CN112030120A - Preparation method of tantalum-silicon alloy sputtering target material - Google Patents

Abstract

The invention relates to a preparation method of a tantalum-silicon alloy sputtering target material, which comprises the following steps: (1) uniformly mixing tantalum powder and silicon powder; (2) filling into a mold and sealing; (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) and (4) obtaining the tantalum-silicon alloy sputtering target material through machining. The preparation method can be used for preparing the tantalum-silicon alloy sputtering target material with the purity and the density meeting the requirements, the density reaches more than 99%, the energy consumption and the cost can be reduced, and the preparation method is suitable for large-scale popularization.

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. In recent years, the demand for high-purity tantalum-silicon alloy sputtering targets in China is greatly increased, on one hand, the tantalum-silicon alloy sputtering targets produced in China are low in density, cannot meet the requirements of high-end electronic industries on the quality of the sputtering targets, and are only suitable for low-end products, on the other hand, only a few developed countries and regions such as Japan and America can produce high-purity high-density tantalum-silicon alloy sputtering targets in the world at present, and the production technology is monopolized abroad, so that the cost of the microelectronic industry is high.

At present, the prior art discloses a preparation method for preparing a tantalum-silicon alloy sputtering target by adopting hot isostatic pressing, for example, CN110952064A discloses a tantalum-silicon alloy sputtering target 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 a tantalum-silicon alloy sputtering target with a density of more than 99% can be obtained.

In addition, the prior art discloses preparation methods for preparing sputtering targets by hot-pressing sintering, for example, CN108754436A discloses a vacuum hot-pressing sintering preparation method for high-purity tantalum-ruthenium alloy targets, which comprises the steps of crushing, ball milling, mixing, mold preparation, mold filling and compacting, heating and pressurizing, heat preservation, sampling and machining in sequence by adopting a vacuum hot-pressing sintering technology, and further the prepared sputtering targets with the density of 10.65-13.08 g/cm³The preparation method is not only complicated in operation, but also not suitable for preparing the tantalum-silicon alloy sputtering target material, because the tantalum-silicon alloy sputtering target material is sensitive to temperature abnormity in the densification process, the prior art can not be carried conveniently.

In summary, there is a need to develop a novel method for preparing a tantalum-silicon alloy sputtering target, which can be used to prepare a tantalum-silicon alloy sputtering target with a purity and a density meeting the requirements, and can reduce energy consumption and cost, and is suitable for large-scale popularization.

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 powder mixing, die filling, hot-pressing sintering and machining, so that the tantalum-silicon alloy sputtering target material with the purity and the density meeting the requirements can be prepared, the density can reach more than 99%, the energy consumption and the cost can be reduced, the preparation method has the advantages of shorter flow and simplicity in operation, and is suitable for large-scale popularization.

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

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

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

(2) filling the tantalum silicon powder in the step (1) into a die and sealing the die;

(3) carrying out hot-pressing sintering treatment on the sealed die in the step (2) at 1130-1170 ℃ to obtain a tantalum-silicon alloy sputtering target crude product;

(4) and (4) machining the tantalum-silicon alloy sputtering target crude product obtained in the step (3) to obtain the tantalum-silicon alloy sputtering target.

The preparation method disclosed by the invention adopts hot-pressing sintering treatment, and the hot-pressing sintering temperature is strictly controlled to be 1130-1170 ℃, so that the density of the tantalum-silicon alloy sputtering target material can be greatly improved, the high requirements of more than 99% of density and uniform internal organization structure are met, the energy consumption and the cost can be reduced, the preparation method has the advantages of short process and simplicity in operation, and is suitable for large-scale popularization.

The temperature of the hot press sintering treatment of the present invention is 1130 to 1170 ℃, for example 1130 ℃, 1135 ℃, 1140 ℃, 1145 ℃, 1150 ℃, 1155 ℃, 1160 ℃, 1165 ℃ or 1170 ℃, etc., but is not limited to the recited values, and other values not recited in the range of the recited values are also applicable.

The preparation method disclosed by the invention strictly limits the temperature of hot-pressing sintering treatment within the range of 1130-1170 ℃, so that the problems of abnormal growth of crystal grains and the like caused by overhigh temperature can be prevented, and the problem of substandard density caused by overlow temperature can be prevented.

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

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 the present invention is not limited to the recited values, and other values not recited in the above range are also applicable.

The total content of inevitable impurities in the mass proportion is less than 0.01 percent.

As a preferable technical scheme of the invention, the particle size of the tantalum powder in the step (1) is less than 75 μm, and the particle size of the tantalum powder is ensured to be less than 75 μm by screening.

Preferably, the particle size of the silicon powder in the step (1) is 3-5 μm, and the particle size of the silicon powder is guaranteed to be within the range of 3-5 μm through screening.

As a preferred embodiment of the present invention, the mixing in step (1) is carried out in a powder mixer.

Preferably, the mixing in step (1) is carried out by dry mixing with silicon spheres.

According to the invention, the silicon balls are added for dry mixing, so that other impurity components can be prevented from being doped, and the tantalum powder and the silicon powder can be uniformly mixed; and after the mixing is finished, taking out the silicon balls to obtain the tantalum silicon powder which is uniformly mixed.

Preferably, the mass ratio of the silicon spheres to the sphere material is 1 (8-12), such as 1:8, 1:9, 1:10, 1:11 or 1:12, but not limited to the recited values, and other values not recited in the range of the values are also applicable.

The mass ratio of the ball material refers to the ratio of the mass of the silicon ball to the sum of the mass of the tantalum powder and the silicon powder.

Preferably, the mixing time in step (1) is 20-24 h, such as 20h, 21h, 22h, 23h or 24h, but not limited to the recited values, and other values not recited in the range of the values are also applicable.

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

Preferably, after the step (2) of loading the tantalum silicon powder into the die and before the sealing, a compaction treatment is further included.

Preferably, the compaction process comprises: firstly, the tantalum-silicon alloy powder in the die is subjected to flattening treatment to ensure that the flatness is less than 5mm, and then is subjected to compaction treatment in a manual compression column mode to ensure that the flatness is less than 0.5 mm.

According to the invention, the flatness is required to be less than 5mm before manual column pressing in the compaction treatment, so that 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, and the flatness is ensured to be less than 0.5mm, so that the initial density requirement required by the hot-pressing sintering treatment can be met, and the tantalum-silicon alloy sputtering target material with the density of more than 99% can be obtained through the subsequent hot-pressing sintering treatment.

As a preferable technical solution of the present invention, the hot press sintering process in the step (3) includes the following steps:

and (3) placing the sealed die in the step (2) into a hot-pressing sintering furnace, vacuumizing to be below 100Pa, heating to 900-1000 ℃, preserving heat for 1-1.5 h, heating to 1130-1170 ℃, preserving heat for 1-1.5 h, and finally pressurizing to 25-35 MPa, preserving heat and maintaining pressure for 2-2.5 h.

The hot-pressing sintering treatment adopts a staged heating operation, the temperature is increased to 900-1000 ℃ through primary heating, the target temperature is increased to 1130-1170 ℃ through secondary heating, and then the target pressure is increased to 25-35 MPa through pressurization, so that the internal and external temperatures of the tantalum-silicon powder are uniform, the integral densification degree of the product is uniform in the heat-preservation and pressure-maintaining processes, and the cracking problem caused by insufficient local shrinkage degree is avoided; and the temperature of the first-stage heating is selected to be 900-1000 ℃, so that the densification requirement can be ensured, and the temperature can be reached through rapid heating, thereby saving the time cost and the energy consumption cost.

The temperature of the first-stage heating in the hot press sintering treatment of the present invention is 900 to 1000 ℃, for example, 900 ℃, 930 ℃, 950 ℃, 980 ℃ or 1000 ℃, but is not limited to the recited values, and other values not recited in the numerical range are also applicable.

The first-stage heating and second-stage heating of the hot-pressing sintering treatment of the invention are carried out for 1-1.5 h, such as 1h, 1.1h, 1.2h, 1.3h, 1.4h or 1.5h, but not limited to the recited values, and other values not recited in the numerical range are also applicable.

The pressure of the hot press sintering treatment of the present invention is 25 to 35MPa, for example, 25MPa, 27MPa, 29MPa, 30MPa, 32MPa, 34MPa or 35MPa, but the pressure is not limited to the above-mentioned values, and other values not shown in the above-mentioned range are also applicable.

The heat-preserving and pressure-maintaining time of the hot-pressing sintering treatment of the present invention is 2 to 2.5 hours, for example, 2 hours, 2.1 hours, 2.2 hours, 2.3 hours, 2.4 hours, or 2.5 hours, but the present invention is not limited to the recited values, and other values not recited in the range of the values are also applicable.

As a preferable embodiment of the present invention, the rate of temperature rise to 900 to 1000 ℃ is 8 to 12 ℃/min, for example, 8 ℃/min, 8.5 ℃/min, 9 ℃/min, 9.5 ℃/min, 10 ℃/min, 10.5 ℃/min, 11 ℃/min, 11.5 ℃/min, or 12 ℃/min, but is not limited to the above-mentioned values, and other values not mentioned within the above-mentioned range are also applicable.

Preferably, the rate of temperature increase to 1130-1170 ℃ is 3-7 ℃/min, such as 3 ℃/min, 4 ℃/min, 5 ℃/min, 6 ℃/min, or 7 ℃/min, but not limited to the recited values, and other values not recited within this range are equally applicable.

Preferably, the pressurization rate to 25 to 35MPa is 0.4 to 0.6MPa/min, such as 0.4MPa/min, 0.45MPa/min, 0.5MPa/min, 0.55MPa/min, or 0.6MPa/min, but not limited to the recited values, and other values not recited in the numerical range are also applicable.

As a preferable technical scheme of the invention, the internal pressure of the sealed die needs to be controlled to be less than 6MPa in the temperature rising processes of rising to 900-1000 ℃ and rising to 1130-1170 ℃, and the reasons are as follows: in the temperature rise process, the pressure in the die is increased due to the fact that tantalum-silicon alloy powder expands when heated, and the internal pressure needs to be controlled to be less than 6MPa to ensure that the die cannot deform.

Preferably, after the heat preservation and pressure maintenance are finished, the hot-pressing sintering furnace is closed and cooled, and then argon is filled until the vacuum representation number is-0.06 to-0.08 MPa, such as-0.06 MPa, -0.065MPa, -0.07MPa, -0.075MPa or-0.08 MPa, but the invention is not limited to the values listed, and other values in the numerical range are also applicable.

Preferably, when the temperature in the hot-pressing sintering furnace is less than 200 ℃, the blank in the die is taken out, and the tantalum-silicon alloy sputtering target crude product can be obtained.

As a preferred technical scheme of the invention, the machining in the step (4) comprises grinding and/or wire cutting, and a person skilled in the art can select a specific machining mode according to actual situations.

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

(1) mixing tantalum powder with the particle size of less than 75 microns and silicon powder with the particle size of 3-5 microns in a powder mixer according to a mass ratio, wherein silicon balls are added for dry mixing, the mass ratio of the balls is controlled to be 1 (8-12), and the tantalum powder and the silicon powder are uniformly mixed for 20-24 hours to obtain tantalum-silicon powder;

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

(2) after the tantalum silicon powder in the step (1) is filled into a graphite die, firstly, flattening the tantalum silicon alloy 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 then, sealing;

(3) putting the sealed die in the step (2) into a hot-pressing sintering furnace, vacuumizing to be below 100Pa, heating to 900-1000 ℃ at a heating rate of 8-12 ℃/min, preserving heat for 1-1.5 h, heating to 1130-1170 ℃ at a heating rate of 3-7 ℃/min, preserving heat for 1-1.5 h, and finally pressurizing to 25-35 MPa at a pressurizing rate of 0.4-0.6 MPa/min, preserving heat and maintaining pressure for 2-2.5 h; wherein, in the temperature rising process of rising to 900-1000 ℃ and rising to 1130-1170 ℃, the internal pressure of the sealed die is required to be controlled to be less than 6 MPa;

after the heat preservation and pressure maintenance are finished, closing the hot-pressing sintering furnace and cooling, then introducing argon gas until the vacuum representation number is-0.06-0.08 MPa, and taking out the blank in the die when the temperature in the hot-pressing sintering furnace is less than 200 ℃ to obtain the tantalum-silicon alloy sputtering target crude product;

(4) and (4) machining the tantalum-silicon alloy sputtering target crude product obtained in the step (3) to obtain the tantalum-silicon alloy sputtering target.

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

(1) the preparation method adopts hot-pressing sintering treatment, strictly controls the hot-pressing sintering temperature to be 1130-1170 ℃, can greatly improve the density of the tantalum-silicon alloy sputtering target material, and meets the high requirements of more than 99% of density and uniform internal organization structure;

(2) the preparation method disclosed by the invention can reduce energy consumption and cost, has the advantages of short process and simplicity in operation, and is suitable for large-scale popularization.

Drawings

FIG. 1 is a flow chart of a method for preparing a tantalum-silicon alloy sputtering target material provided by the invention.

Detailed Description

The technical scheme of the invention is further explained by the specific implementation mode in combination with the attached drawings. 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.

Fig. 1 shows a flowchart of a method for preparing a tantalum-silicon alloy sputtering target provided by the invention, which specifically comprises the following steps:

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

(2) filling the tantalum silicon powder in the step (1) into a die and sealing the die;

(3) carrying out hot-pressing sintering treatment on the sealed die in the step (2) at 1130-1170 ℃ to obtain a tantalum-silicon alloy sputtering target crude product;

(4) and (4) machining the tantalum-silicon alloy sputtering target crude product obtained in the step (3) to obtain the tantalum-silicon alloy sputtering target.

To facilitate understanding of the invention, the following examples are set forth:

example 1

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

(1) mixing tantalum powder with the particle size of less than 75 microns and silicon powder with the particle size of 3-5 microns in a powder mixer according to a mass ratio, wherein the mixing adopts a mode of adding silicon balls for dry mixing, the mass ratio of the ball materials is controlled to be 1:10, and the tantalum powder and the silicon powder are uniformly mixed for 24 hours to obtain tantalum powder;

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

(2) after the tantalum silicon powder in the step (1) is filled into a graphite die, firstly, flattening the tantalum silicon alloy 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 then, sealing;

(3) putting the sealed mould in the step (2) into a hot-pressing sintering furnace, vacuumizing to be below 100Pa, heating to 1000 ℃ at a heating rate of 10 ℃/min, preserving heat for 1h, heating to 1150 ℃ at a heating rate of 5 ℃/min, preserving heat for 1h, pressurizing to 30MPa at a pressurizing rate of 0.5MPa/min, preserving heat and maintaining pressure for 2 h; wherein, in the temperature rising process of rising to 900-1000 ℃ and rising to 1130-1170 ℃, the internal pressure of the sealed die is required to be controlled to be less than 6 MPa;

after the heat preservation and pressure maintenance are finished, closing the hot-pressing sintering furnace and cooling, then introducing argon gas until the vacuum representation number is-0.07 MPa, and taking out the blank in the die when the temperature in the hot-pressing sintering furnace is less than 200 ℃ to obtain the tantalum-silicon alloy sputtering target crude product;

(4) and (4) machining the tantalum-silicon alloy sputtering target crude product obtained in the step (3) to obtain the tantalum-silicon alloy sputtering target.

Example 2

The embodiment provides a preparation method of a tantalum-silicon alloy sputtering target, except that the step heating manner in the step (3) is replaced by one-time heating to the target temperature, and other conditions are completely the same as those in the embodiment 1, and the specific contents are as follows:

(3) putting the sealed mould in the step (2) into a hot-pressing sintering furnace, vacuumizing to be below 100Pa, heating to 1150 ℃ at the heating rate of 5 ℃/min, preserving heat for 2h, and finally pressurizing to 30MPa at the pressurizing rate of 0.5MPa/min, preserving heat and maintaining pressure for 2 h; wherein, in the temperature rising process of rising to 900-1000 ℃ and rising to 1130-1170 ℃, the internal pressure of the sealed die is required to be controlled to be less than 6 MPa;

and after the heat preservation and pressure maintenance are finished, closing the hot-pressing sintering furnace and cooling, then introducing argon gas until the vacuum representation number is-0.07 MPa, and taking out the blank in the die when the temperature in the hot-pressing sintering furnace is less than 200 ℃ to obtain the tantalum-silicon alloy sputtering target crude product.

Example 3

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

(1) mixing tantalum powder with the particle size of less than 75 microns and silicon powder with the particle size of 3-5 microns in a powder mixer according to a mass ratio, wherein the mixing adopts a mode of adding silicon balls for dry mixing, the mass ratio of the ball materials is controlled to be 1:8, and the tantalum powder and the silicon powder are uniformly mixed for 20 hours to obtain tantalum powder;

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

(2) after the tantalum silicon powder in the step (1) is filled into a graphite die, firstly, flattening the tantalum silicon alloy 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 then, sealing;

(3) putting the sealed mould in the step (2) into a hot-pressing sintering furnace, vacuumizing to be below 100Pa, heating to 900 ℃ at the heating rate of 8 ℃/min, preserving heat for 1.5h, heating to 1130 ℃ at the heating rate of 3 ℃/min, preserving heat for 1.5h, and finally pressurizing to 25MPa at the pressurizing rate of 0.4MPa/min, preserving heat and maintaining pressure for 2.5 h; wherein, in the temperature rising process of rising to 900-1000 ℃ and rising to 1130-1170 ℃, the internal pressure of the sealed die is required to be controlled to be less than 6 MPa;

after the heat preservation and pressure maintenance are finished, closing the hot-pressing sintering furnace and cooling, then introducing argon gas until the vacuum representation number is-0.06 MPa, and taking out the blank in the die when the temperature in the hot-pressing sintering furnace is less than 200 ℃ to obtain the tantalum-silicon alloy sputtering target crude product;

(4) and (4) machining the tantalum-silicon alloy sputtering target crude product obtained in the step (3) to obtain the tantalum-silicon alloy sputtering target.

Example 4

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

(1) mixing tantalum powder with the particle size of less than 75 microns and silicon powder with the particle size of 3-5 microns in a powder mixer according to a mass ratio, wherein the mixing adopts a mode of adding silicon balls for dry mixing, the mass ratio of the ball materials is controlled to be 1:12, and the tantalum powder and the silicon powder are uniformly mixed for 24 hours to obtain tantalum powder;

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

(2) after the tantalum silicon powder in the step (1) is filled into a graphite die, firstly, flattening the tantalum silicon alloy 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 then, sealing;

(3) putting the sealed die in the step (2) into a hot-pressing sintering furnace, vacuumizing to be below 100Pa, heating to 950 ℃ at the heating rate of 12 ℃/min, preserving heat for 1.2h, heating to 1170 ℃ at the heating rate of 7 ℃/min, preserving heat for 1.3h, and finally pressurizing to 35MPa at the pressurizing rate of 0.6MPa/min, preserving heat and maintaining pressure for 2.3 h; wherein, in the temperature rising process of rising to 900-1000 ℃ and rising to 1130-1170 ℃, the internal pressure of the sealed die is required to be controlled to be less than 6 MPa;

after the heat preservation and pressure maintenance are finished, closing the hot-pressing sintering furnace and cooling, then introducing argon gas until the vacuum representation number is-0.08 MPa, and taking out the blank in the die when the temperature in the hot-pressing sintering furnace is less than 200 ℃ to obtain the tantalum-silicon alloy sputtering target crude product;

(4) and (4) machining the tantalum-silicon alloy sputtering target crude product obtained in the step (3) to obtain the tantalum-silicon alloy sputtering target.

Comparative example 1

The comparative example provides a method for preparing a tantalum-silicon alloy sputtering target material, and the conditions are completely the same as those in example 1 except that the temperature of the secondary temperature rise in the hot-pressing sintering treatment in step (3) (i.e., the target temperature of hot-pressing sintering) is changed from "1150 ℃.

Comparative example 2

The comparative example provides a method for preparing a tantalum-silicon alloy sputtering target material, and the conditions are completely the same as those in example 1 except that the temperature of the secondary temperature rise in the hot-pressing sintering treatment in step (3) (i.e., the target temperature of hot-pressing sintering) is changed from "1150 ℃.

The tantalum-silicon alloy sputtering target materials prepared in the above examples and comparative examples were tested for compactness and internal structure uniformity, and the specific contents are as follows:

density: the measurement is carried out according to the basket hanging method disclosed in the national standard GB/T3850-2015 Density measurement method for dense sintered metal materials and hard alloys;

internal structure uniformity: firstly, a visual standard sample is taken as a standard, and then the surface is clean and uniform in color and luster after precision processing, and no bunch-shaped or dot-shaped specks appear, so that the segregation phenomenon does not appear when the internal structure is uniform;

the specific test results are shown in table 1.

TABLE 1

Group of	Compactness degree	Internal tissue homogeneity
			Example 1	99.7％	Clean surface and uniform color
Example 2	99.1％	Clean surface, uniform color and occasionally cracks
			Example 3	99.4％	Clean surface and uniform color
Example 4	99.3％	Clean surface and uniform color
			Comparative example 1	86.7％	The product has microscopic cavities and spot-shaped spots
Comparative example 2	99.3％	With cluster-like mottles and abnormal growth of grains

From table 1, the following points can be seen:

(1) the preparation method adopts hot-pressing sintering treatment, strictly controls the hot-pressing sintering temperature to be 1130-1170 ℃, can greatly improve the density of the tantalum-silicon alloy sputtering target material, and meets the high requirements of more than 99% of density and uniform internal organization structure;

(2) comparing example 1 with example 2, it can be seen that in example 2, the temperature is raised to the target temperature at a heating rate of 5 ℃/min at one time, and although the density of the prepared tantalum-silicon alloy sputtering target material can reach more than 99%, the problem of uneven internal and external temperatures of tantalum-silicon powder may occur, so that cracks may occasionally occur in the internal tissue, and moreover, the heating rate of 5 ℃/min is adopted in the early stage of heating, which may cause unnecessary waste of time cost and equipment cost;

(3) comparing example 1 with comparative example 1, it can be seen that in comparative example 1, because the hot-press sintering temperature is lower than the range of 1130-1170 ℃ described in the application, the density of the product is lower and is only 86.7%, and the product has microstructure defects of holes and spot-like spots;

(4) comparing example 1 with comparative example 2, it can be seen that in comparative example 2, because the hot-press sintering temperature is higher than the range of 1130-1170 ℃ described in the present application, although the density of the product reaches more than 99%, the product has bunchy spots and structural defects of abnormal growth of crystal grains.

The applicant declares that the present invention illustrates the detailed structural features of the present invention through the above embodiments, but the present invention is not limited to the above detailed structural features, that is, it does not mean that the present invention must be implemented depending on the above detailed structural features. It should be understood by those skilled in the art that any modifications of the present invention, equivalent substitutions of selected components of the present invention, additions of auxiliary components, selection of specific modes, etc., are within the scope and disclosure of the present invention.

The preferred embodiments of the present invention have been described in detail, however, the present invention is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present invention within the technical idea of the present invention, and these simple modifications are within the protective scope of the present invention.

It should be noted that the various technical features described in the above embodiments can be combined in any suitable manner without contradiction, and the invention is not described in any way for the possible combinations in order to avoid unnecessary repetition.

In addition, any combination of the various embodiments of the present invention is also possible, and the same should be considered as the disclosure of the present invention as long as it does not depart from the spirit of the present invention.

Claims (10)

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;

(2) filling the tantalum silicon powder in the step (1) into a die and sealing the die;

(3) carrying out hot-pressing sintering treatment on the sealed die in the step (2) at 1130-1170 ℃ to obtain a tantalum-silicon alloy sputtering target crude product;

(4) and (4) machining the tantalum-silicon alloy sputtering target crude product obtained in the step (3) to obtain the tantalum-silicon alloy sputtering target.

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

3. The method according to claim 1 or 2, wherein the tantalum powder of step (1) has a particle size of < 75 μm;

preferably, the particle size of the silicon powder in the step (1) is 3-5 μm.

4. The method according to any one of claims 1 to 3, wherein the mixing in step (1) is carried out in a powder mixer;

preferably, the mixing in the step (1) adopts a mode of adding silicon spheres for dry mixing;

preferably, the mass ratio of the ball material corresponding to the silicon ball is 1 (8-12);

preferably, the mixing time in the step (1) is 20-24 h.

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

preferably, after the step (2) of loading the tantalum silicon powder into the die and before the sealing, a compaction treatment is further included;

preferably, the compaction process comprises: firstly, the tantalum-silicon alloy powder in the die is subjected to flattening treatment to ensure that the flatness is less than 5mm, and then is subjected to compaction treatment in a manual compression column mode to ensure that the flatness is less than 0.5 mm.

6. The production method according to any one of claims 1 to 5, wherein the hot press sintering treatment in the step (3) comprises the following steps:

and (3) placing the sealed die in the step (2) into a hot-pressing sintering furnace, vacuumizing to be below 100Pa, heating to 900-1000 ℃, preserving heat for 1-1.5 h, heating to 1130-1170 ℃, preserving heat for 1-1.5 h, and finally pressurizing to 25-35 MPa, preserving heat and maintaining pressure for 2-2.5 h.

7. The method according to claim 6, wherein the rate of temperature rise to 900 to 1000 ℃ is 8 to 12 ℃/min;

preferably, the heating rate of the temperature to 1130-1170 ℃ is 3-7 ℃/min;

preferably, the pressurizing rate for pressurizing to 25-35 MPa is 0.4-0.6 MPa/min.

8. The method according to claim 6 or 7, wherein the internal pressure of the sealed mold is controlled to be less than 6MPa in the temperature raising processes of raising the temperature to 900-1000 ℃ and raising the temperature to 1130-1170 ℃;

preferably, after the heat preservation and pressure preservation are finished, closing the hot-pressing sintering furnace and cooling, and then filling argon until the vacuum representation number is-0.06 to-0.08 MPa;

preferably, when the temperature in the hot-pressing sintering furnace is less than 200 ℃, the blank in the die is taken out, and the tantalum-silicon alloy sputtering target crude product can be obtained.

9. The production method according to any one of claims 1 to 8, wherein the machining in the step (4) includes grinding and/or wire cutting.

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

(1) mixing tantalum powder with the particle size of less than 75 microns and silicon powder with the particle size of 3-5 microns in a powder mixer according to a mass ratio, wherein silicon balls are added for dry mixing, the mass ratio of the balls is controlled to be 1 (8-12), and the tantalum powder and the silicon powder are uniformly mixed for 20-24 hours to obtain tantalum-silicon powder;

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

(2) after the tantalum silicon powder in the step (1) is filled into a graphite die, firstly, flattening the tantalum silicon alloy 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 then, sealing;

(3) putting the sealed die in the step (2) into a hot-pressing sintering furnace, vacuumizing to be below 100Pa, heating to 900-1000 ℃ at a heating rate of 8-12 ℃/min, preserving heat for 1-1.5 h, heating to 1130-1170 ℃ at a heating rate of 3-7 ℃/min, preserving heat for 1-1.5 h, and finally pressurizing to 25-35 MPa at a pressurizing rate of 0.4-0.6 MPa/min, preserving heat and maintaining pressure for 2-2.5 h; wherein, in the temperature rising process of rising to 900-1000 ℃ and rising to 1130-1170 ℃, the internal pressure of the sealed die is required to be controlled to be less than 6 MPa;

after the heat preservation and pressure maintenance are finished, closing the hot-pressing sintering furnace and cooling, then introducing argon gas until the vacuum representation number is-0.06-0.08 MPa, and taking out the blank in the die when the temperature in the hot-pressing sintering furnace is less than 200 ℃ to obtain the tantalum-silicon alloy sputtering target crude product;

(4) and (4) machining the tantalum-silicon alloy sputtering target crude product obtained in the step (3) to obtain the tantalum-silicon alloy sputtering target.

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