容】[Content of the invention]
针对现有技术的缺陷，本发明的目的在于提供基于晶格匹配的化合物掺杂Ge-Sb-Te相变材料和相变存储器，通过晶格匹配的稳定面心立方结构化合物掺杂，加速晶化，保证相变材料晶格结构完整，从而提高器件的循环性能，并减小晶粒尺寸，阻止相变元素的原子迁移，提高器件的稳定性，最终全方位地改善器件的综合性能。In view of the shortcomings of the existing technology, the purpose of the present invention is to provide compound-doped Ge-Sb-Te phase change materials and phase change memories based on lattice matching. By doping stable face-centered cubic structure compounds with lattice matching, the crystallization process can be accelerated. to ensure the integrity of the lattice structure of the phase change material, thereby improving the cycle performance of the device, reducing the grain size, preventing the atomic migration of phase change elements, improving the stability of the device, and ultimately improving the overall performance of the device in an all-round way.
为实现上述目的，本发明提供了一种基于晶格匹配的化合物掺杂Ge-Sb-Te相变材料，其化学式为(MA) x(Ge-Sb-Te) 1-x，其中，MA为面心立方结构的高熔点化合物，其熔点高于Ge-Sb-Te相变材料，熔点大于900K，面心立方结 构的高熔点化合物MA与Ge-Sb-Te体系晶格匹配，x代表面心立方结构化合物分子数占总分子数的百分比，0<x<10％，所述MA包括SrS、CaSe、CaS、ScN、ScBi、TiN和HfN的一种或者多种。 In order to achieve the above objectives, the present invention provides a compound-doped Ge-Sb-Te phase change material based on lattice matching, whose chemical formula is (MA) x (Ge-Sb-Te) 1-x , where MA is The high-melting-point compound with face-centered cubic structure has a melting point higher than that of the Ge-Sb-Te phase change material, with a melting point greater than 900K. The high-melting-point compound MA with face-centered cubic structure matches the lattice of the Ge-Sb-Te system, and x represents the face center The number of cubic structure compound molecules accounts for the percentage of the total number of molecules, 0<x<10%, and the MA includes one or more of SrS, CaSe, CaS, ScN, ScBi, TiN and HfN.
进一步的，面心立方结构的高熔点化合物MA在Ge-Sb-Te体系相变层形成稳定的形核点，晶化过程中用作Ge-Sb-Te体系的晶化模板，能加速Ge-Sb-Te体系晶化。Furthermore, MA, a high-melting compound with a face-centered cubic structure, forms a stable nucleation point in the phase change layer of the Ge-Sb-Te system. It is used as a crystallization template for the Ge-Sb-Te system during the crystallization process, which can accelerate the Ge- Crystallization of Sb-Te system.
进一步的，面心立方结构的高熔点化合物MA中的M元素和A元素与Ge-Sb-Te体系相变材料中的元素相互独立，无键合，无替位和间隙掺杂，从而能保证相变材料晶格结构完整，最终能提高器件的循环性能。Furthermore, the M element and A element in the face-centered cubic structure high melting point compound MA are independent of each other and the elements in the Ge-Sb-Te system phase change material, without bonding, substitution and gap doping, thus ensuring The phase change material has a complete lattice structure, which can ultimately improve the device's cycle performance.
进一步的，面心立方结构的高熔点化合物MA以非晶形式均匀分布于晶态Ge-Sb-Te体系相变材料的晶界处，能用于减小Ge-Sb-Te体系相变材料的晶粒尺寸，阻碍相变元素的原子迁移，最终能提高器件的可靠性。Furthermore, the high melting point compound MA with a face-centered cubic structure is evenly distributed in the amorphous form at the grain boundaries of the crystalline Ge-Sb-Te system phase change material, and can be used to reduce the stress of the Ge-Sb-Te system phase change material. The grain size hinders the atomic migration of phase change elements, which ultimately improves device reliability.
进一步的，所述Ge-Sb-Te体系相变材料包括Ge 2Sb 2Te 5、Ge 1Sb 2Te 4和Ge 1Sb 4Te 7中的一种或者多种。 Further, the Ge-Sb-Te system phase change material includes one or more of Ge 2 Sb 2 Te 5 , Ge 1 Sb 2 Te 4 and Ge 1 Sb 4 Te 7 .
进一步的，采用磁控溅射法、化学气相沉积法、原子层沉积法、电镀法或/和电子束蒸发法制备获得。Further, it is prepared by using magnetron sputtering method, chemical vapor deposition method, atomic layer deposition method, electroplating method or/and electron beam evaporation method.
进一步的，采用Ge-Sb-Te体系靶和MA靶共溅射方式制备获得。Further, it was prepared by co-sputtering of Ge-Sb-Te system target and MA target.
按照本发明的第二个方面，还提供一种相变材料的相变存储器，其包括依次层叠的底电极、隔离层、相变存储材料薄膜层和顶电极，其中，相变存储材料薄膜层采用如上所述的基于晶格匹配的化合物掺杂Ge-Sb-Te相变材料。According to a second aspect of the present invention, a phase change memory of phase change material is also provided, which includes a bottom electrode, an isolation layer, a phase change memory material thin film layer and a top electrode stacked in sequence, wherein the phase change memory material thin film layer The Ge-Sb-Te phase change material is doped with compounds based on lattice matching as described above.
总体而言，通过本发明所构思的以上技术方案与现有技术相比，具有以下有益效果：Generally speaking, compared with the prior art, the above technical solution conceived by the present invention has the following beneficial effects:
本发明的基于晶格匹配的稳定面心立方结构化合物掺杂的相变材料中，化合物MA在Ge-Sb-Te体系相变层形成稳定的形核点，给非晶态Ge-Sb-Te体系晶化提供模板，加速非晶态Ge-Sb-Te体系晶化；化合物MA化学键键能大， 在薄膜材料中几乎不与Ge-Sb-Te体系材料中的元素成键，只形成M-A、M-M和A-A键，不发生替位或者间隙掺杂，保证Ge-Sb-Te体系相变材料晶格结构完整，提高器件的循环性能；此外，化合物MA以非晶形式均匀分布于Ge-Sb-Te体系的晶界处，有效减小晶粒尺寸，阻碍相变元素的原子迁移，提高器件的可靠性，从而全方位地改善器件的综合性能。In the phase change material doped with a stable face-centered cubic structure compound based on lattice matching of the present invention, compound MA forms a stable nucleation point in the phase change layer of the Ge-Sb-Te system, providing amorphous Ge-Sb-Te It provides a template for the crystallization of the system and accelerates the crystallization of the amorphous Ge-Sb-Te system; the chemical bond energy of the compound MA is large, and it hardly bonds with the elements in the Ge-Sb-Te system material in the thin film material, and only forms M-A, M-M and A-A bonds do not undergo substitution or interstitial doping, ensuring the integrity of the lattice structure of the Ge-Sb-Te system phase change material and improving the cycle performance of the device; in addition, the compound MA is evenly distributed in Ge-Sb- in an amorphous form The grain boundaries of the Te system effectively reduce the grain size, hinder the atomic migration of phase change elements, improve the reliability of the device, and thereby improve the overall performance of the device in an all-round way.
【附图说明】[Picture description]
图1是本发明中掺杂的立方结构化合物在Ge-Sb-Te基体材料中稳定存在的原子结构示意图。Figure 1 is a schematic diagram of the atomic structure of the doped cubic structure compound stably existing in the Ge-Sb-Te matrix material in the present invention.
图2是本发明实施例2提供的基于晶格匹配的稳定面心立方结构化合物掺杂的Ge-Sb-Te体系相变材料的相变存储器制备流程图。Figure 2 is a flow chart for preparing a phase change memory based on a Ge-Sb-Te system phase change material doped with a stable face-centered cubic structure compound based on lattice matching provided in Embodiment 2 of the present invention.
图3是实施例4和对比例1中两个不同器件在8ns固定脉冲宽度下的R-V测试图。Figure 3 is an R-V test chart of two different devices in Example 4 and Comparative Example 1 under a fixed pulse width of 8ns.
图4是实施例4中基于TiN-Ge 1Sb 4Te 7的相变存储器件在20ns固定脉冲宽度下的循环特性测试图。 Figure 4 is a cycle characteristic test chart of the phase change memory device based on TiN-Ge 1 Sb 4 Te 7 under a fixed pulse width of 20 ns in Example 4.
图5是对比例1中基于纯Ge 1Sb 4Te 7的相变存储器件在20ns固定脉冲宽度下的循环特性测试图。 Figure 5 is a cycle characteristic test chart of the phase change memory device based on pure Ge 1 Sb 4 Te 7 in Comparative Example 1 under a fixed pulse width of 20 ns.
图6是利用第一性原理模拟基于晶格匹配的稳定面心立方结构化合物掺杂的Ge-Sb-Te体系相变材料模型中的原子在600K温度下的运动60ps后结构位置示意图。Figure 6 is a schematic diagram of the structural position of atoms in the Ge-Sb-Te system phase change material model doped with a stable face-centered cubic structure compound based on lattice matching using first principles simulation at a temperature of 600K after 60ps.
【具体实施方式】【Detailed ways】
为了使本发明的目的、技术方案及优点更加清楚明白，以下结合附图及实施例，对本发明进行进一步详细说明。应当理解，此处所描述的具体实施例仅仅用以解释本发明，并不用于限定本发明。In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention and are not intended to limit the present invention.
本发明申请涉及一种信息存储器，特别是涉及一种新型基于晶格匹配的 稳定面心立方结构化合物掺杂的快速高循环性能Ge-Sb-Te体系相变材料、相变存储器。涉及采用晶格匹配的稳定面心立方结构化合物掺杂工艺，利用化合物组织对Ge-Sb-Te体系相变材料进行调控，通过晶格匹配的稳定面心立方结构化合物掺杂，在Ge-Sb-Te体系相变层形成稳定的形核点，其与Ge-Sb-Te体系晶格匹配的面心立方结构提供了可靠的晶化模板，加速Ge-Sb-Te晶化；稳定的面心立方结构化合物中的元素几乎不与Ge-Sb-Te体系相变材料中的元素成键，因此不发生替位或者间隙掺杂，保证相变材料晶格结构完整，从而提高器件的循环性能；此外，稳定的面心立方结构化合物易以非晶形式均与分布于晶态相变材料的晶界处，减小晶粒尺寸，阻止相变元素的原子迁移，提高器件的稳定性，最终全方位地实现改善器件的综合性能。The application of the present invention relates to an information memory, and in particular to a new type of fast and high cycle performance Ge-Sb-Te system phase change material and phase change memory doped with a stable face-centered cubic structure compound based on lattice matching. It involves the use of a lattice-matched stable face-centered cubic structure compound doping process, using the compound structure to regulate the Ge-Sb-Te system phase change material. Through the lattice-matched stable face-centered cubic structure compound doping, in Ge-Sb -Te system phase change layer forms a stable nucleation point, and its face-centered cubic structure matched with the lattice of the Ge-Sb-Te system provides a reliable crystallization template, accelerating the crystallization of Ge-Sb-Te; stable face-centered The elements in the cubic structure compound hardly bond with the elements in the Ge-Sb-Te system phase change material, so no substitution or interstitial doping occurs, ensuring the integrity of the lattice structure of the phase change material, thereby improving the cycle performance of the device; In addition, stable face-centered cubic structure compounds are easily distributed in the amorphous form at the grain boundaries of crystalline phase change materials, reducing the size of the crystal grains, preventing the atomic migration of phase change elements, improving the stability of the device, and ultimately ensuring the overall safety of the device. Comprehensively improve the overall performance of the device.
图1是本发明中掺杂的立方结构化合物在Ge-Sb-Te基体材料中稳定存在的原子结构示意图，由图可知，立方结构化合物形成稳定的形核点，其与Ge-Sb-Te体系晶格匹配的面心立方结构提供了可靠的晶化模板，加速Ge-Sb-Te晶化。本发明将晶格匹配的稳定面心立方结构化合物MA引入Ge-Sb-Te体系相变材料中得到的相变材料，其化学组成通式为(MA) x(Ge-Sb-Te) 1-x，其中，MA为晶格匹配的稳定面心立方结构化合物，x代表高熔点化合物分子数占总分子数的百分比，较佳的x取值范围为0<x<10％，进一步优选为x＝5％。通过调整制备时MA的溅射功率，可以调控x的取值。优选的，(MA) x(Ge-Sb-Te) 1-x相变薄膜材料厚度为10nm～300nm。 Figure 1 is a schematic diagram of the atomic structure of the doped cubic structure compound stably existing in the Ge-Sb-Te matrix material in the present invention. It can be seen from the figure that the cubic structure compound forms a stable nucleation point, which interacts with the Ge-Sb-Te system The lattice-matched face-centered cubic structure provides a reliable crystallization template and accelerates Ge-Sb-Te crystallization. The present invention introduces the lattice-matched stable face-centered cubic structure compound MA into the Ge-Sb-Te system phase change material to obtain a phase change material. The general chemical composition formula of the material is (MA) x (Ge-Sb-Te) 1- x , where MA is a stable face-centered cubic structure compound with lattice matching, x represents the percentage of the number of high melting point compound molecules in the total number of molecules, the preferred range of x is 0<x<10%, and further preferably x =5%. By adjusting the sputtering power of MA during preparation, the value of x can be controlled. Preferably, the thickness of the (MA) x (Ge-Sb-Te) 1-x phase change film material is 10 nm to 300 nm.
本发明一个实施例中相变存储单元依次包括底电极、隔离层、相变材料薄膜层、顶电极。所述相变材料薄膜层材质为如上所述的基于晶格匹配的稳定面心立方结构化合物掺杂的Ge-Sb-Te相变材料，其被填充在直径为250nm、深度为100nm的小孔中。所述底电极材质为TiN。所述隔离层材质为SiO 2。所述顶电极材质为金属Pt。 In one embodiment of the present invention, the phase change memory unit sequentially includes a bottom electrode, an isolation layer, a phase change material film layer, and a top electrode. The phase change material film layer is made of the above-mentioned Ge-Sb-Te phase change material doped with a stable face-centered cubic structure compound based on lattice matching, which is filled in a small hole with a diameter of 250 nm and a depth of 100 nm. middle. The bottom electrode material is TiN. The material of the isolation layer is SiO 2 . The top electrode material is metal Pt.
本发明还可以提供一种用于相变存储器的晶格匹配的稳定面心立方结构 化合物掺杂的Ge-Sb-Te体系相变材料的制备方法，制备方法包括磁控溅射法、化学气相沉积、原子层沉积法、电镀法、电子束蒸发法等。其中，磁控溅射法制备最为灵活，可以采用Ge-Sb-Te体系靶和MA靶共溅射，这种方法能按照化学通式的配比制备本发明的晶格匹配的稳定面心立方结构化合物掺杂的Ge-Sb-Te体系相变材料。The present invention can also provide a method for preparing a Ge-Sb-Te system phase change material doped with a lattice-matched stable face-centered cubic structure compound for a phase change memory. The preparation method includes magnetron sputtering, chemical vapor phase Deposition, atomic layer deposition, electroplating, electron beam evaporation, etc. Among them, the magnetron sputtering method is the most flexible. It can use Ge-Sb-Te system target and MA target to co-sputter. This method can prepare the lattice-matched stable face-centered cubic of the present invention according to the proportion of the general chemical formula. Ge-Sb-Te system phase change material doped with structural compounds.
本发明的晶格匹配的稳定面心立方结构化合物掺杂的Ge-Sb-Te体系相变存储材料以及器件制备工艺成熟，易于实现与现有微电子工艺技术的兼容。利用掺杂的晶格匹配的稳定面心立方结构化合物组织对Ge-Sb-Te体系相变材料进行调控，在Ge-Sb-Te体系相变层形成稳定的形核点，其与Ge-Sb-Te体系晶格匹配的面心立方结构提供了可靠的晶化模板，加速Ge-Sb-Te晶化；稳定的面心立方结构化合物中的元素几乎不与Ge-Sb-Te体系相变材料中的元素成键，因此不发生替位或者间隙掺杂，保证相变材料晶格结构完整，从而能提高器件的循环性能。此外，稳定的面心立方结构化合物易以非晶形式均匀分布于晶态相变材料的晶界处，减小晶粒尺寸，阻止相变元素的原子迁移，提高器件的稳定性，从而改进Ge-Sb-Te体系相变存储器综合性能。The lattice-matched stable face-centered cubic structure compound-doped Ge-Sb-Te system phase-change memory material and device preparation process of the present invention are mature and easy to achieve compatibility with existing microelectronic process technology. The doped lattice-matched stable face-centered cubic structure compound structure is used to regulate the Ge-Sb-Te system phase change material, forming a stable nucleation point in the Ge-Sb-Te system phase change layer, which interacts with the Ge-Sb The lattice-matched face-centered cubic structure of the -Te system provides a reliable crystallization template and accelerates the crystallization of Ge-Sb-Te; the elements in the stable face-centered cubic structure compound have almost no interaction with the Ge-Sb-Te system phase change material The elements in the material form bonds, so no substitution or interstitial doping occurs, ensuring the integrity of the lattice structure of the phase change material, thereby improving the cycle performance of the device. In addition, stable face-centered cubic structure compounds are easily distributed in the amorphous form at the grain boundaries of crystalline phase change materials, reducing the grain size, preventing the atomic migration of phase change elements, improving the stability of the device, thereby improving Ge -Comprehensive performance of Sb-Te system phase change memory.
为了更加详细的阐述本发明方法和材料，下面结合更加具体的实施例进一步详细说明。In order to explain the methods and materials of the present invention in more detail, the following is further described in detail with reference to more specific examples.
实施例1Example 1
本实施例中制备的用于相变存储器件的晶格匹配的稳定面心立方结构化合物掺杂的Ge 2Sb 2Te 5相变薄膜材料化学通式为(MA)x(GST)1-x，其中MA代表SrS，GST代表Ge 2Sb 2Te 5，本实施例中x＝0.05。 The lattice-matched stable face-centered cubic structure compound-doped Ge 2 Sb 2 Te 5 phase change thin film material prepared in this embodiment has a general chemical formula of (MA)x(GST)1-x , where MA represents SrS, GST represents Ge 2 Sb 2 Te 5 , and x=0.05 in this embodiment.
SrS-Ge 2Sb 2Te 5相变存储薄膜材料采用磁控溅射法制得。制备时通入高纯氩气作为溅射气体，溅射气压为0.5Pa，Ge 2Sb 2Te 5靶采用直流电源，电源功率为30W；SrS靶采用交流电源，电源功率为60W。具体制备工艺包括以下步骤： SrS-Ge 2 Sb 2 Te 5 phase change memory thin film material is produced by magnetron sputtering method. During preparation, high-purity argon was introduced as the sputtering gas, and the sputtering pressure was 0.5Pa. The Ge 2 Sb 2 Te 5 target used a DC power supply with a power supply of 30W; the SrS target used an AC power supply with a power supply of 60W. The specific preparation process includes the following steps:
1.选取尺寸为1cm×1cm的SiO 2/Si(晶格取向为100方向)基片，清洗表面、背面，去除灰尘颗粒、有机和无机杂质。 1. Select a SiO 2 /Si (lattice orientation is 100 direction) substrate with a size of 1cm×1cm, clean the surface and back to remove dust particles, organic and inorganic impurities.
a)将SiO 2/Si(晶格取向为100方向)基片放置在丙酮溶液中用40W功率的超声振动10分钟，去离子水冲洗。 a) Place the SiO 2 /Si (lattice orientation is 100 direction) substrate in an acetone solution, use ultrasonic vibration at 40W power for 10 minutes, and rinse with deionized water.
b)将丙酮处理后的基片在乙醇溶液中用40W功率的超声振动10分钟，去离子水冲洗，高纯N 2气吹干表面和背面，得到待溅射基片。 b) Vibrate the acetone-treated substrate with ultrasonic vibration at 40W power for 10 minutes in an ethanol solution, rinse with deionized water, and blow dry the surface and back with high-purity N2 gas to obtain the substrate to be sputtered.
2.采用直流交流电源共溅射方法制备SrS-Ge 2Sb 2Te 5相变存储薄膜材料。 2. Preparation of SrS-Ge 2 Sb 2 Te 5 phase change memory thin film material using DC AC power co-sputtering method.
a)放置好SrS靶材和Ge 2Sb 2Te 5合金靶材，其纯度均达到99.99％(原子百分比)，将其本底真空抽至10 -4Pa。 a) Place the SrS target material and Ge 2 Sb 2 Te 5 alloy target material, their purity reaches 99.99% (atomic percentage), and evacuate their background vacuum to 10 -4 Pa.
b)使用高纯Ar气作为溅射气体，将溅射气压调节至0.5Pa，靶材和基片距离为120mm。b) Use high-purity Ar gas as the sputtering gas, adjust the sputtering gas pressure to 0.5Pa, and the distance between the target and the substrate is 120mm.
c)设定直流电源功率为30W，交流电源功率为60W。c) Set the DC power supply power to 30W and the AC power supply power to 60W.
d)对SrS靶材和Ge 2Sb 2Te 5靶材进行10min预溅射，清洁靶材表面。 d) Pre-sputter the SrS target and Ge 2 Sb 2 Te 5 target for 10 minutes to clean the target surface.
e)预溅射完成后，开启挡板，溅射时间为6min时，制备的薄膜厚度为100nm左右。e) After the pre-sputtering is completed, open the baffle. When the sputtering time is 6 minutes, the thickness of the prepared film is about 100nm.
实施例2Example 2
本实施例中采用SrS掺杂的Ge 2Sb 2Te 5相变薄膜材料作为相变层材料制备存储器件，其中SrS掺杂的Ge 2Sb 2Te 5相变层采用磁控溅射法制得。制备时通入高纯氩气作为溅射气体，溅射气压为0.5Pa，Ge 2Sb 2Te 5靶采用直流电源，电源功率为30W；SrS靶采用交流电源，电源功率为60W。图2是本发明实施例2提供的基于晶格匹配的稳定面心立方结构化合物掺杂的Ge-Sb-Te体系相变材料的相变存储器制备流程图，由图可知，具体制备工艺包括以下步骤： In this embodiment, SrS-doped Ge 2 Sb 2 Te 5 phase change film material is used as the phase change layer material to prepare a memory device, wherein the SrS doped Ge 2 Sb 2 Te 5 phase change layer is produced by magnetron sputtering. During preparation, high-purity argon was introduced as the sputtering gas, and the sputtering pressure was 0.5Pa. The Ge 2 Sb 2 Te 5 target used a DC power supply with a power supply of 30W; the SrS target used an AC power supply with a power supply of 60W. Figure 2 is a flow chart for the preparation of a phase change memory based on the Ge-Sb-Te system phase change material doped with a stable face-centered cubic structure compound based on lattice matching provided in Embodiment 2 of the present invention. As can be seen from the figure, the specific preparation process includes the following step:
1.选取尺寸为1cm×1cm的SiO 2/Si(100)基片，清洗表面、背面，去除灰尘颗粒、有机和无机杂质。 1. Select a SiO 2 /Si(100) substrate with a size of 1cm×1cm, clean the surface and back, and remove dust particles, organic and inorganic impurities.
a)将SiO 2/Si(100)基片放置在丙酮溶液中用40W功率的超声振动10分 钟，去离子水冲洗。 a) Place the SiO 2 /Si(100) substrate in an acetone solution, use ultrasonic vibration with a power of 40W for 10 minutes, and rinse with deionized water.
b)将丙酮处理后的基片在乙醇溶液中用40W功率的超声振动10分钟，去离子水冲洗，高纯N 2气吹干表面和背面，得到待溅射基片。 b) Vibrate the acetone-treated substrate with ultrasonic vibration at 40W power for 10 minutes in an ethanol solution, rinse with deionized water, and blow dry the surface and back with high-purity N2 gas to obtain the substrate to be sputtered.
2.采用直流电源溅射方法制备100nm TiN底电极。2. Use DC power sputtering method to prepare 100nm TiN bottom electrode.
3.采用化学气相沉积法在TiN底电极上沉积100nm SiO 2绝缘层。 3. Deposit a 100nm SiO 2 insulating layer on the TiN bottom electrode using chemical vapor deposition.
4.通过电子束光刻刻蚀等工艺SiO 2绝缘层形成深度为100nm、直径为250nm的通孔。 4. Form a through hole with a depth of 100nm and a diameter of 250nm through the SiO 2 insulating layer through electron beam photolithography and other processes.
5.通过光刻工艺形成存储阵列。5. Form the memory array through photolithography process.
6.采用交流电源溅射方法在通孔内填充SrS-Ge 2Sb 2Te 5相变存储薄膜材料 6. Use AC power sputtering method to fill the through hole with SrS-Ge 2 Sb 2 Te 5 phase change memory film material
a)放置好SrS靶材和Ge 2Sb 2Te 5合金靶材，其纯度均达到99.99％(原子百分比)，将其本底真空抽至10 -4Pa。 a) Place the SrS target material and Ge 2 Sb 2 Te 5 alloy target material, their purity reaches 99.99% (atomic percentage), and evacuate their background vacuum to 10 -4 Pa.
b)使用高纯Ar气作为溅射气体，将溅射气压调节至0.5Pa，靶材和基片距离为120mm。b) Use high-purity Ar gas as the sputtering gas, adjust the sputtering gas pressure to 0.5Pa, and the distance between the target and the substrate is 120mm.
c)设定直流电源功率为30W，交流电源功率为60W。c) Set the DC power supply power to 30W and the AC power supply power to 60W.
d)对SrS靶材和Ge 2Sb 2Te 5靶材进行10min预溅射，清洁靶材表面。 d) Pre-sputter the SrS target and Ge 2 Sb 2 Te 5 target for 10 minutes to clean the target surface.
e)预溅射完成后，开启挡板，溅射时间为6min时，制备的相变层厚度为100nm左右。e) After the pre-sputtering is completed, open the baffle. When the sputtering time is 6 minutes, the thickness of the phase change layer prepared is about 100nm.
7.采用直流电源溅射方法制备100nm Pt顶电极，得到完整的基于SrS-Ge 2Sb 2Te 5相变层的相变存储器件阵列。 7. Use DC power sputtering method to prepare 100nm Pt top electrode to obtain a complete phase change memory device array based on SrS-Ge 2 Sb 2 Te 5 phase change layer.
实施例3Example 3
本实施例中制备的用于相变存储器件的晶格匹配的稳定面心立方结构化合物掺杂的Ge 1Sb 4Te 7相变薄膜材料化学通式为(MA) x(GST) 1-x，其中，MA代表TiN，GST代表Ge 1Sb 4Te 7，本实施例中x＝0.05。 The lattice-matched stable face-centered cubic structure compound-doped Ge 1 Sb 4 Te 7 phase change thin film material prepared in this embodiment has a general chemical formula of (MA) x (GST) 1-x , where MA represents TiN, GST represents Ge 1 Sb 4 Te 7 , and x=0.05 in this embodiment.
TiN-Ge 1Sb 4Te 7相变存储薄膜材料采用磁控溅射法制得。制备时通入高纯氩气作为溅射气体，溅射气压为0.5Pa，Ge 1Sb 4Te 7靶采用直流电源，电源功率 为30W。TiN靶采用直流电源，电源功率为20W。具体制备工艺包括以下步骤： TiN-Ge 1 Sb 4 Te 7 phase change memory thin film material is produced by magnetron sputtering method. During preparation, high-purity argon gas was introduced as the sputtering gas, the sputtering pressure was 0.5Pa, and the Ge 1 Sb 4 Te 7 target used a DC power supply with a power supply of 30W. The TiN target uses a DC power supply with a power supply of 20W. The specific preparation process includes the following steps:
1.选取尺寸为1cm×1cm的SiO 2/Si(100)基片，清洗表面、背面，去除灰尘颗粒、有机和无机杂质。 1. Select a SiO 2 /Si(100) substrate with a size of 1cm×1cm, clean the surface and back, and remove dust particles, organic and inorganic impurities.
a)将SiO 2/Si(100)基片放置在丙酮溶液中用40W功率的超声振动10分钟，去离子水冲洗。 a) Place the SiO 2 /Si(100) substrate in an acetone solution, use ultrasonic vibration with a power of 40W for 10 minutes, and rinse with deionized water.
b)将丙酮处理后的基片在乙醇溶液中用40W功率的超声振动10分钟，去离子水冲洗，高纯N 2气吹干表面和背面，得到待溅射基片。 b) Vibrate the acetone-treated substrate with ultrasonic vibration at 40W power for 10 minutes in an ethanol solution, rinse with deionized water, and blow dry the surface and back with high-purity N2 gas to obtain the substrate to be sputtered.
2.采用直流交流电源共溅射方法制备TiN-Ge 1Sb 4Te 7相变存储薄膜材料。 2. Preparation of TiN-Ge 1 Sb 4 Te 7 phase change memory thin film material using DC AC power co-sputtering method.
a)放置好TiN靶材和Ge 1Sb 4Te 7合金靶材，其纯度均达到99.99％(原子百分比)，将其本底真空抽至10 -4Pa。 a) Place the TiN target and Ge 1 Sb 4 Te 7 alloy target, their purity reaches 99.99% (atomic percent), and evacuate their background vacuum to 10 -4 Pa.
b)使用高纯Ar气作为溅射气体，将溅射气压调节至0.5Pa，靶材和基片距离为120mm。b) Use high-purity Ar gas as the sputtering gas, adjust the sputtering gas pressure to 0.5Pa, and the distance between the target and the substrate is 120mm.
c)设定Ge 1Sb 4Te 7靶材直流电源功率为30W，TiN靶材直流电源功率为20W。 c) Set the DC power supply power of the Ge 1 Sb 4 Te 7 target to 30W and the DC power supply of the TiN target to 20W.
d)对TiN靶材和Ge1Sb4Te7靶材进行10min预溅射，清洁靶材表面。d) Pre-sputter the TiN target and Ge1Sb4Te7 target for 10 minutes to clean the target surface.
e)预溅射完成后，开启挡板，溅射时间为6min时，制备的薄膜厚度为100nm左右。e) After the pre-sputtering is completed, open the baffle. When the sputtering time is 6 minutes, the thickness of the prepared film is about 100nm.
实施例4Example 4
本实施例中采用TiN掺杂的Ge 1Sb 4Te 7相变薄膜材料作为相变层材料制备存储器件，其中TiN掺杂的Ge 1Sb 4Te 7相变层采用磁控溅射法制得。制备时通入高纯氩气作为溅射气体，溅射气压为0.5Pa，Ge 1Sb 4Te 7靶采用直流电源，电源功率为30W；TiN靶采用直流电源，电源功率为20W。具体制备工艺包括以下步骤： In this embodiment, TiN-doped Ge 1 Sb 4 Te 7 phase change film material is used as the phase change layer material to prepare a memory device, in which the TiN-doped Ge 1 Sb 4 Te 7 phase change layer is produced by magnetron sputtering. During preparation, high-purity argon was introduced as the sputtering gas, and the sputtering pressure was 0.5Pa. The Ge 1 Sb 4 Te 7 target used a DC power supply with a power supply of 30W; the TiN target used a DC power supply with a power supply of 20W. The specific preparation process includes the following steps:
1.选取尺寸为1cm×1cm的SiO 2/Si(100)基片，清洗表面、背面，去除 灰尘颗粒、有机和无机杂质。 1. Select a SiO 2 /Si(100) substrate with a size of 1cm×1cm, clean the surface and back, and remove dust particles, organic and inorganic impurities.
a)将SiO 2/Si(100)基片放置在丙酮溶液中用40W功率的超声振动10分钟，去离子水冲洗。 a) Place the SiO 2 /Si(100) substrate in an acetone solution, use ultrasonic vibration with a power of 40W for 10 minutes, and rinse with deionized water.
b)将丙酮处理后的基片在乙醇溶液中用40W功率的超声振动10分钟，去离子水冲洗，高纯N 2气吹干表面和背面，得到待溅射基片。 b) Vibrate the acetone-treated substrate with ultrasonic vibration at 40W power for 10 minutes in an ethanol solution, rinse with deionized water, and blow dry the surface and back with high-purity N2 gas to obtain the substrate to be sputtered.
2.采用直流电源溅射方法制备100nm TiN底电极。2. Use DC power sputtering method to prepare 100nm TiN bottom electrode.
3.采用化学气相沉积法在TiN底电极上沉积100nm SiO 2绝缘层。 3. Deposit a 100nm SiO 2 insulating layer on the TiN bottom electrode using chemical vapor deposition.
4.通过电子束光刻刻蚀等工艺在SiO 2绝缘层形成深度为100nm、直径为250nm的通孔。 4. Form a through hole with a depth of 100nm and a diameter of 250nm in the SiO 2 insulation layer through electron beam photolithography and other processes.
5.通过光刻工艺形成存储阵列。5. Form the memory array through photolithography process.
6.采用交流电源溅射方法在通孔内填充TiN-Ge 1Sb 4Te 7相变存储薄膜材料 6. Use AC power sputtering method to fill the through hole with TiN-Ge 1 Sb 4 Te 7 phase change memory film material
a)放置好TiN靶材和Ge 1Sb 4Te 7合金靶材，其纯度均达到99.99％(原子百分比)，将其本底真空抽至10 -4Pa。 a) Place the TiN target and Ge 1 Sb 4 Te 7 alloy target, their purity reaches 99.99% (atomic percent), and evacuate their background vacuum to 10 -4 Pa.
b)使用高纯Ar气作为溅射气体，将溅射气压调节至0.5Pa，靶材和基片距离为120mm。b) Use high-purity Ar gas as the sputtering gas, adjust the sputtering gas pressure to 0.5Pa, and the distance between the target and the substrate is 120mm.
c)设定Ge 1Sb 4Te 7靶材直流电源功率为30W，TiN靶材直流电源功率为20W。 c) Set the DC power supply power of the Ge 1 Sb 4 Te 7 target to 30W and the DC power supply of the TiN target to 20W.
d)对TiN靶材和Ge 1Sb 4Te 7靶材进行10min预溅射，清洁靶材表面。 d) Pre-sputter the TiN target and Ge 1 Sb 4 Te 7 target for 10 minutes to clean the target surface.
e)预溅射完成后，开启挡板，溅射时间为6min时，制备的相变层厚度为100nm左右。e) After the pre-sputtering is completed, open the baffle. When the sputtering time is 6 minutes, the thickness of the phase change layer prepared is about 100nm.
7.采用直流电源溅射方法制备100nm Pt顶电极，得到完整的基于TiN-Ge 1Sb 4Te 7相变层的相变存储器件阵列。 7. Use DC power sputtering method to prepare 100nm Pt top electrode to obtain a complete phase change memory device array based on TiN-Ge 1 Sb 4 Te 7 phase change layer.
对比例1Comparative example 1
本对比例中采用纯Ge 1Sb 4Te 7相变薄膜材料作为相变层材料制备存储器件， 其中，纯Ge 1Sb 4Te 7相变层采用磁控溅射法制得。制备时通入高纯氩气作为溅射气体，溅射气压为0.5Pa，Ge 1Sb 4Te 7靶采用直流电源，电源功率为30W。具体制备工艺包括以下步骤： In this comparative example, pure Ge 1 Sb 4 Te 7 phase change film material is used as the phase change layer material to prepare a memory device. The pure Ge 1 Sb 4 Te 7 phase change layer is produced by magnetron sputtering. During preparation, high-purity argon gas was introduced as the sputtering gas, the sputtering pressure was 0.5Pa, and the Ge 1 Sb 4 Te 7 target used a DC power supply with a power supply of 30W. The specific preparation process includes the following steps:
1.选取尺寸为1cm×1cm的SiO 2/Si(100)基片，清洗表面、背面，去除灰尘颗粒、有机和无机杂质。 1. Select a SiO 2 /Si(100) substrate with a size of 1cm×1cm, clean the surface and back, and remove dust particles, organic and inorganic impurities.
a)将SiO 2/Si(100)基片放置在丙酮溶液中用40W功率的超声振动10分钟，去离子水冲洗。 a) Place the SiO 2 /Si(100) substrate in an acetone solution, use ultrasonic vibration with a power of 40W for 10 minutes, and rinse with deionized water.
b)将丙酮处理后的基片在乙醇溶液中用40W功率的超声振动10分钟，去离子水冲洗，高纯N 2气吹干表面和背面，得到待溅射基片。 b) Vibrate the acetone-treated substrate with ultrasonic vibration at 40W power for 10 minutes in an ethanol solution, rinse with deionized water, and blow dry the surface and back with high-purity N2 gas to obtain the substrate to be sputtered.
2.采用直流电源溅射方法制备100nm TiN底电极。2. Use DC power sputtering method to prepare 100nm TiN bottom electrode.
3.采用化学气相沉积法在TiN底电极上沉积100nm SiO 2绝缘层。 3. Deposit a 100nm SiO 2 insulating layer on the TiN bottom electrode using chemical vapor deposition.
4.通过电子束光刻刻蚀等工艺在SiO 2绝缘层形成深度为100nm、直径为250nm的通孔。 4. Form a through hole with a depth of 100nm and a diameter of 250nm in the SiO 2 insulation layer through electron beam photolithography and other processes.
5.通过光刻工艺形成存储阵列。5. Form the memory array through photolithography process.
6.采用交流电源溅射方法在通孔内填充Ge 1Sb 4Te 7相变存储薄膜材料。 6. Use AC power sputtering method to fill the through hole with Ge 1 Sb 4 Te 7 phase change memory film material.
a)放置好Ge 1Sb 4Te 7合金靶材，其纯度均达到99.99％(原子百分比)，将其本底真空抽至10 -4Pa。 a) Place the Ge 1 Sb 4 Te 7 alloy target, its purity reaches 99.99% (atomic percent), and evacuate its background vacuum to 10 -4 Pa.
b)使用高纯Ar气作为溅射气体，将溅射气压调节至0.5Pa，靶材和基片距离为120mm。b) Use high-purity Ar gas as the sputtering gas, adjust the sputtering gas pressure to 0.5Pa, and the distance between the target and the substrate is 120mm.
c)设定Ge 1Sb 4Te 7靶材直流电源功率为30W。 c) Set the Ge 1 Sb 4 Te 7 target DC power supply to 30W.
d)对Ge 1Sb 4Te 7靶材进行10min预溅射，清洁靶材表面。 d) Pre-sputter the Ge 1 Sb 4 Te 7 target for 10 minutes and clean the target surface.
e)预溅射完成后，开启挡板，溅射时间为6min时，制备的相变层厚度为100nm左右。e) After the pre-sputtering is completed, open the baffle. When the sputtering time is 6 minutes, the thickness of the phase change layer prepared is about 100nm.
7.采用直流电源溅射方法制备100nm Pt顶电极，得到完整的基于Ge 1Sb 4Te 7相变层的相变存储器件阵列。 7. Use DC power sputtering method to prepare 100nm Pt top electrode to obtain a complete phase change memory device array based on Ge 1 Sb 4 Te 7 phase change layer.
将上述实施例4和对比例1中的基于TiN-Ge 1Sb 4Te 7相变存储器件和纯Ge 1Sb 4Te 7相变存储器件分别进行电学特性测试。 The TiN-Ge 1 Sb 4 Te 7 phase change memory device and the pure Ge 1 Sb 4 Te 7 phase change memory device in the above Example 4 and Comparative Example 1 were respectively tested for electrical characteristics.
图3是实施例4和对比例1中两个不同器件在8ns固定脉冲宽度下的R-V测试图，反映的是器件SET速度性能，由图可知，明显地，基于TiN-Ge 1Sb 4Te 7的相变存储器在8ns脉冲宽度下可以成功从高阻值状态SET至低阻值状态；而基于纯Ge 1Sb 4Te 7的相变存储器件脉冲幅值增加到2.4V都不能成功SET器件。说明基于晶格匹配化合物掺杂的TiN-Ge 1Sb 4Te 7相变存储器件操作速度得到大幅提升。 Figure 3 is an RV test chart of two different devices in Example 4 and Comparative Example 1 under a fixed pulse width of 8ns, which reflects the SET speed performance of the device. As can be seen from the figure, it is obvious that based on TiN-Ge 1 Sb 4 Te 7 The phase change memory can successfully SET from the high resistance state to the low resistance state under an 8ns pulse width; while the phase change memory device based on pure Ge 1 Sb 4 Te 7 cannot successfully SET the device even if the pulse amplitude is increased to 2.4V. This shows that the operation speed of TiN-Ge 1 Sb 4 Te 7 phase change memory devices based on lattice matching compound doping has been greatly improved.
图4和图5是实施例4和对比例1中两个不同器件在20ns固定脉冲宽度下的循环特性测试图。图4中基于TiN-Ge 1Sb 4Te 7的相变存储器件最大循环次数接近E9次，而图5中基于纯Ge 1Sb 4Te 7的相变存储器件最大循环次数为3.5E6次。验证了稳定面心立方结构化合物掺杂可以提高Ge-Sb-Te体系相变存储器件的循环性能。 Figures 4 and 5 are cycle characteristic test charts of two different devices in Example 4 and Comparative Example 1 under a fixed pulse width of 20 ns. The maximum cycle number of the phase change memory device based on TiN-Ge 1 Sb 4 Te 7 in Figure 4 is close to E9 times, while the maximum cycle number of the phase change memory device based on pure Ge 1 Sb 4 Te 7 in Figure 5 is 3.5E6 times. It has been verified that doping with stable face-centered cubic structure compounds can improve the cycle performance of Ge-Sb-Te system phase change memory devices.
利用Materials Studio软件对基于晶格匹配化合物掺杂的TiN-Ge 1Sb 4Te 7相变存储薄膜材料进行建模，利用第一性原理模拟模型中的原子在600K温度下的运动情况。图6是利用第一性原理模拟基于晶格匹配的稳定面心立方结构化合物掺杂的Ge-Sb-Te体系相变材料模型中的原子在600K温度下的运动60ps后结构位置示意图，可以发现掺入的TiN在Ge 1Sb 4Te 7体系中仍然保持化合状态稳定存在，为体系提供稳定的结构匹配的形核点。 Materials Studio software was used to model the TiN-Ge 1 Sb 4 Te 7 phase change memory thin film material doped with lattice matching compounds, and first principles were used to simulate the movement of atoms in the model at a temperature of 600K. Figure 6 is a schematic diagram of the structural position after 60ps of simulating the movement of atoms at a temperature of 600K in the Ge-Sb-Te system phase change material model doped with a stable face-centered cubic structure compound based on lattice matching using first principles. It can be found The incorporated TiN still maintains a stable compound state in the Ge 1 Sb 4 Te 7 system, providing a stable structurally matched nucleation point for the system.
以上实施例中，面心立方结构的高熔点化合物MA选用了SrS和TiN，Ge-Sb-Te体系相变材料选用Ge 2Sb 2Te 5和Ge 1Sb 4Te 7，实际上，Ge-Sb-Te体系相变材料还可以选用Ge 1Sb 2Te 4，面心立方结构的高熔点化合物MA还可以选用CaSe、CaS、ScN、ScBi和HfN的一种或者多种，比如，CaSe-Ge 1Sb 2Te 4，CaS-Ge 2Sb 2Te 5，ScN-Ge 1Sb 4Te 7，ScBi-Ge 2Sb 2Te 5和HfN-Ge 2Sb 2Te 5等。 In the above examples, SrS and TiN were selected as the high melting point compound MA with a face-centered cubic structure, and Ge 2 Sb 2 Te 5 and Ge 1 Sb 4 Te 7 were selected as the Ge-Sb-Te system phase change material. In fact, Ge-Sb The -Te system phase change material can also choose Ge 1 Sb 2 Te 4 , and the high melting point compound MA with a face-centered cubic structure can also choose one or more of CaSe, CaS, ScN, ScBi and HfN, such as CaSe-Ge 1 Sb 2 Te 4 , CaS-Ge 2 Sb 2 Te 5 , ScN-Ge 1 Sb 4 Te 7 , ScBi-Ge 2 Sb 2 Te 5 and HfN-Ge 2 Sb 2 Te 5 , etc.
与现有技术中未经晶格匹配的稳定面心立方结构化合物组织调控的Ge- Sb-Te体系相变存储材料相比，本发明的基于晶格匹配的稳定面心立方结构化合物掺杂的Ge-Sb-Te体系相变材料中，利用掺杂的晶格匹配的稳定面心立方结构化合物组织对Ge-Sb-Te体系相变材料进行调控，在Ge-Sb-Te体系相变层形成稳定的形核点，其与Ge-Sb-Te体系晶格匹配的面心立方结构提供了可靠的晶化模板，加速晶化；稳定的面心立方结构化合物中的元素几乎不与Ge-Sb-Te体系相变材料中的元素成键，因此不发生替位或者间隙掺杂，保证相变材料晶格结构完整，从而提高器件的循环性能；此外，稳定的面心立方结构化合物易以非晶形式均与分布于晶态相变材料的晶界处，减小晶粒尺寸，阻止相变元素的原子迁移，提高器件的稳定性，最终全方位地实现改善器件的综合性能。Compared with the Ge-Sb-Te system phase change memory materials in the prior art that have no lattice-matched stable face-centered cubic structure compound structure control, the present invention is doped with a stable face-centered cubic structure compound based on lattice matching. In the Ge-Sb-Te system phase change material, the doped lattice-matched stable face-centered cubic structure compound structure is used to regulate the Ge-Sb-Te system phase change material, and the Ge-Sb-Te system phase change layer is formed Stable nucleation point, its face-centered cubic structure that matches the lattice of the Ge-Sb-Te system provides a reliable crystallization template and accelerates crystallization; the elements in the stable face-centered cubic structure compound have almost no interaction with Ge-Sb The elements in the -Te system phase change materials form bonds, so no substitution or interstitial doping occurs, ensuring the integrity of the lattice structure of the phase change material, thus improving the cycle performance of the device; in addition, stable face-centered cubic structure compounds are easy to be The crystal forms are distributed at the grain boundaries of crystalline phase change materials, reducing the grain size, preventing the atomic migration of phase change elements, improving the stability of the device, and ultimately improving the overall performance of the device in an all-round way.
本领域的技术人员容易理解，以上所述仅为本发明的较佳实施例而已，并不用以限制本发明，凡在本发明的精神和原则之内所作的任何修改、等同替换和改进等，均应包含在本发明的保护范围之内。It is easy for those skilled in the art to understand that the above descriptions are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements, etc., made within the spirit and principles of the present invention, All should be included in the protection scope of the present invention.

Claims (8)

  1. 一种基于晶格匹配的化合物掺杂Ge-Sb-Te相变材料，其特征在于，其化学式为(MA) x(Ge-Sb-Te) 1-x，其中，MA为面心立方结构的高熔点化合物，其熔点高于900K，面心立方结构的高熔点化合物MA与Ge-Sb-Te体系晶格匹配，x代表面心立方结构化合物分子数占总分子数的百分比，0<x<10％，所述MA包括SrS、CaSe、CaS、ScN、ScBi、TiN和HfN的一种或者多种。 A compound-doped Ge-Sb-Te phase change material based on lattice matching, characterized in that its chemical formula is (MA) x (Ge-Sb-Te) 1-x , where MA is a face-centered cubic structure A high-melting-point compound with a melting point higher than 900K. The high-melting-point compound MA with a face-centered cubic structure matches the lattice of the Ge-Sb-Te system. x represents the percentage of the number of molecules of the face-centered cubic structure compound in the total number of molecules, 0<x< 10%, the MA includes one or more of SrS, CaSe, CaS, ScN, ScBi, TiN and HfN.
  2. 如权利要求1所述的一种基于晶格匹配的化合物掺杂Ge-Sb-Te相变材料，其特征在于，面心立方结构的高熔点化合物MA掺杂在Ge-Sb-Te体系相变层形成稳定的形核点，晶化过程中用作Ge-Sb-Te体系的晶化模板，能加速Ge-Sb-Te体系晶化。A compound-doped Ge-Sb-Te phase change material based on lattice matching according to claim 1, characterized in that the high melting point compound MA with a face-centered cubic structure is doped in the Ge-Sb-Te system phase change material. The layer forms a stable nucleation point and is used as a crystallization template for the Ge-Sb-Te system during the crystallization process, which can accelerate the crystallization of the Ge-Sb-Te system.
  3. 如权利要求1所述的一种基于晶格匹配的化合物掺杂Ge-Sb-Te相变材料，其特征在于，面心立方结构的高熔点化合物MA中的M元素和A元素与Ge-Sb-Te体系相变材料中的元素相互独立，无键合，无替位和间隙掺杂，从而能保证相变材料晶化时晶格结构完整，最终能提高器件的循环性能。A compound-doped Ge-Sb-Te phase change material based on lattice matching according to claim 1, characterized in that the M element and the A element in the face-centered cubic structure high melting point compound MA are different from the Ge-Sb The elements in the -Te system phase change materials are independent of each other, without bonding, substitution and interstitial doping, thus ensuring the integrity of the lattice structure when the phase change material is crystallized, and ultimately improving the cycle performance of the device.
  4. 如权利要求1-3之一所述的一种基于晶格匹配的化合物掺杂Ge-Sb-Te相变材料，其特征在于，面心立方结构的高熔点化合物MA以非晶形式均匀分布于晶态Ge-Sb-Te体系相变材料的晶界处，能用于减小Ge-Sb-Te体系相变材料的晶粒尺寸，阻碍相变元素的原子迁移，最终能提高器件的可靠性。A compound-doped Ge-Sb-Te phase change material based on lattice matching according to one of claims 1-3, characterized in that the high melting point compound MA with a face-centered cubic structure is evenly distributed in an amorphous form. The grain boundaries of the crystalline Ge-Sb-Te system phase change material can be used to reduce the grain size of the Ge-Sb-Te system phase change material, hinder the atomic migration of phase change elements, and ultimately improve the reliability of the device. .
  5. 如权利要求4所述的一种基于晶格匹配的化合物掺杂Ge-Sb-Te相变材料，其特征在于，所述Ge-Sb-Te体系相变材料选自Ge 2Sb 2Te 5、Ge 1Sb 2Te 4和Ge 1Sb 4Te 7中的一种或者多种。 A compound-doped Ge-Sb-Te phase change material based on lattice matching according to claim 4, characterized in that the Ge-Sb-Te system phase change material is selected from the group consisting of Ge 2 Sb 2 Te 5 , One or more of Ge 1 Sb 2 Te 4 and Ge 1 Sb 4 Te 7 .
  6. 如权利要求5所述的一种基于晶格匹配的化合物掺杂Ge-Sb-Te相变材料，其特征在于，采用磁控溅射法、化学气相沉积法、原子层沉积法、电镀法或/和电子束蒸发法制备获得。A compound-doped Ge-Sb-Te phase change material based on lattice matching according to claim 5, characterized in that the magnetron sputtering method, chemical vapor deposition method, atomic layer deposition method, electroplating method or / and prepared by electron beam evaporation.
  7. 如权利要求5所述的一种基于晶格匹配的化合物掺杂Ge-Sb-Te相变材 料，其特征在于，采用Ge-Sb-Te体系靶和MA靶共溅射方式制备获得。A compound-doped Ge-Sb-Te phase change material based on lattice matching according to claim 5, characterized in that it is prepared by co-sputtering of a Ge-Sb-Te system target and an MA target.
  8. 一种相变材料的相变存储器，其特征在于，其包括依次层叠的底电极、隔离层、相变存储材料薄膜层和顶电极，其中，相变存储材料薄膜层采用权利要求1-7之一所述的基于晶格匹配的化合物掺杂Ge-Sb-Te相变材料。A phase change memory of phase change material, characterized in that it includes a bottom electrode, an isolation layer, a phase change storage material thin film layer and a top electrode stacked in sequence, wherein the phase change storage material thin film layer adopts the method of claims 1-7 1. The compound doped Ge-Sb-Te phase change material based on lattice matching.
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