Tungsten-silicon alloy target material and preparation method thereof

Abstract

The invention provides a tungsten-silicon alloy target material and a preparation method thereof.The preparation method comprises the following steps that tungsten powder and silicon powder are subjected to high-energy ball milling, and tungsten-silicon alloy powder is obtained; the tungsten-silicon alloy powder is subjected to reduction heat treatment and acid pickling, and pretreated tungsten-silicon alloy powder is obtained; and the pretreated tungsten-silicon alloy powder is subjected to hot pressed sintering, and the tungsten-silicon alloy target material is obtained. According to the preparation method provided by the invention, the WSi2 phase content in the tungsten-silicon alloy target material is remarkably improved through the cooperation of ball milling, reduction and hot pressing sintering processes, the oxygen content of the target material is reduced, the sputtering performance of the tungsten-silicon alloy target material is effectively improved, and the coating quality is improved.

Description

Technical Field

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

[0002] Tungsten-silicon alloys are alloys composed of tungsten and silicon atoms in a specific ratio. Tungsten disilicide (WSi2) is increasingly used in CMOS (Complementary Metal-Oxide-Semiconductor) processes due to its high melting point, good stability, and low resistivity. It is primarily used to enhance the ohmic contact between aluminum and silicon and as a gate conductor alongside polysilicon to reduce gate resistivity.

[0003] Tungsten-silicon alloy thin films feature low resistivity, strong thermal stability, and excellent chemical corrosion resistance. They are a critical component of semiconductor integrated circuits, primarily serving as gate contact layers, diffusion barriers, or adhesion layers. Tungsten-silicon alloy thin films are produced by sputtering a tungsten-silicon alloy target. Due to the significant difference in melting points between tungsten and silicon, with tungsten having a higher melting point, tungsten-silicon alloy targets are typically produced using powder metallurgy.

[0004] CN110714185A discloses a method for preparing a tungsten-silicon target. This method involves mixing polycrystalline silicon particles with tungsten powder, ball-milling the particles to crush them, mixing them with the tungsten powder, and then cold-pressing and vacuum-hot-pressing the sintered target. This method replaces silicon powder with high-purity silicon particles, reducing target production costs.

[0005] CN113862623A discloses a method for preparing a tungsten-silicon target blank, which comprises ball-milling a mixture of tungsten powder and silicon powder, and combining the mixture with heat treatment and sintering to obtain a tungsten-silicon target material with uniformly distributed crystal phases.

[0006] The conventional ball milling and sintering processes used in existing technologies ensure a certain degree of density and uniformity in tungsten-silicon targets. However, the tungsten-silicon alloy contains a relatively high amount of elemental tungsten and silicon phases, resulting in a relatively low amount of WSi2. Furthermore, the target also contains a relatively high oxygen content, which affects the performance of thin films produced during sputtering. Therefore, the present invention provides a low-oxygen, WSi2-rich tungsten-silicon alloy target and a method for preparing the same. Summary of the Invention

[0007] The purpose of the present invention is to provide a tungsten-silicon alloy target material and a preparation method thereof, thereby increasing the WSi2 phase content in the tungsten-silicon alloy target material, reducing the impurity oxygen content, and improving the sputtering performance of the target material.

[0008] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a method for preparing a tungsten-silicon alloy target, the preparation method comprising the following steps:

[0010] (1) high-energy ball milling of tungsten powder and silicon powder to obtain tungsten-silicon alloy powder;

[0011] (2) subjecting the tungsten silicon alloy powder to reduction heat treatment and pickling to obtain pretreated tungsten silicon alloy powder;

[0012] (3) hot pressing and sintering the pretreated tungsten-silicon alloy powder to obtain the tungsten-silicon alloy target.

[0013] The preparation method provided by the present invention first completes a certain degree of alloying of tungsten and silicon through grading of tungsten powder and silicon powder and high-energy ball milling, solves the problem of oxygen increase in the alloy through reduction heat treatment and pickling, and then completes the densification and further alloying of the target material through hot pressing and sintering to prepare a tungsten-silicon alloy target material with high density, high WSi2 phase and low oxygen.

[0014] In the present invention, the "high-energy ball milling" includes any one of stirring ball milling, planetary ball milling or vibration ball milling, or a combination of at least two of them.

[0015] Preferably, the tungsten powder in step (1) has a Fisher particle size of 2-6 μm, for example, 2 μm, 2.5 μm, 3 μm, 3.5 μm, 4 μm, 4.5 μm, 5 μm, 5.5 μm or 6 μm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0016] Preferably, the purity of the tungsten powder in step (1) is ≥3N, for example, it can be 3N, 3.5N, 4N, 4.5N, 5N, 5.5N or 6N, but is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable.

[0017] Preferably, the Fisher particle size of the silicon powder in step (1) is 14-16 μm, for example, 14 μm, 14.5 μm, 15 μm, 15.5 μm or 16 μm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0018] Preferably, the purity of the silicon powder in step (1) is ≥3N, for example, it can be 3N, 3.5N, 4N, 4.5N, 5N, 5.5N or 6N, but is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable.

[0019] Preferably, the mass ratio of the tungsten powder and the silicon powder in step (1) is (2-3):1, for example, it can be 2:1, 2.2:1, 2.42:1, 2.5:1, 2.8:1 or 3:1, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0020] Preferably, the ball-to-material ratio of the high-energy ball milling in step (1) is 1:(4-6), for example, it can be 1:4, 1:4.2, 1:4.5, 1:4.8, 1:5, 1:5.2, 1:5.5, 1:5.8 or 1:6, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0021] Preferably, the rotation speed of the high-energy ball mill in step (1) is 350-450 r / min, for example, it can be 350 r / min, 360 r / min, 380 r / min, 390 r / min, 400 r / min, 410 r / min, 420 r / min, 440 r / min or 450 r / min, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0022] Preferably, the time of the high-energy ball milling in step (1) is 8-16 h, for example, 8 h, 9 h, 10 h, 11 h, 12 h, 13 h, 14 h, 15 h or 16 h, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0023] Preferably, the gas atmosphere of the high-energy ball milling in step (1) includes an inert gas.

[0024] Preferably, the temperature of the reduction heat treatment in step (2) is 600-1000°C, for example, it can be 600°C, 650°C, 700°C, 750°C, 800°C, 850°C, 900°C, 950°C or 1000°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0025] Preferably, the time of the reduction heat treatment in step (2) is 2-6 h, for example, 2 h, 2.5 h, 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.

[0026] Preferably, the reduction heat treatment in step (2) is carried out under a hydrogen atmosphere.

[0027] Preferably, the acid used for pickling in step (2) includes hydrochloric acid and / or hydrofluoric acid.

[0028] Preferably, the mass ratio of hydrochloric acid to hydrofluoric acid is 1:(1.5-2.5), for example, it can be 1:1.5, 1:1.8, 1:2, 1:2.2 or 1:2.5, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0029] Preferably, the mass concentration of the acid used for pickling in step (2) is 20-30%, for example, it can be 20%, 22%, 25%, 28% or 30%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0030] Preferably, the temperature of the hot pressing sintering in step (3) is 1200-1400°C, for example, it can be 1200°C, 1250°C, 1300°C, 1350°C or 1400°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0031] Preferably, the pressure of the hot pressing sintering in step (3) is 20-50 MPa, for example, it can be 20 MPa, 25 MPa, 30 MPa, 35 MPa, 40 MPa, 45 MPa or 50 MPa, but is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable.

[0032] Preferably, the heat preservation and pressure holding time of the hot pressing sintering in step (3) is 2-6 hours, for example, it can be 2 hours, 3 hours, 4 hours, 5 hours or 6 hours, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0033] Preferably, the heating process of the hot pressing sintering in step (3) includes: first heating to 790-810° C. at a first heating rate and keeping the temperature, and then heating to the sintering temperature at a second heating rate.

[0034] The temperature is raised to 790-810°C, for example, 790°C, 795°C, 800°C, 805°C or 810°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0035] Preferably, the first heating rate is 2-4°C / min, for example, it can be 2°C / min, 2.5°C / min, 3°C / min, 3.5°C / min or 4°C / min, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0036] Preferably, the holding time at 790-810° C. is 2-4 h, for example, 2 h, 2.5 h, 3 h, 3.5 h or 4 h, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0037] Preferably, the second heating rate is 4-6°C / min, for example, 4°C / min, 4.5°C / min, 5°C / min, 5.5°C / min or 6°C / min, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0038] Preferably, during the hot pressing sintering process, the temperature and pressure are increased simultaneously to reach the hot pressing sintering pressure and sintering temperature at the same time.

[0039] As a preferred technical solution of the preparation method provided by the present invention, the preparation method comprises the following steps:

[0040] (1) High-energy ball milling of tungsten powder with a Fisher particle size of 2-6 μm and a purity of ≥3N and silicon powder with a Fisher particle size of 14-16 μm and a purity of ≥3N in a mass ratio of (2-3):1, wherein the ball-to-material ratio is 1:(4-6), the rotation speed is 350-450 r / min, and positive pressure argon is filled during the ball milling process for 8-16 hours to obtain tungsten-silicon alloy powder;

[0041] (2) subjecting the tungsten silicon alloy powder to a reduction heat treatment at a temperature of 600-1000° C. for 2-6 hours, cooling the powder in the furnace after the reduction heat treatment, and then performing pickling, wherein the mass concentration of the acid used for pickling is 20-30%, the acid comprising hydrochloric acid and hydrofluoric acid, and the mass ratio of the hydrochloric acid to the hydrofluoric acid is 1:(1.5-2.5), thereby obtaining a pretreated tungsten silicon alloy powder;

[0042] (3) The pretreated tungsten silicon alloy powder is subjected to hot pressing and sintering. The hot pressing and sintering process includes: first heating to 790-810°C at a rate of 2-4°C / min, keeping warm for 2-4h, and then heating to a sintering temperature of 1200-1400°C at a rate of 4-6°C / min. At the same time, the pressure is increased to reach a hot pressing sintering pressure of 20-50MPa when the sintering temperature is reached, and the heat and pressure are kept for 2-6h. After the hot pressing and sintering is completed, the target material is cooled in the furnace to obtain a tungsten silicon alloy target.

[0043] In a second aspect, the present invention provides a tungsten-silicon alloy target material, which is prepared by the preparation method described in the first aspect.

[0044] The tungsten-silicon alloy target provided by the present invention increases the proportion of the WSi2 phase in the tungsten-silicon alloy in the target, reduces the oxygen content of the target, and improves the sputtering quality of the tungsten-silicon alloy target.

[0045] Preferably, the content of WSi2 phase in the tungsten silicon alloy target is 50-90%, for example, it can be 50%, 60%, 70%, 80% or 90%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] The preparation method provided by the present invention significantly increases the WSi2 phase content in the tungsten-silicon alloy target material and reduces the oxygen content of the target material through the coordinated cooperation of ball milling, reduction and hot pressing sintering processes, thereby effectively improving the sputtering performance of the tungsten-silicon alloy target material and improving the coating quality. DETAILED DESCRIPTION

[0048] The technical solution of the present invention is further described below by way of specific embodiments. It should be understood by those skilled in the art that the embodiments are merely to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0049] Example 1

[0050] This embodiment provides a method for preparing a tungsten-silicon alloy target, the method comprising the following steps:

[0051] (1) Tungsten powder with a purity of 3N and a Fisher particle size of 4 μm and silicon powder with a purity of 3N and a Fisher particle size of 15 μm were mixed in a mass ratio of 2.42:1 and subjected to high-energy ball milling. The ball-to-material ratio was 1:5, the ball milling speed was 400 r / min, and positive pressure argon gas was filled for protection during the ball milling process. The ball milling time was 12 h, and tungsten-silicon alloy powder was obtained after ball milling.

[0052] (2) placing the tungsten silicon alloy powder in a reduction furnace and introducing hydrogen to perform reduction heat treatment at a temperature of 800° C. for 4 hours, followed by cooling in the furnace;

[0053] (3) pickling the tungsten silicon alloy powder after the reduction heat treatment with an acid solution, wherein the acid in the acid solution includes hydrochloric acid and hydrofluoric acid, and the mass ratio of hydrochloric acid, hydrofluoric acid and water in the acid solution is 1:2:10, that is, the mass concentration of the acid in the acid solution is 23%, and then washing with water to obtain a pretreated tungsten silicon alloy powder;

[0054] (4) The pretreated tungsten silicon alloy powder is subjected to hot pressing and sintering. The hot pressing and sintering process includes: first heating to 800°C at a rate of 3°C / min and keeping warm for 3 hours, then heating to 1300°C sintering temperature at a rate of 5°C / min, and applying pressure at the same time as the heating process, with a pressure of 40 MPa. When the sintering temperature is reached, the sintering pressure is reached, and the heat and pressure are kept for 4 hours. After the hot pressing and sintering is completed, the tungsten silicon alloy target is obtained by cooling with the furnace.

[0055] Example 2

[0056] This embodiment provides a method for preparing a tungsten-silicon alloy target, the method comprising the following steps:

[0057] (1) 3N purity, 2 μm tungsten powder and 3N purity, 14 μm tungsten powder were mixed in a mass ratio of 2:1 and subjected to high-energy ball milling. The ball-to-material ratio was 1:4 and the ball milling speed was 350 r / min. Positive pressure argon gas was filled for protection during the ball milling process. After ball milling, tungsten-silicon alloy powder was obtained.

[0058] (2) placing the tungsten silicon alloy powder in a reduction furnace and introducing hydrogen to perform reduction heat treatment, wherein the temperature of the reduction heat treatment is 600° C., the time of the reduction heat treatment is 6 hours, and the powder is cooled in the furnace after the reduction is completed;

[0059] (3) pickling the reduced tungsten silicon alloy powder with an acid solution having a mass concentration of 20%, wherein the acid in the acid solution includes hydrochloric acid and hydrofluoric acid, and the mass ratio of hydrochloric acid to hydrofluoric acid is 1:1.5, and then washing with water to obtain a pretreated tungsten silicon alloy powder;

[0060] (4) The pretreated tungsten silicon alloy powder is subjected to hot pressing and sintering. The hot pressing and sintering process includes: first heating to 800°C at a rate of 2°C / min and keeping warm for 4 hours, then heating to a sintering temperature of 1200°C at a rate of 4°C / min, and applying pressure at the same time as the heating process, with a pressure of 50 MPa. When the sintering temperature is reached, the sintering pressure is reached, and the heat and pressure are kept for 2 hours. After the hot pressing and sintering is completed, the target material is cooled in the furnace to obtain the tungsten silicon alloy target.

[0061] Example 3

[0062] This embodiment provides a method for preparing a tungsten-silicon alloy target, the method comprising the following steps:

[0063] (1) 3N purity, 6 μm tungsten powder and 3N purity, 16 μm tungsten powder were mixed with 3N purity, 16 μm tungsten powder in a mass ratio of 3:1 and subjected to high-energy ball milling. The ball-to-material ratio was 1:6, the ball milling speed was 450 r / min, and positive pressure argon gas was filled for protection during the ball milling process. After ball milling, tungsten-silicon alloy powder was obtained.

[0064] (2) placing the tungsten silicon alloy powder in a reduction furnace and introducing hydrogen to perform reduction heat treatment, wherein the temperature of the reduction heat treatment is 1000° C., the time of the reduction heat treatment is 2 h, and the powder is cooled in the furnace after the reduction is completed;

[0065] (3) pickling the reduced tungsten silicon alloy powder with an acid solution having a mass concentration of 30%, wherein the acid in the acid solution includes hydrochloric acid and hydrofluoric acid, and the mass ratio of hydrochloric acid to hydrofluoric acid is 1:2.5, and then washing with water to obtain a pretreated tungsten silicon alloy powder;

[0066] (4) The pretreated tungsten silicon alloy powder is subjected to hot pressing and sintering. The hot pressing and sintering process includes: first heating to 800°C at a rate of 4°C / min and keeping warm for 2 hours, then heating to 1400°C sintering temperature at a rate of 6°C / min, and applying pressure at the same time as the heating process, with a pressure of 20 MPa. When the sintering temperature is reached, the sintering pressure is reached, and the heat and pressure are kept for 6 hours. After the hot pressing and sintering is completed, the tungsten silicon alloy target is cooled in the furnace to obtain the tungsten silicon alloy target.

[0067] Example 4

[0068] This embodiment provides a method for preparing a tungsten-silicon alloy target. Compared with Example 1, the Fisher particle size of the tungsten powder and the silicon powder in step (1) is controlled to be 15 μm, and the rest is the same as Example 1.

[0069] Example 5

[0070] This embodiment provides a method for preparing a tungsten-silicon alloy target. Compared with Example 1, the ball-to-material ratio in the ball milling in step (1) is controlled to be 1:3, and the rest is the same as Example 1.

[0071] Example 6

[0072] This embodiment provides a method for preparing a tungsten-silicon alloy target. Compared with Example 1, the ball-to-material ratio in the ball milling in step (1) is controlled to be 1:7, and the rest is the same as Example 1.

[0073] Example 7

[0074] This embodiment provides a method for preparing a tungsten-silicon alloy target. Compared with Example 1, the rotation speed of the ball mill in step (1) is controlled to be 300 r / min, and the rest are the same as Example 1.

[0075] Example 8

[0076] This embodiment provides a method for preparing a tungsten-silicon alloy target. Compared with Example 1, the rotation speed of the ball mill in step (1) is controlled to be 500 r / min, and the rest are the same as Example 1.

[0077] Example 9

[0078] This embodiment provides a method for preparing a tungsten-silicon alloy target. Compared with Example 1, the pressure of the hot pressing sintering in step (3) is controlled to be 10 MPa, and the rest is the same as Example 1.

[0079] Example 10

[0080] This embodiment provides a method for preparing a tungsten-silicon alloy target. Compared with Example 1, the pressure of the hot pressing sintering in step (3) is controlled to be 60 MPa, and the rest is the same as Example 1.

[0081] Comparative Example 1

[0082] This comparative example provides a method for preparing a tungsten-silicon alloy target. Compared with Example 1, the ball milling in step (1) is not performed, and the rest is the same as Example 1.

[0083] Comparative Example 2

[0084] This comparative example provides a method for preparing a tungsten-silicon alloy target. Compared with Example 1, the reduction heat treatment in step (2) is not performed, and the rest is the same as Example 1.

[0085] Comparative Example 3

[0086] This comparative example provides a method for preparing a tungsten-silicon alloy target. Compared with Example 1, no pressure is applied during sintering in step (3), and the rest is the same as Example 1.

[0087] The density, oxygen content and WSi2 phase content of the tungsten silicon alloy targets prepared in the examples and comparative examples were measured, and the results are listed in Table 1.

[0088] The density test was performed using the Archimedes drainage method, the oxygen content was tested using an oxygen, nitrogen and hydrogen analyzer, and the phase content was determined using X-ray diffraction analysis.

[0089] Table 1

[0090]

[0091]

[0092] As can be seen from Table 1, the tungsten silicon alloy target prepared by the preparation method provided by the present invention has good compactness, high density, high purity, low impurity content, effective control of the oxygen content, high WSi2 phase content, and WSi2 phase content of more than 77%, which can significantly improve the conductivity and thermal stability of the target material, improve the sputtering performance of the target material, and have good film uniformity and consistency. Compared with Example 1, in Comparative Example 1, high-energy ball milling is not performed, and the WSi2 phase content in the target material is significantly reduced, and the density is significantly reduced; in Comparative Example 2, no reduction heat treatment is performed, and the oxygen content in the target material is significantly increased, thereby affecting the alloying and densification of the hot pressing sintering process, and the WSi2 phase content is also reduced at the same time; in Comparative Example 3, no pressurization is performed, the target material density is significantly reduced, and the alloying effect is slightly reduced, and the WSi2 phase content is also reduced at the same time.

[0093] In summary, the preparation method provided by the present invention significantly increases the WSi2 phase content in the tungsten-silicon alloy target material and reduces the oxygen content of the target material through the coordinated cooperation of ball milling, reduction and hot pressing sintering processes, thereby effectively improving the sputtering performance of the tungsten-silicon alloy target material and improving the coating quality.

[0094] The applicant declares that the above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention fall within the scope of protection and disclosure of the present invention.

Claims

1. A method for preparing a tungsten-silicon alloy target, characterized in that: The preparation method comprises the following steps: (1) high-energy ball milling of tungsten powder and silicon powder to obtain tungsten-silicon alloy powder; (2) subjecting the tungsten silicon alloy powder to reduction heat treatment and pickling to obtain pretreated tungsten silicon alloy powder; (3) hot pressing and sintering the pretreated tungsten-silicon alloy powder to obtain the tungsten-silicon alloy target.

2. The preparation method according to claim 1, characterized in that The tungsten powder in step (1) has a Fisher particle size of 2-6 μm; Preferably, the purity of the tungsten powder in step (1) is ≥3N; Preferably, the silicon powder in step (1) has a Fisher particle size of 14-16 μm; Preferably, the purity of the silicon powder in step (1) is ≥3N.

3. The preparation method according to claim 1 or 2, characterized in that The mass ratio of tungsten powder to silicon powder in step (1) is (2-3):

1.

4. The preparation method according to any one of claims 1 to 3, characterized in that The rotation speed of the high-energy ball mill in step (1) is 350-450 r / min; Preferably, the high-energy ball milling time in step (1) is 8-16 hours; Preferably, the ball-to-material ratio of the high-energy ball milling in step (1) is 1:(4-6); Preferably, the gas atmosphere of the high-energy ball milling in step (1) includes an inert gas.

5. The preparation method according to any one of claims 1 to 4, characterized in that The temperature of the reduction heat treatment in step (2) is 600-1000° C. Preferably, the reduction heat treatment time in step (2) is 2-6 hours; Preferably, the reduction heat treatment in step (2) is carried out under a hydrogen atmosphere.

6. The preparation method according to any one of claims 1 to 5, characterized in that The acid used for pickling in step (2) includes hydrochloric acid and / or hydrofluoric acid; Preferably, the mass ratio of hydrochloric acid to hydrofluoric acid is 1:(1.5-2.5); Preferably, the mass concentration of the acid used in the pickling in step (2) is 20-30%.

7. The preparation method according to any one of claims 1 to 6, characterized in that The pressure of the hot pressing sintering in step (3) is 20-50 MPa; Preferably, the sintering temperature of the hot pressing sintering in step (3) is 1200-1400°C; Preferably, the heat preservation and pressure holding time of the hot pressing sintering in step (3) is 2-6 hours.

8. The preparation method according to claim 7, characterized in that The heating process of the hot pressing sintering in step (3) includes: first heating the temperature to 790-810° C. at a first heating rate and then heating the temperature to the sintering temperature at a second heating rate; Preferably, the first heating rate is 2-4°C / min; Preferably, the holding time at 790-810°C is 2-4h; Preferably, the second heating rate is 4-6°C / min; Preferably, during the hot pressing sintering process, the temperature and pressure are increased simultaneously to reach the hot pressing sintering pressure and sintering temperature at the same time.

9. The preparation method according to any one of claims 1 to 8, characterized in that The preparation method comprises the following steps: (1) High-energy ball milling of tungsten powder with a Fisher particle size of 2-6 μm and a purity of ≥3N and silicon powder with a Fisher particle size of 14-16 μm and a purity of ≥3N in a mass ratio of (2-3):1, wherein the ball-to-material ratio is 1:(4-6), the rotation speed is 350-450 r / min, and positive pressure argon is filled during the ball milling process for 8-16 hours to obtain tungsten-silicon alloy powder; (2) subjecting the tungsten silicon alloy powder to a reduction heat treatment at a temperature of 600-1000° C. for 2-6 hours, cooling the powder in the furnace after the reduction heat treatment, and then performing pickling, wherein the mass concentration of the acid used for pickling is 20-30%, the acid comprising hydrochloric acid and hydrofluoric acid, and the mass ratio of the hydrochloric acid to the hydrofluoric acid is 1:(1.5-2.5), thereby obtaining a pretreated tungsten silicon alloy powder; (3) The pretreated tungsten silicon alloy powder is subjected to hot pressing and sintering. The hot pressing and sintering process includes: first heating to 790-810°C at a rate of 2-4°C / min, keeping warm for 2-4h, and then heating to a sintering temperature of 1200-1400°C at a rate of 4-6°C / min. At the same time, the pressure is increased to reach a hot pressing sintering pressure of 20-50MPa when the sintering temperature is reached, and the heat and pressure are kept for 2-6h. After the hot pressing and sintering is completed, the target material is cooled in the furnace to obtain a tungsten silicon alloy target.

10. A tungsten-silicon alloy target, characterized in that: The tungsten-silicon alloy target is prepared by the preparation method according to any one of claims 1 to 9.

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