CN-121992266-A - Tungsten-copper alloy target and preparation method thereof

CN121992266ACN 121992266 ACN121992266 ACN 121992266ACN-121992266-A

Abstract

The invention relates to the technical field of alloy materials, in particular to a tungsten-copper alloy target and a preparation method thereof, wherein the tungsten-copper alloy target comprises, by mass, 80% -95% of tungsten powder, 4.5% -19.5% of copper powder and 0.5% -1% of modifying elements, the modifying elements are a mixture of nickel powder and niobium powder, the mass ratio of the nickel powder to the niobium powder is 2:1-3:1, the average particle size of the tungsten powder is 1-5 mu m, the average particle size of the copper powder is 2-8 mu m, and the average particle sizes of the nickel powder and the niobium powder are 0.5-2 mu m. The tungsten-copper alloy target material prepared by optimizing the components and the process has high compactness, low resistivity, high thermal conductivity and excellent hardness, can meet the requirements of sputtering coating in the high-end fields of semiconductors, display panels and the like, and has good industrialized application prospect.

Inventors

MAO SINING
CHEN XIAOXIAO
CHEN LONGLONG
CHEN LINGPENG

Assignees

亚芯半导体材料(江苏)有限公司

Dates

Publication Date: 20260508
Application Date: 20260203

Claims (9)

1. The tungsten-copper alloy target is characterized by comprising, by mass, 80% -95% of tungsten powder, 4.5% -19.5% of copper powder and 0.5% -1% of modified elements, wherein the modified elements are a mixture of nickel powder and niobium powder, the mass ratio of the nickel powder to the niobium powder is 2:1-3:1, the average particle size of the tungsten powder is 1-5 mu m, the average particle size of the copper powder is 2-8 mu m, and the average particle sizes of the nickel powder and the niobium powder are all 0.5-2 mu m.
2. The tungsten-copper alloy target according to claim 1, wherein the purity of the tungsten powder is more than or equal to 99.95%, the purity of the copper powder is more than or equal to 99.99%, and the purity of the nickel powder and the niobium powder is more than or equal to 99.9%.
3. The tungsten-copper alloy target according to claim 1 is characterized by comprising, by mass, 85% -92% of tungsten powder, 7.2% -14.3% of copper powder and 0.7% -0.8% of modifying element, wherein the mass ratio of nickel powder to niobium powder is 2.5:1.
4. A method for preparing a tungsten copper alloy target according to any one of claims 1 to 3, comprising the steps of: s1, raw material pretreatment, namely respectively drying tungsten powder, copper powder, nickel powder and niobium powder in a vacuum drying oven at 80-120 ℃ for 2-4 hours, and removing surface adsorbed water; S2, ball milling and mixing, namely adding the pretreated raw materials into a planetary ball mill according to a proportion, taking hard alloy balls as grinding balls, wherein the ball-material ratio is 8:1-12:1, the rotating speed is 200-300r/min, ball milling is carried out for 4-8 hours under the protection of argon gas to obtain mixed powder, the ball milling process adopts intermittent operation, wherein each ball milling is stopped for 10min, heat dissipation is carried out through intermittent shutdown, the temperature in a ball milling cavity is controlled to be less than or equal to 60 ℃, and copper powder is prevented from being oxidized due to high temperature; S3, cold press molding, namely filling the mixed powder into a mold, and maintaining the pressure for 5-10min under the pressure of 200-300MPa to obtain a green body; S4, vacuum sintering, namely placing the green body into a vacuum sintering furnace, firstly heating to 600-800 ℃ at the speed of 5-8 ℃ per minute, preserving heat for 2-3 hours, then heating to 1200-1400 ℃ at the speed of 3-5 ℃ per minute, preserving heat for 4-6 hours, wherein the vacuum degree in the sintering process is less than or equal to 5 multiplied by 10 - 3 Pa; S5, hot isostatic pressing treatment, namely placing the sintered blank into a hot isostatic pressing machine, preserving heat for 2-4 hours under the argon atmosphere at the temperature of 1000-1200 ℃ under the pressure of 100-150MPa, and cooling to obtain the tungsten-copper alloy target.
5. The method for preparing a tungsten copper alloy target according to claim 1, wherein in the step S2, zinc stearate accounting for 0.1-0.3% of the mass of the mixed powder is added into the ball mill before ball milling as a dispersing agent.
6. The method for preparing the tungsten copper alloy target according to claim 1, wherein in the step S2, grinding balls of the planetary ball mill adopt three-level particle size proportion, wherein the grinding balls with the diameters of 10mm account for 40%, the grinding balls with the diameters of 6mm account for 35%, and the grinding balls with the diameters of 3mm account for 25%.
7. The method for preparing the tungsten-copper alloy target according to claim 1, wherein in the step S4, the high-temperature section of vacuum sintering, namely the process of temperature of 1200-1400 ℃ adopts 'step-type heat preservation', wherein the heat preservation is firstly carried out for 1-2h at 1200 ℃, then the heat preservation is carried out for 1-2h at 1300 ℃, finally the heat preservation is carried out for 1-2h at 1400 ℃, and the sintering temperature is gradually increased, so that the segregation of components caused by too fast migration of copper phases is avoided, and the uniformity fluctuation of the components of the target is less than or equal to 0.5%.
8. The method for preparing the tungsten-copper alloy target according to claim 1, wherein in the step S4, a 'dynamic vacuum degree adjustment' is adopted in a heating stage of a vacuum sintering furnace, wherein the vacuum degree is controlled to be 1 multiplied by 10 - 2 Pa in a low-temperature section, namely room temperature to 600 ℃, the vacuum degree is controlled to be 5 multiplied by 10 -2 Pa in a high-temperature section, namely 600 ℃ to 1400 ℃, the vacuum degree is relaxed at a low temperature Duan Shidang to rapidly remove water vapor, and the vacuum degree is increased at the high-temperature section to thoroughly remove volatile impurities, so that the porosity of the target is less than or equal to 0.8%.
9. The method for preparing a tungsten copper alloy target according to claim 1, wherein in the step S5, the cooling rate of the hot isostatic pressing treatment is 2-4 ℃ per minute.

Description

Tungsten-copper alloy target and preparation method thereof Technical Field The invention relates to the technical field of alloy materials, in particular to a tungsten-copper alloy target and a preparation method thereof. Background The tungsten-copper alloy has the advantages of high melting point, high hardness, low expansion coefficient of tungsten and high electric conductivity and thermal conductivity of copper, is an ideal sputtering target material, and is widely applied to coating scenes such as semiconductor chip interconnection layers, flat panel display electrodes and the like. However, in the traditional tungsten-copper target preparation process, because the density and melting point difference of tungsten and copper are large, the problems of partial aggregation of components, difficult sintering densification and the like are easy to occur, the density of the target is low, the electric conduction and heat conduction properties are poor, particles are easy to generate during sputtering, the loss of the target is uneven, and the quality and the production efficiency of a coating film are influenced. In the prior art, part of schemes improve sintering performance by adding a single modifying element, but the single element is difficult to solve the balance problem of densification and mechanical property at the same time, and the other schemes adopt a hot-press sintering process, but the process is easy to cause uneven pressure distribution in the target material and local loosening defect. Therefore, research and development of a tungsten-copper alloy target material which is reasonable in component proportion, stable in preparation process, high in compactness, excellent in electric conductivity, thermal conductivity and mechanical property becomes a problem to be solved urgently in the industry. Disclosure of Invention The invention aims to solve the defects in the prior art and provides a tungsten-copper alloy target and a preparation method thereof. In order to achieve the above purpose, the present invention adopts the following technical scheme: The tungsten-copper alloy target comprises, by mass, 80% -95% of tungsten powder, 4.5% -19.5% of copper powder and 0.5% -1% of a modifying element, wherein the modifying element is a mixture of nickel powder and niobium powder, the mass ratio of the nickel powder to the niobium powder is 2:1-3:1, the average particle size of the tungsten powder is 1-5 mu m, the sintering activity is reduced when the particle size is too large, agglomeration is easy when the particle size is too small, the average particle size of the copper powder is 2-8 mu m, and the average particle sizes of the nickel powder and the niobium powder are both 0.5-2 mu m. As a preferable technical scheme of the application, the purity of the tungsten powder is more than or equal to 99.95%, the purity of the copper powder is more than or equal to 99.99%, the purity of the nickel powder and the purity of the niobium powder are more than or equal to 99.9%, and the component segregation in the sintering process is reduced and the component uniformity of the target is improved by controlling the particle size difference of the tungsten powder and the copper powder to be 1-3 mu m. The application adopts a preferable technical scheme that the alloy comprises, by mass, 85% -92% of tungsten powder, 7.2% -14.3% of copper powder and 0.7% -0.8% of modified elements, wherein the mass ratio of nickel powder to niobium powder is 2.5:1, nickel can reduce the interfacial tension of tungsten and copper and promote sintering densification, niobium can form a ternary solid solution with tungsten and copper, the hardness and impact resistance of a target material are enhanced, and the synergistic effect of the tungsten powder and the niobium can simultaneously promote the compactness and mechanical properties of the target material. The preparation method of the tungsten-copper alloy target is characterized by comprising the following steps of: s1, raw material pretreatment, namely respectively drying tungsten powder, copper powder, nickel powder and niobium powder in a vacuum drying oven at 80-120 ℃ for 2-4 hours, and removing surface adsorbed water; S2, ball milling and mixing, namely adding the pretreated raw materials into a planetary ball mill according to a proportion, taking hard alloy balls as grinding balls, wherein the ball-material ratio is 8:1-12:1, the rotating speed is 200-300r/min, ball milling is carried out for 4-8 hours under the protection of argon gas to obtain mixed powder, the ball milling process adopts intermittent operation, wherein each ball milling is stopped for 10min, heat dissipation is carried out through intermittent shutdown, the temperature in a ball milling cavity is controlled to be less than or equal to 60 ℃, and copper powder is prevented from being oxidized due to high temperature; S3, cold press molding, namely filling the mixed powder into a mold, and maintain