Electro-thermal analysis method and system for phase change memory

Abstract

The application provides an electrothermal analysis method and system for a phase change memory, comprising: proportionally dividing a phase change layer of the phase change memory into a plurality of sub-regions with the same volume; determining a doping proportion of the doping material, and calculating the number of sub-regions occupied by the doping material according to the doping proportion; randomly selecting a corresponding number of sub-regions to fill the doping material according to the calculated number of sub-regions, and filling the remaining sub-regions with a phase change material; determining electrothermal parameters of the doping material, the phase change material, an upper electrode, a lower electrode and an insulating and heat-insulating layer; determining boundary conditions and current parameters of the phase change memory; the boundary conditions are thermal boundary conditions, and the current parameters are RESET / SET current pulses; and combining the above-mentioned electrothermal parameters, current parameters and boundary conditions to perform thermal simulation analysis on the phase change memory, so as to determine the temperature field distribution inside the phase change memory after the phase change memory receives the RESET / SET current pulses, and further analyze the phase change region inside the phase change memory and the RESET / SET power consumption.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of microelectronic devices and storage technology, and more particularly, to a method and system for electro-thermal analysis of phase change memory. BACKGROUND

[0002] Human activities cannot be separated from information transmission and storage. The storage capacity of the current memory is getting higher and higher. The traditional DRAM has the characteristics of fast erasing and writing speed, long service life, and volatility. The FLASH has the characteristics of low cost, non-volatility, and slow erasing and writing speed. Users hope that the memory has the advantages of high speed and long service life of DRAM and low cost and non-volatility of FLASH, so the concept of phase change memory is proposed. Phase change memory is considered to be one of the next generation of non-volatile storage devices that can replace DRAM and FLASH, and has the characteristics of fast storage speed, high reliability, and long service life.

[0003] Phase change memory is a non-volatile memory based on phase change material (one or more chalcogenide compounds), which mainly uses the Joule heat of current to realize the conversion between the crystalline state and the amorphous state of the material to achieve storage. In phase change memory, the phase change material is the key. The resistance of this material is high in the amorphous state and low in the crystalline state, and we use the difference between the high and low resistance to realize the information storage of "0" and "1". A large amplitude and short duration electric pulse is applied to the crystalline material. Because of the large amplitude and high energy, the material can quickly reach the melting temperature and lose the crystalline structure, but because of the short duration and a rapid cooling process, the atoms have not had time to rearrange, so the material realizes the conversion from the crystalline state to the amorphous state. A medium amplitude and long duration electric pulse is applied to the amorphous material. The energy of the pulse can make the material reach the crystallization temperature and be lower than the melting temperature. Within the duration of the pulse, the atoms can rearrange and crystallize, realizing the conversion of the material from the amorphous state to the crystalline state.

[0004] In the design of phase change memory, it is usually necessary to use finite element analysis method to simulate its electro-thermal process. The actual device three-dimensional model is continuous, it seems impossible to analyze it, but if they are divided into finite elements, it can be easily analyzed in the temperature field of electro-thermal process. This method is finite element analysis. The advantage of finite element analysis is that it defines functions on simple geometric element domains and ignores more complex boundary conditions. Common finite element analysis software includes COMSOL Multiphysic, ANSYS, FEPG, etc. Among them, COMSOL is a multi-physical field coupling analysis tool, which explains many physical phenomena by solving partial differential equations, and its range covers heat conduction, fluid flow, electromagnetic field and even structural mechanics, etc. COMSOL is widely used in simulation of various fields due to its excellent multi-physical field two-way direct coupling analysis capability and high-speed effective computing capability.

[0005] Taking COMSOL software as an example, the steps of finite element analysis software analysis problem are as follows: first, a geometric model needs to be built. Then, material parameters are set. Then, the physical field is set, that is, the boundary conditions are set. The boundary conditions include the basic thermal equation, the current continuity equation and the current conservation equation. Before calculation, mesh division is needed to determine the calculation precision. Finally, the solution is solved and the data is processed, and the results are analyzed. The most important thing in the parameter setting process is the setting of the electrical conductivity and thermal conductivity of the phase change material. At present, the finite element electro-thermal simulation of phase change material and phase change memory device is only limited to intrinsic undoped chalcogenide materials, because after doping, the electrical conductivity and thermal conductivity of the phase change material and other electro-thermal parameters will inevitably change, and with the change of doping concentration and doping substance, these electro-thermal parameters will also change, which will ultimately affect the simulation results of the temperature field of the electro-thermal process. In order to obtain more accurate simulation results, it is necessary to measure the electro-thermal parameters of the doped phase change material through experiment, but the electro-thermal parameter measurement technology of thin film is not perfect so far, it needs a more complex process flow and test flow, and the preparation process of the test sample has a great influence on the test accuracy of the doped material parameters, it is difficult to obtain reliable electro-thermal parameters of the doped chalcogenide thin film, therefore, the finite element electro-thermal simulation of phase change material and phase change memory device is only limited to undoped phase change material.

[0006] On the other hand, doping is an effective method to improve the performance of phase change memory material and device, therefore, developing a finite element electro-thermal analysis method suitable for doped phase change material and its memory device has important significance for the design and analysis of doped phase change material and device. SUMMARY

[0007] In view of the defects of the prior art, the present application aims to provide an electro-thermal analysis method and system for phase change memory, aiming to solve the problem that the finite element electro-thermal simulation of the phase change memory device is limited to undoped phase change materials, and the electro-thermal parameters of compound-doped phase change materials are difficult to obtain, so that the existing compound-doped phase change memory cannot perform finite element electro-thermal simulation.

[0008] To achieve the above-mentioned purpose, in a first aspect, the present application provides an electro-thermal analysis method for phase change memory, the phase change memory comprising: an upper electrode, a phase change layer, an insulating and heat-insulating layer, and a lower electrode, the upper electrode being arranged on the upper surface of the phase change layer, the lower electrode being arranged on the lower surface of the phase change layer, and the insulating and heat-insulating layer being arranged on both sides of the phase change layer; characterized in that the phase change layer comprises a phase change material and a doping material, the phase change material and the doping material are independent of each other and crystallize respectively during the heating process of the phase change layer, and the doping material does not react with the phase change material; the electro-thermal analysis method comprises the following steps:

[0009] The phase change layer is equally divided into a plurality of sub-regions of the same volume;

[0010] The doping ratio of the doping material is determined, and the number of sub-regions occupied by the doping material is calculated according to the doping ratio;

[0011] A corresponding number of sub-regions are randomly selected according to the calculated number of sub-regions to fill the doping material, and the remaining sub-regions are filled with the phase change material;

[0012] The electro-thermal parameters of the doping material, the phase change material, the upper electrode, the lower electrode, and the insulating and heat-insulating layer are determined;

[0013] The boundary conditions and the current parameters of the phase change memory are determined; the boundary conditions are thermal boundary conditions, and the current parameters are RESET current pulses or SET current pulses;

[0014] The phase change memory is subjected to thermal simulation analysis in combination with the above-mentioned electro-thermal parameters, current parameters, and boundary conditions to determine the temperature field distribution inside the phase change memory after it receives the RESET current pulse or the SET current pulse, so as to further analyze the phase change region and the power consumption inside the phase change memory according to the temperature field distribution; when the phase change memory receives the RESET current pulse, the power consumption is the RESET power consumption, and when the phase change memory receives the SET current pulse, the power consumption is the SET power consumption.

[0015] In an optional example, the phase change layer is equally divided into a plurality of sub-regions of the same volume, specifically:

[0016] The phase change layer is spatially divided to obtain a plurality of sub-regions of equal volume.

[0017] In an optional example, the more the number of the sub-regions, the more accurate the electro-thermal analysis result of the phase change memory.

[0018] In an optional example, the electro-thermal parameters include material density, electrical conductivity and thermal conductivity.

[0019] In an optional example, the phase change material is any one of Sb single element, Ge-Te binary compound, Ge-Sb binary compound, Sb-Te binary compound, Bi-Te binary compound, In-Se binary compound, Ge-Sb-Te ternary compound, Ge-Bi-Te ternary compound and Ge-Sb-Bi-Te quaternary compound.

[0020] In an optional example, the doping material is a compound that is stable in structure and does not chemically react with the phase change material during the heating process of the phase change layer.

[0021] In a second aspect, the present application provides an electro-thermal analysis system of a phase change memory, the phase change memory comprising: an upper electrode, a phase change layer, an insulating and heat-insulating layer and a lower electrode, the upper electrode being disposed on the upper surface of the phase change layer, the lower electrode being disposed on the lower surface of the phase change layer, and the insulating and heat-insulating layer being disposed on both sides of the phase change layer; characterized in that the phase change layer comprises a phase change material and a doping material, the phase change material and the doping material being independent of each other and crystallizing separately during the heating process of the phase change layer, and the doping material does not chemically react with the phase change material; and the electro-thermal analysis system comprising:

[0022] a phase change layer dividing unit for dividing the phase change layer into a plurality of sub-regions with the same volume in equal proportions;

[0023] a phase change layer filling unit for determining a doping proportion of the doping material, calculating the number of sub-regions occupied by the doping material according to the doping proportion, and filling the corresponding number of sub-regions with the doping material and the remaining sub-regions with the phase change material according to the calculated number of sub-regions;

[0024] a parameter determining unit for determining the electro-thermal parameters of the doping material, the phase change material, the upper electrode, the lower electrode and the insulating and heat-insulating layer, and determining the boundary conditions and current parameters of the phase change memory; the boundary conditions being thermal boundary conditions, and the current parameters being RESET current pulses or SET current pulses;

[0025] An electrothermal analysis unit is configured to perform thermal simulation analysis on the phase change memory in combination with the above-mentioned electrothermal parameters, current parameters and boundary conditions, to determine the temperature field distribution inside the phase change memory after the phase change memory receives a RESET current pulse or a SET current pulse, so as to further analyze the phase change region inside the phase change memory and power consumption according to the temperature field distribution; when the phase change memory receives the RESET current pulse, the power consumption is RESET power consumption; and when the phase change memory receives the SET current pulse, the power consumption is SET power consumption.

[0026] In an optional example, the phase change layer dividing unit divides the phase change layer into multiple sub-regions with equal volumes in a proportional manner, specifically, the phase change layer is spatially divided to obtain multiple sub-regions with equal volumes.

[0027] Overall, compared with the prior art, the above technical solutions conceived by the present application have the following beneficial effects:

[0028] The present application provides a kind of electrothermal analysis method and system of phase change memory, compound doped phase change material in the present application, require compound structure stable in phase change process, neither decompose, also can not melt, also can not occur chemical reaction with any one of chalcogen elements in phase change material. Compared with the method of directly using compound doped phase change material whole film electrothermal parameter to carry out electrothermal analysis, the electrothermal analysis method of the present application simplifies the acquisition process of electrothermal parameter, only needs to obtain the electrothermal parameter of doped material and phase change material respectively.Doped material and the electrothermal parameter of phase change material can be obtained by reading literature or relevant material manual.

[0029] The present application provides a kind of electrothermal analysis method and system of phase change memory, compared with the method of directly using compound doped phase change material whole film electrothermal parameter to carry out electrothermal analysis, the electrothermal analysis method of the present application can more directly observe phase change region area, RESET / SET power consumption.

[0030] The present application provides a kind of electrothermal analysis method and system of phase change memory, compared with the method of directly using compound doped phase change material whole film electrothermal parameter to carry out electrothermal analysis, the electrothermal analysis method of the present application is not influenced by process and test technology, and the more the number of square division is, the higher the accuracy of temperature field simulation calculation is. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 The electrothermal analysis method flow chart of phase change memory provided for the embodiment of the present application;

[0032] Figure 2 The implementation flow chart of the electrothermal analysis method of compound doped phase change material provided for the embodiment of the present application;

[0033] Figure 3 A cross-sectional view of a model structure of a phase change memory cell used in Example 1 of the present application;

[0034] Figure 4 A (TiTe2) phase change memory cell used in Example 2 of the present application 0.1 (Sb2Te3) phase change memory cell used in Example 2 of the present application 0.9 A two-dimensional model of a phase change memory cell;

[0035] Figure 5 A (TiTe2) phase change memory cell used in Example 3 of the present application 0.1 (Sb2Te3) phase change memory cell used in Example 3 of the present application 0.9 A temperature field distribution map of a thermal simulation result of a phase change memory cell;

[0036] Figure 6 A (TiTe2) phase change memory cell used in Example 3 of the present application 0.4 (Sb2Te3) phase change memory cell used in Example 3 of the present application 0.6 A two-dimensional model of a phase change memory cell;

[0037] Figure 7 A (TiTe2) phase change memory cell used in Example 3 of the present application 0.4 (Sb2Te3) phase change memory cell used in Example 3 of the present application 0.6 A temperature field distribution map of a thermal simulation result of a phase change memory cell;

[0038] Figure 8 A two-dimensional model of a Sb2Te3 phase change memory cell used in a comparative example of the present application;

[0039] Figure 9 A temperature field distribution map of a thermal simulation result of a Sb2Te3 phase change memory cell used in a comparative example of the present application;

[0040] Figure 10 An architecture diagram of an electro-thermal analysis system for a phase change memory provided by the present application. DETAILED DESCRIPTION

[0041] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application.

[0042] In view of the deficiencies of the prior art, the present application aims to provide an electro-thermal analysis method for a compound-doped phase change material, which aims to solve the problem that electro-thermal parameters of a compound-doped phase change material are difficult to obtain. In the present application, the compound-doped phase change material requires that the compound is structurally stable during the phase change process, neither decomposes nor melts, and does not chemically react with any one of the chalcogen elements in the phase change material.

[0043] In this condition, to achieve the above object, the application provides an electrothermal analysis method of compound doped phase change material: dividing the phase change layer into small squares with equal area in proportion; determining the number of small squares occupied by the doped material and the phase change material according to the compound doping ratio; setting the electrothermal parameters of the doped material and the phase change material respectively; filling the doped material and the phase change material in the phase change layer; setting the electrothermal parameters of the upper electrode, the lower electrode and the insulating and heat-insulating material; setting the boundary condition and the current parameter; and thermal simulation and analysis.

[0044] The electrothermal analysis method provided by the application does not need to obtain the electrothermal parameters of the compound doped phase change material, but only needs to find the electrothermal parameters of the doped material and the phase change material respectively.

[0045] The electrothermal analysis method provided by the application can directly display the area of the phase change region.

[0046] The thermal simulation temperature field distribution result of the electrothermal analysis method provided by the application is beneficial to predicting and analyzing the RESET / SET power consumption of the phase change memory unit.

[0047] The more the number of squares in the electrothermal analysis method provided by the application, the more accurate the calculation result.

[0048] Further, the phase change memory unit built by the application comprises a lower electrode, a phase change material layer and an upper electrode, and the phase change material is filled with insulating and heat-insulating material to realize the electrothermal isolation between units in the horizontal direction.

[0049] Further, the phase change material is any one of Sb single element, Ge-Te binary compound, Ge-Sb binary compound, Sb-Te binary compound, Bi-Te binary compound, In-Se binary compound, Ge-Sb-Te ternary compound, Ge-Bi-Te ternary compound and Ge-Sb-Bi-Te quaternary compound.

[0050] Further, the doped material is a compound which is stable in structure and does not chemically react with the elements in the phase change material during the heating process.

[0051] Further, the insulating and heat-insulating material has low thermal conductivity, and the insulating and heat-insulating material is any one of silicon oxide, silicon nitride, aluminum oxide, aluminum nitride, zinc oxide, tungsten oxide, titanium oxide, boron nitride and silicon carbide.

[0052] Further, the material of the upper electrode and the lower electrode comprises metal single element Au, Ta, Pt, Al, W, Ti, Cu, Ir and metal alloy and metal compound thereof, such as TiW and TiN.

[0053] The application uses COMSOL Multiphysic software to perform thermal simulation on the RESET / SET process of a phase change memory cell.

[0054] Figure 1 A flowchart of an electro-thermal analysis method of a phase change memory is provided for an embodiment of the application, the phase change memory comprising an upper electrode, a phase change layer, an insulating and heat-insulating layer and a lower electrode, the upper electrode being disposed on an upper surface of the phase change layer, the lower electrode being disposed on a lower surface of the phase change layer, and the insulating and heat-insulating layer being disposed on both sides of the phase change layer; the phase change layer comprising a phase change material and a doping material, the phase change material and the doping material being independent of each other and crystallizing separately during the heating process of the phase change layer, and the doping material not chemically reacting with the phase change material. Figure 1 The electro-thermal analysis method comprises the following steps:

[0055] S101, the phase change layer is equally divided into a plurality of sub-regions of the same volume;

[0056] S102, the doping proportion of the doping material is determined, and the number of sub-regions occupied by the doping material is calculated according to the doping proportion;

[0057] S103, a corresponding number of sub-regions are randomly selected according to the calculated number of sub-regions to fill the doping material, and the remaining sub-regions are filled with the phase change material;

[0058] S104, the electro-thermal parameters of the doping material, the phase change material, the upper electrode, the lower electrode and the insulating and heat-insulating layer are determined;

[0059] S105, the boundary conditions and the current parameters of the phase change memory are determined; the boundary conditions are thermal boundary conditions, and the current parameters are RESET current pulses or SET current pulses;

[0060] S106, the phase change memory is subjected to finite element thermal simulation analysis in combination with the above-mentioned electro-thermal parameters, current parameters and boundary conditions, to determine the temperature field distribution inside the phase change memory after receiving the RESET current pulses or the SET current pulses, so as to further analyze the phase change region and the power consumption inside the phase change memory according to the temperature field distribution; when the phase change memory receives the RESET current pulses, the power consumption is the RESET power consumption, and when the phase change memory receives the SET current pulses, the power consumption is the SET power consumption.

[0061] Specifically, the compound material selected by the application is TiTe2, and the phase change material is Sb2Te3. Sb2Te3 is a phase change material that grows dominant crystallization, has a faster SET speed, but a lower crystallization temperature, and a poorer amorphous stability. The amorphous stability can be effectively improved by doping. TiTe2 has stable performance at room temperature and high temperature, good electrical conductivity, and low thermal conductivity, which is conducive to reducing heat dissipation. In the crystallization process, TiTe2 and Sb2Te3 in the Sb2Te3 phase change material doped with TiTe2 crystallize independently, and the elements in TiTe2 do not chemically react with the elements in Sb2Te3.

[0062] Figure 2 The implementation process of the electrothermal analysis method of the compound-doped phase change material provided by the embodiment of the application is shown, only the parts related to the embodiment of the application are shown for the convenience of description, and the details are as follows:

[0063] (1) The phase change material layer is equally divided into small squares of the same area; specifically, the phase change material layer is divided into a certain number of small squares in the horizontal and vertical directions. The more the number of small squares is divided, the more accurate the simulation result is.

[0064] It should be noted that the shape of each region can not necessarily be a small square, as long as the volume of each sub-region is the same.

[0065] (2) The number of small squares occupied by the doped material and the phase change material is calculated according to the doping ratio of the compound; specifically, the composition analysis of the compound-doped phase change material is performed by EDS and other test methods to obtain the doping ratio. Multiply the total number of small squares by the doping ratio to obtain the number of small squares occupied by the doped material, and the rest is the phase change material.

[0066] (3) The electrothermal parameters of the doped material and the phase change material are set respectively; specifically, the parameters include material density, electrical conductivity, thermal conductivity, etc. These parameters of the doped material and the phase change material can be obtained by consulting literature or material performance manual.

[0067] (4) Fill the doped material and the phase change material in the phase change material layer; specifically, randomly select the corresponding number of small squares to fill as the doped material, and the rest is filled as the phase change material. Note that the doped material and the phase change material are distinguished by color.

[0068] (5) Set the electrothermal parameters of the upper and lower electrodes and the insulating and heat-insulating material; specifically, the parameters include material density, electrical conductivity, thermal conductivity, etc., which can be obtained by consulting literature or material performance manual.

[0069] (6) Set the boundary conditions and current parameters; specifically, the boundary condition is a thermal boundary condition, and a RESET / SET current pulse is applied.

[0070] Specifically, the application adopts the convective heat flux as the thermal boundary condition. The convective heat flux is a mixed boundary condition, which assumes that the model boundary exchanges heat with the outside through convection. The formula of the convective heat flux is as follows:

[0071] q=h(Text-T)

[0072] wherein q is the heat flow, h is the heat transfer coefficient, which is taken as 5 W / (m 2 K) in this case, Text is the outside temperature, which is taken as 293.15 K in this case, and T is the internal temperature of the material. The adoption of the convective heat flux boundary condition can simplify the model, thereby effectively reducing the calculation time and the calculation scale.

[0073] (7) Thermal simulation and analysis. Specifically, the thermal simulation result is a temperature field distribution diagram. Under the same RESET / SET current pulse, the greater the maximum internal temperature of the phase change memory cell is, the smaller the power consumption required for completing the RESET / SET operation is.

[0074] The electrothermal analysis method of the compound doped phase change material provided by the application can effectively solve the problem that the overall thin film electrothermal parameters of the compound doped phase change material are difficult to obtain, and can more intuitively display the phase change area. The thermal simulation temperature field distribution result is beneficial to the analysis of the RESET / SET power consumption of the device.

[0075] In order to further illustrate the electrothermal analysis method of the compound doped phase change material provided by the application, the following specific embodiments are described in detail as follows:

[0076] Embodiment 1:

[0077] As shown in Figure 3 , the simulation model provided by the application is a T-shaped small hole structure phase change memory cell, which comprises a lower electrode 1, an insulating and heat-insulating material 2, a phase change material layer 3, and an upper electrode 4.

[0078] Specifically, the lower electrode 1 is a conductive material, which requires low resistivity and stable properties, and can adopt materials such as TiW, TiN, HfN, Ag, Al, Cu, W, Ta, Pt, etc. The upper electrode 4 can adopt the same material as the lower electrode 2.

[0079] Specifically, the insulating and heat-insulating material 2 requires high resistivity, low thermal conductivity, and stable properties, and can adopt materials such as SiO2, ZrO2, Y2O3, TiO2, etc.

[0080] Specifically, the phase change material layer 3 is a compound doped phase change material, which requires reversible phase change properties.

[0081] Embodiment 2:

[0082] In order to simplify the model and facilitate the calculation, the embodiment adopts a two-dimensional modeling method to perform two-dimensional finite element analysis on the RESET process of the phase change memory cell. The model is a T-shaped small hole structure phase change memory cell. The lower electrode material and the upper electrode material are both set as Pt, the insulating and heat insulating material is SiO2, and the phase change layer material is (TiTe2) 0.1 (Sb2Te3) 0.9 The thickness of the lower electrode, the insulating material, the phase change material and the upper electrode is all set as 100 nm, and the diameter of the cell device is 190 nm.

[0083] The most important thing in the parameter setting process is the setting of the crystalline conductivity and the thermal conductivity coefficient. However, (TiTe2) 0.1 (Sb2Te3) 0.9 The crystalline conductivity and the thermal conductivity coefficient of the thin film material are difficult to obtain. It is considered that TiTe2 and Sb2Te3 are crystallized and independent of each other, so the phase change material layer is divided into 190 small squares in the horizontal and vertical directions when modeling. According to the doping ratio of TiTe2, the same proportion of small squares is set as TiTe2 material, and the remaining small squares are set as Sb2Te3 material. Since TiTe2 is doped by 10%, 19 white squares are randomly selected and filled with TiTe2 material, and the color is set as black. The remaining 171 white squares are filled with Sb2Te3 material, and the color is unchanged. As shown in Figure 4 , the dark gray is the Pt material, the light gray is the SiO2 material, the white square is the Sb2Te3 material, and the black square is the TiTe2 material. It can be clearly seen from Figure 4 that (TiTe2) 0.1 (Sb2Te3) 0.9 The area of TiTe2 in the phase change layer accounts for 10%, the area of Sb2Te3 accounts for 90%, and the area ratio of the phase change material region accounts for 90% of the total area.

[0084] Table 1 is the material parameters used in the embodiment. The thermal conductivity coefficient of the selected material in the embodiment does not change much with temperature, so the thermal conductivity coefficient is set as a constant.

[0085] Table 1 Material physical property parameters

[0086]

[0087] The thermal simulation performed in the embodiment is mainly heat conduction, so the solid heat transfer interface is selected. The current is set as a downward flow, the RESET pulse is applied to the lower electrode, and the voltage value of the upper electrode is set as 0. Among them, the applied RESET pulse is a current pulse, the amplitude is 100 μA, the pulse width is 50 ns, and the rising edge and the falling edge are both 8 ns. The embodiment adopts convective heat flux as the thermal boundary condition.

[0088] After preprocessing, the internal temperature distribution diagram of the phase change memory cell after RESET is obtained, as shown below. Figure 5 As shown. The results show that (TiTe2) 0.1 (Sb2Te3) 0.9 The phase change memory unit can reach a maximum temperature of 617K.

[0089] Example 3:

[0090] The simulation model established in this embodiment differs from that in Embodiment 2 only in the phase change material layer; all other parameters are the same. The phase change material layer used in this embodiment is (TiTe2). 0.4 (Sb2Te3) 0.6 During modeling, the phase change material layer was divided into 190 small squares, both horizontally and vertically. Based on the TiTe2 doping ratio, squares with an equal proportion were designated as TiTe2 material, and the remaining squares as Sb2Te3 material. Since the doping content was 40% TiTe2, 76 white squares were randomly selected and filled with TiTe2 material, with the color set to black. The remaining 114 white squares were filled with Sb2Te3 material, with the color unchanged. Figure 6 As shown, dark gray represents Pt material, light gray represents SiO2 material, white squares represent Sb2Te3 material, and black squares represent TiTe2 material. From... Figure 6 It can be clearly seen from (TiTe2) 0.4 (Sb2Te3) 0.6 In the phase change layer, TiTe2 accounts for 40% of the area, Sb2Te3 accounts for 60%, and the area of ​​the phase change material region accounts for 60% of the total area.

[0091] The material parameters, RESET current parameters, and thermal boundary conditions in this embodiment are the same as in Embodiment 2. After preprocessing, the internal temperature distribution diagram of the phase change memory cell after RESET is obtained, as shown below. Figure 7 As shown. The results show that (TiTe2) 0.4 (Sb2Te3) 0.6 The phase change memory unit can reach a maximum temperature of 803K.

[0092] Comparative example:

[0093] This embodiment is a comparative example of Embodiments 2 and 3. The simulation model established is the same as that of Embodiments 2 and 3, except that the phase change material layer is different. The phase change material layer used in this embodiment is pure Sb₂Te₃. During modeling, the phase change material layer is divided into 190 small squares both horizontally and vertically. Each small square is filled with Sb₂Te₃ material. Figure 8 As shown, black represents Pt material, gray represents SiO2 material, and white squares represent Sb2Te3 material. From...Figure 8 It can be seen that the ratio of the area of the phase change material region to the total area is 100%.

[0094] The material parameters, RESET current parameters and thermal boundary conditions of this embodiment are the same as those of Embodiments 2 and 3. After the pre-processing is completed, the internal temperature distribution of the phase change memory cell after RESET is solved, as shown in FIG. 6. Figure 9 The results show that the maximum temperature of the Sb2Te3 phase change memory cell can reach 447K.

[0095] By COMSOL thermal simulation of the Sb2Te3 phase change memory cell doped with TiTe2 and the pure Sb2Te3 phase change memory cell, the comparison data in Table 2 is obtained. Table 2 can directly reflect the trend that the RESET power consumption of the Sb2Te3 phase change memory cell doped with TiTe2 decreases with the increase of the TiTe2 doping concentration.

[0096] Table 2 Comparison of thermal simulation results of Sb2Te3 phase change memory cells doped with TiTe2 and pure Sb2Te3

[0097]

[0098]

[0099] It can be understood that by setting the current pulse parameters in the above simulation process as the SET current pulse and setting the corresponding parameters of each material, the temperature field distribution, the phase change region and the corresponding SET power consumption of the phase change memory under the SET current pulse can be simulated and analyzed. For the sake of simplicity, the specific simulation process will not be exemplified, and those skilled in the art can directly and without doubt realize the corresponding simulation analysis according to the above idea.

[0100] Figure 10 is the system architecture diagram of the electro-thermal analysis system of the phase change memory provided by the embodiment of the present application, as shown in FIG. 10, comprising: Figure 10

[0101] The phase change layer dividing unit 1010 is configured to divide the phase change layer into a plurality of sub-regions with the same volume in equal proportions.

[0102] The phase change layer filling unit 1020 is configured to determine the doping proportion of the doping material, calculate the number of sub-regions occupied by the doping material according to the doping proportion, and fill the doping material in the corresponding number of sub-regions and fill the phase change material in the remaining sub-regions according to the calculated number of sub-regions.

[0103] ​The parameter determination unit 1030 is configured to determine electro-thermal parameters of the doping material, the phase change material, the upper electrode, the lower electrode, and the insulating and heat-insulating layer, and determine boundary conditions and current parameters of the phase change memory; the boundary conditions are thermal boundary conditions, and the current parameters are RESET current pulses or SET current pulses;

[0104] The electro-thermal analysis unit 1040 is configured to perform finite element thermal simulation analysis on the phase change memory by combining the above-mentioned electro-thermal parameters, current parameters, and boundary conditions, to determine a temperature field distribution of the phase change memory after the phase change memory receives the RESET current pulse or the SET current pulse, so as to further analyze a phase change region and power consumption in the phase change memory according to the temperature field distribution; when the phase change memory receives the RESET current pulse, the power consumption is RESET power consumption; and when the phase change memory receives the SET current pulse, the power consumption is SET power consumption.

[0105] It can be understood that, Figure 10 Detailed function implementation of each unit in the system can refer to the description of the foregoing method embodiments, and will not be described herein.

[0106] The present application discloses a kind of electro-thermal analysis method and system of phase change memory, belongs to microelectronic device and memory technical field, specifically includes: proportionally divide phase change material layer into small square of same area;According to compound doping proportion, the number of small squares of doping material and phase change material is calculated respectively;Respectively set the electro-thermal parameters of doping material and phase change material;In phase change material layer, doping material and phase change material are filled;The electro-thermal parameters of upper electrode, lower electrode and insulating and heat-insulating material are set;Boundary conditions and current parameters are set;Thermal simulation and analysis.This method can effectively solve the problem that the electro-thermal parameters of compound doped phase change material are difficult to obtain;Division square can more intuitively display phase change region area;Thermal simulation temperature field distribution result is conducive to the analysis of RESET / SET power consumption of phase change memory cell.

[0107] Those skilled in the art can easily understand that the above description is only a preferred embodiment of the present application, and is not intended to limit the present application, and any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for electrothermal analysis of a phase change memory, the phase change memory comprising: The device comprises an upper electrode, a phase change layer, an insulating and heat-insulating layer, and a lower electrode. The upper electrode is placed on the upper surface of the phase change layer, the lower electrode is placed on the lower surface of the phase change layer, and the insulating and heat-insulating layer is placed on both sides of the phase change layer. The phase change layer comprises a phase change material and a doped material. During the heating process of the phase change layer, the phase change material and the doped material crystallize independently, and the doped material does not chemically react with the phase change material. The electrothermal analysis method includes the following steps: The phase change layer is divided into multiple sub-regions of equal volume; Determine the doping ratio of the doped material, and calculate the number of sub-regions occupied by the doped material according to the doping ratio; Based on the calculated number of sub-regions, a corresponding number of sub-regions are randomly selected to be filled with doped material, and the remaining sub-regions are filled with phase change material. Determine the electrothermal parameters of the doped material, phase change material, upper electrode, lower electrode, and insulating layer; Determine the boundary conditions and current parameters of the phase-change memory; the boundary conditions are thermal boundary conditions, and the current parameters are RESET current pulses or SET current pulses. Based on the aforementioned electrothermal parameters, current parameters, and boundary conditions, a finite element thermal simulation analysis is performed on the phase change memory to determine the internal temperature field distribution after the phase change memory receives a RESET current pulse or a SET current pulse. This allows for further analysis of the phase change region and power consumption within the phase change memory based on the temperature field distribution. When the phase change memory receives a RESET current pulse, the power consumption is the RESET power consumption; when the phase change memory receives a SET current pulse, the power consumption is the SET power consumption.

2. The method according to claim 1, characterized in that, The phase change layer is divided into multiple sub-regions of equal volume, specifically: The phase transition layer is spatially divided to obtain multiple sub-regions of equal volume.

3. The method according to claim 1 or 2, characterized in that, The more sub-regions there are, the more accurate the electrothermal analysis results of the phase change memory will be.

4. The method according to claim 1, characterized in that, The electrothermal parameters include: material density, electrical conductivity, and thermal conductivity.

5. The method according to claim 1, characterized in that, The phase change material is any one of elemental Sb, Ge-Te binary compound, Ge-Sb binary compound, Sb-Te binary compound, Bi-Te binary compound, In-Se binary compound, Ge-Sb-Te ternary compound, Ge-Bi-Te ternary compound, and Ge-Sb-Bi-Te quaternary compound.

6. The method according to claim 1 or 5, characterized in that, The doping material is a compound that is structurally stable during the heating process of the phase change layer and does not chemically react with the phase change material.

7. An electrothermal analysis system for a phase change memory, the phase change memory comprising: The system comprises an upper electrode, a phase change layer, an insulating layer, and a lower electrode, wherein the upper electrode is placed on the upper surface of the phase change layer, the lower electrode is placed on the lower surface of the phase change layer, and the insulating layer is placed on both sides of the phase change layer; characterized in that the phase change layer includes a phase change material and a doped material, wherein the phase change material and the doped material crystallize independently during the heating process of the phase change layer, and the doped material does not chemically react with the phase change material; the electrothermal analysis system includes: A phase change layer partitioning unit is used to divide the phase change layer into multiple sub-regions of equal volume in an equal proportion; A phase change layer filling unit is used to determine the doping ratio of the doped material, calculate the number of sub-regions occupied by the doped material according to the doping ratio, and randomly select a corresponding number of sub-regions to fill with the doped material according to the calculated number of sub-regions, and fill the remaining sub-regions with the phase change material. The parameter determination unit is used to determine the electrothermal parameters of the doped material, phase change material, upper electrode, lower electrode, and insulating layer; and to determine the boundary conditions and current parameters of the phase change memory; the boundary conditions are thermal boundary conditions, and the current parameters are RESET current pulses or SET current pulses. The electrothermal analysis unit is used to perform finite element thermal simulation analysis on the phase change memory by combining the above-mentioned electrothermal parameters, current parameters, and boundary conditions, to determine the internal temperature field distribution of the phase change memory after receiving a RESET current pulse or a SET current pulse, so as to further analyze the phase change region and power consumption inside the phase change memory based on the temperature field distribution; when the phase change memory receives a RESET current pulse, the power consumption is the RESET power consumption, and when the phase change memory receives a SET current pulse, the power consumption is the SET power consumption.

8. The system according to claim 7, characterized in that, The phase change layer partitioning unit divides the phase change layer into multiple sub-regions of equal volume proportionally. Specifically, the phase change layer is spatially partitioned to obtain multiple sub-regions of equal volume.

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