CN115537740A

CN115537740A - Preparation method of tantalum-silicon alloy sputtering target material

Info

Publication number: CN115537740A
Application number: CN202211324124.6A
Authority: CN
Inventors: 姚力军; 潘杰; 周友平; 黄洁文; 吴东青
Original assignee: Ningbo Jiangfeng Electronic Material Co Ltd
Current assignee: Ningbo Jiangfeng Electronic Material Co Ltd
Priority date: 2022-10-27
Filing date: 2022-10-27
Publication date: 2022-12-30

Abstract

The invention provides a preparation method of a tantalum-silicon alloy sputtering target material, which comprises the steps of uniformly mixing tantalum powder and silicon powder according to a mass ratio, loading the obtained tantalum-silicon powder into a die, compacting to ensure that the flatness is less than 0.5mm, sealing, carrying out hot-pressing sintering for one time to obtain a crude product of a tantalum-silicon alloy blank, then carrying out grinding to ensure that the flatness is less than 0.05mm, putting the obtained tantalum-silicon alloy blank into the die again, sealing, and carrying out hot-pressing sintering for the second time to obtain the tantalum-silicon alloy sputtering target material. The preparation method comprises two times of hot-pressing sintering, firstly, the flatness of tantalum-silicon powder in the die is ensured to be less than 0.5mm, the density of the product is enabled to be more than 97% through the one-time hot-pressing sintering, then, the product is taken out and ground to ensure that the flatness is less than 0.05mm, and then, the tantalum-silicon alloy sputtering target material with the density of more than 99% is obtained through the two-time hot-pressing sintering, so that the risk of cracking of the target material is greatly reduced, and the double effects of improving the density and the yield of the tantalum-silicon alloy sputtering target material at the same time are realized.

Description

Preparation method of tantalum-silicon alloy sputtering target material

Technical Field

The invention relates to the field of target preparation, in particular to a preparation method of a tantalum-silicon alloy sputtering target.

Background

Physical Vapor Deposition (PVD) refers to a process of evaporating a material source by using a low-voltage and large-current arc discharge technique under a vacuum condition, ionizing both evaporated substances and gas by using gas discharge, and then depositing the evaporated substances and reaction products thereof on a workpiece by an acceleration action of an electric field to form a film with a special function. The PVD technology is a core technology of various industries such as semiconductor chip manufacturing industry, solar energy industry, LCD manufacturing industry and the like, and the main methods comprise vacuum evaporation, arc plasma plating, ion coating, molecular beam epitaxy, sputtering coating and the like.

Sputtering is one of the main techniques for preparing thin film materials, and is characterized in that ions generated by an ion source are accelerated and gathered in vacuum to form ion beam flow with high speed energy, the ion beam flows bombard the surface of a solid, kinetic energy exchange is carried out between the ions and atoms on the surface of the solid, the atoms on the surface of the solid leave the solid and are deposited on the surface of a substrate, and the bombarded solid is a raw material for preparing a thin film deposited by a sputtering method and is generally called as a sputtering target material.

Sputtering targets are generally obtained by powder metallurgy sintering molding processes because the sputtering targets prepared by the processes have unique chemical compositions and mechanical and physical properties that cannot be obtained by conventional fusion casting methods. The powder metallurgy sintering forming process is divided into a hot pressing sintering method and a hot isostatic pressing method, and although the sputtering target material prepared by the hot isostatic pressing method can realize higher densification and has more uniform internal organization structure, the hot isostatic pressing method has the defects of high energy consumption and high cost. In contrast, hot press sintering presses powder or pressed compact uniaxially at high temperature, which generates activation diffusion and creep phenomena, and is widely applied in the fields of sintering of solid materials, large-area welding of dissimilar metals and the like. The main principle of hot-pressing sintering is that crystal lattice and crystal boundary diffusion and plastic flow are carried out at high temperature, and the microstructure of the hot-pressing sintered material, such as grain size, grain distribution and the like, is generally ideal, so that the hot-pressing sintered material has the advantages of low energy consumption and low cost.

The tantalum-silicon alloy sputtering target is a novel sputtering target, is used as a good conductor for vacuum sputtering, and can be used in the fields of electronic gate materials and electronic films. In order to make the tantalum-silicon alloy sputtering target material perform good performance during vacuum sputtering, the tantalum-silicon alloy sputtering target material is required to have higher compactness and more uniform internal structure. However, on one hand, the silicon phase in the tantalum-silicon alloy sputtering target is a brittle phase, stress concentration is easy to occur in the sintering and pressurizing process to cause target cracking, and in order to improve the yield of products, the temperature in the sintering process is not too high, so that the tantalum-silicon alloy sputtering target produced in China has low density, cannot meet the requirements of high-end electronic industry on the quality of the sputtering target, and is only suitable for low-end products.

At present, the prior art discloses a preparation method for preparing a tantalum-silicon alloy sputtering target material by adopting hot isostatic pressing, for example, CN110952064a discloses a tantalum-silicon alloy sputtering target material and a preparation method thereof, wherein the preparation method comprises powder mixing, mold filling, cold isostatic pressing, degassing treatment, hot isostatic pressing at 1050-1350 ℃ and machining, so that the tantalum-silicon alloy sputtering target material with the density of more than 99% can be obtained.

In addition, the prior art also discloses a preparation method for preparing a tantalum-silicon alloy sputtering target by adopting hot-pressing sintering, for example, CN112030120a discloses a preparation method for a tantalum-silicon alloy sputtering target, which comprises the following steps: uniformly mixing tantalum powder and silicon powder; (2) filling the mixture into a mold and sealing the mold; (3) Carrying out hot-pressing sintering treatment on the sealed die at 1130-1170 ℃ to obtain a tantalum-silicon alloy sputtering target crude product; (4) machining to obtain a tantalum-silicon alloy sputtering target material; the hot-pressing sintering treatment in the step (3) is preferably a two-stage heating operation, wherein the temperature is firstly increased to 900-1000 ℃ through the first-stage heating, then the temperature is increased to 1130-1170 ℃ through the second-stage heating, and then the pressure is increased to 25-35 MPa. However, even if the hot-pressing sintering treatment in the technical scheme is preferably a two-stage heating operation, the hot-pressing sintering still belongs to the one-step hot-pressing sintering in a hot-pressing sintering furnace, and the high risks of target cracking and low density still exist. The reason is that the density requirement needs to be ensured by one-time hot-pressing sintering, the required temperature is generally high, particularly, the product is basically alloyed in the subsequent high-temperature pressurizing stage, but the surface flatness of the product is poor, stress concentration is caused by uneven stress in the high-temperature pressurizing process, and the target material is easy to crack.

At present, the tantalum-silicon alloy sputtering target material mainly adopts a powder sintering method, and because the silicon phase in the tantalum-silicon alloy sputtering target material is a brittle phase, if the silicon phase is unevenly distributed or silicon particles are agglomerated in the tantalum-silicon target material, the silicon phase is easily a stress concentration point, so that cracking occurs in the sintering and pressurizing process; in addition, the temperature of one-time hot-pressing sintering is set to be too high, and the surface of the tantalum-silicon blank is uneven, so that the tantalum-silicon blank is uneven in stress and is easy to crack in a high-temperature pressurizing stage, and if the sintering temperature is lower, the powder falling phenomenon of a product can be caused, and the density cannot reach the standard. Therefore, how to improve the compactness of the tantalum-silicon alloy sputtering target material and the yield at the same time becomes a technical problem which needs to be solved urgently at present.

Disclosure of Invention

In view of the problems in the prior art, the invention provides a preparation method of a tantalum-silicon alloy sputtering target material, which comprises the steps of uniformly mixing tantalum powder and silicon powder according to a mass ratio, loading the obtained tantalum-silicon powder into a die, compacting to ensure that the flatness is less than 0.5mm, sealing, carrying out hot-pressing sintering for one time to obtain a tantalum-silicon alloy blank crude product, then carrying out grinding to ensure that the flatness is less than 0.05mm, placing the obtained tantalum-silicon alloy blank into the die again, sealing, and carrying out hot-pressing sintering for the second time to obtain the tantalum-silicon alloy sputtering target material. The preparation method comprises two times of hot-pressing sintering, wherein the flatness of tantalum silicon powder in a die is ensured to be less than 0.5mm, the density of a product is enabled to be more than 97% through one time of hot-pressing sintering, then the product is taken out and ground to ensure that the flatness is less than 0.05mm, and then the tantalum silicon alloy sputtering target with the density of more than 99% is obtained through the second time of hot-pressing sintering, so that the risk of cracking of the target is greatly reduced, and the double effects of improving the density and the yield of the tantalum silicon alloy sputtering target are realized simultaneously.

In order to achieve the purpose, the invention adopts the following technical scheme:

the invention aims to provide a preparation method of a tantalum-silicon alloy sputtering target material, which comprises the following steps:

(1) Tantalum powder and silicon powder are uniformly mixed according to the mass ratio to obtain tantalum silicon powder;

(2) Putting the tantalum silicon powder in the step (1) into a die, compacting to ensure that the flatness is less than 0.5mm, and sealing;

(3) Carrying out primary hot-pressing sintering on the sealed die in the step (2) to obtain a tantalum-silicon alloy blank crude product;

(4) Grinding the crude tantalum silicon alloy blank obtained in the step (3) to ensure that the flatness is less than 0.05mm to obtain a tantalum silicon alloy blank;

(5) And (4) putting the tantalum-silicon alloy blank obtained in the step (4) into a mould again, sealing the mould, and performing secondary hot-pressing sintering to obtain the tantalum-silicon alloy sputtering target material.

In order to avoid the problem of cracking caused by stress concentration due to poor flatness in the process of one-time hot-pressing sintering, the invention adopts a two-time hot-pressing sintering method, firstly obtains a tantalum silicon alloy blank crude product with the density of more than 97% through one-time hot-pressing sintering at a lower temperature, then takes out the tantalum silicon alloy blank crude product and improves the flatness of the surface of the target material to be less than 0.05mm through grinding, and then obtains a tantalum silicon alloy sputtering target material with the density of more than 99% through two-time hot-pressing sintering at a higher temperature, thereby greatly reducing the risk of cracking of the target material and realizing the double effects of simultaneously improving the density and yield of the tantalum silicon alloy sputtering target material.

In a preferred embodiment of the present invention, in the step (1), the percentage by mass of silicon is 11 to 15%, and the balance is tantalum and inevitable impurities.

It is to be noted that the percentage by mass of silicon in the mass ratio of the present invention is 11 to 15%, for example, 11%, 12%, 13%, 14%, or 15%, but is not limited to the recited values, and other values not recited in the above numerical range are also applicable.

Preferably, the particle size of the tantalum powder in the step (1) is less than 10 μm, and the particle size of the tantalum powder is guaranteed to be less than 10 μm through screening.

Preferably, the particle size of the silicon powder in the step (1) is less than 10 μm, and the particle size of the silicon powder is guaranteed to be less than 10 μm through screening.

As a preferred technical scheme of the invention, the mixing in the step (1) is carried out under the protection of inert gas.

Preferably, the inert gas comprises any one or a combination of at least two of helium, nitrogen or argon, preferably argon.

Preferably, the pressure of the inert gas is 0.02 to 0.06MPa, for example 0.02MPa, 0.03MPa, 0.04MPa, 0.05MPa or 0.06MPa, but not limited to the recited values, and other values not recited within the above numerical range are also applicable.

It is worth to say that, when the tantalum powder and the silicon powder are mixed, the preparation method provided by the invention is carried out under the protection of the inert gas, and the pressure of the inert gas is controlled within the range of 0.02-0.06 MPa, so that the uniformity of the mixed powder is ensured on one hand, but the main purposes are to reduce the air content and reduce the risk of air adsorption and oxidation of the non-metal silicon powder due to fine particle size, and thus the product purity of the tantalum-silicon alloy sputtering target is finally improved.

Preferably, the mixing time of the step (1) is more than or equal to 48 hours.

Preferably, the mixing of step (1) is carried out in a three-dimensional powder mixer.

As a preferable technical scheme of the invention, the mould in the step (2) is a graphite mould.

Preferably, the compaction process of step (2) comprises: firstly, the tantalum silicon powder in the die is subjected to flattening treatment, the flatness is guaranteed to be less than 5mm, and then the tantalum silicon powder is subjected to compaction treatment in a manual compression column mode, and the flatness is guaranteed to be less than 0.5mm.

It is worth pointing out that the degree of flatness of the compaction treatment needs to be less than 5mm before the manual column pressing, the situation of local looseness in the manual column pressing process can be effectively prevented, then the compaction treatment is carried out through the manual column pressing, the degree of flatness is less than 0.5mm, and the initial density requirement required by one-time hot-pressing sintering treatment can be met.

As a preferred embodiment of the present invention, the target temperature of the primary hot press sintering in the step (3) is 1150 to 1200 ℃, for example 1150 ℃, 1160 ℃, 1170 ℃, 1180 ℃, 1190 ℃ or 1200 ℃, but is not limited to the above-mentioned values, and other values not listed in the above-mentioned range of values are also applicable.

Preferably, the holding time of the one-time hot-pressing sintering in the step (3) is 60 to 120min, such as 60min, 70min, 80min, 90min, 100min, 110min or 120min, but not limited to the recited values, and other unrecited values in the above-mentioned value range are also applicable.

Preferably, the temperature increase rate of the one-time hot-pressing sintering in step (3) is 2 to 8 ℃/min, such as 2 ℃/min, 3 ℃/min, 4 ℃/min, 5 ℃/min, 6 ℃/min, 7 ℃/min or 8 ℃/min, etc., but is not limited to the recited values, and other values not recited in the above-mentioned range of values are also applicable.

Preferably, in the primary hot press sintering in the step (3), the internal pressure of the sealed mold is controlled to be 30 to 45MPa, for example, 30MPa, 31MPa, 33MPa, 35MPa, 37MPa, 40MPa, 43MPa or 45MPa, but the internal pressure is not limited to the above-mentioned values, and other values not listed in the above-mentioned range of values are also applicable.

Preferably, the one-time hot-pressing sintering in the step (3) is performed in a hot-pressing sintering furnace.

As the preferable technical scheme of the invention, after the primary hot pressing sintering in the step (3), the tantalum-silicon alloy blank crude product is obtained through primary cooling.

Preferably, the temperature reduction rate of the primary temperature reduction is 5 to 10 ℃/min, such as 5 ℃/min, 6 ℃/min, 7 ℃/min, 8 ℃/min, 9 ℃/min, or 10 ℃/min, but is not limited to the recited values, and other values within the above-mentioned range are also applicable.

Preferably, the target temperature of the primary cooling is 100 to 300 ℃, for example, 100 ℃, 130 ℃, 150 ℃, 180 ℃, 200 ℃, 220 ℃, 250 ℃, 280 ℃, or 300 ℃, but is not limited to the recited values, and other values not recited in the above numerical range are also applicable.

In a preferred embodiment of the present invention, the grinding process in step (4) is performed by a surface grinder, and the cutting amount is controlled to be 0.01 to 0.02mm, for example, 0.01mm, 0.012mm, 0.014mm, 0.015mm, 0.017mm, 0.018mm, or 0.02mm, but the present invention is not limited to the above-mentioned values, and other values not listed in the above-mentioned range of values are also applicable.

In a preferred embodiment of the present invention, the target temperature of the secondary hot press sintering in step (5) is 1200 to 1300 ℃, for example, 1200 ℃, 1210 ℃, 1230 ℃, 1250 ℃, 1270 ℃, 1290 ℃ or 1300 ℃, but is not limited to the above-mentioned values, and other values not listed in the above-mentioned range of values are also applicable.

Preferably, the holding time of the secondary hot press sintering in step (5) is 60 to 120min, such as 60min, 70min, 80min, 90min, 100min, 110min or 120min, but not limited to the recited values, and other values not recited in the above range are also applicable.

Preferably, the temperature increase rate of the second hot press sintering in the step (5) is 2 to 5 ℃/min, such as 2 ℃/min, 2.5 ℃/min, 3 ℃/min, 3.5 ℃/min, 4 ℃/min, 4.5 ℃/min, or 5 ℃/min, but is not limited to the recited values, and other values not recited within the above-mentioned range of values are also applicable.

Preferably, in the secondary hot press sintering in the step (5), the internal pressure of the sealed mold is controlled to be 30 to 45MPa, for example, 30MPa, 31MPa, 33MPa, 35MPa, 37MPa, 40MPa, 43MPa or 45MPa, but the internal pressure is not limited to the above-mentioned values, and other values not listed in the above-mentioned range of values are also applicable.

Preferably, the mold of step (5) is a graphite mold.

Preferably, the secondary hot-press sintering of step (5) is performed in a hot-press sintering furnace.

As a preferable technical scheme of the invention, after the secondary hot-pressing sintering in the step (5), secondary temperature reduction is further included.

Preferably, the cooling rate of the secondary cooling is 5 to 10 ℃/min, such as 5 ℃/min, 6 ℃/min, 7 ℃/min, 8 ℃/min, 9 ℃/min, or 10 ℃/min, but not limited to the recited values, and other values within the above range are also applicable.

Preferably, the target temperature of the secondary cooling is 100 to 300 ℃, for example, 100 ℃, 130 ℃, 150 ℃, 180 ℃, 200 ℃, 220 ℃, 250 ℃, 280 ℃ or 300 ℃, but is not limited to the recited values, and other unrecited values within the above-mentioned range of values are also applicable.

As a preferred technical scheme of the invention, the preparation method comprises the following steps:

(1) Adding tantalum powder with the particle size less than 10 mu m and silicon powder with the particle size less than 10 mu m into a three-dimensional powder mixer according to the mass ratio, and uniformly mixing for more than or equal to 48 hours under the protection of inert gas with the pressure of 0.02-0.06 MPa to obtain tantalum-silicon powder;

wherein, the mass percentage of the silicon in the mass proportion is 11-15%, and the rest is tantalum and inevitable impurities;

(2) Placing the tantalum silicon powder in the step (1) into a graphite die, firstly, flattening the tantalum silicon powder in the die to ensure that the flatness is less than 5mm, then, compacting by adopting a manual compression column mode to ensure that the flatness is less than 0.5mm, and sealing;

(3) Putting the sealed die in the step (2) into a hot-pressing sintering furnace for primary hot-pressing sintering, heating to 1150-1200 ℃ at a heating rate of 2-8 ℃/min, and keeping the temperature for 60-120 min, controlling the internal pressure of the sealed die to be 30-45 MPa in the primary hot-pressing sintering, and cooling to a target temperature of 100-300 ℃ at a cooling rate of 5-10 ℃/min to obtain a tantalum-silicon alloy blank crude product;

(4) Grinding the tantalum-silicon alloy blank crude product obtained in the step (3) by using a surface grinding machine, controlling the cutting amount to be 0.01-0.02 mm, and ensuring the flatness to be less than 0.05mm to obtain a tantalum-silicon alloy blank;

(5) And (3) putting the tantalum-silicon alloy blank obtained in the step (4) into a graphite die again, sealing, putting the sealed die into a hot-pressing sintering furnace, performing secondary hot-pressing sintering, heating to 1200-1300 ℃ at a heating rate of 2-5 ℃/min, and keeping the temperature for 60-120 min, wherein in the secondary hot-pressing sintering, the internal pressure of the sealed die is controlled to be 30-45 MPa, and the temperature is secondarily reduced to a target temperature of 100-300 ℃ at a cooling rate of 5-10 ℃/min, so as to obtain the tantalum-silicon alloy sputtering target material.

Compared with the prior art, the invention at least has the following beneficial effects:

the preparation method comprises two times of hot-pressing sintering, firstly, the flatness of tantalum-silicon powder in the die is ensured to be less than 0.5mm, the density of the product is enabled to be more than 97% through the one-time hot-pressing sintering, then, the product is taken out and ground to ensure that the flatness is less than 0.05mm, and then, the tantalum-silicon alloy sputtering target material with the density of more than 99% is obtained through the two-time hot-pressing sintering, so that the risk of cracking of the target material is greatly reduced, and the double effects of improving the density and the yield of the tantalum-silicon alloy sputtering target material at the same time are realized.

Detailed Description

For the purpose of facilitating an understanding of the present invention, the present invention will now be described by way of examples. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.

Example 1

The embodiment provides a preparation method of a tantalum-silicon alloy sputtering target material, which comprises the following steps:

(1) Adding tantalum powder with the particle size less than 10 mu m and silicon powder with the particle size less than 10 mu m into a three-dimensional powder mixer according to the mass ratio, and uniformly mixing for 48 hours under the protection of argon with the pressure of 0.04MPa to obtain tantalum silicon powder;

wherein, the mass percentage of the silicon in the mass proportion is 13.44 percent, and the balance is tantalum and inevitable impurities;

(3) Putting the sealed die in the step (2) into a hot-pressing sintering furnace for primary hot-pressing sintering, heating to 1180 ℃ at a heating rate of 5 ℃/min, and keeping the temperature for 100min, wherein in the primary hot-pressing sintering, the internal pressure of the sealed die is controlled to be 40MPa, and the temperature is reduced to 200 ℃ at a cooling rate of 8 ℃/min to obtain a tantalum-silicon alloy blank crude product;

(4) Grinding the tantalum-silicon alloy blank crude product obtained in the step (3) by using a surface grinding machine, controlling the cutting amount to be 0.01mm, and ensuring the flatness to be less than 0.05mm to obtain a tantalum-silicon alloy blank;

(5) And (3) putting the tantalum-silicon alloy blank obtained in the step (4) into a graphite die again, sealing, putting the sealed die into a hot-pressing sintering furnace, performing secondary hot-pressing sintering, heating to 1250 ℃ at a heating rate of 3 ℃/min, and keeping the temperature for 100min, wherein in the secondary hot-pressing sintering, the internal pressure of the sealed die is controlled to be 40MPa, and the temperature is secondarily reduced to 100 ℃ at a cooling rate of 8 ℃/min to obtain the tantalum-silicon alloy sputtering target material.

Example 2

(1) Adding tantalum powder with the particle size less than 10 mu m and silicon powder with the particle size less than 10 mu m into a three-dimensional powder mixer according to the mass ratio, uniformly mixing for 52 hours, and carrying out mixing under the protection of argon with the pressure of 0.02MPa to obtain tantalum-silicon powder;

wherein, the mass percentage of the silicon in the mass proportion is 11 percent, and the balance is tantalum and inevitable impurities;

(3) Putting the sealed die in the step (2) into a hot-pressing sintering furnace to carry out primary hot-pressing sintering, heating to 1150 ℃ at a heating rate of 2 ℃/min, and keeping the temperature for 60min, controlling the internal pressure of the sealed die to be 30MPa in the primary hot-pressing sintering, and cooling to 100 ℃ at a cooling rate of 5 ℃/min to obtain a tantalum-silicon alloy blank crude product;

(5) And (3) putting the tantalum-silicon alloy blank obtained in the step (4) into a graphite die again, sealing, putting the sealed die into a hot-pressing sintering furnace, performing secondary hot-pressing sintering, heating to 1200 ℃ at a heating rate of 2 ℃/min, and keeping the temperature for 60min, wherein in the secondary hot-pressing sintering, the internal pressure of the sealed die is controlled to be 30MPa, and the temperature is secondarily reduced to a target temperature of 100 ℃ at a cooling rate of 5 ℃/min to obtain the tantalum-silicon alloy sputtering target material.

Example 3

(1) Adding tantalum powder with the particle size less than 10 mu m and silicon powder with the particle size less than 10 mu m into a three-dimensional powder mixer according to the mass ratio, and uniformly mixing for 48 hours under the protection of argon with the pressure of 0.06MPa to obtain tantalum silicon powder;

wherein, the mass percentage of the silicon in the mass proportion is 15 percent, and the balance is tantalum and inevitable impurities;

(3) Putting the sealed die in the step (2) into a hot-pressing sintering furnace for primary hot-pressing sintering, heating to 1200 ℃ at a heating rate of 8 ℃/min, and keeping the temperature for 120min, wherein in the primary hot-pressing sintering, the internal pressure of the sealed die is controlled to be 45MPa, and the temperature is reduced to 300 ℃ at a cooling rate of 10 ℃/min to obtain a tantalum-silicon alloy blank crude product;

(5) And (3) putting the tantalum-silicon alloy blank obtained in the step (4) into a graphite die again, sealing, putting the sealed die into a hot-pressing sintering furnace, performing secondary hot-pressing sintering, heating to 1300 ℃ at a heating rate of 5 ℃/min, and keeping the temperature for 120min, wherein in the secondary hot-pressing sintering, the internal pressure of the sealed die is controlled to be 45MPa, and the temperature is secondarily reduced to a target temperature of 100 ℃ at a cooling rate of 10 ℃/min to obtain the tantalum-silicon alloy sputtering target material.

Example 4

The embodiment provides a preparation method of a tantalum-silicon alloy sputtering target material, which is different from the embodiment 1 only in that: setting the target temperature of the secondary hot-pressing sintering in the step (5) to 1180 ℃.

Example 5

The embodiment provides a preparation method of a tantalum-silicon alloy sputtering target material, which is different from the embodiment 1 only in that: setting the target temperature of the secondary hot-pressing sintering in the step (5) to 1320 ℃.

Example 6

The embodiment provides a preparation method of a tantalum-silicon alloy sputtering target material, which is different from the embodiment 1 only in that: setting the target temperature of the primary hot-pressing sintering in the step (3) to be 1100 ℃.

Example 7

The embodiment provides a preparation method of a tantalum-silicon alloy sputtering target material, which is different from the embodiment 1 only in that: setting the target temperature of the primary hot-pressing sintering in the step (3) to be 1220 ℃.

Comparative example 1

The comparative example provides a preparation method of a tantalum-silicon alloy sputtering target material, and compared with example 1, the method is only different in that: completely omitting the grinding process in the step (4); the specific contents are as follows:

(1') adding tantalum powder with the particle size of less than 10 microns and silicon powder with the particle size of less than 10 microns into a three-dimensional powder mixer according to the mass ratio, and uniformly mixing for 48 hours under the protection of argon with the pressure of 0.04MPa to obtain tantalum-silicon powder;

(2 ') placing the tantalum silicon powder in the step (1') into a graphite die, firstly, flattening the tantalum silicon powder in the die to ensure that the flatness is less than 5mm, then, compacting by adopting a manual compression column mode to ensure that the flatness is less than 0.5mm, and sealing;

(3 ') placing the sealed die in the step (2') into a hot-pressing sintering furnace for hot-pressing sintering for one time, heating to 1180 ℃ at a heating rate of 5 ℃/min, and keeping the temperature for 100min, wherein in the hot-pressing sintering for one time, the internal pressure of the sealed die is controlled to be 40MPa, and the temperature is reduced to 200 ℃ at a cooling rate of 8 ℃/min to obtain a tantalum-silicon alloy blank crude product;

and (4 ') putting the tantalum-silicon alloy blank crude product obtained in the step (3') into a graphite mold again, sealing, putting the sealed mold into a hot-pressing sintering furnace, performing secondary hot-pressing sintering, heating to 1250 ℃ at a heating rate of 3 ℃/min, keeping the temperature for 100min, controlling the internal pressure of the sealed mold to be 40MPa, and performing secondary cooling to a target temperature of 100 ℃ at a cooling rate of 8 ℃/min to obtain the tantalum-silicon alloy sputtering target material.

Comparative example 2

The comparative example provides a preparation method of a tantalum-silicon alloy sputtering target material, and compared with example 1, the method is only different in that: and (4) grinding to obtain the flatness of 0.08mm.

Comparative example 3

This comparative example used the method of preparation of tantalum silicon alloy sputter target described in example 1 of CN112030120a, i.e. only one hot press sintering.

Respectively preparing 50 tantalum-silicon alloy sputtering target materials by adopting the preparation methods in the embodiment and the comparative example, then carrying out statistics on the density and surface cracking conditions of each tantalum-silicon alloy sputtering target material to obtain the average density and the average cracking conditions, and further calculating to obtain the yield; the relevant test methods are as follows:

density: the measurement is carried out according to a basket hanging method disclosed in the national standard GB/T3850-2015 dense sintered metal material and hard alloy density measurement method;

surface cracking condition: judging whether cracks exist or not by visually observing the surface of the tantalum-silicon alloy sputtering target material;

yield X: and counting the number of tantalum-silicon alloy sputtering targets which meet the density and have no cracks on the surface, recording as M, and calculating to obtain the yield corresponding to the corresponding preparation method according to a formula X = M/50 × 100%.

The specific test results are shown in table 1.

TABLE 1

Item	Average density	Average cracking	Yield X
				Example 1	99.92％	Basically does not crack, and only 2 target materials have cracks on the surface	96％
Example 2	99.85％	Is basically notCracking, only 1 target material surface cracks	98％
				Example 3	99.98％	Basically does not crack, and only 2 target materials have cracks on the surface	96％
Example 4	97.52％	Basically does not crack, and only 3 target materials have cracks on the surface	64％
				Example 5	99.98％	Cracks appear on the surface of up to 12 target materials	76％
Example 6	98.85％	Basically does not crack, and only 3 target materials have cracks on the surface	66％
				Example 7	99.97％	Cracks appear on the surface of up to 13 target materials	74％
Comparative example 1	99.95％	Cracks appear on the surface of up to 23 target materials	54％
				Comparative example 2	99.93％	Cracks appear on the surface of up to 6 target materials	88％
Comparative example 3	99.89％	Cracks appear on the surface of up to 25 target materials	50％

From table 1, the following points can be seen:

(1) The preparation method comprises two times of hot-pressing sintering, wherein the flatness of tantalum-silicon powder in a die is ensured to be less than 0.5mm, the density of a product is enabled to be more than 97% through one time of hot-pressing sintering, then the product is taken out and ground to ensure that the flatness is less than 0.05mm, and then the tantalum-silicon alloy sputtering target material with the density of more than 99% is obtained through the two times of hot-pressing sintering, so that the risk of cracking of the target material is greatly reduced, and the double effects of improving the density and the yield of the tantalum-silicon alloy sputtering target material at the same time are realized;

(2) Comparing the example 1 with the examples 4 and 5, since the target temperature of the secondary hot-pressing sintering is set to 1180 ℃ in the example 4, which is lower than the range of 1200-1300 ℃ in the invention, even if the surface of the target material basically does not crack, the density of the target material does not reach the standard, and the yield is low; in the embodiment 5, the target temperature of the secondary hot-pressing sintering is set to be 1320 ℃, which is higher than the range of 1200-1300 ℃, so that even if the density of the target reaches the standard, the overburning causes overlarge stress, cracks appear on the surface of 12 targets, and the yield is low;

(3) Comparing the embodiment 1 with the embodiments 6 and 7, since the embodiment 6 sets the target temperature of one-time hot-pressing sintering to be 1100 ℃ which is lower than the range of 1150-1200 ℃ in the invention, the target material has insufficient density and is easy to fall off powder even though the surface of the target material is basically not cracked, thereby leading to lower yield; in the embodiment 7, the target temperature of the one-time hot-pressing sintering is set to be 1220 ℃ which is higher than the range of 1150-1200 ℃ in the invention, so that even if the density of the target reaches the standard, local stress is concentrated due to over-sintering, cracks appear on the surface of up to 13 targets, and the yield is low;

(4) Comparing the embodiment 1 with the comparative example 1, the comparative example 1 completely omits grinding processing, so that the surface of the tantalum-silicon blank is uneven, the tantalum-silicon blank is stressed unevenly and is easy to crack in the subsequent secondary hot-pressing sintering process, cracks appear on the surface of 23 target materials, and the yield is only 54%;

(5) Comparing the embodiment 1 with the comparative example 2, the flatness of the tantalum-silicon blank surface is still not high due to the fact that the planeness obtained by the limited grinding processing of the comparative example 2 is 0.08mm which is higher than the range of less than 0.05mm, and the tantalum-silicon blank still has the problem of uneven stress in the subsequent secondary hot pressing sintering process, so that cracks appear on the surfaces of 6 target materials, and the yield is reduced to 88%;

(6) Comparing the embodiment 1 with the comparative example 3, as the comparative example 3 only adopts one-time hot-pressing sintering, and the silicon phase in the tantalum-silicon alloy sputtering target material is a brittle phase, the silicon phase is not uniformly distributed or the silicon particles are agglomerated in the tantalum-silicon target material and are easily to become stress concentration points, so that cracking occurs in the sintering and pressurizing process, and the temperature of one-time hot-pressing sintering is set to be too high, meanwhile, the surface of a tantalum-silicon blank is not flat, cracking easily occurs due to nonuniform stress in the high-temperature pressurizing stage, so that the comparative example 3 has 25 target material surfaces with cracks, and the yield is only 50%.

The present invention is illustrated by the above-mentioned examples, but the present invention is not limited to the above-mentioned detailed process equipment and process flow, i.e. it is not meant to imply that the present invention must rely on the above-mentioned detailed process equipment and process flow to be practiced. It should be understood by those skilled in the art that any modification of the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific modes, etc., are within the scope and disclosure of the present invention.

Claims

1. The preparation method of the tantalum-silicon alloy sputtering target is characterized by comprising the following steps:

(1) Uniformly mixing tantalum powder and silicon powder according to a mass ratio to obtain tantalum silicon powder;

(4) Grinding the tantalum-silicon alloy blank crude product obtained in the step (3) to ensure that the flatness is less than 0.05mm to obtain a tantalum-silicon alloy blank;

2. The production method according to claim 1, wherein the mass percentage of silicon in the mass proportion in step (1) is 11 to 15%, and the balance is tantalum and inevitable impurities;

preferably, the particle size of the tantalum powder in the step (1) is less than 10 μm;

preferably, the particle size of the silicon powder in the step (1) is less than 10 μm.

3. The method according to claim 1 or 2, wherein the mixing of step (1) is performed under an inert gas atmosphere;

preferably, the inert gas comprises any one or a combination of at least two of helium, nitrogen or argon, preferably argon;

preferably, the pressure of the inert gas is 0.02 to 0.06MPa;

preferably, the mixing time of the step (1) is more than or equal to 48 hours;

4. The production method according to any one of claims 1 to 3, wherein the mold of step (2) is a graphite mold;

5. The preparation method according to any one of claims 1 to 4, wherein the target temperature of the primary hot-pressing sintering in the step (3) is 1150 to 1200 ℃;

preferably, the heat preservation time of the one-time hot-pressing sintering in the step (3) is 60-120 min;

preferably, the heating rate of the primary hot-pressing sintering in the step (3) is 2-8 ℃/min;

preferably, in the one-time hot-pressing sintering in the step (3), the internal pressure of the sealed die is controlled to be 30-45 MPa;

6. The preparation method according to any one of claims 1 to 5, characterized in that after the primary hot-pressing sintering in step (3), the tantalum-silicon alloy blank crude product is obtained through primary cooling;

preferably, the cooling rate of the primary cooling is 5-10 ℃/min;

preferably, the target temperature of the primary cooling is 100-300 ℃.

7. The production method according to any one of claims 1 to 6, wherein the grinding in step (4) is carried out by a surface grinder, and the amount of the lower blade is controlled to be 0.01 to 0.02mm.

8. The method according to any one of claims 1 to 7, wherein the target temperature of the secondary hot press sintering in the step (5) is 1200 to 1300 ℃;

preferably, the heat preservation time of the secondary hot-pressing sintering in the step (5) is 60-120 min;

preferably, the heating rate of the secondary hot-pressing sintering in the step (5) is 2-5 ℃/min;

preferably, in the secondary hot-pressing sintering in the step (5), the internal pressure of the sealed die is controlled to be 30-45 MPa;

preferably, the mold of step (5) is a graphite mold;

9. The preparation method according to any one of claims 1 to 8, characterized by further comprising a second temperature reduction after the second hot-pressing sintering in step (5);

preferably, the cooling rate of the secondary cooling is 5-10 ℃/min;

preferably, the target temperature of the secondary cooling is 100-300 ℃.

10. The method according to any one of claims 1 to 9, characterized by comprising the steps of: