A method for atomic layer deposition of chalcogenide phase change thin films

Abstract

The application discloses a method for depositing a chalcogenide phase change film by atomic layer deposition, which comprises the following steps: S1, performing surface modification on a substrate by pulse injection of chalcogenide precursor molecules A, so that the surface of the substrate is saturatedly adsorbed with a bonding chalcogenide modification layer; S2, purging the surface-modified substrate by introducing a carrier gas, so as to eliminate the excess chalcogenide precursor molecules A which are not adsorbed on the surface of the substrate; and S3, alternately pulse-injecting chalcogenide precursor molecules A and chalcogenide precursor molecules B on the surface of the purged substrate by using an atomic layer deposition method, so as to grow a chalcogenide phase change film. By pulse-injecting a single chalcogenide precursor molecule to modify the surface of the substrate before atomic layer deposition, the chalcogenide phase change film with high shape retention and no pinholes can be efficiently prepared.

Description

Technical Field

[0001] This invention belongs to the technical field of sulfur-based phase change thin film preparation methods, and more specifically, relates to a method for atomic layer deposition of sulfur-based phase change thin films. Background Technology

[0002] Sulfur-based phase change materials are information storage materials that can undergo thermally induced phase changes. The time it takes to melt to the amorphous state is only a few hundred picoseconds, and the time to crystallize to the crystalline state is only a few nanoseconds. Compared with traditional non-volatile memory, they have a significant improvement in erase and write speed.

[0003] Currently, the main methods for preparing chalcogenide phase change materials include magnetron sputtering, chemical vapor deposition (CVD), and atomic layer deposition (ALD). Chalcogenide phase change films prepared by magnetron sputtering and CVD exhibit poor conformal stability, failing to meet the requirements of high aspect ratio integrated device fabrication processes. Atomic layer deposition (ALD) is considered an effective method for growing chalcogenide phase change films, utilizing the substitution reaction of gaseous chalcogenide precursors at high temperatures to achieve the deposition and growth of chalcogenide phase change films on different substrates. However, current ALD-grown chalcogenide phase change films suffer from drawbacks such as numerous surface particles, long incubation periods, and pinholes. Obtaining high conformal stability and pinhole-free chalcogenide phase change films has become a key research focus and hot topic in the field of three-dimensional phase change memory. Undoubtedly, breakthroughs in this technology will not only drive breakthroughs in the fabrication processes of a series of phase change materials, such as high conformal stability and pinhole-free germanium telluride, antimony telluride, germanium-antimony-telluride, and antimony telluride / germanium telluride superlattices, but will also be a significant driving force for the development of new storage materials and the field of information storage. Therefore, the growth technology of high-fidelity, pinhole-free sulfur-based phase change films has a huge market prospect. Summary of the Invention

[0004] In view of the above-mentioned defects or improvement needs of the prior art, the present invention provides a method for atomic layer deposition of sulfide phase change thin films, the purpose of which is to prepare high conformity, pinhole-free sulfide phase change thin films.

[0005] To achieve the above objectives, according to one aspect of the present invention, a method for atomic layer deposition of chalcogenide phase change thin films is provided, comprising:

[0006] Step S1: The substrate is surface modified by continuously multi-pulse injection of chalcogenide precursor molecule A, so that the surface of the substrate is saturated with a bonded chalcogenide modification layer.

[0007] Step S2: Introduce carrier gas to purge the surface-modified substrate to remove excess sulfide precursor molecules A that have not been adsorbed on the substrate surface.

[0008] Step S3: Using atomic layer deposition, alternating pulse implantation of chalcogenide precursor molecules A and chalcogenide precursor molecules B is performed on the surface of the purged substrate to grow a chalcogenide phase change film.

[0009] In one embodiment, in step S1, 300 to 500 pulse cycles are injected, the injection duration of the sulfide precursor molecule A in each pulse cycle is 300 ms to 1500 ms, the purge duration in each pulse cycle is 800 ms to 1500 ms, and the carrier gas flow rate is 300 sccm to 650 sccm.

[0010] In one embodiment, in step S1, a sulfide precursor molecule with stronger oxidizing power in atomic layer deposition is selected for substrate surface modification.

[0011] In one embodiment, in step S2, the carrier gas flow rate for purging is 100 sccm-650 sccm, and the purging time is 2 min-15 min.

[0012] In one embodiment, in step S3, the reaction temperature of atomic layer deposition is 80°C to 110°C, 300 to 1000 pulse cycles are injected, the injection time of sulfide precursor molecules in each pulse cycle is 500ms to 1000ms, the purge time of each pulse cycle is 4s to 6s, and the carrier gas flow rate is 300sccm to 650sccm.

[0013] In one embodiment, the reaction temperatures of steps S1 and S3 are the same.

[0014] In one embodiment, prior to step S1, the method further includes:

[0015] The substrate surface was cleaned sequentially with acetone, ethanol, and deionized water.

[0016] In one embodiment, the carrier gas is nitrogen.

[0017] In one embodiment, the combination of the chalcogenide precursor molecule A and the chalcogenide precursor molecule B is any one of the following:

[0018] Germanium dichloride, diethylsilyl tellurium; antimony trichloride, diethylsilyl tellurium; tetramethoxygermanium, diethylsilyl tellurium; tetramethoxygermanium, dimethylsilyl tellurium; triethoxyantimony, dimethylsilyl tellurium.

[0019] In one embodiment,

[0020] The substrate is any one of silicon-silicon dioxide substrate, quartz substrate, aluminum oxide substrate, titanium dioxide substrate, tungsten, titanium nitride, and tungsten-titanium alloy.

[0021] In summary, compared with the prior art, the above-described technical solutions conceived by this invention can achieve the following beneficial effects:

[0022] In atomic layer deposition (ALD) to form chalcogenide phase change films, two components, chalcogenide precursor molecules A and B, are alternately implanted. This invention modifies the substrate surface with either chalcogenide precursor molecule A before ALD. During surface modification, multiple cycles of chalcogenide precursor molecules A are implanted in a pulsed implantation-purge manner until the substrate surface is saturated with chalcogenide precursor molecules A, thus completing the substrate surface modification process. Then, excess chalcogenide precursor molecules A are removed before ALD, and a chalcogenide phase change film is grown on the modified layer. Experiments show that compared to direct ALD, pre-modification before ALD results in a chalcogenide phase change film with superior performance, achieving high conformability and pinhole-free chalcogenide phase change films. Attached Figure Description

[0023] Figure 1 This is a flowchart of the method steps for atomic layer deposition of a sulfur-based phase change thin film in one embodiment;

[0024] Figure 2 This is a surface view of the germanium telluride thin film obtained without surface modification in the comparative example;

[0025] Figure 3 This is a cross-sectional view of the germanium telluride thin film obtained without surface modification in the comparative example;

[0026] Figure 4 This is a surface view of the germanium telluride thin film obtained after surface modification in Example 1;

[0027] Figure 5 This is a cross-sectional view of the germanium telluride thin film obtained after surface modification in Example 1;

[0028] Figure 6 This is a diagram showing the high step coverage effect of the germanium telluride thin film obtained after surface modification in Example 1. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the 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 herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0030] like Figure 1 The diagram shows a flowchart of a method for atomic layer deposition of a sulfur-based phase change film in one embodiment, which mainly includes the following steps.

[0031] Step S100: The substrate is surface modified by continuously multi-pulse injection of chalcogenide precursor molecule A, so that the surface of the substrate is saturated with a bonded chalcogenide modification layer.

[0032] Among them, sulfide precursor molecule A is one of the sulfide precursor molecules used in subsequent atomic layer deposition.

[0033] Specifically, after placing the substrate in the reaction chamber, chalcogenide precursor molecules A are injected. Chalcogenide precursor molecules A adsorb onto the active sites on the substrate surface. This adsorption includes physical adsorption and chemical bonding with surface dangling bonds. To maximize the adsorption of chalcogenide precursor molecules A on the substrate surface, i.e., to maximize the coverage of the substrate surface by chalcogenide precursor molecules A, this invention employs a pulsed injection method, i.e., injecting chalcogenide precursor molecules A in a pulsed injection-purge-injection-purge pattern until adsorption saturation.

[0034] In a specific embodiment, during modification, the injection duration of the chalcogenide precursor molecule A in each pulse cycle is 300 ms to 1500 ms, the purge duration in each pulse cycle is 800 ms to 1500 ms, and the carrier gas flow rate is 300 sccm to 650 sccm. This process can be repeated for 300 to 500 pulse cycles, essentially reaching a state of saturated adsorption. Furthermore, the temperature of the reaction chamber can be set to 80°C to 110°C, the same as the reaction temperature for subsequent atomic layer deposition.

[0035] In one embodiment, the chalcogenide precursor molecule A used for surface modification is preferably a precursor with stronger oxidizing power in atomic layer deposition. For example, when germanium dichloride and disilicide-based tellurium are selected for atomic layer deposition to form a germanium telluride thin film, germanium dichloride is preferred for surface modification, i.e., germanium dichloride is used as chalcogenide precursor molecule A, and disilicide-based tellurium is used as chalcogenide precursor molecule B.

[0036] In one embodiment, prior to surface modification, a cleaning step is included to remove surface impurities and grease molecules. The specific steps are as follows: first, the surface is cleaned with acetone for 10 minutes, then with ethanol for 10 minutes, and finally ultrasonically cleaned with deionized water for 5 minutes to remove excess ethanol.

[0037] In one embodiment, the substrate can be any one of a silicon-silicon dioxide substrate, a quartz substrate, an aluminum oxide substrate, a titanium dioxide substrate, tungsten, titanium nitride, or a tungsten-titanium alloy. The silicon dioxide grown on the silicon-silicon dioxide substrate through surface heat treatment has a thickness of approximately 100 nm to 1000 nm. The growth surfaces of the quartz substrate, aluminum oxide substrate, and titanium dioxide substrate are multiple crystal planes such as

[100] and

[111] . The tungsten-titanium alloy has multiple tungsten-to-titanium element ratios such as 7:3 and 9:1. The titanium nitride can be a metal layer prepared by processes such as PVD or EBE.

[0038] Step S200: Introduce carrier gas to purge the surface-modified substrate to remove excess sulfur-based precursor molecules A that have not been adsorbed on the substrate surface.

[0039] After surface modification, a carrier gas needs to be continuously introduced to remove excess unadsorbed sulfide precursor molecules A from the substrate surface, preventing chemical vapor deposition of these molecules with subsequently injected sulfide precursor molecules B. The carrier gas can be high-purity nitrogen, with a flow rate of 100-650 sccm and a purging time of 2-15 minutes.

[0040] Step S300: Using atomic layer deposition, alternating pulse implantation of chalcogenide precursor molecules A and chalcogenide precursor molecules B is performed on the surface of the purged substrate to grow a chalcogenide phase change film.

[0041] After the purging in step S200, atomic layer deposition can be performed. Chalcogenide precursor molecules A and B are alternately injected into the reaction chamber in a pulsed pattern of injection-purge-injection-purge, growing a chalcogenide phase change film of a certain thickness. During this process, the pulsed and purging steps reduce the probability of both precursors appearing simultaneously in the reaction chamber, preventing the occurrence of chemical vapor phase processes.

[0042] Specifically, the temperature of the reaction chamber can be set to 80℃~110℃. Sulfide precursor molecules A and B are injected into the reaction chamber alternately. The injection time of the sulfur precursor molecules in each pulse cycle is 500ms~1000ms, the purging time of each pulse cycle is 4s~6s, and the carrier gas flow rate is 300sccm-650sccm. After injecting for 300~1000 pulse cycles, a sulfur-based phase change film is grown.

[0043] Specifically, the combination of the above-mentioned sulfur-based precursor molecule A and sulfur-based precursor molecule B can be any of the following: germanium dichloride and disilyl telluride to form germanium telluride thin film; antimony trichloride and disilyl telluride to form antimony tritelluride thin film.

[0044] Taking the formation of germanium telluride thin films from germanium dichloride and disilicon-based tellurium as an example, solid germanium dichloride and liquid disilicon-based tellurium are placed in the precursor chamber, respectively. The purity of the raw materials is not less than 99.9%, and the heating temperatures are 60-90℃ and 40-60℃, respectively. A pretreated substrate is placed in the reaction chamber, and the reaction temperature is 80-110℃. The germanium dichloride precursor is implanted for 500-750 ms and purged for 4-6 s. The disilicon-based tellurium precursor is implanted for 750-1000 ms and purged for 4-6 s. The reaction cycle is 300-1000 cycles, and the carrier gas flows... The growth rate is 400-650 sccm, and the reaction system pressure is 0.5-5 mbar. To match the reaction chamber volume and dry vacuum pump power of the equipment used in this embodiment, the preferred heating temperatures for the solid raw material germanium dichloride and the liquid raw material diethylene silicon-based tellurium precursor are 80°C and 55°C, respectively. The reaction temperature is 90°C, the germanium dichloride precursor injection time is 500 ms and the purge time is 4 s, the diethylene silicon-based tellurium precursor injection time is 750 ms and the purge time is 4 s, the carrier gas flow rate is 600 sccm, and the reaction system pressure is 1 mbar. When the reaction cycle of the above reaction is greater than 300 cycles, a high-conformity, pinhole-free germanium telluride thin film formed by the sequential alternating connection of germanium atoms and tellurium atoms is obtained. Specifically, before introducing the precursor molecules, the air in the reaction chamber is evacuated using a mechanical vacuum pump. When the vacuum reaches 1.0*10-1 mbar, high-purity nitrogen is introduced. This process is to reduce the influence of oxygen and water vapor in the reaction chamber. In one embodiment, the above process requires heating three chambers. When the experiment uses a single heating device, the germanium dichloride precursor temperature zone can be heated first, with a heating rate controlled at 1°C / min to 80°C. When the germanium dichloride precursor reaches 40°C, the diethylsilicon-based tellurium precursor begins to be heated at a rate of 1°C / min to 55°C. This reduces the impact of the high-temperature precursor heating on the low-temperature precursor heating, allowing both precursors to quickly stabilize at the preset temperature. When both precursors are stable at the set temperature, the reaction chamber begins to be heated at a rate of 5°C / min to 90°C. When the reaction chamber temperature stabilizes at the set temperature, the carrier gas is turned on at a flow rate of 600 sccm to expel other gases from the chamber and create a high-purity nitrogen atmosphere. The germanium telluride thin film growth cycle is 500 cycles. After growth is complete, high-purity nitrogen is introduced into the sample delivery chamber to break the vacuum. During this process, the reaction chamber is continuously purged with carrier gas. The sample is then removed after cooling to room temperature. This process can prevent the severe oxidation that may occur when the material surface comes into contact with air at high temperatures, thus ensuring the consistency of the material surface.

[0045] The following is a description using specific embodiments.

[0046] Comparative Example

[0047] A silicon-silicon dioxide substrate was used as the growth substrate, wherein the thickness of the silicon dioxide layer on the silicon surface after heat treatment was 1000 nm. The substrate treatment process is as follows:

[0048] First, the silicon-silicon dioxide substrate was cleaned with acetone for 10 minutes, then with ethanol for 10 minutes, and then ultrasonically cleaned with deionized water for 5 minutes to remove excess ethanol from the surface.

[0049] Germanium telluride thin films were grown in a gas-flow reactor using the aforementioned silicon-silicon dioxide substrate. The growth process is as follows: high-purity germanium dichloride and diethylsilicon-based telluride were used as precursors, high-purity nitrogen was used as the carrier gas, and the growth furnace was a gas-flow alternating injection furnace. Solid germanium dichloride and liquid diethylsilicon-based telluride were placed in the precursor region, and the silicon wafer was placed in the reaction region. The carrier gas flow direction was from the precursor to the reaction chamber. First, the air in the reaction chamber was evacuated using a mechanical vacuum pump. When the vacuum level reached 1.0 × 10⁻¹ mbar, high-purity nitrogen was then introduced. The germanium telluride thin film was epitaxially grown at a pressure of 1 mbar. The growth process involves first heating germanium dichloride at a rate of 1°C / min to 80°C; when the germanium dichloride reaches 40°C, the diethylenesilane-based tellurium is then heated at a rate of 1°C / min to 55°C; once the precursors have reached their set temperatures, the reaction chamber is heated at a rate of 5°C / min to 90°C; and when the reaction chamber temperature stabilizes at the set temperature, the carrier gas is activated at a flow rate of 600 sccm; the growth cycle is 500 cycles. After growth, high-purity nitrogen is introduced into the sample chamber to break the vacuum, while the carrier gas continues to flow through the reaction chamber throughout this process. The sample is then removed after cooling to room temperature.

[0050] Figure 2 The image shows the surface of the germanium telluride thin film obtained in the comparative example, which has a large number of randomly distributed particles and pinhole defects.

[0051] Figure 3 The image shows a cross-sectional view of the germanium telluride thin film obtained in the comparative example. It can be seen from the figure that the cross-section is uneven, the overall thickness is less than 50 nm, the in-plane pinhole defects are obvious, and large particles are present at the top of the film.

[0052] Example 1

[0053] A silicon-silicon dioxide substrate was used as the growth substrate, wherein the thickness of the silicon dioxide layer on the silicon surface after heat treatment was 1000 nm. The substrate treatment process is as follows:

[0054] First, the silicon-silicon dioxide substrate was cleaned with acetone for 10 minutes, then with ethanol for 10 minutes, and then ultrasonically cleaned with deionized water for 5 minutes to remove excess ethanol from the surface.

[0055] The surface treatment is then performed using a germanium dichloride precursor for 300-500 pulse cycles, with the germanium dichloride implantation time being 300-1500 ms within each pulse cycle.

[0056] Finally, the surface-modified substrate was purged with high-purity nitrogen for 2-15 minutes to remove excess precursors from the surface.

[0057] Germanium telluride thin films were grown in a gas-flow reactor using the aforementioned silicon-silicon dioxide substrate. The growth process is as follows: high-purity germanium dichloride and diethylsilicon-based telluride were used as precursors, high-purity nitrogen was used as the carrier gas, and the growth furnace was a gas-flow alternating injection furnace. Solid germanium dichloride and liquid diethylsilicon-based telluride were placed in the precursor region, and the silicon wafer was placed in the reaction region. The carrier gas flow direction was from the precursor to the reaction chamber. First, the air in the reaction chamber was evacuated using a mechanical vacuum pump. When the vacuum level reached 1.0 × 10⁻¹ mbar, high-purity nitrogen was then introduced. The germanium telluride thin film was epitaxially grown at a pressure of 1 mbar. The growth process involves first heating germanium dichloride at a rate of 1°C / min to 80°C; when the germanium dichloride reaches 40°C, the diethylenesilane-based tellurium is then heated at a rate of 1°C / min to 55°C; once the precursors have reached their set temperatures, the reaction chamber is heated at a rate of 5°C / min to 90°C; and when the reaction chamber temperature stabilizes at the set temperature, the carrier gas is activated at a flow rate of 600 sccm; the growth cycle is 500 cycles. After growth, high-purity nitrogen is introduced into the sample chamber to break the vacuum, while the carrier gas continues to flow through the reaction chamber throughout this process. The sample is then removed after cooling to room temperature.

[0058] Figure 4 The image shows the surface of the germanium telluride thin film grown on the silicon-silicon dioxide substrate in Example 1. The surface roughness of the 60nm thick germanium telluride thin film can reach below 0.8nm, the film surface is smooth, and pinholes and particles are not obvious.

[0059] Figure 5 This is a cross-sectional view of the high-conformity germanium telluride thin film grown on the silicon-silicon dioxide substrate in Example 1. The figure shows that the cross-sectional thickness is uniformly high at 60 nm, with no in-plane defects, and the top of the film is continuous without depressions or protrusions.

[0060] Example 2

[0061] A silicon-silicon dioxide substrate was used as the growth substrate, wherein the thickness of the silicon dioxide layer after thermal treatment of the silicon surface was 1000 nm, and the depth of the surface trenches was 200 nm. The substrate processing procedure is as follows:

[0062] First, the silicon-silicon dioxide substrate with silicon dioxide channels is cleaned with acetone for 10 minutes, then with ethanol for 10 minutes, and then ultrasonically cleaned with deionized water for 5 minutes to remove excess ethanol from the surface.

[0063] Then, a germanium dichloride precursor with an injection time of 300-1500 ms is used to treat the surface for 300-500 pulse cycles.

[0064] Finally, the surface-modified substrate was purged with high-purity nitrogen for 2-15 minutes to remove excess precursors from the surface.

[0065] Germanium telluride thin films were grown in a gas-flow reactor using a silicon-silicon dioxide substrate with silicon dioxide channels. The growth process is as follows: high-purity germanium dichloride and diethylsilicon-based telluride were used as precursors, high-purity nitrogen was used as the carrier gas, and the growth furnace was a gas-flow alternating injection furnace. Solid germanium dichloride and liquid diethylsilicon-based telluride were placed in the precursor region, and the silicon wafer was placed in the reaction region. The carrier gas flow direction was from the precursor to the reaction chamber. First, the air in the reaction chamber was evacuated using a mechanical vacuum pump. When the vacuum level reached 1.0 × 10⁻¹ mbar, high-purity nitrogen was then introduced. The germanium telluride thin film was epitaxially grown at a pressure of 1 mbar. The growth process involves first heating germanium dichloride at a rate of 1°C / min to 80°C; when the germanium dichloride reaches 40°C, the diethylenesilane tellurium is then heated at a rate of 1°C / min to 55°C; once the precursors have reached their set temperatures, the reaction chamber is heated at a rate of 5°C / min to 90°C; and when the reaction chamber temperature stabilizes at the set temperature, the carrier gas is activated at a flow rate of 600 sccm; the growth cycle is 1000 cycles. After growth, high-purity nitrogen is introduced into the sample chamber to break the vacuum, while the carrier gas continues to flow through the reaction chamber throughout this process. The sample is then removed after cooling to room temperature.

[0066] Figure 6 This image shows the effect of high step coverage of germanium telluride thin films grown on a typical silica channel. The channel depth is 200 nm, and the film thicknesses at the top, side, and bottom of the steps are 121.73 nm, 118.26 nm, and 115.21 nm, respectively, with a step coverage of over 95%.

[0067] In summary, this invention utilizes pulse implantation of a single chalcogenide precursor molecule to modify the substrate surface before atomic layer deposition, enabling the efficient fabrication of high-conformity, pinhole-free chalcogenide phase change films. This method allows for the production of large-scale batches of chalcogenide phase change films using different types, sizes, and aspect ratios of growth substrates, without requiring high growth temperatures, special surface modifiers, or lengthy fabrication times. The high-conformity, pinhole-free chalcogenide phase change films can be used to fabricate three-dimensional phase change memories with high aspect ratio structures.

[0068] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for atomic layer deposition of chalcogenide phase change thin films, characterized in that, include: Step S1: The substrate is surface modified by continuously multi-pulse injection of chalcogenide precursor molecule A, so that the surface of the substrate is saturated with a bonded chalcogenide modification layer. Step S2: Introduce carrier gas to purge the surface-modified substrate to remove excess sulfide precursor molecules A that have not been adsorbed on the substrate surface. Step S3: Using atomic layer deposition, alternating pulse implantation of chalcogenide precursor molecules A and chalcogenide precursor molecules B is performed on the surface of the purged substrate to grow a chalcogenide phase change film. In step S1, 300 to 500 pulse cycles are injected, the injection time of sulfide precursor molecule A in each pulse cycle is 300 ms to 1500 ms, the purge time in each pulse cycle is 800 ms to 1500 ms, and the carrier gas flow rate is 300 sccm to 650 sccm. In step S3, 300 to 1000 pulse cycles are injected, with the injection duration of sulfide precursor molecules in each pulse cycle being 500 ms to 1000 ms, the purge duration of each pulse cycle being 4 s to 6 s, and the carrier gas flow rate being 300 sccm to 650 sccm. In step S1, sulfur-based precursor molecules with stronger oxidizing properties are selected for substrate surface modification during atomic layer deposition.

2. The method for atomic layer deposition of chalcogenide phase change thin films as described in claim 1, characterized in that, In step S2, the carrier gas flow rate for purging is 100 sccm-650 sccm, and the purging time is 2 min-15 min.

3. The method for atomic layer deposition of chalcogenide phase change thin films as described in claim 1, characterized in that, In step S3, the reaction temperature for atomic layer deposition is 80℃~110℃.

4. The method for atomic layer deposition of chalcogenide phase change thin films as described in claim 3, characterized in that, The reaction temperatures in steps S1 and S3 are the same.

5. The method for atomic layer deposition of chalcogenide phase change thin films as described in claim 1, characterized in that, Before step S1, the following is also included: The substrate surface was cleaned sequentially with acetone, ethanol, and deionized water.

6. The method for atomic layer deposition of chalcogenide phase change thin films as described in claim 1, characterized in that, The carrier gas is nitrogen.

7. The method for atomic layer deposition of chalcogenide phase change thin films as described in claim 1, characterized in that, The combination of the chalcogenide precursor molecule A and the chalcogenide precursor molecule B is any one of the following: Germanium dichloride, diethylsilyl tellurium; antimony trichloride, diethylsilyl tellurium; tetramethoxygermanium, diethylsilyl tellurium; tetramethoxygermanium, dimethylsilyl tellurium; triethoxyantimony, dimethylsilyl tellurium.

8. The method for atomic layer deposition of chalcogenide phase change thin films as described in claim 1, characterized in that, The substrate is any one of silicon-silicon dioxide substrate, quartz substrate, aluminum oxide substrate, titanium dioxide substrate, tungsten, titanium nitride, and tungsten-titanium alloy.

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