Germanium-antimony-tellurium alloy target material and preparation method thereof

Abstract

The invention provides a germanium-antimony-tellurium alloy target material and a preparation method thereof, and the preparation method comprises the following steps: sequentially carrying out vacuum degassing, first heat treatment and hot isostatic pressing sintering on germanium-antimony-tellurium alloy powder to obtain the germanium-antimony-tellurium alloy target material. According to the preparation method of the germanium-antimony-tellurium alloy target material, densification of the germanium-antimony-tellurium alloy target material is achieved through the two-step treatment process of the first heat treatment and the hot isostatic pressing sintering, the complex target material preparation process in the prior art is simplified, the compactness of the germanium-antimony-tellurium alloy target material is improved, the compactness of the obtained target material is 97.2% or above, the uniformity of a target body is good, and the preparation process is simple. And the sputtering performance is excellent.

Description

Technical Field

[0001] The invention belongs to the technical field of target material preparation, and in particular relates to a germanium-antimony-tellurium alloy target material and a preparation method thereof. Background Art

[0002] Phase change memory, referred to as PCM, is usually an information storage device that uses the huge difference in conductivity between chalcogenides in the crystalline and amorphous states to store data. Compared with other memories, it has the advantages of small size, low energy consumption, low data loss, and high read and write times. It has a tendency to replace the third-generation memory. Studies have found that germanium antimony telluride materials have the characteristics of fast crystallization rate and large resistivity difference between the crystalline and amorphous states, which can meet the requirements of phase change memory for storage media. Germanium antimony telluride thin films are usually prepared by sputtering coating, and the performance of the germanium antimony telluride alloy target used for sputtering determines the quality of the film.

[0003] At present, the industry mostly uses germanium, antimony and tellurium as raw materials, and produces germanium antimony tellurium alloy by vacuum induction melting combined with casting. Then, the germanium antimony tellurium alloy is used to prepare the target material. The target material prepared by this method has microscopic defects such as multiple pores and uneven composition, which leads to low density of the alloy target material and cannot meet the requirements of magnetron sputtering.

[0004] CN110342473A discloses a method for preparing germanium antimony tellurium powder and target material, wherein Ge powder, Te powder and Sb powder are used to prepare GeTe alloy and Sb 2 Te 3 The two alloys are then ball-milled and homogenized, and heat treated to obtain Ge 2 Sb 2 Te 5 Alloy powder, and then use the alloy powder to fill the mold, and hot press sinter under vacuum at 500-600℃ and 30-45MPa to obtain germanium antimony tellurium target. The density of the target obtained by this method can only reach 98%, there are pores inside, and the sputtering performance is poor.

[0005] CN116947491A discloses a germanium antimony tellurium phase change target material and its preparation method and application, wherein the germanium antimony tellurium alloy powder is subjected to mold processing, vacuum hot pressing sintering processing and machining processing, wherein the vacuum hot pressing sintering processing includes sequentially performing a first pressurization processing, a first heating processing, a first heat preservation and pressure holding processing, a second heating processing, a second heat preservation and pressure holding processing and a second pressurization processing to obtain a germanium antimony tellurium phase change target material. This method requires multiple pressurization and heat preservation and pressure holding processing, has many process steps, and is not conducive to cost reduction and efficiency improvement. Summary of the invention

[0006] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a germanium-antimony-tellurium alloy target and a preparation method thereof, to obtain a germanium-antimony-tellurium alloy target with high density and excellent performance, and to simplify the preparation process.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a method for preparing a germanium-antimony-tellurium alloy target, the preparation method comprising the following steps:

[0009] The germanium antimony tellurium alloy powder is subjected to vacuum degassing, a first heat treatment and hot isostatic pressing sintering in sequence to obtain the germanium antimony tellurium alloy target.

[0010] The preparation method provided by the present invention firstly performs a first heat treatment and then performs hot isostatic pressing sintering. The densification of the germanium antimony tellurium alloy target material is achieved through only two-step processing processes, which simplifies the complex target material preparation process in the prior art, and the obtained target material has high density and good sputtering performance.

[0011] In the present invention, the germanium antimony tellurium alloy powder is Ge 2 Sb 2 Te 5 .

[0012] Preferably, the particle size of the germanium antimony tellurium alloy powder is <75 μm, for example, it can be 1 μm, 10 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm or 74 μm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0013] Preferably, the temperature of the first heat treatment is 200-300°C, for example, it can be 200°C, 220°C, 240°C, 250°C, 260°C, 280°C or 300°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0014] Preferably, the time of the first heat treatment is 50-80 min, for example, it can be 50 min, 55 min, 60 min, 65 min, 70 min, 75 min or 80 min, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0015] Preferably, the hot isostatic pressing sintering temperature is 350-550°C, for example, it can be 350°C, 380°C, 400°C, 420°C, 450°C, 480°C, 500°C, 520°C or 550°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0016] Preferably, the hot isostatic pressing sintering pressure is 90-170 MPa, for example, 90 MPa, 100 MPa, 110 MPa, 120 MPa, 130 MPa, 140 MPa, 150 MPa, 160 MPa or 170 MPa, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0017] Preferably, the hot isostatic pressing sintering time is 3-6 h, for example, 3 h, 3.5 h, 4 h, 4.5 h, 5 h, 5.5 h or 6 h, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0018] Preferably, the temperature of the vacuum degassing is 200-350°C, for example, it can be 200°C, 220°C, 250°C, 280°C, 300°C, 320°C or 350°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0019] Preferably, the vacuum degassing time is 4-8 hours, for example, 4 hours, 5 hours, 6 hours, 7 hours or 8 hours, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0020] Preferably, the endpoint vacuum degree of the vacuum degassing is ≤5.0E-3Pa, for example, it can be 1.0E-4Pa, 5.0E-4Pa, 1.0E-3Pa, 2.0E-3Pa, 3.0E-3Pa, 4.0E-3Pa or 5.0E-3Pa, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0021] Preferably, molding is performed before the vacuum degassing.

[0022] As a preferred technical solution of the preparation method provided by the present invention, the preparation method comprises the following steps:

[0023] (1) selecting germanium antimony tellurium alloy powder with a particle size of less than 75 μm, and placing the germanium antimony tellurium alloy powder into a stainless steel sleeve for molding;

[0024] (2) The alloy powder after molding is subjected to vacuum degassing treatment at a temperature of 200-350° C. for 4-8 hours until the vacuum degree is ≤5.0E-3Pa, and the degassing is terminated;

[0025] (3) The degassed alloy powder is first heat treated at 200-300° C. for 50-80 min, then hot isostatic pressing sintered at 350-550° C. and 90-170 MPa for 3-6 h, and then machined to obtain a germanium antimony tellurium alloy target.

[0026] In a second aspect, the present invention provides a germanium-antimony-tellurium alloy target material, wherein the germanium-antimony-tellurium alloy target material is prepared by the preparation method described in the first aspect.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] The preparation method of the germanium antimony tellurium alloy target provided by the present invention realizes the densification of the germanium antimony tellurium alloy target through a two-step treatment process of a first heat treatment and hot isostatic pressing sintering, simplifies the complex target preparation process of the prior art, and improves the density of the germanium antimony tellurium alloy target. The density of the obtained target is above 97.2%, and the target body has good uniformity and excellent sputtering performance. DETAILED DESCRIPTION

[0029] The technical solution of the present invention is further illustrated below through specific implementation methods.

[0030] A certain embodiment of the present invention provides a method for preparing a germanium-antimony-tellurium alloy target, the preparation method comprising the following steps:

[0031] The germanium antimony tellurium alloy powder is subjected to vacuum degassing, a first heat treatment and hot isostatic pressing sintering in sequence to obtain the germanium antimony tellurium alloy target.

[0032] The preparation method provided by the present invention firstly performs a first heat treatment and then performs hot isostatic pressing sintering. The densification of the germanium antimony tellurium alloy target material is achieved through only two-step processing processes, which simplifies the complex target material preparation process in the prior art, and the obtained target material has high density and good sputtering performance.

[0033] In some embodiments, the particle size of the germanium antimony tellurium alloy powder is <75μm, for example, it can be 1μm, 10μm, 20μm, 30μm, 40μm, 50μm, 60μm, 70μm or 74μm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0034] In some embodiments, the temperature of the first heat treatment is 200-300°C, for example, 200°C, 220°C, 240°C, 250°C, 260°C, 280°C or 300°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0035] In some embodiments, the time of the first heat treatment is 50-80 min, for example, it can be 50 min, 55 min, 60 min, 65 min, 70 min, 75 min or 80 min, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0036] In some embodiments, the hot isostatic pressing sintering temperature is 350-550°C, for example, it can be 350°C, 380°C, 400°C, 420°C, 450°C, 480°C, 500°C, 520°C or 550°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0037] In some embodiments, the hot isostatic pressing sintering pressure is 90-170 MPa, for example, it can be 90 MPa, 100 MPa, 110 MPa, 120 MPa, 130 MPa, 140 MPa, 150 MPa, 160 MPa or 170 MPa, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0038] In some embodiments, the hot isostatic pressing sintering time is 3-6 hours, for example, 3 hours, 3.5 hours, 4 hours, 4.5 hours, 5 hours, 5.5 hours or 6 hours, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0039] In some embodiments, the vacuum degassing temperature is 200-350°C, for example, it can be 200°C, 220°C, 250°C, 280°C, 300°C, 320°C or 350°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0040] In some embodiments, the vacuum degassing time is 4-8 hours, for example, 4 hours, 5 hours, 6 hours, 7 hours or 8 hours, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0041] In some embodiments, the endpoint vacuum degree of the vacuum degassing is ≤5.0E-3Pa, for example, it can be 1.0E-4Pa, 5.0E-4Pa, 1.0E-3Pa, 2.0E-3Pa, 3.0E-3Pa, 4.0E-3Pa or 5.0E-3Pa, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0042] In certain embodiments, molding is performed before the vacuum degassing.

[0043] In order to clearly illustrate the technical solution of the present invention, in a specific embodiment, the germanium antimony tellurium alloy powder used is Ge 2 Sb 2 Te 5 , for purchased commercial products.

[0044] Example 1

[0045] This embodiment provides a method for preparing a germanium-antimony-tellurium alloy target, and the preparation method comprises the following steps:

[0046] (1) selecting germanium antimony tellurium alloy powder with a particle size range of ≤70 μm, placing the germanium antimony tellurium alloy powder into a stainless steel sleeve for molding, and compacting it with a tool;

[0047] (2) Place the welded stainless steel sheath into a heating furnace for vacuum degassing at a temperature of 300°C for 6 hours until the vacuum degree is below 5.0E-3Pa, and then end the degassing process;

[0048] (3) The package is placed in a hot isostatic pressing sintering furnace, first kept at 250° C. for 60 minutes, then kept at 500° C. and 120 MPa for 5 hours, and then machined after sintering to obtain a germanium antimony tellurium alloy target.

[0049] Example 2

[0050] This embodiment provides a method for preparing a germanium-antimony-tellurium alloy target, and the preparation method comprises the following steps:

[0051] (1) selecting germanium antimony tellurium alloy powder with a particle size range of ≤70 μm, placing the germanium antimony tellurium alloy powder into a stainless steel sleeve for molding, and compacting it with a tool;

[0052] (2) Place the welded stainless steel sheath into a heating furnace for vacuum degassing at a temperature of 200°C for 8 hours until the vacuum degree is below 5.0E-3Pa, and then end the degassing process;

[0053] (3) The package is placed in a hot isostatic pressing sintering furnace, first kept at 200° C. for 60 minutes, then kept at 350° C. and 90 MPa for 6 hours, and then machined after sintering to obtain a germanium antimony tellurium alloy target.

[0054] Example 3

[0055] This embodiment provides a method for preparing a germanium-antimony-tellurium alloy target, and the preparation method comprises the following steps:

[0056] (1) selecting germanium antimony tellurium alloy powder with a particle size range of ≤70 μm, placing the germanium antimony tellurium alloy powder into a stainless steel sleeve for molding, and compacting it with a tool;

[0057] (2) Place the welded stainless steel sheath into a heating furnace for vacuum degassing at a temperature of 350°C for 4 hours until the vacuum degree is below 5.0E-3Pa, and then end the degassing process;

[0058] (3) The package is placed in a hot isostatic pressing furnace, first kept at 300° C. for 60 min, then kept at 550° C. and 170 MPa for 3 h, and then machined after sintering to obtain a germanium antimony tellurium alloy target.

[0059] Example 4

[0060] This embodiment provides a method for preparing a germanium-antimony-tellurium alloy target. Compared with Embodiment 1, the temperature of the hot isostatic pressing sintering in step (3) is 300° C., and the rest is the same as Embodiment 1.

[0061] Example 5

[0062] This embodiment provides a method for preparing a germanium-antimony-tellurium alloy target. Compared with Embodiment 1, the temperature of the hot isostatic pressing sintering in step (3) is 600° C., and the rest is the same as Embodiment 1.

[0063] Example 6

[0064] This embodiment provides a method for preparing a germanium-antimony-tellurium alloy target. Compared with Embodiment 1, the pressure of the hot isostatic pressing sintering in step (3) is 60 MPa, and the rest is the same as Embodiment 1.

[0065] Example 7

[0066] This embodiment provides a method for preparing a germanium-antimony-tellurium alloy target. Compared with Embodiment 1, the pressure of the hot isostatic pressing sintering in step (3) is 200 MPa, and the rest is the same as Embodiment 1.

[0067] Comparative Example 1

[0068] This comparative example provides a method for preparing a germanium-antimony-tellurium alloy target. Compared with Example 1, the first heat treatment in step (3) is not performed, and the rest is the same as Example 1.

[0069] Table 1

[0070] Density(%) Uniformity Example 1 99.9 Uniform Example 2 98.1 More uniform Example 3 99.4 Uniform Example 4 97.5 Uneven Example 5 98.7 More uniform Example 6 97.2 More uniform Example 7 98.6 More uniform Comparative Example 1 96.3 Uneven

[0071] As can be seen from Table 1, by comparing Example 1 with Examples 2 and 4, it can be found that when the sintering temperature is low, the diffusion coefficient between the components in the material is small, the atomic diffusion rate is slow, the components cannot be completely homogenized, and the product pores in the sintered product cause low density. By comparing Example 1 with Example 6, it can be found that when the pressure is low, the pores and defects inside the material may not be fully squeezed and filled, resulting in insufficient increase in the density of the material. By comparing Example 1 with Example 7, when the sintering pressure is high, the density and uniformity of the sintered product are good, but this high pressure has high requirements on the equipment and is not suitable for wide application.

[0072] In summary, the preparation method provided by the present invention has simple process steps and can prepare a high-density germanium-antimony-tellurium alloy target material with microscopic uniformity and excellent sputtering performance.

[0073] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a germanium-antimony-tellurium alloy target, characterized in that: The preparation method comprises the following steps: The germanium antimony tellurium alloy powder is subjected to vacuum degassing, a first heat treatment and hot isostatic pressing sintering in sequence to obtain the germanium antimony tellurium alloy target.

2. The preparation method according to claim 1, characterized in that: The particle size of the germanium antimony tellurium alloy powder is less than 75 μm.

3. The preparation method according to claim 1 or 2, characterized in that: The temperature of the first heat treatment is 200-300°C.

4. The preparation method according to any one of claims 1 to 3, characterized in that The first heat treatment time is 50-80 minutes.

5. The preparation method according to any one of claims 1 to 4, characterized in that: The temperature of the hot isostatic pressing sintering is 350-550°C.

6. The preparation method according to any one of claims 1 to 5, characterized in that: The hot isostatic pressing sintering pressure is 90-170 MPa.

7. The preparation method according to any one of claims 1 to 6, characterized in that: The hot isostatic pressing sintering time is 3-6 hours.

8. The preparation method according to any one of claims 1 to 7, characterized in that: The temperature of the vacuum degassing is 200-350°C; Preferably, the vacuum degassing time is 4-8h; Preferably, the endpoint vacuum degree of the vacuum degassing is ≤5.0E-3Pa; Preferably, molding is performed before the vacuum degassing.

9. The preparation method according to any one of claims 1 to 8, characterized in that: The preparation method comprises the following steps: (1) selecting germanium antimony tellurium alloy powder with a particle size of less than 75 μm, and placing the germanium antimony tellurium alloy powder into a stainless steel sleeve for molding; (2) The alloy powder after molding is subjected to vacuum degassing treatment at a temperature of 200-350° C. for 4-8 hours until the vacuum degree is ≤5.0E-3Pa, and the degassing is terminated; (3) The degassed alloy powder is first heat treated at 200-300° C. for 50-80 min, then hot isostatic pressing sintered at 350-550° C. and 90-170 MPa for 3-6 h, and then machined to obtain a germanium antimony tellurium alloy target.

10. A germanium-antimony-tellurium alloy target, characterized in that: The germanium antimony tellurium alloy target is prepared by the preparation method described in any one of claims 1-9.