A nickel-platinum alloy target material for magnetron sputtering and a preparation method thereof

Abstract

The application belongs to the technical field of precious metal sputtering target material, and discloses a preparation method of a nickel-platinum alloy target material for magnetron sputtering. The preparation method of the nickel-platinum alloy target material for magnetron sputtering comprises the following steps: (1) mixing nickel powder and platinum powder and ball milling; (2) hot-pressing sintering; (3) smelting; (4) rolling; and (5) performing shape processing after annealing to obtain the nickel-platinum alloy target material. The nickel-platinum alloy target material prepared by the method has uniform internal grain structure and high density, and the nickel-platinum alloy target material has high yield, fine grains and stable sputtering, which is beneficial to obtaining a high-quality thin film with uniform thickness.

Description

Technical Field

[0001] This application relates to the field of precious metal sputtering target technology, and in particular to a method for preparing a nickel-platinum alloy target for magnetron sputtering. Background Technology

[0002] Magnetron sputtering is a commonly used physical vapor deposition (PVD) thin film technique characterized by high-speed deposition, low temperature, and low damage. Sputtering targets are high-value-added products required for sputtering thin film preparation and are commonly used raw materials for coating in the advanced materials industry. Currently, sputtering targets are mainly used in microelectronics, data storage media, advanced displays, machinery / chemical equipment, and optical coatings. With the rapid development of the technology industry, the performance requirements for thin film materials are constantly increasing, and the quality requirements for sputtering targets as raw materials for film preparation are also becoming increasingly stringent. Therefore, target preparation technology is exceptionally important.

[0003] Nickel possesses excellent corrosion resistance, unique ferromagnetism, and good plasticity, making it a typical metal target material for magnetron sputtering. In large-scale and very large-scale CMOS integrated circuits, after reaching the 65nm and 45nm technology nodes, due to linewidth limitations, nickel silicides prepared from nickel and nickel alloy (mainly NiPt) targets have replaced titanium silicides and cobalt silicides as the most commonly used silicides to reduce resistance and leakage current, thereby achieving higher device performance. Semiconductor integrated circuit manufacturing places high demands on the purity of sputtering targets. If the target contains too many impurities or gases, microparticles are easily formed on the wafer during sputtering, leading to short circuits or open circuits in interconnects, or resulting in uneven thin films, all of which severely affect the film's performance. Currently, there is still room for improvement in the purity, oxygen content, and grain size of high-purity nickel-platinum alloy targets. Summary of the Invention

[0004] In order to solve at least one of the above-mentioned technical problems, and to develop a nickel-platinum alloy target for magnetron sputtering with good density, internal continuity and consistency, and containing fewer impurities and gases, this application provides a nickel-platinum alloy target for magnetron sputtering and a preparation method thereof.

[0005] In a first aspect, this application provides a method for preparing a nickel-platinum alloy target for magnetron sputtering, comprising the following steps: S1, ball milling a mixture of nickel powder and platinum powder to obtain a mixed powder; S2. Add a binder to the mixed powder, press to form a green blank, perform hot pressing sintering, cool, and obtain a pre-sintered bonded gold ingot. S3. The pre-burned gold ingot obtained in step S2 is cut to obtain an alloy sheet; the alloy sheet is placed in a high-purity alumina crucible for vacuum induction melting and molding to obtain a nickel-platinum alloy. S4. The nickel-platinum alloy obtained in step S3 is subjected to warm rolling. S5. Anneal the nickel-platinum alloy processed in step S4, and after cooling, process it to obtain the nickel-platinum alloy target material of the required size.

[0006] By adopting the above technical solution, unlike the traditional single smelting method, this application uses powder metallurgy for hot pressing sintering in the pre-process, which can significantly improve the density of the nickel-platinum alloy and remove residual gases from the alloy. Furthermore, after the above pre-process, the alloy melt does not need to undergo a hot extrusion process to densify the alloy after smelting. Therefore, the preparation process of this application, compared with the traditional smelting method, does not rely on hot extrusion equipment, greatly reducing preparation costs and improving preparation efficiency. In step S2, pre-sintering before smelting is beneficial to improving the compatibility of nickel and platinum in the molten state and also helps to remove gases from the nickel-platinum melt in advance, preparing for smelting. At the same time, the hot pressing sintering in step S2 differs from the general hot pressing sintering process; after reaching the designated temperature, pressure is applied, and the pressure value and holding time are significantly lower than in the general hot pressing sintering process.

[0007] Optionally, in step S1, the weight ratio of nickel powder to platinum powder is 85-90:10-15.

[0008] Optionally, the nickel powder and platinum powder used in step S1 are both of 4N grade or higher purity.

[0009] Optionally, in step S1, the ball milling is wet ball milling, and the solvent includes at least one of anhydrous ethanol, acetone and deionized water; the grinding media includes at least one of zirconium oxide and alumina, and the particle size of the grinding media is 0.2 mm-2 mm.

[0010] By adopting the above technical solution, the grinding media are zirconium oxide and alumina. The melting point of zirconium oxide is about 2700℃ and the melting point of alumina is about 2070℃. Both of their melting points are higher than those of nickel and platinum. Therefore, even if grinding media are mixed into nickel powder and platinum powder during the ball milling process in step S1, resulting in the mixing of zirconium oxide or alumina into the pre-sintered gold ingot, the nickel-platinum alloy is in a molten state during the smelting process in step S3. The zirconium oxide or alumina mixed in in step S1 can be removed by filtering the nickel-platinum alloy melt before casting.

[0011] Optionally, in step S1, the weight ratio of the mixed powder, solvent and grinding media is 0.8-2:2-3:2.2-3.8; the ball mill speed is 160-300 r / min; and the ball milling time is 5.5-8.5 h.

[0012] Optionally, the hot-pressing sintering in step S2 includes: placing the green blank into a hot-pressing sintering furnace, raising the temperature to 1400-1550℃ at a heating rate of 3-5℃ / min, and holding at that temperature for 0.5-1.2 hours; adjusting the pressure in the hot-pressing sintering furnace to 15-25 MPa, and lowering the temperature to 1000-1200℃, maintaining a constant temperature and pressure for 2-3 hours. During the hot-pressing sintering process, an inert gas is introduced into the hot-pressing sintering furnace to protect the sintered green blank.

[0013] Optionally, during vacuum induction melting in step S3, the vacuum level is controlled to be 0.01-0.001 Pa, and the melting and casting temperature is 1550-1900℃.

[0014] Optionally, during the warm rolling process in step S4, the temperature is controlled at 400-500℃, the deformation per pass is 3-6%, and the total deformation is 50-80%.

[0015] By adopting the above technical solution, nickel alloys are easily oxidized. When the system is oxidized, the grain boundaries are the preferential sites of oxidation. At the same time, the distribution of oxides along the grain boundaries further weakens the bonding between the grain boundaries. Therefore, when nickel-platinum alloys are annealed in an atmospheric environment, they are prone to cracking. In actual production, when nickel-platinum alloys are processed by conventional rolling or forging methods, cracks are easily generated at the grain boundaries. Fresh cracks are also the first sites to be oxidized and contaminated by gaseous impurities, resulting in a significant reduction in the purity of the target material and a high scrap rate of the nickel-platinum alloy target material. Therefore, in this application, no hot extrusion process or alternating hot and cold rolling process is used after smelting. In this application, after the nickel-platinum alloy is smelted and cast, it is subjected to warm rolling at a single temperature and annealing in an inert gas environment.

[0016] Optionally, the annealing process in step S5 includes: holding the warm-rolled nickel-platinum alloy at 650-900℃ for 2-4 hours. Step S5 involves annealing in an inert gas environment.

[0017] Secondly, this application provides a nickel-platinum alloy target for magnetron sputtering prepared by the above-mentioned method.

[0018] In summary, the present invention has at least one of the following beneficial technical effects: The method for preparing the nickel-platinum alloy sputtering target in this application involves steps such as hot pressing sintering, vacuum induction melting, warm rolling, and annealing. The resulting nickel-platinum alloy sputtering target has a more uniform internal structure, a high yield, fine grains, and a uniform internal structure. It also provides more stable sputtering and uniform film formation during use, which is beneficial for obtaining high-quality thin films with uniform thickness. Detailed Implementation

[0019] The present application will be further described in detail below with reference to the embodiments.

[0020] This application discloses a method for preparing a nickel-platinum alloy target for magnetron sputtering, comprising the following steps: S1. The mixture of nickel powder and platinum powder is ball-milled to obtain a mixed powder; S2. Add a binder to the mixed powder, press to form a green blank, perform hot pressing sintering, cool, and obtain a pre-sintered bonded gold ingot. S3. The pre-burned gold ingot obtained in step S2 is cut to obtain an alloy sheet; the alloy sheet is placed in a high-purity alumina crucible for vacuum induction melting and molding to obtain a nickel-platinum alloy. S4. The nickel-platinum alloy obtained in step S3 is subjected to warm rolling. S5. Anneal the nickel-platinum alloy processed in step S4, and after cooling, process it to obtain the nickel-platinum alloy target material of the required size.

[0021] The hot-pressing sintering in step S2 includes: placing the green blank into a hot-pressing sintering furnace, raising the temperature to 1400-1550℃ at a rate of 3-5℃ / min, and holding it at that temperature for 0.5-1.2 hours; adjusting the pressure in the hot-pressing sintering furnace to 15-25 MPa, and lowering the temperature to 1000-1200℃, maintaining a constant temperature and pressure for 2-3 hours. During the hot-pressing sintering process, an inert gas is introduced into the hot-pressing sintering furnace to protect the sintered green blank.

[0022] During vacuum induction melting in step S3, the vacuum level is controlled to be 1×10⁻⁶. -2 -1×10 -3 Pa, with smelting and casting temperatures of 1550-1900℃.

[0023] This application designs a nickel-platinum alloy target for magnetron sputtering prepared according to the above-described method for preparing nickel-platinum alloy targets for magnetron sputtering.

[0024] The technical problem addressed by this application is that the high purity, high gas content, and relatively large grain size of existing high-purity nickel-platinum alloy targets can lead to the formation of microparticles on the wafer during magnetron sputtering, causing short circuits or open circuits in interconnects, or resulting in uneven film formation. This application significantly improves the density of the nickel-platinum alloy by employing powder metallurgy-based hot-pressing sintering in the pre-process, removing residual gases from the alloy. Combined with subsequent vacuum induction melting, warm rolling, and annealing steps, a nickel-platinum alloy target with high density and uniform grain size is ultimately produced.

[0025] The raw materials used in the embodiments of this application are all commercially available, and their sources are as follows: Nickel powder (≥4N), item number PA04922, Guangdong Wengjiang Chemical Reagent Co., Ltd.; Platinum powder (≥4N), item number GF99967561-1EA, Sigma-Aldrich (Shanghai) Trading Co., Ltd.

[0026] Example 1 The preparation method of the nickel-platinum alloy target in Example 1 includes the following steps: S1. Add a mixture of nickel powder and platinum powder in a weight ratio of 90:10 to a ball mill for ball milling, filter, and retain the filtered mixed powder; ball milling is performed using wet ball milling, with anhydrous ethanol as the solvent, zirconium oxide as the grinding medium, and a grinding medium particle size of 1 mm. The weight ratio of mixed powder, solvent, and grinding medium is 1.2:2:3; the ball mill speed is set to 180 r / min, and the ball milling time is 7 h; a two-stage ceramic filter plate is used for filtration, with the mesh size combination of the two-stage ceramic filter plate set as follows: the first stage filter plate is 300 mesh, and the second stage filter plate is 500 mesh.

[0027] S2. Add a binder to the mixed powder, granulate the mixture, press it into a green blank using a mold, perform hot pressing sintering, and cool it to obtain a pre-sintered bonded gold ingot. The binder used is polyethylene glycol, and the weight ratio of the binder to the mixed powder is 0.1:1. During the hot pressing sintering process, the green blank is placed in a hot pressing sintering furnace, and the temperature is raised to 1500℃ at a heating rate of 3.5℃ / min and held for 1 hour. The pressure in the hot pressing sintering furnace is adjusted to 20 MPa, and the temperature is lowered to 1100℃ and kept constant for 2.5 hours.

[0028] S3. The pre-burned gold ingot obtained in step S2 is cut to obtain an alloy sheet; the alloy sheet is placed in a high-purity alumina crucible and vacuum induction melting is performed, followed by casting to obtain a nickel-platinum alloy; during vacuum induction melting, the vacuum degree is controlled at 0.01 Pa, and the melting and casting temperature is 1750℃.

[0029] S4. The nickel-platinum alloy obtained in step S3 is subjected to warm rolling; the temperature of warm rolling is controlled at 400℃, the deformation per pass is controlled at about 5%, and the total deformation is controlled at 60%.

[0030] S5. Anneal the nickel-platinum alloy processed in step S4, and after cooling, process it to obtain the nickel-platinum alloy target material of the required size. During the annealing process, the vacuum degree is controlled at 0.5 Pa, and inert gas is introduced for protection. The temperature is controlled at 750℃ and kept at constant temperature and pressure for 2.5 h.

[0031] The nickel-platinum alloy target material prepared in Example 1 has a Na content of approximately 0.05 ppm, a K content of approximately 0.1 ppm, a Si content of approximately 0.08 ppm, a B content of approximately 0.02 ppm, a Ca content of approximately 0.01 ppm, an Al content of approximately 0.05 ppm, an oxygen content of approximately 20.5 ppm, and an average grain size of 36.4 micrometers.

[0032] The nickel-platinum alloy target material prepared in Example 1 has the following contents: Na content < 0.1 ppm, K content < 0.2 ppm, Si content < 0.5 ppm, B content < 0.1 ppm, Ca content < 0.05 ppm, Al content < 0.1 ppm, oxygen content < 50 ppm, and average grain size < 80 micrometers.

[0033] Example 2 The preparation method of the nickel-platinum alloy target in Example 2 includes the following steps: S1. Add a mixture of nickel powder and platinum powder in a weight ratio of 90:10 to a ball mill for ball milling, filter, and retain the filtered mixed powder; ball milling is performed using wet ball milling, with anhydrous ethanol as the solvent, zirconium oxide as the grinding medium, and a grinding medium particle size of 1 mm. The weight ratio of mixed powder, solvent, and grinding medium is 1.2:2:3; the ball mill speed is set to 180 r / min, and the ball milling time is 7 h; a two-stage ceramic filter plate is used for filtration, with the mesh size combination of the two-stage ceramic filter plate set as follows: the first stage filter plate is 300 mesh, and the second stage filter plate is 500 mesh.

[0034] S2. Add a binder to the mixed powder, granulate the mixture, press it into a green blank using a mold, perform hot pressing sintering, and cool it to obtain a pre-sintered bonded gold ingot. The binder is polyethylene glycol, and the weight ratio of the binder to the mixed powder is 0.1:1. During the hot pressing sintering process, the green blank is placed in a hot pressing sintering furnace, and the temperature is raised to 1550℃ at a heating rate of 5℃ / min and held for 1 hour. The pressure in the hot pressing sintering furnace is adjusted to 25 MPa, and the temperature is lowered to 1200℃ and kept constant for 3 hours.

[0035] S3. The pre-burned gold ingot obtained in step S2 is cut to obtain an alloy sheet; the alloy sheet is placed in a high-purity alumina crucible and vacuum induction melting is performed, followed by casting to obtain a nickel-platinum alloy; during vacuum induction melting, the vacuum degree is controlled at 0.01 Pa, and the melting and casting temperature is 1750℃.

[0036] S4. The nickel-platinum alloy obtained in step S3 is subjected to warm rolling; the temperature of warm rolling is controlled at 400℃, the deformation per pass is controlled at about 5%, and the total deformation is controlled at 60%.

[0037] S5. Anneal the nickel-platinum alloy processed in step S4, and after cooling, process it to obtain the nickel-platinum alloy target material of the required size. During the annealing process, the vacuum degree is controlled at 0.5 Pa, and inert gas is introduced for protection. The temperature is controlled at 750℃ and kept at constant temperature and pressure for 2.5 h.

[0038] The nickel-platinum alloy target material prepared in Example 2 has a Na content of approximately 0.05 ppm, a K content of approximately 0.12 ppm, a Si content of approximately 0.2 ppm, a B content of approximately 0.06 ppm, a Ca content of approximately 0.03 ppm, an Al content of approximately 0.04 ppm, an oxygen content of approximately 29.8 ppm, and an average grain size of 64.4 micrometers.

[0039] The nickel-platinum alloy target material prepared in Example 2 has the following contents: Na content < 0.1 ppm, K content < 0.2 ppm, Si content < 0.5 ppm, B content < 0.1 ppm, Ca content < 0.05 ppm, Al content < 0.1 ppm, oxygen content < 50 ppm, and average grain size < 80 micrometers.

[0040] Example 3 The preparation method of the nickel-platinum alloy target in Example 3 includes the following steps: S1. Add a mixture of nickel powder and platinum powder in a weight ratio of 90:10 to a ball mill for ball milling, filter, and retain the filtered mixed powder; ball milling is performed using wet ball milling, with anhydrous ethanol as the solvent, zirconium oxide as the grinding medium, and a grinding medium particle size of 1 mm. The weight ratio of mixed powder, solvent, and grinding medium is 1.2:2:3; the ball mill speed is set to 180 r / min, and the ball milling time is 7 h; a two-stage ceramic filter plate is used for filtration, with the mesh size combination of the two-stage ceramic filter plate set as follows: the first stage filter plate is 300 mesh, and the second stage filter plate is 500 mesh.

[0041] S2. Add a binder to the mixed powder, granulate the mixture, press it into a green blank using a mold, perform hot pressing sintering, and cool it to obtain a pre-sintered bonded gold ingot. The binder is polyethylene glycol, and the weight ratio of the binder to the mixed powder is 0.1:1. During the hot pressing sintering process, the green blank is placed in a hot pressing sintering furnace, and the temperature is raised to 1400℃ at a heating rate of 3.5℃ / min and held for 0.5h. The pressure in the hot pressing sintering furnace is adjusted to 15MPa, and the temperature is lowered to 1000℃ and kept constant for 3h.

[0042] S3. The pre-burned gold ingot obtained in step S2 is cut to obtain an alloy sheet; the alloy sheet is placed in a high-purity alumina crucible and vacuum induction melting is performed, followed by casting to obtain a nickel-platinum alloy; during vacuum induction melting, the vacuum degree is controlled at 0.01 Pa, and the melting and casting temperature is 1750℃.

[0043] S4. The nickel-platinum alloy obtained in step S3 is subjected to warm rolling; the temperature of warm rolling is controlled at 400℃, the deformation per pass is controlled at about 5%, and the total deformation is controlled at 60%.

[0044] S5. Anneal the nickel-platinum alloy processed in step S4, and after cooling, process it to obtain the nickel-platinum alloy target material of the required size. During the annealing process, the vacuum degree is controlled at 0.5 Pa, and inert gas is introduced for protection. The temperature is controlled at 750℃ and kept at constant temperature and pressure for 2.5 h.

[0045] The nickel-platinum alloy target material prepared in Example 3 has a Na content of approximately 0.04 ppm, a K content of approximately 0.15 ppm, a Si content of approximately 0.33 ppm, a B content of approximately 0.05 ppm, a Ca content of approximately 0.04 ppm, an Al content of approximately 0.05 ppm, an oxygen content of approximately 36.8 ppm, and an average grain size of 71.8 micrometers.

[0046] The nickel-platinum alloy target material prepared in Example 3 has the following contents: Na content < 0.1 ppm, K content < 0.2 ppm, Si content < 0.5 ppm, B content < 0.1 ppm, Ca content < 0.05 ppm, Al content < 0.1 ppm, oxygen content < 50 ppm, and average grain size < 80 micrometers.

[0047] Example 4 The preparation method of the nickel-platinum alloy target in Example 4 includes the following steps: S1. Add a mixture of nickel powder and platinum powder in a weight ratio of 90:10 to a ball mill for ball milling, filter, and retain the filtered mixed powder; ball milling is performed using wet ball milling, with anhydrous ethanol as the solvent, zirconium oxide as the grinding medium, and a grinding medium particle size of 1 mm. The weight ratio of mixed powder, solvent, and grinding medium is 1.2:2:3; the ball mill speed is set to 180 r / min, and the ball milling time is 7 h; a two-stage ceramic filter plate is used for filtration, with the mesh size combination of the two-stage ceramic filter plate set as follows: the first stage filter plate is 300 mesh, and the second stage filter plate is 500 mesh.

[0048] S2. Add a binder to the mixed powder, granulate the mixture, press it into a green blank using a mold, perform hot pressing sintering, and cool it to obtain a pre-sintered bonded gold ingot. The binder used is polyethylene glycol, and the weight ratio of the binder to the mixed powder is 0.1:1. During the hot pressing sintering process, the green blank is placed in a hot pressing sintering furnace, and the temperature is raised to 1500℃ at a heating rate of 3.5℃ / min and held for 1 hour. The pressure in the hot pressing sintering furnace is adjusted to 20 MPa, and the temperature is lowered to 1100℃ and kept constant for 2.5 hours.

[0049] S3. The pre-burned gold ingot obtained in step S2 is cut to obtain an alloy sheet; the alloy sheet is placed in a high-purity alumina crucible and vacuum induction melting is performed, followed by casting to obtain a nickel-platinum alloy; during vacuum induction melting, the vacuum degree is controlled at 0.01 Pa, and the melting and casting temperature is 1900℃.

[0050] S4. The nickel-platinum alloy obtained in step S3 is subjected to warm rolling. The temperature of the warm rolling is controlled at 400℃, the deformation per pass is controlled at about 5%, and the total deformation is controlled at 80%.

[0051] S5. Anneal the nickel-platinum alloy processed in step S4, and after cooling, process it to obtain the nickel-platinum alloy target material of the required size. During the annealing process, the vacuum degree is controlled at 0.5 Pa, and inert gas is introduced for protection. The temperature is controlled at 900℃ and kept at constant temperature and pressure for 2 hours.

[0052] The nickel-platinum alloy target material prepared in Example 4 has a Na content of approximately 0.03 ppm, a K content of approximately 0.1 ppm, a Si content of approximately 0.15 ppm, a B content of approximately 0.02 ppm, a Ca content of approximately 0.01 ppm, an Al content of approximately 0.06 ppm, an oxygen content of approximately 33.5 ppm, and an average grain size of 48.6 micrometers.

[0053] The nickel-platinum alloy target material prepared in Example 4 has the following contents: Na content < 0.1 ppm, K content < 0.2 ppm, Si content < 0.5 ppm, B content < 0.1 ppm, Ca content < 0.05 ppm, Al content < 0.1 ppm, oxygen content < 50 ppm, and average grain size < 80 micrometers.

[0054] Example 5 The preparation method of the nickel-platinum alloy target in Example 5 includes the following steps: S1. Add a mixture of nickel powder and platinum powder in a weight ratio of 90:10 to a ball mill for ball milling, filter, and retain the filtered mixed powder; ball milling is performed using wet ball milling, with anhydrous ethanol as the solvent, zirconium oxide as the grinding medium, and a grinding medium particle size of 1 mm. The weight ratio of mixed powder, solvent, and grinding medium is 1.2:2:3; the ball mill speed is set to 180 r / min, and the ball milling time is 7 h; a two-stage ceramic filter plate is used for filtration, with the mesh size combination of the two-stage ceramic filter plate set as follows: the first stage filter plate is 300 mesh, and the second stage filter plate is 500 mesh.

[0055] S2. Add a binder to the mixed powder, granulate the mixture, press it into a green blank using a mold, perform hot pressing sintering, and cool it to obtain a pre-sintered bonded gold ingot. The binder used is polyethylene glycol, and the weight ratio of the binder to the mixed powder is 0.1:1. During the hot pressing sintering process, the green blank is placed in a hot pressing sintering furnace, and the temperature is raised to 1500℃ at a heating rate of 3.5℃ / min and held for 1 hour. The pressure in the hot pressing sintering furnace is adjusted to 20 MPa, and the temperature is lowered to 1100℃ and kept constant for 2.5 hours.

[0056] S3. The pre-burned gold ingot obtained in step S2 is cut to obtain an alloy sheet; the alloy sheet is placed in a high-purity alumina crucible and vacuum induction melting is performed, followed by casting to obtain a nickel-platinum alloy; during vacuum induction melting, the vacuum degree is controlled at 0.01 Pa, and the melting and casting temperature is 1550℃.

[0057] S4. The nickel-platinum alloy obtained in step S3 is subjected to warm rolling. The temperature of the warm rolling is controlled at 400℃, the deformation per pass is controlled at about 5%, and the total deformation is controlled at 50%.

[0058] S5. Anneal the nickel-platinum alloy processed in step S4, and after cooling, process it to obtain the nickel-platinum alloy target material of the required size. During the annealing process, the vacuum degree is controlled at 0.5 Pa, and inert gas is introduced for protection. The temperature is controlled at 650℃ and kept at constant temperature and pressure for 4 hours.

[0059] The nickel-platinum alloy target material prepared in Example 5 has a Na content of approximately 0.08 ppm, a K content of approximately 0.13 ppm, a Si content of approximately 0.28 ppm, a B content of approximately 0.06 ppm, a Ca content of approximately 0.03 ppm, an Al content of approximately 0.05 ppm, an oxygen content of approximately 44.5 ppm, and an average grain size of 64.7 micrometers.

[0060] The nickel-platinum alloy target material prepared in Example 5 has the following contents: Na content < 0.1 ppm, K content < 0.2 ppm, Si content < 0.5 ppm, B content < 0.1 ppm, Ca content < 0.05 ppm, Al content < 0.1 ppm, oxygen content < 50 ppm, and average grain size < 80 micrometers.

[0061] Comparative Example 1 Comparative Example 1 is based on Example 1, except that step S2 is omitted from the preparation method of Comparative Example 1. That is, the preparation method of the nickel-platinum alloy target in Comparative Example 1 includes the following steps: S1. Add a mixture of nickel powder and platinum powder in a weight ratio of 90:10 to a ball mill for ball milling, filter, and retain the filtered mixed powder; ball milling is performed using wet ball milling, with anhydrous ethanol as the solvent, zirconium oxide as the grinding medium, and a grinding medium particle size of 1 mm. The weight ratio of mixed powder, solvent, and grinding medium is 1.2:2:3; the ball mill speed is set to 180 r / min, and the ball milling time is 7 h; a two-stage ceramic filter plate is used for filtration, with the mesh size combination of the two-stage ceramic filter plate set as follows: the first stage filter plate is 300 mesh, and the second stage filter plate is 500 mesh.

[0062] S2. Add the mixed powder obtained in step S1 to a high-purity alumina crucible and perform vacuum induction melting and casting to obtain a nickel-platinum alloy. During vacuum induction melting, the vacuum degree is controlled at 0.01 Pa, and the melting and casting temperature is 1750℃.

[0063] S3. The nickel-platinum alloy obtained in step S2 is subjected to warm rolling. The temperature of the warm rolling is controlled at 400℃, the deformation per pass is controlled at about 5%, and the total deformation is controlled at 60%.

[0064] S4. Anneal the nickel-platinum alloy processed in step S3, and after cooling, process it to obtain the nickel-platinum alloy target material of the required size. During the annealing process, the vacuum degree is controlled at 0.5 Pa, and inert gas is introduced for protection. The temperature is controlled at 750℃ and kept at constant temperature and pressure for 2.5 h.

[0065] The nickel-platinum alloy target material prepared in Comparative Example 1 has an oxygen content of approximately 137.5 ppm and an average grain size of 106.2 micrometers.

[0066] Comparative Example 2 Comparative Example 2 describes the preparation of the target material using a traditional hot-pressing method after melting. The preparation method of the nickel-platinum alloy target material in Comparative Example 2 includes the following steps: S1. Add a mixture of nickel powder and platinum powder in a weight ratio of 90:10 to a ball mill for ball milling, filter, and retain the filtered mixed powder; ball milling is performed using wet ball milling, with anhydrous ethanol as the solvent, zirconium oxide as the grinding medium, and a grinding medium particle size of 1 mm. The weight ratio of mixed powder, solvent, and grinding medium is 1.2:2:3; the ball mill speed is set to 180 r / min, and the ball milling time is 7 h; a two-stage ceramic filter plate is used for filtration, with the mesh size combination of the two-stage ceramic filter plate set as follows: the first stage filter plate is 300 mesh, and the second stage filter plate is 500 mesh.

[0067] S2. Add the mixed powder obtained in step S1 to a high-purity alumina crucible and perform vacuum induction melting and casting to obtain a nickel-platinum alloy. During vacuum induction melting, the vacuum degree is controlled at 0.01 Pa, and the melting and casting temperature is 1750℃.

[0068] S3. The nickel-platinum alloy obtained in step S2 is subjected to vacuum hot pressing. The vacuum degree is 0.01 Pa and the hot pressing temperature is 1200℃. A pressure of 50 MPa is applied to the nickel-platinum alloy and the temperature and pressure are maintained for 120 min. During the hot pressing process, the nickel-platinum alloy is fixed in length and width directions by a mold, and the deformation of the nickel-platinum alloy along the thickness direction is controlled.

[0069] S4. The nickel-platinum alloy obtained in step S3 is subjected to warm rolling; the temperature of warm rolling is controlled at 400℃, the deformation per pass is controlled at about 5%, and the total deformation is controlled at 60%.

[0070] S5. Anneal the nickel-platinum alloy processed in step S4, and after cooling, process it to obtain the nickel-platinum alloy target material of the required size. During the annealing process, the vacuum degree is controlled at 0.5 Pa, and inert gas is introduced for protection. The temperature is controlled at 750℃ and kept at constant temperature and pressure for 2.5 h.

[0071] The nickel-platinum alloy target material prepared in Comparative Example 2 has an oxygen content of approximately 63.5 ppm and an average grain size of 85.7 micrometers.

[0072] Performance testing 1. The average grain size of the nickel-platinum alloy targets prepared in Examples 1-5 and Comparative Examples 1-2 was determined according to the standard GB / T 6394-2017 "Method for Determination of Average Grain Size of Metals".

[0073] 2. The preferred orientation of the crystal planes of the nickel-platinum alloy targets prepared in Examples 1-5 and Comparative Examples 1-2 was determined using scanning electron microscopy (SEM), and the orientation rate was measured.

[0074] 3. The magnetron sputtering parameters were adjusted as follows: working gas was argon, power was 250W, sputtering pressure was 2.5Pa, and a metal thin film of approximately 0.1μm thickness was sputtered (using the target materials obtained in Examples 1-5 and Comparative Examples 1-2, respectively), at approximately 600℃. The sputtering rate and film roughness were measured respectively.

[0075] The measurement results are shown in Table 1.

[0076] Table 1 Analysis of the data in Table 1 shows that the nickel-platinum alloy targets prepared in Examples 1-5 of this application have smaller average grain size and higher crystal orientation rate, resulting in thin films with lower roughness obtained by magnetron sputtering. Therefore, the preparation method of the nickel-platinum alloy targets in this application, through steps such as hot pressing sintering, vacuum induction melting, warm rolling, and annealing, produces nickel-platinum alloy targets with a more uniform internal structure, high yield, fine grains, and uniform internal structure; more stable sputtering; and uniform film formation during use, which is beneficial for obtaining high-quality thin films with uniform thickness.

[0077] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A method for preparing a nickel-platinum alloy target for magnetron sputtering, characterized in that, Includes the following steps: S1. The mixture of nickel powder and platinum powder is ball-milled to obtain a mixed powder; S2. Add a binder to the mixed powder, press to form a green blank, perform hot pressing sintering, cool, and obtain a pre-sintered bonded gold ingot. S3. The pre-burned gold ingot obtained in step S2 is cut to obtain an alloy sheet; the alloy sheet is placed in a high-purity alumina crucible for vacuum induction melting and molding to obtain a nickel-platinum alloy. S4. The nickel-platinum alloy obtained in step S3 is subjected to warm rolling. S5. Anneal the nickel-platinum alloy processed in step S4, cool it, and then process it to obtain the nickel-platinum alloy target material. The hot pressing sintering in step S2 includes: placing the green blank into a hot pressing sintering furnace, raising the temperature to 1400-1550℃ at a heating rate of 3-5℃ / min, and holding it at that temperature for 0.5-1.2h; adjusting the pressure in the hot pressing sintering furnace to 15-25MPa, and lowering the temperature to 1000-1200℃, maintaining a constant temperature and pressure for 2-3h; In step S3, when vacuum induction melting is performed, the vacuum degree is controlled at 0.01-0.001 Pa, and the melting and casting temperature is 1550-1900℃. In step S1, the weight ratio of nickel powder to platinum powder is 85-90:10-15; In step S4, the temperature is controlled at 400-500℃ during warm rolling, the deformation per pass is 3-6%, and the total deformation is 50-80%. The annealing process in step S5 includes: holding the warm-rolled nickel-platinum alloy at 650-900℃ for 2-4 hours.

2. The method for preparing a nickel-platinum alloy target for magnetron sputtering according to claim 1, characterized in that, In step S1, the ball milling is wet ball milling. The solvent used in the wet ball milling includes at least one of anhydrous ethanol, acetone and deionized water. The grinding media used in the wet ball milling includes at least one of zirconium oxide and alumina, and the particle size of the grinding media is 0.2 mm to 2 mm.

3. The method for preparing the nickel-platinum alloy target for magnetron sputtering according to claim 1, characterized in that, In step S1, the weight ratio of the mixed powder, solvent and grinding media is 0.8-2:2-3:2.2-3.8; the ball mill speed is 160-300 r / min; and the ball milling time is 5.5-8.5 h.

4. A nickel-platinum alloy target for magnetron sputtering prepared by the method according to any one of claims 1-3.

Images