CN112397644B - A kind of phase-change material, phase-change storage unit and preparation method thereof - Google Patents

Abstract

The invention provides a phase-change material, a phase-change memory cell and a preparation method thereof, wherein the phase-change material comprises erbium element, antimony element and tellurium element, and the chemical formula of the phase-change material is Er _x Sb _y Te _z Wherein x, y, z each refer to an atomic composition of an element and satisfy 0<x/(x+y+z) is not more than 2/9, and 1/3 is not more than z/y is not more than 3/2. Er of the invention _x Sb _y Te _z The phase change material has good thermal stability, higher data retention, faster crystallization speed and lower density change rate, and the phase change memory unit adopting the phase change material has higher operation speed and better cycle times, and the reliability of the device is greatly improved. Meanwhile, the phase change preparation method disclosed by the invention is simple in process and convenient for precisely controlling the material components.

Description

A kind of phase-change material, phase-change storage unit and preparation method thereof

technical field

The invention belongs to the technical field of microelectronics, and relates to a phase-change material, a phase-change storage unit and a preparation method thereof.

Background technique

Phase change memory (PCM) is a non-volatile semiconductor memory whose technology has developed rapidly in recent years. Compared with traditional memory, it has the advantages of strong size miniaturization, fast read and write speed, high data retention, low power consumption, long cycle life and excellent radiation resistance. Therefore, phase change memory has become a strong competitor in various new storage technologies, and it is extremely expected to replace Flash+DRAM technology and become the mainstream storage technology of the next generation of non-volatile memory, so it has a broad market prospect. At the same time, it can generate new applications in some fields where ordinary memory cannot reach, such as space, aerospace technology and military fields.

The application of phase change memory is based on the reversible conversion between high and low resistance of the phase change material under the operation of electric pulse signal to realize the writing and erasing of "0" and "1". The core of phase change memory is the phase change storage medium material. The traditional phase change material is mainly Ge ₂ Sb ₂ Te ₅ , which has been widely used in phase change optical discs and phase change memory due to its good comprehensive performance. However, there are still some problems with this material: 1) The crystallization temperature is low, the thermal stability is not good, the data retention cannot be guaranteed, and it faces the danger of data loss. For example, in the field of automotive electronics, the serviceable temperature of storage devices is required to be higher than 120°C, while Ge ₂ Sb ₂ Te ₅ can provide 10-year reliable data storage at only about 85°C; 2) The phase change speed is low , some studies have shown that the electrical pulse for a phase change memory based on Ge ₂ Sb ₂ Te ₅ to achieve a stable SET operation is at least on the order of hundreds of nanoseconds, and the electrical pulse to achieve a stable RESET operation also needs 20 ns, which cannot meet the speed requirements of DRAM. ; 3) The density change is too large. After crystallization, the density change rate reaches 6%, which is not conducive to the reliability of the device.

Therefore, how to find a phase-change thin film material with high speed, high data retention, and low density change rate, so that it has a wide temperature range, has become an important technical problem to be solved urgently by those skilled in the art.

Contents of the invention

In view of the shortcomings of the prior art described above, the purpose of the present invention is to provide a phase change material, a phase change memory unit and a preparation method thereof, which are used to solve the problem of crystallization of Ge ₂ Sb ₂ Te ₅ and other phase change materials in the prior art. Low temperature and poor thermal stability make the data retention not guaranteed, facing the problem of data loss, and the high density change rate of the phase change material before and after crystallization leads to low device reliability and low phase change speed, which cannot meet the requirements The question of DRAM speed requirements.

To achieve the above object and other related objects, the present invention provides a phase change material, the phase change material includes erbium element, antimony element and tellurium element, the chemical formula of the phase change material is Er _x Sb _{y Tez} , wherein, x, y, and z all refer to atomic components of elements, and satisfy 0<x/(x+y+z)≤2/9, 1/3≤z/y≤3/2.

Optionally, in the Er _x Sb _y Te _z , 1/100≤x/(x+y+z)≤1/9, 1/3≤z/y≤3/2 are satisfied.

Optionally, in the Er _x Sb _y Te _z , 0.01≤x≤0.35, y=2, z=1 are satisfied.

Optionally, in the Er _x Sb _y Te _z , 0.03≤x≤0.3, y=2, z=1 are satisfied.

Optionally, in the Er _x Sb _y Te _z , 0.05≤x≤0.25, y=2, z=1 are satisfied.

The present invention also provides a phase-change memory unit, which includes a phase-change material layer, and the material of the phase-change material layer includes the phase-change material described in any one of the above.

Optionally, the thickness of the phase change material layer ranges from 40nm to 200nm.

Optionally, the phase-change memory unit further includes a lower electrode layer, an adhesive layer, and an extraction electrode layer, the phase-change material layer is disposed on the lower electrode layer, and the adhesive layer is disposed on the On the phase change material layer, the extraction electrode layer is disposed on the adhesive layer.

Optionally, the materials of the lower electrode layer, the adhesive layer and the extraction electrode layer respectively include at least one of W, Pt, Au, Ti, Al, Ag, Cu and Ni, or at least one of them species of nitrides or oxides.

The present invention also provides a preparation method of a phase change material, using any one of the magnetron sputtering method, chemical vapor deposition method, atomic layer deposition method and electron beam evaporation method to prepare the phase change material described in any one of the above Material.

Optionally, the phase change material is prepared by co-sputtering an Er simple substance target and an _{Sby Tez} alloy target according to the chemical formula Er _x Sby _{Tez of} the phase change material.

Optionally, during co-sputtering with the Er elemental target and the Sby _{Tez alloy} target, the background vacuum degree is less than 3.0×10 ^-4 Pa, the sputtering gas includes argon, and the sputtering pressure range is 0.40 Pa to 0.45Pa, the sputtering temperature range is 1°C to 80°C, and the sputtering time range is 10 minutes to 30 minutes.

The present invention also provides a preparation method of a phase change memory unit, comprising the following steps:

Form an electrode layer;

forming a phase-change material layer on the lower electrode layer, the material of the phase-change material layer includes the phase-change material described in any one of the above;

forming an adhesive layer on the phase change material layer,

An extraction electrode layer is formed on the adhesive layer.

Optionally, the methods for forming the lower electrode layer, the adhesive layer and the extraction electrode layer respectively include sputtering, evaporation, chemical vapor deposition, plasma enhanced chemical vapor deposition, low pressure chemical vapor deposition method, metal compound vapor deposition method, molecular beam epitaxy method, atomic vapor deposition method and atomic layer deposition method; the method of forming the phase change material layer includes magnetron sputtering method, chemical vapor deposition method, atomic Any one of the layer deposition method and the electron beam evaporation method.

As mentioned above, the Er _x Sb _y Te _z phase change material of the present invention can obtain storage materials with different crystallization temperature, resistivity and crystallization activation energy by adjusting the content of Er element, and the resistance difference before and after the phase change of the system phase change material Large, with very strong adjustability, which can provide specific performance according to actual needs. Among them, Er _0.17 Sb ₂ Te not only has better data retention, but also has faster operation speed and better cycle times when it is applied to the device unit in the phase change memory. It can be seen that it is used to prepare phase change memory. Suitable storage medium material for variable memory. Compared with the traditional Ge ₂ Sb ₂ Te ₅ , the Er _x Sb _{y Tez} phase change material of the present invention has better thermal stability, stronger data retention, faster crystallization speed, and lower density rate of change. Moreover, the preparation method of the phase change material provided by the invention is simple in process and convenient for precise control of material components.

Description of drawings

Fig. 1 shows the resistance-temperature relationship diagram of Sb ₂ Te and Er _x Sb _{y Tez} phase change materials with different compositions provided by the present invention.

Fig. 2 is a diagram showing the calculation results of data retention capacity of Sb ₂ Te and Er _{x Sby Tez} phase change materials with different compositions provided by the present invention.

Fig. 3 shows the fitted density change rate diagram of the phase change memory using the Er _0.17 Sb ₂ Te phase change material provided by the present invention.

Fig. 4 shows the resistance-voltage relationship diagram of the phase change memory using the Er _0.17 Sb ₂ Te phase change material provided by the present invention.

Fig. 5 shows the fatigue performance diagram of the phase change memory using the Er _0.17 Sb ₂ Te phase change material provided by the present invention.

Detailed ways

Embodiments of the present invention are described below through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation modes, and various modifications or changes can be made to the details in this specification based on different viewpoints and applications without departing from the spirit of the present invention.

See Figures 1 through 5. It should be noted that the diagrams provided in this embodiment are only schematically illustrating the basic idea of the present invention, and only the components related to the present invention are shown in the diagrams rather than the number, shape and shape of the components in actual implementation. Dimensional drawing, the type, quantity and proportion of each component can be changed arbitrarily during actual implementation, and the component layout type may also be more complicated.

Embodiment one

In this embodiment, a phase change material is provided. The phase change material includes erbium (Er) element, antimony (Sb) element and tellurium (Te) element. The chemical formula of the phase change material is Er _x Sb _y Te _z , Wherein, x, y, and z all refer to atomic components of elements, and satisfy 0<x/(x+y+z)≤2/9, 1/3≤z/y≤3/2.

Specifically, in the Er _x Sb _{y Tez} , the contents of Er, Sb and Te can be adjusted to obtain storage materials with different crystallization temperatures, resistivities and crystallization activation energies. For example, the Er _x Sb _y Te _z may further satisfy 1/100≤x/(x+y+z)≤1/9, 1/3≤z/y≤3/2.

As an example, in the Er _x Sb _y Te _z , the atomic composition ratio z/y of Te and Sb is 1/2, and when y=2, z=1, the composition of Er satisfies 0.01≤x≤0.35 . Of course, the atomic composition of Er may further satisfy 0.03≤x≤0.3, or further satisfy 0.05≤x≤0.25.

As an example, the phase change material exists in the form of a thin film, and the thickness of the thin film ranges from 40 nm to 200 nm.

Please refer to Figure 1, which shows the resistance-temperature relationship diagram of Sb ₂ Te and Er _x Sb _y Te _z phase change materials with different compositions. In this embodiment, three Er _x Sb _{y Tez} phase change materials with different compositions are provided, namely Er _0.05 Sb ₂ Te, Er _0.17 Sb ₂ Te, and Er _0.25 Sb ₂ Te.

It should be noted that, in this embodiment, the Er _x Sb _{y Tez phase} change material is not only compared with Sb ₂ Te, but also compared with Ge ₂ Sb ₂ Te ₅ (GST for short). Since the current research data of GST are very detailed, the relevant data in this embodiment and the following embodiments are not shown.

It can be seen from Figure 1 that the crystallization temperature of Er _x Sb _y Te _z phase change materials can be adjusted between 190 and 240°C, which is higher than that of Sb ₂ Te (about 150°C) and Ge ₂ Sb ₂ Te ₅ (about 150°C , not shown) has a significant increase.

In addition, it can be seen that the high and low resistance values of the Er _{x Sby Tez} phase change memory material increase with the increase of Er content, and its crystallization temperature increases with the increase of Er content. Therefore, the crystallization temperature of Er-Sb-Te phase change materials can be controlled by adjusting the content of Er.

Please refer to Figure 2, which shows the calculation results of data retention capabilities of Sb ₂ Te and Er _x Sb _y Te _z phase change materials with different components. In this example, three Er _x Sb _{y Tez} phase change materials with different components are provided, namely Er _0.05 Sb ₂ Te (referred to as sample EST-1), Er _0.17 Sb ₂ Te (referred to as sample EST-1). 2), Er _0.25 Sb ₂ Te (denoted as sample EST-3). It can be seen from Figure 2 that the 10-year data retention temperature of Er _x Sb _y Te _z phase change materials increases with the increase of Er content. At the same time, it can be seen that the 10-year data retention of the Er _x Sb _{y Tez} material system is greatly improved compared with Sb ₂ Te and Ge ₂ Sb ₂ Te ₅ (not shown). Among them, the data retention of Er _0.25 Sb ₂ Te is as high as 138 °C. Therefore, the thermal stability and data retention of Er _x Sb _{y Tez} phase change materials can be optimized by adjusting the content of Er.

It can be seen from the above that the Er _x Sb _{y Tez} phase change material of this embodiment has at least two stable resistance states under the action of electric pulses, and can realize reversible conversion of high and low resistance values under the operation of electric pulse signals, and can be reversible without electric pulses. The resistance value remains unchanged under pulse signal operation, and it is a suitable storage medium material for preparing phase change memory. At the same time, the Er _{x Sby Tez} phase change material has a strong ten-year data retention, and has better thermal stability and stronger data retention than traditional phase change materials.

Embodiment two

This embodiment provides a phase-change memory unit, the phase-change memory unit includes a phase-change material layer, the material of the phase-change material layer includes the Er _x Sb _{y Tez} phase-change material described in Embodiment 1 .

As an example, the thickness range of the phase change material layer is 40nm-200nm.

As an example, the phase change memory unit further includes a lower electrode layer, an adhesive layer and an extraction electrode layer, the phase change material layer is disposed on the lower electrode layer, and the adhesive layer is disposed on the phase On the variable material layer, the extraction electrode layer is disposed on the adhesive layer. The adhesive layer is used to increase the degree of bonding between the upper electrode layer and the phase-change material, and the material of the adhesive layer requires stable chemical properties and does not react with the phase-change material in a relatively high temperature range. The role of the extraction electrode layer is to protect the phase change material layer and serve as an upper electrode when the device is under electrical testing.

As an example, the materials of the lower electrode layer, the adhesive layer and the extraction electrode layer respectively include at least one of W, Pt, Au, Ti, Al, Ag, Cu and Ni, or at least one of them nitrides or oxides. In this embodiment, the material of the extraction electrode layer is preferably Al, and the material of the adhesive layer is preferably TiN.

It should be pointed out that if the material of the extraction electrode layer itself has a high bonding strength with the phase change material, and does not react with the phase change material during the heating process, the adhesive layer may not be required, or the adhesive layer may be considered The layer is made of the same material as that of the extraction electrode layer.

Please refer to FIG. 3 , which shows a fitted density change rate diagram of a phase-change memory using Er _0.17 Sb ₂ Te phase-change material. The phase-change memory contains multiple phase-change memory cells. In the phase-change memory cells, The thickness of the phase-change material layer using the Er _0.17 Sb ₂ Te phase-change material is 40 nm, and through calculation and fitting, the density change rate after crystallization is 2.4%. Compared with the 6% density change rate of the Ge ₂ Sb ₂ Te ₅ phase change material, it has been greatly improved, which is conducive to further improving the reliability of the device.

It should be noted that, compared with Sb ₂ Te and Ge ₂ Sb ₂ Te ₅ , the density change rates of Er _0.05 Sb ₂ Te and Er _0.25 Sb ₂ Te phase change materials are also reduced (not shown). Therefore, the Er _x Sb _{y Tez} material system of Er doping can greatly improve the device reliability.

Please refer to FIG. 4 , which shows a resistance-voltage relationship diagram of a phase change memory using Er _0.17 Sb ₂ Te phase change material. It can be seen that under the action of electric pulses, the phase change memory realizes reversible phase change. The voltage pulses used for the test were 70 ns, 50 ns, 30 ns and 10 ns. Under the electrical pulse of 70 nanoseconds, the phase change memory can be obtained to realize "erase" (high resistance to low resistance) and "write" (low resistance to high resistance) operation at 1.3V and 2.7V respectively.

It is worth noting that the phase-change memory cell device made of Er _x Sb _{y Tez} material can realize "erasing and writing" operation under the electric pulse as short as 10 nanoseconds, which is much faster than Ge ₂ Sb ₂ Te ₅ The operating speed of the material is on the order of hundreds of nanoseconds. Among them, for the phase change memory using Er _0.17 Sb ₂ Te phase change material, under the electric pulse of 10 nanoseconds, the operating voltages of "erase" and "write" of the unit device are 2.3V and 4.0V respectively.

It should be noted that the erasing and writing speeds of phase-change memory cell devices using Er _0.05 Sb ₂ Te, Er _0.17 Sb ₂ Te, and Er _0.25 Sb ₂ Te can all reach 10 ns, but their window RESET voltages are different, which are 4.9 V (Er _0.05 Sb ₂ Te), 4.1V (Er _0.17 Sb ₂ Te), 5.5V (Er _0.25 Sb ₂ Te). However, the devices with three components have little difference in crystal resistance, the higher the RESET voltage, the higher the power consumption. It can be seen that compared with Er _0.05 Sb ₂ Te and Er _0.25 Sb ₂ Te, the device using Er _0.17 Sb ₂ Te phase change material has lower power consumption.

Please refer to FIG. 5 , which shows the fatigue performance diagram of the phase change memory using Er _0.17 Sb ₂ Te phase change material. It can be seen that the device can be repeatedly erased and written 1.0×10 ⁵ times without fatigue, and both high and low resistance states have relatively stable resistance values, which ensures the reliability required for device applications.

It should be noted that the number of erasing and writing cycles of the phase change memory using Er _0.05 Sb ₂ Te phase change material or Er _0.25 Sb ₂ Te phase change material is close to 5×10 ⁴ times, which is relatively lower than that of using Er _0.17 Sb ₂ Te Phase change memory of phase change material.

The phase change memory cell of the present embodiment adopts Er _{x Sby Tez} phase change material, makes phase change memory have faster operation speed, better number of cycles and higher stability, lower density change rate can Further improve the reliability of the device. Among them, Er _0.17 Sb ₂ Te has better overall performance, faster erasing and writing speed and more cycle times.

Embodiment three

This example provides a method for preparing a phase change material, which is used to prepare the Er _{x Sby Tez} phase change material described in Example 1.

Specifically, any one of the Er _x Sb _{y Tez phase} change material in magnetron sputtering, chemical vapor deposition, atomic layer deposition and electron beam evaporation can be used. In this embodiment, the Er _{x Sby Tez} phase change material is preferably prepared by magnetron sputtering, which can more conveniently adjust the contents of the three elements in the Er _{x Sby Tez} phase change material to obtain different crystals. Storage materials for temperature, resistivity and crystallization activation energy.

As an example, the phase change material is prepared by co-sputtering an Er simple substance target and an _{Sby Tez} alloy target according to the chemical formula Er _x Sby _{Tez of} the phase change material.

In this embodiment, the Er _x Sb ₂ Te phase change material is prepared by co-sputtering with the Er simple substance target and the Sb ₂ Te alloy target.

As an example, the Er simple substance target uses a radio frequency power supply, and the sputtering power range of the radio frequency power supply is 5W-15W. The Sb ₂ Te alloy target uses a radio frequency power supply, and the sputtering power of the radio frequency power supply is 20W. By adjusting the power of Er simple substance target, three components of Er _x Sb ₂ Te phase change materials were obtained: Er _0.05 Sb ₂ Te, Er _0.17 Sb ₂ Te, Er _0.25 Sb ₂ Te. Of course, in other embodiments, the sputtering power used by the Sb ₂ Te alloy target can also be other values, for example, in the range of 10W-30W, and the protection scope of the present invention should not be overly limited here.

As an example, in the co-sputtering project, the background vacuum is less than 3.0×10 ^-4 Pa, the sputtering gas includes argon, the sputtering pressure ranges from 0.40Pa to 0.45Pa, and the sputtering temperature ranges from 1°C to 80°C , the sputtering time range is 10 minutes to 30 minutes. Phase change material layers with different thicknesses can be obtained by adjusting the sputtering time.

Embodiment four

In this embodiment, a method for preparing a phase-change memory cell is provided, including the following steps:

S1: Form an electrode layer;

S2: forming a phase-change material layer on the lower electrode layer, the material of the phase-change material layer includes the phase-change material described in Embodiment 1;

S3: forming an adhesive layer on the phase change material layer,

S4: forming an extraction electrode layer on the adhesive layer.

As examples, sputtering, evaporation, chemical vapor deposition, plasma enhanced chemical vapor deposition, low pressure chemical vapor deposition, metal compound vapor deposition, molecular beam epitaxy, atomic vapor deposition, and atomic layer deposition can be employed. any one of the methods to prepare the lower electrode layer. The material of the bottom electrode layer may include at least one of W, Pt, Au, Ti, Al, Ag, Cu and Ni, or may be at least one of nitride or oxide. In this embodiment, the material of the lower electrode layer is preferably W.

As an example, any one of magnetron sputtering, chemical vapor deposition, atomic layer deposition and electron beam evaporation can be used to prepare the phase change material layer. In this embodiment, the Er _{x Sby Tez} phase change material is preferably prepared by magnetron sputtering, which can more conveniently adjust the contents of the three elements in the Er _{x Sby Tez} phase change material to obtain different crystals. Storage materials for temperature, resistivity and crystallization activation energy. Phase change material layers with different thicknesses can be obtained by adjusting the sputtering time.

As examples, sputtering, evaporation, chemical vapor deposition, plasma enhanced chemical vapor deposition, low pressure chemical vapor deposition, metal compound vapor deposition, molecular beam epitaxy, atomic vapor deposition, and atomic layer deposition can be employed. Any one of the methods to prepare the adhesive layer. The adhesive layer is used to enhance the bonding force between the phase change material layer and the extraction electrode layer, and its material may include at least one of W, Pt, Au, Ti, Al, Ag, Cu and Ni , can also be at least one of the nitrides or oxides. In this embodiment, the material of the adhesive layer is preferably TiN material.

As examples, sputtering, evaporation, chemical vapor deposition, plasma enhanced chemical vapor deposition, low pressure chemical vapor deposition, metal compound vapor deposition, molecular beam epitaxy, atomic vapor deposition, and atomic layer deposition can be employed. Any one of the methods to prepare the extraction electrode layer. The material of the extraction electrode layer may include at least one of W, Pt, Au, Ti, Al, Ag, Cu and Ni, or may be at least one of nitride or oxide. In this embodiment, the material of the lower electrode layer is preferably Al.

In summary, the Er _x Sb _y Te _z phase change material of the present invention can obtain storage materials with different crystallization temperature, resistivity and crystallization activation energy by adjusting the content of Er element, and the resistance difference before and after the phase change of the system phase change material is The value is large and has very strong adjustability, so that specific performance can be provided according to actual needs. Among them, Er _0.17 Sb ₂ Te not only has better data retention, but also has faster operation speed and better cycle times when it is applied to the device unit in the phase change memory. It can be seen that it is used to prepare phase change memory. Suitable storage medium material for variable memory. Compared with the traditional Ge ₂ Sb ₂ Te ₅ , the Er _x Sb _{y Tez} phase change material of the present invention has better thermal stability, stronger data retention, faster crystallization speed, and lower density rate of change. Moreover, the preparation method of the phase change material provided by the invention is simple in process and convenient for precise control of material components. Therefore, the present invention effectively overcomes various shortcomings in the prior art and has high industrial application value.

The above-mentioned embodiments only illustrate the principles and effects of the present invention, but are not intended to limit the present invention. Anyone skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical ideas disclosed in the present invention should still be covered by the claims of the present invention.

Claims (14)

1. A phase-change material, characterized in that: the phase-change material comprises erbium, antimony and tellurium, and the chemical formula of the phase-change material is Er _x Sb _y Te _z , wherein x, y, and z are all Refers to the atomic composition of an element, and satisfies 0<x/(x+y+z)≤2/9, 1/3≤z/y≤3/2. 2. The phase change material according to claim 1, characterized in that: among the Er _x Sb _y Te _z , 1/100≤x/(x+y+z)≤1/9, 1/3≤ z/y≤3/2. 3. The phase change material according to claim 1, characterized in that: among the Er _x Sb _y Te _z , 0.01≤x≤0.35, y=2, z=1 are satisfied. 4. The phase change material according to claim 1, characterized in that: among the Er _x Sb _y Te _z , 0.03≤x≤0.3, y=2, z=1 are satisfied. 5. The phase change material according to claim 1, characterized in that: among the Er _x Sb _y Te _z , 0.05≤x≤0.25, y=2, z=1 are satisfied. 6. A phase-change memory unit, characterized in that: the phase-change memory unit comprises a phase-change material layer, and the material of the phase-change material layer comprises the phase-change material according to any one of claims 1-5 . 7. The phase-change memory unit according to claim 6, characterized in that: the thickness of the phase-change material layer is in the range of 40nm-200nm. 8. The phase-change memory unit according to claim 6, characterized in that: the phase-change memory unit further comprises a lower electrode layer, an adhesive layer and an extraction electrode layer, and the phase-change material layer is arranged on the On the lower electrode layer, the adhesive layer is arranged on the phase change material layer, and the extraction electrode layer is arranged on the adhesive layer. 9. The phase-change memory cell according to claim 8, characterized in that: the materials of the lower electrode layer, the adhesive layer and the lead-out electrode layer respectively include W, Pt, Au, Ti, Al, Ag At least one of , Cu and Ni, or at least one of the nitrides or oxides. 10. A method for preparing a phase change material, characterized in that: any one of magnetron sputtering, chemical vapor deposition, atomic layer deposition and electron beam evaporation is used to prepare such as any of claims 1-5 One of the phase change materials. 11. the preparation method of phase-change material according to claim 10 is characterized in that: according to the chemical formula Er _x Sby _{y Tez} of described phase-change material, adopt Er simple substance target and Sby _{y Tez} alloy target co-sputtering to prepare institute phase change materials. 12. The method for preparing phase change materials according to claim 11, characterized in that: during the co-sputtering process using the Er elemental target and the _{Sby Tez} alloy target, the background vacuum degree is less than 3.0×10 ^{- 4} Pa, the sputtering gas includes argon, the sputtering pressure ranges from 0.40Pa to 0.45Pa, the sputtering temperature ranges from 1°C to 80°C, and the sputtering time ranges from 10 minutes to 30 minutes. 13. A method for preparing a phase-change memory cell, comprising the following steps: Form an electrode layer; forming a phase-change material layer on the lower electrode layer, the material of the phase-change material layer comprising the phase-change material according to any one of claims 1-5; forming an adhesive layer on the phase change material layer, An extraction electrode layer is formed on the adhesive layer. 14. The method for preparing a phase-change memory cell according to claim 13, characterized in that: the methods for forming the lower electrode layer, the adhesive layer, and the lead-out electrode layer respectively include sputtering, evaporation, Any one of chemical vapor deposition, plasma-enhanced chemical vapor deposition, low-pressure chemical vapor deposition, metal compound vapor deposition, molecular beam epitaxy, atomic vapor deposition, and atomic layer deposition; forming said phase transition The method of material layer includes any one of magnetron sputtering method, chemical vapor deposition method, atomic layer deposition method and electron beam evaporation method.

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