Tungsten-titanium-silicon alloy sputtering target material and hot isostatic pressing preparation method thereof

Abstract

The invention relates to a tungsten-titanium-silicon alloy sputtering target material and a hot isostatic pressing preparation method thereof, and the hot isostatic pressing preparation method comprises the following steps: (1) filling tungsten-titanium-silicon mixed powder into a mold, sealing, and degassing the sealed mold; (2) carrying out hot isostatic pressing treatment on the mold subjected to degassing treatment in the step (1) at 1100-1200 DEG C to obtain a tungsten-titanium-silicon alloy sputtering target blank; and (3) machining the tungsten-titanium-silicon alloy sputtering target blank obtained in the step (2) to obtain the tungsten-titanium-silicon alloy sputtering target material. The hot isostatic pressing process is adopted, the hot isostatic pressing sintering temperature is controlled to be at the relatively low temperature of 1100-1200 DEG C, the prepared tungsten-titanium-silicon alloy sputtering target material is uniform and compact in internal microstructure and excellent in sputtering performance, the process is simple, the cost is low, the machining production efficiency and the yield are improved, and large-scale popularization is facilitated.

Description

Technical Field

[0001] The invention relates to the technical field of metal materials, and in particular to a tungsten-titanium-silicon alloy sputtering target and a hot isostatic pressing preparation method thereof. Background Art

[0002] At present, sputtering technology is widely used in thin film deposition and surface treatment, especially in the manufacture of semiconductor devices and large-scale integrated circuits in the electronics industry. Sputtering is a technology that uses high-energy particles to bombard the surface of a solid target material, so that atoms or molecules in the target material are emitted and deposited on the substrate to form a thin film. Furthermore, the sputtering method is divided into magnetron sputtering, DC sputtering, and radio frequency sputtering.

[0003] In the sputtering process, the sputtering target is one of the important parts. The purity, surface state and internal structure of the sputtering target directly affect the sputtering efficiency and the quality of the film. High-purity targets help to obtain uniform, dense and defect-free films. Sputtering targets with excellent performance usually have high melting point, high hardness, high density, good thermomechanical properties, excellent corrosion resistance and chemical stability, and high purity.

[0004] Sputtering targets are usually processed and formed by smelting ingot casting, powder metallurgy or mechanical alloying. The smelting ingot casting method is a traditional preparation method, which is to melt the raw material powder and pour it into a mold to form it, but this method has obvious structural defects such as uneven mixing of components and internal pores that cannot be discharged; the mechanical alloying method is to mix the raw materials into alloys through high-energy ball milling, but due to the influence of factors such as reaction conditions during the preparation process of this method, the reaction conditions are uncontrollable, and there is a phenomenon of uneven alloying degree or low alloying degree, which leads to unstable performance of the target during use; the powder metallurgy method is currently the most common method for preparing sputtering targets, which is divided into hot pressing sintering process and hot isostatic pressing process. The hot pressing sintering process refers to loading the mixed powder into a graphite mold, and then placing it in a hot pressing sintering furnace, evacuating to below a certain vacuum degree to ensure that the internal vacuum degree is always at a low state during the sintering process, and then applying pressure vertically from the top. , pressurization and temperature increase are carried out simultaneously, and the rate of temperature increase and the rate of program pressurization are regulated so as to reach the sintering temperature and the vertical pressure at the same time. However, the hot pressing sintering process can only realize longitudinal pressure increase, and cannot realize the same pressure in all directions at the same time, which leads to uneven force on the internal powder, lattice defects, and reduced density. In addition, the pressure that the graphite mold used can withstand is limited. Too high pressure will cause damage to the mold, and then a higher sintering temperature needs to be matched to achieve a higher density; the hot isostatic pressing process refers to placing the mixed powder into a closed sleeve mold, degassing the powder blank in the sleeve at a certain temperature and vacuum degree, ensuring that the sleeve is in a state of low vacuum degree, and then applying the same pressure in all directions at the same time, accompanied by sintering at a certain temperature, combining high pressure with sintering process to achieve the densification of the sputtering target. The sputtering target prepared by the hot isostatic pressing process generally has a uniform fine-grained structure, fewer lattice defects, and uniform and dense internal components, which can improve the process performance and mechanical properties of the material.

[0005] At present, the use of tungsten-titanium-silicon alloy sputtering targets to prepare corresponding tungsten-titanium-silicon thin films in the semiconductor industry has gradually attracted attention. In the magnetron sputtering process of semiconductors, the purity, internal structure, mechanical strength and external dimensions of tungsten-titanium-silicon alloy sputtering targets are extremely high. At the same time, the composition and preparation process of the target have a decisive influence on the various properties of the film layer. In the tungsten-titanium-silicon alloy sputtering target, the melting point of tungsten is as high as 3410℃, the melting point of titanium is 1668℃, and the melting point of silicon is 1410℃. Due to the large difference in the melting points of the three materials, the temperature and pressure of the sintering process need to be strictly controlled during the production of the sputtering target blank. Otherwise, it is very easy to cause the prepared sputtering target to produce more pores, uneven distribution of internal components, and microscopic defects, which will lead to low densification or the production of other impurity products, which will lead to low purity and fail to meet the requirements of the sputtering process.

[0006] CN112111719A discloses a hot pressing sintering method for preparing a tungsten-titanium-silicon alloy sputtering target material, which adopts hot pressing sintering. The sealed mold is placed in a hot pressing sintering furnace, evacuated to below 100Pa, and then heated to 1000-1050°C and kept warm for 1-1.5h, then heated to 1280-1320°C and kept warm for 0.8-1.2h, and finally pressurized to 25-35MPa and kept warm and pressure for 1-3h. In the heating process of heating to 1000-1050°C and heating to 1280-1320°C, it is necessary to control the internal pressure of the sealed mold to be less than 1MPa, and the density of the tungsten-titanium-silicon alloy sputtering target material is greater than 99% and the internal structure is uniform. Through the preparation method disclosed by the invention, the sintering temperature of the hot pressing sintering process is relatively high, the size of the internal grains is relatively large, the energy consumption is relatively high, and no pressure is applied during the heating process, and the heating and pressure increase are not carried out simultaneously, which results in the density of the prepared tungsten-titanium-silicon alloy sputtering target material still being relatively low.

[0007] Therefore, how to achieve low molding temperature and effectively solve the internal pores and uneven composition of the tungsten-titanium-silicon alloy sputtering target has become a problem that needs to be solved urgently, so as to make the tungsten-titanium-silicon alloy sputtering target have high density and high purity, and show excellent sputtering performance. Summary of the invention

[0008] In order to solve the above technical problems, the present invention provides a tungsten-titanium-silicon alloy sputtering target and a hot isostatic pressing preparation method thereof. The hot isostatic pressing process is adopted and the hot isostatic pressing sintering temperature is controlled at a relatively low temperature of 1100-1200°C. The prepared tungsten-titanium-silicon alloy sputtering target has a uniform and dense internal microstructure and excellent sputtering performance. The process is simple, the cost is low, the processing production efficiency and yield are improved, and it is easy to promote on a large scale.

[0009] To achieve this object, the present invention adopts the following technical solutions:

[0010] In a first aspect, the present invention provides a method for preparing a tungsten-titanium-silicon alloy sputtering target by hot isostatic pressing, the preparation method comprising the following steps:

[0011] (1) loading the tungsten-titanium-silicon mixed powder into a mold and sealing it, and degassing the sealed mold;

[0012] (2) subjecting the mold after the degassing treatment in step (1) to hot isostatic pressing at 1100° C. to 1200° C. to obtain a tungsten-titanium-silicon alloy sputtering target blank;

[0013] (3) Machining the tungsten-titanium-silicon alloy sputtering target blank described in step (2) to obtain a tungsten-titanium-silicon alloy sputtering target material.

[0014] The present invention adopts the hot isostatic pressing process and controls the hot isostatic pressing sintering temperature at a relatively low temperature of 1100°C to 1200°C. The purity of the prepared tungsten-titanium-silicon alloy sputtering target material is ≥99.99%, the density is ≥99.50%, and the internal microstructure is uniform and dense, the sputtering performance is excellent, the process is simple, the cost is low, the processing production efficiency and the yield rate are improved, and it is easy to promote on a large scale.

[0015] The hot isostatic pressing process is adopted. The tungsten-titanium-silicon mixed powder in the mold is first degassed to reach a certain density. Then, uniform pressure is applied in all directions of the tungsten-titanium-silicon mixed powder to ensure that the sintered target blank has good density and mechanical properties, uniform internal microstructure, fine particles, and easy machining, thereby improving the overall performance of the tungsten-titanium-silicon alloy sputtering target.

[0016] The temperature of the hot isostatic pressing treatment of the present invention is 1100°C to 1200°C, for example, 1100°C, 1110°C, 1120°C, 1130°C, 1140°C, 1150°C, 1160°C, 1170°C, 1180°C, 1190°C or 1200°C.

[0017] The preparation method of the present invention controls the temperature of the hot isostatic pressing treatment within a relatively low range of 1100°C to 1200°C, so that the tungsten-titanium-silicon alloy target material has better density and purity and meets the performance requirements of the sputtering target material; if the temperature is too high, on the one hand, it will not only fail to further increase the density and purity of the material, but also cause excessive growth of grains inside the target material, thereby reducing the strength and other properties of the target material, affecting the sputtering performance of the target material, reducing stability, and on the other hand, increasing production costs and energy consumption; if the temperature is too low, it is impossible to achieve an increase in the density of the material.

[0018] As a preferred technical solution of the present invention, the hot isostatic pressing treatment in step (2) also includes pre-sintering.

[0019] Preferably, the heating rate of the pre-sintering is 2°C / min to 8°C / min, for example, 2°C / min, 3°C / min, 4°C / min, 5°C / min, 6°C / min, 7°C / min or 8°C / min.

[0020] Preferably, the sintering temperature of the pre-sintering is 850°C to 900°C, for example, 850°C, 860°C, 870°C, 880°C, 890°C or 900°C.

[0021] Preferably, the pressurization rate of the pre-sintering is 0.2 MPa / min to 0.8 MPa / min, for example, 0.2 MPa / min, 0.3 MPa / min, 0.4 MPa / min, 0.5 MPa / min, 0.6 MPa / min, 0.7 MPa / min or 0.8 MPa / min.

[0022] Preferably, the pre-sintering holding time is 1 h to 2 h, such as 1 h, 1.5 h or 2 h.

[0023] As a preferred technical solution of the present invention, the heating rate of the hot isostatic pressing treatment in step (2) is 2°C / min to 8°C / min, for example, 2°C / min, 3°C / min, 4°C / min, 5°C / min, 6°C / min, 7°C / min or 8°C / min, etc.

[0024] Preferably, the pressurization rate of the hot isostatic pressing treatment is 0.2 MPa / min to 0.8 MPa / min, for example, 0.2 MPa / min, 0.3 MPa / min, 0.4 MPa / min, 0.5 MPa / min, 0.6 MPa / min, 0.7 MPa / min or 0.8 MPa / min.

[0025] Preferably, the sintering pressure of the hot isostatic pressing treatment is 90 MPa to 170 MPa, for example, 90 MPa, 100 MPa, 110 MPa, 120 MPa, 130 MPa, 140 MPa, 150 MPa, 160 MPa or 170 MPa.

[0026] Preferably, the heat preservation and pressure holding time of the hot isostatic pressing treatment is 3 hours to 6 hours, such as 3 hours, 4 hours, 5 hours or 6 hours.

[0027] In the present invention, the pre-sintering and hot isostatic pressing processes are accompanied by pressurization at a rate of 0.2MPa / min to 0.8MPa / min, and the pressurization, heating and heat preservation processes are carried out simultaneously, thereby ensuring that the product is sintered densely. When the temperature of the hot isostatic pressing reaches 1100°C to 1200°C and the pressure reaches 90MPa to 170MPa, heat preservation and pressure preservation are started. The pressure and temperature work together, thereby making the tungsten-titanium-silicon alloy sputtering target blank have higher density and purity.

[0028] As a preferred technical solution of the present invention, the temperature of the degassing treatment in step (1) is 200°C to 350°C, for example, 200°C, 220°C, 250°C, 280°C, 300°C, 320°C or 350°C.

[0029] Preferably, the degassing treatment time in step (1) is 4 h to 8 h, for example, 4 h, 5 h, 6 h, 7 h or 8 h.

[0030] Preferably, the degassing treatment in step (1) is carried out in a heating furnace.

[0031] Preferably, the degassing treatment is terminated when the vacuum degree of the degassing treatment in step (1) is ≤5.0E-3Pa, for example, 5.0E-3Pa, 4.0E-3Pa, 3.0E-3Pa, 2.0E-3Pa, 1.0E-3Pa, 9.0E-4Pa, 5.0E-4Pa, 1.0E-4Pa, etc.

[0032] In the present invention, before hot isostatic pressing treatment is carried out, it is necessary to ensure that the gas in the mold is fully removed. On the one hand, it is prevented that the air inside the mold oxidizes the tungsten-titanium-silicon mixed powder under high temperature conditions during the hot isostatic pressing process, and introduces other impurities, causing the target material composition to change and the purity to be low; on the other hand, it can reduce the pores and defects caused by the presence of gas inside the material, and can also make the powder easier to compact during the hot isostatic pressing process, thereby improving the density and uniformity of the material.

[0033] As a preferred technical solution of the present invention, the method for preparing the tungsten-titanium-silicon mixed powder in step (1) comprises: uniformly mixing tungsten powder, titanium powder and silicon powder.

[0034] Preferably, the purity of the tungsten powder is 99.990% to 99.999%, for example, 99.990%, 99.993%, 99.995%, 99.997% or 99.999%.

[0035] Preferably, the particle size of the tungsten powder is 4 μm to 5 μm, such as 4 μm, 4.5 μm or 5 μm.

[0036] Preferably, the purity of the titanium powder is 99.90% to 99.99%, for example, 99.90%, 99.93%, 99.95%, 99.97% or 99.99%.

[0037] Preferably, the particle size of the titanium powder is less than 48μm, for example 47.5μm, 47μm, 46.5μm, 46μm, 45.5μm, 45μm, 44.5μm, 44μm, 43.5μm, 43μm, 42.5μm, 42μm, 41.5μm, 41μm, 40.5μm, 40μm, 38μm, 36μm, 34μm, 32μm or 30μm, etc., preferably 35μm to 47μm.

[0038] Preferably, the purity of the silicon powder is 99.990% to 99.999%, for example, 99.990%, 99.993%, 99.995%, 99.997% or 99.999%.

[0039] Preferably, the particle size of the silicon powder is less than 5 μm, for example, 4.5 μm, 4 μm, 3.5 μm, 3 μm, 2.5 μm, 2 μm, 1.5 μm or 1 μm.

[0040] In the present invention, the particle size of tungsten powder is limited to 4μm to 5μm, the particle size of titanium powder is 35μm to 47μm, and the particle size of silicon powder is less than 5μm. Titanium powder is used as a skeleton, and tungsten powder and silicon powder are filled into the skeleton of titanium powder by utilizing the coordination between large and small particle sizes, so that the mixed tungsten-titanium-silicon mixed powder can achieve a dense effect. Combined with the mixing process, it can ensure that the tungsten powder, titanium powder and silicon powder are fully mixed to obtain a tungsten-titanium-silicon mixed powder with uniform mixing and uniform components, which further determines that the prepared tungsten-titanium-silicon alloy sputtering target has good density and excellent sputtering performance.

[0041] Preferably, in the tungsten-titanium-silicon mixed powder, the content of the titanium powder is 8wt% to 12wt%, for example, 8wt%, 9wt%, 10wt%, 11wt% or 12wt%, etc., the content of the silicon powder is 13wt% to 17wt%, for example, 13wt%, 14wt%, 15wt%, 16wt% or 17wt%, etc., and the rest is tungsten powder and unavoidable impurities.

[0042] As a preferred technical solution of the present invention, the mixing is carried out under a protective atmosphere.

[0043] Preferably, the protective atmosphere comprises argon or nitrogen.

[0044] Preferably, the mixing in step (1) comprises dry ball milling.

[0045] Preferably, the mass ratio of the balls in the dry ball milling is 10:(1-3), such as 10:1, 10:1.5, 10:2, 10:2.5 or 10:3.

[0046] Preferably, the dry ball milling uses zirconium balls or zirconium oxide balls.

[0047] Preferably, the mixing time is ≥48 h, for example 48 h, 54 h, 60 h, 66 h, 72 h, 78 h, 84 h, 90 h or 96 h, etc.

[0048] In the present invention, the mixing time is limited to ≥48h, which can ensure that the tungsten powder, titanium powder and silicon powder are fully mixed to obtain a tungsten-titanium-silicon mixed powder with uniform mixing and uniform composition, thereby determining that the prepared tungsten-titanium-silicon alloy sputtering target has good density and excellent sputtering performance.

[0049] As a preferred technical solution of the present invention, the mold in step (1) is a stainless steel mold.

[0050] Preferably, after the tungsten-titanium-silicon mixed powder is loaded into the mold in step (1) and before the sealing, a compaction process is also included.

[0051] As a preferred technical solution of the present invention, the machining in step (3) includes any one of grinding, wire cutting or machine turning.

[0052] Preferably, after the machining in step (3), the process further includes testing, cleaning, drying and packaging in sequence to obtain a tungsten-titanium-silicon alloy sputtering target.

[0053] As a preferred technical solution of the present invention, the hot isostatic pressing preparation method comprises the following steps:

[0054] (1) dry-milling tungsten powder, titanium powder and silicon powder under a protective atmosphere for ≥48 h, loading the obtained tungsten-titanium-silicon mixed powder into a mold, compacting and sealing it, and degassing the sealed mold at 200° C. to 350° C. for 4 h to 8 h until the vacuum degree is ≤5.0E-3Pa, and then completing the degassing;

[0055] Wherein, the purity of the tungsten powder is 99.990% to 99.999%; the particle size of the tungsten powder is 4μm to 5μm; the purity of the titanium powder is 99.90% to 99.99%; the particle size of the titanium powder is 35μm to 47μm; the purity of the silicon powder is 99.990% to 99.999%; the particle size of the silicon powder is less than 5μm; in the tungsten-titanium-silicon mixed powder, the content of the titanium powder is 8wt% to 12wt%, the content of the silicon powder is 13wt% to 17wt%, and the rest is tungsten powder and inevitable impurities; the protective atmosphere includes argon or nitrogen; the mass ratio of the ball in the dry ball milling is 10:(1 to 3); the dry ball milling uses zirconium balls or zirconium oxide balls; the degassing treatment is carried out in a heating furnace;

[0056] (2) heating the mold after the degassing treatment in step (1) to 850°C to 900°C at a rate of 2°C / min to 8°C / min and keeping it at that temperature for 1h to 2h for pre-sintering; during the heating and keeping process, pressurizing at a rate of 0.2MPa / min to 0.8MPa / min; then heating to 1100°C to 1200°C at a rate of 2°C / min to 8°C / min, and continuing to pressurize to 90MPa to 170MPa at a rate of 0.2MPa / min to 0.8MPa / min; keeping the temperature and pressure for 3h to 6h, and performing hot isostatic pressing treatment to obtain a tungsten-titanium-silicon alloy sputtering target blank;

[0057] (3) machining, inspecting, cleaning, drying and packaging the tungsten-titanium-silicon alloy sputtering target blank of step (2) to obtain a tungsten-titanium-silicon alloy sputtering target;

[0058] The machining includes any one of grinding, wire cutting or machine turning.

[0059] In a second aspect, the present invention further provides a tungsten-titanium-silicon alloy sputtering target, which is prepared according to the hot isostatic pressing preparation method described in the first aspect.

[0060] Compared with the prior art, the present invention has at least the following beneficial effects:

[0061] 1) The preparation method of the present invention controls the sintering temperature of the hot isostatic pressing treatment at 1100°C to 1200°C, and the prepared tungsten-titanium-silicon alloy sputtering target has a purity of ≥99.99%, a density of ≥99.50%, and a uniform and dense internal microstructure, and excellent sputtering performance.

[0062] 2) The hot isostatic pressing sintering preparation method of the present invention can obtain a tungsten-titanium-silicon alloy sputtering target with high density and high purity at a relatively low sintering temperature, has a simple process, low cost, improves processing production efficiency and yield, and is easy to promote on a large scale. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1 It is a schematic diagram of the process of preparing tungsten-titanium-silicon alloy sputtering target material by hot isostatic pressing process of the present invention.

[0064] Figure 2 This is a scanning electron microscope image of the surface of the tungsten-titanium-silicon alloy sputtering target prepared in Example 1 of the present invention.

[0065] Figure 3 This is an EDS image of the surface of the tungsten-titanium-silicon alloy sputtering target prepared in Example 1 of the present invention.

[0066] Figure 4 This is the distribution diagram of the W element in the EDS diagram of the surface of the tungsten-titanium-silicon alloy sputtering target prepared in Example 1 of the present invention.

[0067] Figure 5 This is the distribution diagram of Ti element in the EDS diagram of the surface of the tungsten-titanium-silicon alloy sputtering target prepared in Example 1 of the present invention.

[0068] Figure 6 This is the distribution diagram of Si element in the EDS diagram of the surface of the tungsten-titanium-silicon alloy sputtering target prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0069] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and through specific implementation methods. However, the following examples are only simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims.

[0070] Unless otherwise specified, the raw materials and reagents used in the following examples are commercially available or can be prepared by known methods.

[0071] Figure 1 The schematic diagram of the process of preparing a tungsten-titanium-silicon alloy sputtering target by a hot isostatic pressing process of the present invention is shown. The hot isostatic pressing preparation method comprises the following steps:

[0072] (1) loading the tungsten-titanium-silicon mixed powder into a mold and sealing it, and degassing the sealed mold;

[0073] (2) subjecting the mold after the degassing treatment in step (1) to hot isostatic pressing at 1100° C. to 1200° C. to obtain a tungsten-titanium-silicon alloy sputtering target blank;

[0074] (3) Machining the tungsten-titanium-silicon alloy sputtering target blank described in step (2) to obtain a tungsten-titanium-silicon alloy sputtering target material.

[0075] Example 1

[0076] This embodiment provides a hot isostatic pressing method for preparing a tungsten-titanium-silicon alloy sputtering target, and the hot isostatic pressing method comprises the following steps:

[0077] (1) Dry-milling tungsten powder with a purity of 99.999% and a particle size of 4 μm to 5 μm, titanium powder with a purity of 99.99% and a particle size of 35 μm to 47 μm, and silicon powder with a purity of 99.999% and a particle size of less than 5 μm under an argon atmosphere for 72 hours, with a material ball mass ratio of 10:3, and loading the obtained tungsten-titanium-silicon mixed powder into a mold, compacting and sealing it, and degassing the sealed mold at 300° C. in a heating furnace for 6 hours until the vacuum degree is 1.0E-3Pa, and then degassing is terminated. In the tungsten-titanium-silicon mixed powder, the content of titanium powder is 10wt%, the content of silicon powder is 15wt%, and the rest is tungsten powder and unavoidable impurities;

[0078] (2) heating the mold after the degassing treatment in step (1) to 880° C. at a rate of 5° C. / min and keeping the temperature for 1.5 h. During the heating and keeping temperature, the mold is pressurized at a rate of 0.5 MPa / min. Then, the mold is heated to 1150° C. at a rate of 5° C. / min and pressurized to 120 MPa at a rate of 0.5 MPa / min. The temperature and pressure are kept for 5 h to obtain a tungsten-titanium-silicon alloy sputtering target blank.

[0079] (3) The tungsten-titanium-silicon alloy sputtering target blank described in step (2) is subjected to wire cutting, inspection, cleaning, drying and packaging to obtain a tungsten-titanium-silicon alloy sputtering target material.

[0080] Figure 2The scanning electron microscope image of the surface of the tungsten-titanium-silicon alloy sputtering target prepared in Example 1 is shown. It can be seen from the image that the elements on the target surface are evenly distributed, and no obvious holes or spots are observed.

[0081] Figure 3 The EDS image of the surface of the tungsten-titanium-silicon alloy sputtering target prepared in Example 1 is shown. Figure 4 The distribution diagram of W element in the EDS diagram of the surface of the tungsten-titanium-silicon alloy sputtering target prepared in Example 1 is shown. Figure 5 The distribution diagram of Ti element in the EDS diagram of the surface of the tungsten-titanium-silicon alloy sputtering target prepared in Example 1 is shown. Figure 6 The distribution diagram of Si element in the EDS image of the surface of the tungsten-titanium-silicon alloy sputtering target prepared in Example 1 is shown. It can be seen from the figure that the surface of the target is evenly distributed, and W, Ti and Si elements are evenly distributed on the surface of the target.

[0082] Example 2

[0083] This embodiment provides a hot isostatic pressing method for preparing a tungsten-titanium-silicon alloy sputtering target, and the hot isostatic pressing method comprises the following steps:

[0084] (1) Dry-milling tungsten powder with a purity of 99.999% and a particle size of 4 μm to 5 μm, titanium powder with a purity of 99.95% and a particle size of 35 μm to 47 μm, and silicon powder with a purity of 99.999% and a particle size of less than 5 μm under an argon atmosphere for 48 hours, with a material ball mass ratio of 10:1, and loading the obtained tungsten-titanium-silicon mixed powder into a mold, compacting and sealing it, and degassing the sealed mold at 200° C. in a heating furnace for 8 hours until the vacuum degree is 5.0E-3Pa, and then degassing is terminated. In the tungsten-titanium-silicon mixed powder, the content of titanium powder is 8wt%, the content of silicon powder is 17wt%, and the rest is tungsten powder and unavoidable impurities;

[0085] (2) heating the mold after the degassing treatment in step (1) to 900° C. at a rate of 2° C. / min and keeping the temperature for 1 hour. During the heating and keeping temperature, the mold is pressurized at a rate of 0.8 MPa / min. Then, the mold is heated to 1200° C. at a rate of 2° C. / min, and the mold is pressurized to 170 MPa at a rate of 0.8 MPa / min. The mold is kept at this temperature and pressure for 3 hours to obtain a tungsten-titanium-silicon alloy sputtering target blank.

[0086] (3) The tungsten-titanium-silicon alloy sputtering target blank described in step (2) is subjected to wire cutting, inspection, cleaning, drying and packaging to obtain a tungsten-titanium-silicon alloy sputtering target material.

[0087] Example 3

[0088] This embodiment provides a hot isostatic pressing method for preparing a tungsten-titanium-silicon alloy sputtering target, and the hot isostatic pressing method comprises the following steps:

[0089] (1) Dry-milling tungsten powder with a purity of 99.999% and a particle size of 4 μm to 5 μm, titanium powder with a purity of 99.99% and a particle size of 35 μm to 47 μm, and silicon powder with a purity of 99.999% and a particle size of less than 5 μm under an argon atmosphere for 96 hours, with a material ball mass ratio of 5:1, and loading the obtained tungsten-titanium-silicon mixed powder into a mold, compacting and sealing it, and degassing the sealed mold at 350° C. in a heating furnace for 4 hours until the vacuum degree is 3.0E-3Pa, and then degassing is terminated. In the tungsten-titanium-silicon mixed powder, the content of titanium powder is 12wt%, the content of silicon powder is 13wt%, and the rest is tungsten powder and unavoidable impurities;

[0090] (2) heating the mold after the degassing treatment in step (1) to 850° C. at a rate of 8° C. / min and keeping the temperature for 2 h. During the heating and keeping temperature, the mold was pressurized at a rate of 0.2 MPa / min. Then, the mold was heated to 1100° C. at a rate of 8° C. / min and continued to be pressurized to 100 MPa at a rate of 0.2 MPa / min. The mold was kept at this temperature and pressure for 6 h to obtain a tungsten-titanium-silicon alloy sputtering target blank.

[0091] (3) The tungsten-titanium-silicon alloy sputtering target blank described in step (2) is subjected to wire cutting, inspection, cleaning, drying and packaging to obtain a tungsten-titanium-silicon alloy sputtering target material.

[0092] Example 4

[0093] The present embodiment provides a hot isostatic pressing preparation method for a tungsten-titanium-silicon alloy sputtering target. The hot isostatic pressing preparation method differs from that of Embodiment 1 in that, in step (2), the pre-sintering process is omitted, and the temperature is directly raised to 1150°C at a rate of 5°C / min, and the pressure is increased to 120MPa at a rate of 0.5MPa / min, and the heat and pressure are maintained. The remaining preparation methods and parameters are consistent with those of Embodiment 1.

[0094] Example 5

[0095] The present embodiment provides a hot isostatic pressing preparation method for a tungsten-titanium-silicon alloy sputtering target. The difference between the hot isostatic pressing preparation method and the embodiment 1 is that in step (2), the temperature is raised to 880°C at a rate of 5°C / min and kept at this temperature for 1.5 hours. During the heating and keeping process, the pressure is not increased. After the keeping is completed, the temperature is raised to 1150°C at a rate of 5°C / min. During the heating process, the pressure is increased to 120MPa at a rate of 0.5MPa / min to start keeping the temperature and pressure. The rest of the preparation method and parameters are consistent with the embodiment 1.

[0096] Example 6

[0097] This embodiment provides a hot isostatic pressing preparation method for a tungsten-titanium-silicon alloy sputtering target. The difference between the hot isostatic pressing preparation method and Example 1 is that the particle size of the silicon powder is replaced with 10 μm to 20 μm, and the rest of the preparation method and parameters are consistent with Example 1.

[0098] Example 7

[0099] This embodiment provides a hot isostatic pressing preparation method for a tungsten-titanium-silicon alloy sputtering target. The hot isostatic pressing preparation method is different from that of Example 1 in that the particle size of the titanium powder is replaced with 3 μm to 10 μm, and the rest of the preparation method and parameters remain consistent with those of Example 1.

[0100] Example 8

[0101] This embodiment provides a hot isostatic pressing preparation method for a tungsten-titanium-silicon alloy sputtering target. The difference between the hot isostatic pressing preparation method and Example 1 is that the dry ball milling time is 42 hours, and the other preparation methods and parameters are consistent with Example 1.

[0102] Comparative Example 1

[0103] This comparative example provides a hot isostatic pressing preparation method for a tungsten-titanium-silicon alloy sputtering target. The difference between the hot isostatic pressing preparation method and Example 1 is that the temperature of the hot isostatic pressing treatment in step (3) is 1000°C, and the other preparation methods and parameters are consistent with Example 1.

[0104] Comparative Example 2

[0105] This comparative example provides a hot isostatic pressing preparation method for a tungsten-titanium-silicon alloy sputtering target. The difference between the hot isostatic pressing preparation method and Example 1 is that the temperature of the hot isostatic pressing treatment in step (3) is 1300°C, and the other preparation methods and parameters are consistent with Example 1.

[0106] Comparative Example 3

[0107] This comparative example provides a hot pressing and sintering preparation method for a tungsten-titanium-silicon alloy sputtering target, and the hot pressing and sintering preparation method comprises the following steps:

[0108] (1) dry-milling tungsten powder with a purity of 99.999% and a particle size of 4 μm to 5 μm, titanium powder with a purity of 99.99% and a particle size of 35 μm to 47 μm, and silicon powder with a purity of 99.999% and a particle size of less than 5 μm under an argon atmosphere for 72 hours, with a material ball mass ratio of 10:3, and loading the obtained tungsten-titanium-silicon mixed powder into a mold, compacting and sealing, wherein the content of titanium powder in the tungsten-titanium-silicon mixed powder is 10wt%, the content of silicon powder is 15wt%, and the rest is tungsten powder and unavoidable impurities;

[0109] (2) placing the sealed mold in step (1) into a hot pressing sintering furnace, evacuating to below 100 Pa, then heating to 1000° C. at a heating rate of 10° C. / min and keeping the temperature for 1.5 h, then heating to 1280° C. at a heating rate of 5° C. / min and keeping the temperature for 1 h, and finally pressurizing to 30 MPa at a pressurizing rate of 0.5 MPa / min and keeping the temperature and pressure for 2 h; wherein, during the heating process of heating to 1000° C. and heating to 1280° C., it is necessary to control the internal pressure of the sealed mold to be less than 1 MPa; obtaining a tungsten-titanium-silicon alloy sputtering target blank;

[0110] (3) The tungsten-titanium-silicon alloy sputtering target blank described in step (2) is subjected to wire cutting, inspection, cleaning, drying and packaging to obtain a tungsten-titanium-silicon alloy sputtering target material.

[0111] The tungsten-titanium-silicon alloy sputtering targets prepared in Examples 1 to 8 and Comparative Examples 1 to 3 were tested for density and internal structural uniformity;

[0112] Density test: Determined according to the hanging basket method disclosed in the national standard GB / T3850-2015 "Density measurement method for dense sintered metal materials and cemented carbide";

[0113] Internal structure uniformity: First, visual inspection of the standard sample is used as the standard. Then, after precision processing, the surface is clean and the color is uniform. There are no bundles or spots, which indicates that the internal structure is uniform and there is no segregation.

[0114] The specific test results are shown in Table 1.

[0115] Table 1

[0116] project Density(%) Internal tissue uniformity Example 1 100 The surface is clean, the color is uniform, and there are no spots Example 2 99.7 The surface is clean, the color is uniform, and there are no spots Example 3 99.6 The surface is clean, the color is uniform, and there are no spots Example 4 98.3 Clean surface, uniform color, occasional spots Example 5 96.9 The surface is clean, the color is uniform, and there are large spots Example 6 99.4 Clean surface, uniform color, occasional spots Example 7 99.5 Clean surface, uniform color, occasional spots Example 8 99.2 Clean surface, uniform color, occasional spots Comparative Example 1 94.6 The surface is clean, the color is uniform, and there are large spots Comparative Example 2 96.8 Clean surface, uniform color, occasional spots Comparative Example 3 98.6 The surface is clean, the color is uniform, and there are no spots

[0117] The test results show that:

[0118] (1) It can be seen from Examples 1 to 3 that the hot isostatic pressing preparation method of the present invention can make the tungsten-titanium-silicon alloy sputtering target material have a dense structure with a density of more than 99.50%, a clean surface, uniform color, no spots, a uniform and dense internal microstructure, and excellent sputtering performance.

[0119] (2) It can be seen from Examples 1 and 4 that the pre-sintering process before the hot isostatic pressing process can form a preliminary bond between the powder particles, thereby reducing deformation and cracking during the final sintering process, improving the product yield, and further improving the density and internal uniformity of the material.

[0120] (3) It can be seen from Example 1 and Example 5 that the pre-sintering and hot isostatic pressing processes of the present invention are accompanied by pressurization at a rate of 0.2 to 0.8 MPa / min, and the pressurization, heating and insulation processes are carried out simultaneously, which can ensure the dense sintering of the product and better improve the density and internal uniformity of the material.

[0121] (4) It can be seen from Examples 1 and 6 to 8 that the present invention limits the particle size of tungsten powder to 4 μm to 5 μm, the particle size of titanium powder to 35 μm to 47 μm, and the particle size of silicon powder to less than 5 μm. Titanium powder is used as a skeleton, and tungsten powder and silicon powder are filled into the skeleton of titanium powder by utilizing the coordination between large and small particle sizes, so that the mixed tungsten-titanium-silicon mixed powder achieves a dense effect. Combined with the mixing process, it can ensure that the tungsten powder, titanium powder and silicon powder are fully mixed to obtain a tungsten-titanium-silicon mixed powder with uniform mixing and uniform composition, which further determines that the prepared tungsten-titanium-silicon alloy sputtering target has good density and excellent sputtering performance.

[0122] (5) It can be seen from Example 1 and Comparative Examples 1 to 2 that the present invention limits the temperature of hot isostatic pressing treatment to 1100°C to 1200°C. At a relatively low temperature, the prepared tungsten-titanium-silicon alloy sputtering target has a density of ≥99.50%, and the internal microstructure is uniform and dense, with excellent sputtering performance. If the sintering temperature is too high, the excessively high sintering temperature may cause the product to be overburned, resulting in performance degradation and dimensional changes, and even in severe cases, the product may be scrapped. If the sintering temperature is too low, the powder particles will not be fully combined, resulting in an increase in the porosity of the sintered body and a decrease in the density.

[0123] (6) It can be seen from Example 1 and Comparative Example 3 that, although the surface of the tungsten-titanium-silicon alloy sputtering target prepared by the traditional hot pressing sintering process is clean, uniform in color, and free of spots, its density is low, only reaching 98.6%, which leads to a decrease in sputtering performance.

[0124] In the solution provided by the present invention, a hot isostatic pressing process is adopted and the hot isostatic pressing sintering temperature is controlled at a relatively low temperature of 1100-1200°C. The prepared tungsten-titanium-silicon alloy sputtering target has a uniform and dense internal microstructure and excellent sputtering performance. The process is simple, the cost is low, the processing production efficiency and yield are improved, and it is easy to promote on a large scale.

[0125] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope 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 shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A hot isostatic pressing method for preparing a tungsten-titanium-silicon alloy sputtering target, characterized in that: The hot isostatic pressing preparation method comprises the following steps: (1) loading the tungsten-titanium-silicon mixed powder into a mold and sealing it, and degassing the sealed mold; (2) subjecting the mold after the degassing treatment in step (1) to hot isostatic pressing at 1100° C. to 1200° C. to obtain a tungsten-titanium-silicon alloy sputtering target blank; (3) Machining the tungsten-titanium-silicon alloy sputtering target blank described in step (2) to obtain a tungsten-titanium-silicon alloy sputtering target material.

2. The hot isostatic pressing preparation method according to claim 1, characterized in that: Before the hot isostatic pressing treatment in step (2), pre-sintering is also included; Preferably, the heating rate of the pre-sintering is 2°C / min to 8°C / min; Preferably, the sintering temperature of the pre-sintering is 850°C to 900°C; Preferably, the pressurization rate of the pre-sintering is 0.2MPa / min to 0.8MPa / min; Preferably, the pre-sintering holding time is 1 h to 2 h.

3. The hot isostatic pressing preparation method according to claim 1 or 2, characterized in that: The heating rate of the hot isostatic pressing treatment in step (2) is 2°C / min to 8°C / min; Preferably, the pressurization rate of the hot isostatic pressing treatment is 0.2MPa / min to 0.8MPa / min; Preferably, the sintering pressure of the hot isostatic pressing treatment is 90MPa to 170MPa; Preferably, the heat preservation and pressure holding time of the hot isostatic pressing treatment is 3h to 6h.

4. The hot isostatic pressing preparation method according to any one of claims 1 to 3, characterized in that: The temperature of the degassing treatment in step (1) is 200° C. to 350° C.; Preferably, the degassing time in step (1) is 4 to 8 hours; Preferably, when the vacuum degree of the degassing treatment in step (1) is ≤5.0E-3Pa, the degassing is terminated.

5. The hot isostatic pressing preparation method according to any one of claims 1 to 4, characterized in that: The preparation method of the tungsten-titanium-silicon mixed powder in step (1) comprises: uniformly mixing tungsten powder, titanium powder and silicon powder; Preferably, the purity of the tungsten powder is 99.990% to 99.999%; Preferably, the particle size of the tungsten powder is 4 μm to 5 μm; Preferably, the purity of the titanium powder is 99.90% to 99.99%; Preferably, the particle size of the titanium powder is less than 48 μm, preferably 35 μm to 47 μm; Preferably, the purity of the silicon powder is 99.990% to 99.999%; Preferably, the particle size of the silicon powder is less than 5 μm; Preferably, in the tungsten-titanium-silicon mixed powder, the content of the titanium powder is 8wt% to 12wt%, the content of the silicon powder is 13wt% to 17wt%, and the rest is tungsten powder and inevitable impurities.

6. The hot isostatic pressing preparation method according to claim 5, characterized in that: The mixing is carried out under a protective atmosphere; Preferably, the protective atmosphere comprises argon or nitrogen; Preferably, the mixing comprises dry ball milling; Preferably, the ball mass ratio of the dry ball mill is 10:(1-3); Preferably, the dry ball milling uses zirconium balls or zirconium oxide balls; Preferably, the mixing time is ≥48h.

7. The hot isostatic pressing preparation method according to any one of claims 1 to 6, characterized in that: The mold in step (1) is a stainless steel mold; Preferably, after the tungsten-titanium-silicon mixed powder is loaded into the mold in step (1) and before the sealing, a compaction process is also included.

8. The hot isostatic pressing preparation method according to any one of claims 1 to 7, characterized in that: The machining in step (3) includes any one of grinding, wire cutting or machine turning; Preferably, after the machining in step (3), the process further includes testing, cleaning, drying and packaging in sequence to obtain a tungsten-titanium-silicon alloy sputtering target.

9. The hot isostatic pressing preparation method according to claim 1, characterized in that: The hot isostatic pressing preparation method comprises the following steps: (1) dry-milling tungsten powder, titanium powder and silicon powder under a protective atmosphere for ≥48 h, loading the obtained tungsten-titanium-silicon mixed powder into a mold, compacting and sealing it, and degassing the sealed mold at 200° C. to 350° C. for 4 h to 8 h until the vacuum degree is ≤5.0E-3Pa, and then completing the degassing; Wherein, the purity of the tungsten powder is 99.990% to 99.999%; the particle size of the tungsten powder is 4μm to 5μm; the purity of the titanium powder is 99.90% to 99.99%; the particle size of the titanium powder is 35μm to 47μm; the purity of the silicon powder is 99.990% to 99.999%; the particle size of the silicon powder is less than 5μm; in the tungsten-titanium-silicon mixed powder, the content of the titanium powder is 8wt% to 12wt%, the content of the silicon powder is 13wt% to 17wt%, and the rest is tungsten powder and inevitable impurities; the protective atmosphere includes argon or nitrogen; the mass ratio of the ball in the dry ball milling is 10:(1 to 3); the dry ball milling uses zirconium balls or zirconium oxide balls; the degassing treatment is carried out in a heating furnace; (2) heating the mold after the degassing treatment in step (1) to 850°C to 900°C at a rate of 2°C / min to 8°C / min and keeping it at that temperature for 1h to 2h for pre-sintering; during the heating and keeping process, pressurizing at a rate of 0.2MPa / min to 0.8MPa / min; then heating to 1100°C to 1200°C at a rate of 2°C / min to 8°C / min, and continuing to pressurize to 90MPa to 170MPa at a rate of 0.2MPa / min to 0.8MPa / min; keeping the temperature and pressure for 3h to 6h, and performing hot isostatic pressing treatment to obtain a tungsten-titanium-silicon alloy sputtering target blank; (3) machining, inspecting, cleaning, drying and packaging the tungsten-titanium-silicon alloy sputtering target blank of step (2) to obtain a tungsten-titanium-silicon alloy sputtering target; The machining includes any one of grinding, wire cutting or machine turning.

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

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