Preparation method of molybdenum-titanium alloy target material

Abstract

The invention relates to a preparation method of a molybdenum-titanium alloy target material, which comprises the following steps: mixing molybdenum powder and titanium powder in a protective gas atmosphere to obtain mixed powder; the mixed powder is subjected to cold isostatic pressing, sheath degassing, hot isostatic pressing and vacuum annealing in sequence, and then the molybdenum-titanium alloy target material is obtained; the average particle size of the molybdenum powder is 3-5 [mu] m, and the average particle size of the titanium powder is 100-150 [mu] m; according to the preparation method, the molybdenum-titanium alloy target material which only contains a pure molybdenum phase and a molybdenum-titanium alloy phase and is high in density and low in content of gas impurity elements is prepared by selecting raw materials with specific particle sizes and matching specific procedures; wherein the proportion of the molybdenum-titanium alloy phase is preferably as high as 50% or above, the density is preferably as high as 99.9% or above, the hydrogen content is preferably as low as 3 ppm or below, the oxygen content is preferably as low as 576 ppm or below, and the problem that the product yield is low due to the fact that an existing molybdenum-titanium target is likely to be abnormal in the sputtering process is effectively solved.

Description

Technical Field

[0001] This invention relates to the field of alloy target technology, and in particular to a method for preparing a molybdenum-titanium alloy target. Background Technology

[0002] Molybdenum-titanium sputtering targets are widely used in the flat panel display industry, primarily as a base or barrier layer for copper sputtering. They control reflectivity and provide protection against corrosion during photolithography. Compared to pure molybdenum, they offer better strength, low-temperature plasticity, and corrosion resistance. Currently, with the miniaturization and refinement of display panels, the requirements for molybdenum-titanium sputtering targets are becoming increasingly stringent. Conventional molybdenum-titanium sputtering targets contain multiple phases (pure molybdenum phase, pure titanium phase, and molybdenum-titanium alloy phase, etc.), with high gas content at the phase interfaces, which can easily lead to abnormalities in the sputtering process. This is because current molybdenum-titanium sputtering targets are generally prepared using powder metallurgy processes combined with sintering and rolling or hot isostatic pressing, which cannot completely alloy the pure titanium phase. This results in gas accumulation at the phase interfaces, easily causing particle abnormalities during sputtering and affecting the final product yield. Furthermore, existing molybdenum-titanium sputtering processes generally use raw material powders with small particle sizes, and sometimes even require the addition of raw materials containing other impurity elements, resulting in lower product purity, more complex processes, and higher energy consumption.

[0003] For example, CN118064848A discloses a molybdenum-titanium target material, its preparation method, and its application. The preparation method involves using a mixture of molybdenum-titanium alloy powder and TiH2 powder as raw materials, and sequentially subjecting the ball-milled mixture to cold isostatic pressing, three-stage sintering, hot isostatic pressing, and machining processes. However, the TiH2 powder used in this preparation method readily reacts with oxygen during dehydrogenation, generating oxide impurities that affect the purity of the target material. Furthermore, the TiH2 powder may form spherical (Mo,Ti)4O4 during sintering. y Impurities such as impurities lead to uneven microstructure of the target material, resulting in poor sputtering performance and reduced yield of subsequent products.

[0004] Therefore, how to provide a new method for preparing molybdenum-titanium alloy sputtering targets to solve the problems of existing molybdenum-titanium sputtering targets having multiple phases, high gas content at phase interfaces, which easily leads to abnormalities in the sputtering process, as well as cumbersome process flow and difficult-to-control process conditions, is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a method for preparing a molybdenum-titanium alloy target, achieving the preparation of a molybdenum-titanium alloy target with high alloying degree, high density, and high purity. This method increases the proportion of the molybdenum-titanium alloy phase, avoids the presence of pure titanium phase and other impurity phases, reduces the gas content at the phase interface, and improves the purity of the molybdenum-titanium alloy target.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] This invention provides a method for preparing a molybdenum-titanium alloy target, the method comprising the following steps:

[0008] Molybdenum powder and titanium powder are mixed in a protective gas atmosphere to obtain a mixed powder; the mixed powder is then subjected to cold isostatic pressing, cladding degassing, hot isostatic pressing and vacuum annealing to obtain a molybdenum-titanium alloy target.

[0009] The molybdenum powder has an average particle size of 3–5 μm, and the titanium powder has an average particle size of 100–150 μm.

[0010] The molybdenum powder has an average particle size of 3 to 5 μm, for example, it can be 3 μm, 3.2 μm, 3.5 μm, 3.8 μm, 4 μm, 4.2 μm, 4.5 μm, 4.8 μm or 5 μm, etc.

[0011] The average particle size of the titanium powder is 100-150 μm, for example, it can be 100 μm, 105 μm, 110 μm, 115 μm, 120 μm, 125 μm, 130 μm, 135 μm, 140 μm, 145 μm or 150 μm, etc.

[0012] This invention improves the alloying degree by selecting molybdenum powder and titanium powder with specific particle sizes and combining them with specific processes. This results in a molybdenum-titanium alloy target containing only pure molybdenum phase and molybdenum-titanium alloy phase, without pure titanium phase or other impurity phases. This increases the proportion of the molybdenum-titanium alloy phase and reduces the gas content at the phase interface, thereby improving the purity of the obtained molybdenum-titanium alloy target and thus improving its sputtering performance to increase product yield.

[0013] In this invention, the molybdenum powder has an average particle size of 3-5 μm, and the titanium powder has an average particle size of 100-150 μm. Using them together facilitates subsequent sintering due to the smaller particle size of the molybdenum powder, while the larger particle size of the titanium powder promotes molybdenum-titanium alloying. If the average particle size of the titanium powder is too small, it will result in a high surface oxygen content, inhibiting the alloying reaction and generating impurity phases. If the average particle size of the titanium powder is too large, alloying will be incomplete, easily forming a pure titanium phase, leading to a decrease in the density of the target material. If the average particle size of the molybdenum powder is too large, it will not achieve sufficient densification. If the average particle size of the molybdenum powder is too small, it will also easily introduce oxygen impurities, which is detrimental to subsequent forming and can cause cracks or delamination in the target material product.

[0014] Preferably, the protective gas in the protective gas atmosphere includes argon and / or nitrogen.

[0015] It is worth noting that the argon or nitrogen gas used in this invention is high-purity argon and high-purity nitrogen, that is, argon gas with a purity of ≥99.999% or nitrogen gas with a purity of ≥99.999%.

[0016] Preferably, the purity of the molybdenum powder is ≥3N5, for example, it can be 3N5, 3N6, 3N7, 3N8, 3N9 or 4N, etc.

[0017] Preferably, the purity of the titanium powder is ≥3N, for example, it can be 3N, 3N2, 3N5, 3N8 or 4N, etc.

[0018] Preferably, by weight, the mixing includes mixing 25 to 70 parts of molybdenum powder and 30 to 75 parts of titanium powder, and more preferably, the total amount of molybdenum powder and titanium powder is 100 parts.

[0019] The components include 25 to 70 parts of molybdenum powder, such as 25, 30, 35, 40, 45, 50, 55, 60, 65, or 70 parts; and 30 to 75 parts of titanium powder, such as 30, 35, 40, 45, 50, 55, 60, 65, 70, or 75 parts, preferably 45 to 65 parts of molybdenum powder and 35 to 55 parts of titanium powder.

[0020] The present invention further preferably includes mixing 45-65 parts of molybdenum powder and 35-55 parts of titanium powder, with the total amount of molybdenum powder and titanium powder being 100 parts. Combined with the selection of a specific average particle size, the mixture works synergistically to further improve the quality of the molybdenum-titanium alloy target.

[0021] Preferably, the mixing process includes first dividing the molybdenum powder and the titanium powder into n equal parts, then mixing each part of molybdenum powder with each part of titanium powder in a first mixing process to obtain n equal parts of molybdenum-titanium mixed powder, and then mixing the n equal parts of molybdenum-titanium mixed powder in a second mixing process to obtain mixed powder, wherein n≥2, for example, it can be 2, 3, 4, 5, 6, 7 or 8, preferably 3 to 6.

[0022] The present invention further preferably adopts the above-mentioned mixing method to ensure that the molybdenum powder and the titanium powder are fully and uniformly mixed, which is beneficial to the subsequent alloying reaction, avoids phase segregation, and improves the quality of the obtained molybdenum-titanium alloy target.

[0023] Preferably, the mixing is carried out in a powder mixer.

[0024] Preferably, the rotation speed of the mixer during the first mixing is 10 to 12 r / min, for example, it can be 10 r / min, 11 r / min or 12 r / min.

[0025] Preferably, the first mixing time is 12 to 18 hours, for example, it can be 12 hours, 13 hours, 14 hours, 15 hours, 16 hours, 17 hours or 18 hours.

[0026] Preferably, the rotation speed of the mixer during the second mixing is 7 to 9 r / min, for example, it can be 7 r / min, 8 r / min or 9 r / min, etc.

[0027] Preferably, the second mixing time is 8 to 12 hours, for example, 8 hours, 9 hours, 10 hours, 11 hours or 12 hours.

[0028] Preferably, the pressure of the cold isostatic pressing is 160-230 MPa, for example, it can be 160 MPa, 170 MPa, 180 MPa, 190 MPa, 200 MPa, 210 MPa, 220 MPa, or 230 MPa, etc.

[0029] Preferably, the holding time for cold isostatic pressing is 20 to 25 minutes, for example, 20 minutes, 21 minutes, 22 minutes, 23 minutes, 24 minutes, or 25 minutes.

[0030] Preferably, the degassing process includes placing the cold isostatically pressed blank in a sleeve for degassing.

[0031] The enclosure is a fully sealed structure with a degassing tube welded to its end for degassing. The degassing tube is connected to a vacuum pump for evacuation.

[0032] Preferably, the material of the sheath includes carbon steel and / or stainless steel.

[0033] Preferably, the degassing process includes a first vacuuming, a first heating, a second vacuuming, a second heating, a third vacuuming, a third heating, and a fourth vacuuming, performed sequentially.

[0034] Preferably, the first vacuuming is performed at room temperature, i.e., 22 to 28°C, for example, 22°C, 24°C, 25°C, 26°C or 28°C.

[0035] Preferably, the first vacuuming includes evacuating to a vacuum level ≤ 3 × 10⁻⁶. -3 Pa, for example, could be 3 × 10 - 3 Pa, 2.8 × 10 -3 Pa, 2.6 × 10 -3 Pa, 2.4 × 10 -3 Pa or 2.2 × 10 -3 Pa, etc.

[0036] Preferably, the endpoint temperature of the first heating is 100-200°C, for example, it can be 100°C, 120°C, 150°C, 180°C or 200°C.

[0037] Preferably, the second vacuuming includes evacuating to a vacuum level ≤ 2 × 10⁻⁶. -3 Pa, for example, could be 2 × 10 - 3 Pa, 1.8 × 10 -3 Pa, 1.5×10 -3 Pa or 1.2 × 10 -3 Pa.

[0038] Preferably, the endpoint temperature of the second heating is 300-400°C, for example, it can be 300°C, 320°C, 350°C, 380°C or 400°C.

[0039] Preferably, the third vacuuming includes evacuating to a vacuum level < 1 × 10⁻⁶. -3 Pa, for example, could be 1×10 - 3 Pa, 9×10 -4 Pa, 8×10 -4 Pa, 7×10 -4 Pa or 6×10 -4 Pa, etc.

[0040] Preferably, the endpoint temperature of the third heating is 600-700°C, for example, it can be 600°C, 620°C, 650°C, 670°C or 700°C.

[0041] Preferably, the fourth vacuuming includes evacuating to a vacuum level of <5×10⁻⁶. -4 Pa, for example, could be 4.5 × 10 - 4 Pa, 4×10 -4 Pa, 3.5 × 10 -4 Pa, 3×10 -4 Pa, 2.5 × 10 -4 Pa or 2×10 -4 Pa, etc.

[0042] The present invention further preferably includes the following degassing process: a first vacuuming, a first heating, a second vacuuming, a second heating, a third vacuuming, a third heating, and a fourth vacuuming, i.e., four vacuumings and three heatings are performed respectively, and the vacuum degree and the heating endpoint temperature range are further selected respectively, so as to make the degassing more thorough, so as not to affect the subsequent sintering and reduce the hydrogen and oxygen content in the obtained molybdenum-titanium alloy target.

[0043] Preferably, the temperature of the hot isostatic pressing is 1200-1400℃, for example, it can be 1200℃, 1250℃, 1300℃, 1350℃ or 1400℃.

[0044] Preferably, the pressure of the hot isostatic pressing is 160-180 MPa, for example, it can be 160 MPa, 162 MPa, 165 MPa, 168 MPa, 170 MPa, 172 MPa, 175 MPa, 178 MPa or 180 MPa.

[0045] Preferably, the heat preservation and pressure holding time of the hot isostatic pressing is 5 to 12 hours, for example, it can be 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours, 11 hours or 12 hours.

[0046] Preferably, the vacuum annealing temperature is 1100-1300℃, for example, it can be 1100℃, 1150℃, 1200℃, 1250℃ or 1300℃.

[0047] Preferably, the heating rate of the vacuum annealing is 5 to 10 °C / min, for example, it can be 5 °C / min, 6 °C / min, 7 °C / min, 8 °C / min, 9 °C / min or 10 °C / min, etc.

[0048] The present invention further optimizes the heating rate of the vacuum annealing to 5-10°C / min, which facilitates more thorough alloying of the molybdenum-titanium alloy target material and eliminates pure titanium phase and gaseous impurities. If the heating rate of the vacuum annealing is too low, the risk of oxidation on the target surface will increase, increasing the risk of reaction with residual oxygen or impurity gases in the furnace, resulting in increased oxygen content in the target material and reduced production efficiency. If the heating rate of the vacuum annealing is too high, it will lead to increased residual stress, cracking, and decreased density.

[0049] Preferably, the holding time for vacuum annealing is 8 to 12 hours, for example, 8 hours, 9 hours, 10 hours, 11 hours, or 12 hours.

[0050] As a further preferred technical solution of the present invention, the preparation method includes the following steps:

[0051] Molybdenum powder with a purity ≥3N5 and an average particle size of 3-5 μm, and titanium powder with a purity ≥3N and an average particle size of 100-150 μm are selected. 25-70 parts of molybdenum powder and 30-75 parts of titanium powder are divided into n equal parts, where n ≥ 2. In a powder mixer under a protective gas atmosphere, each part of molybdenum powder and each part of titanium powder are first mixed at a speed of 10-12 r / min for 12-18 h to obtain n equal parts of molybdenum-titanium mixed powder. Then, the n equal parts of the molybdenum-titanium mixed powder are second mixed at a speed of 7-9 r / min for 8-12 h to obtain mixed powder.

[0052] First, the mixed powder is subjected to cold isostatic pressing at a pressure of 160–230 MPa for 20–25 min. The resulting compact is then placed in a sleeve for degassing. The degassing process includes: firstly, evacuating the vacuum to a vacuum degree ≤ 3 × 10⁻⁶. -3 Pa, then heat to 100-200℃, then evacuate to a vacuum level ≤2×10. -3 Pa, then raise the temperature a second time to 300-400℃, followed by a third evacuation to a vacuum level <1×10⁻⁶. -3 Pa, then raise the temperature a third time to 600-700℃, and finally evacuate to a vacuum level of <5×10⁻⁶. -4 Pa; subsequently, the degassed compact is subjected to hot isostatic pressing at 1200-1400℃ and 160-180MPa for 5-12 hours; finally, the hot isostatic pressed compact is heated to 1100-1300℃ at a heating rate of 5-10℃ / min and held for 8-12 hours for vacuum annealing to obtain the molybdenum-titanium alloy target.

[0053] Compared with the prior art, the present invention has at least the following beneficial effects:

[0054] The method for preparing molybdenum-titanium alloy targets provided by this invention, through specific selection of the average particle size and mass ratio of raw material molybdenum powder and titanium powder, combined with a specific process flow, and further optimization of the mixing method of molybdenum powder and titanium powder and the degassing procedure of the encapsulation, combined with a vacuum annealing process with a specific heating rate, results in a molybdenum-titanium alloy target with a density preferably as high as 99.9% or more, containing only pure molybdenum phase and molybdenum-titanium alloy phase, with the proportion of the molybdenum-titanium alloy phase preferably increased to more than 50%, while reducing the gas content at the phase interface, so that the hydrogen content in the molybdenum-titanium alloy target is preferably as low as below 3 ppm and the oxygen content is preferably as low as below 576 ppm, providing a high-quality target for the semiconductor field and improving the yield of subsequent processed products. Attached Figure Description

[0055] Figure 1 This is a backscattering image of the molybdenum-titanium alloy target obtained by the preparation method of the molybdenum-titanium alloy target provided in Example 1 of the present invention. Detailed Implementation

[0056] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. However, the following examples are merely 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 is determined by the claims.

[0057] The powder mixer used in the following examples is model HD-400.

[0058] I. Implementation Examples

[0059] Example 1

[0060] This embodiment provides a method for preparing a molybdenum-titanium alloy target, the method comprising the following steps:

[0061] Molybdenum powder with a purity ≥3N5 and an average particle size of 4μm and titanium powder with a purity ≥3N and an average particle size of 125μm were selected. 55 parts of molybdenum powder and 45 parts of titanium powder were divided into 4 equal parts, n≥2. In a powder mixer under an argon atmosphere, each part of molybdenum powder and each part of titanium powder were first mixed at a speed of 11 r / min for 15 h to obtain 4 equal parts of molybdenum-titanium mixed powder. Then, the 4 equal parts of the molybdenum-titanium mixed powder were second mixed at a speed of 8 r / min for 10 h to obtain the mixed powder.

[0062] The mixed powder is first subjected to cold isostatic pressing at 200 MPa for 22 minutes, and the resulting compact is then placed in a sleeve for degassing. The degassing process includes: firstly, evacuating the vacuum to a vacuum degree of 2.5 × 10⁻⁶. -3 Pa, then the temperature is raised to 150℃ for the first time, and then a vacuum is drawn to a vacuum degree of 2×10. -3 Pa, then the temperature is raised to 350℃ for the second time, followed by a third evacuation to a vacuum degree of 8×10. -4 Pa, then the temperature is raised to 650℃ for the third time, and finally a vacuum is drawn to a vacuum degree of 4×10⁻⁶. -4 Pa; then the degassed billet is held at 1300℃ and 170MPa for 8 hours for hot isostatic pressing; finally, the hot isostatic pressed billet is heated to 1150℃ at a heating rate of 8℃ / min and held for 10 hours for vacuum annealing, and then naturally cooled to room temperature (25℃) to obtain the molybdenum-titanium alloy target.

[0063] like Figure 1 The image shown is a backscattering image of the molybdenum-titanium alloy target obtained by the preparation method of the molybdenum-titanium alloy target provided in this embodiment. EDS detection shows that there are only two phases: white and gray. The white area is the pure molybdenum phase, and the gray area is the molybdenum-titanium alloy phase. No pure titanium phase was found, indicating that the molybdenum-titanium alloy target obtained in this embodiment contains only the pure molybdenum phase and the molybdenum-titanium alloy phase.

[0064] Example 2

[0065] This embodiment provides a method for preparing a molybdenum-titanium alloy target, the method comprising the following steps:

[0066] Molybdenum powder with a purity ≥3N8 and an average particle size of 3μm and titanium powder with a purity ≥3N2 and an average particle size of 100μm were selected, and 45 parts of molybdenum powder and 55 parts of titanium powder were divided into 3 equal parts. In a powder mixer under an argon atmosphere, each part of molybdenum powder and each part of titanium powder were first mixed for 18 hours at a speed of 10 r / min to obtain 3 equal parts of molybdenum-titanium mixed powder. Then, the 3 equal parts of the molybdenum-titanium mixed powder were second mixed for 12 hours at a speed of 7 r / min to obtain mixed powder.

[0067] First, the mixed powder is subjected to cold isostatic pressing at 160 MPa for 25 minutes. The resulting compact is then placed in a sleeve for degassing. The degassing process includes: firstly, evacuating the vacuum to a vacuum degree of 3 × 10⁻⁶. -3 Pa, then heat to 100℃ for the first time, then evacuate to a vacuum level of 1.8 × 10⁻⁶. -3 Pa, then the temperature is raised to 300℃ for the second time, followed by a third evacuation to a vacuum degree of 9×10. -4 Pa, then the temperature is raised to 600℃ for the third time, and finally a vacuum is drawn to a vacuum degree of 3×10. -4 Pa; then the degassed compact is held at 1200℃ and 160MPa for 6 hours for hot isostatic pressing; finally, the hot isostatic pressed compact is heated to 1100℃ at a heating rate of 5℃ / min and held for 12 hours for vacuum annealing, and then naturally cooled to room temperature (25℃) to obtain the molybdenum-titanium alloy target.

[0068] The molybdenum-titanium alloy target obtained in this embodiment contains only pure molybdenum phase and molybdenum-titanium alloy phase.

[0069] Example 3

[0070] This embodiment provides a method for preparing a molybdenum-titanium alloy target, the method comprising the following steps:

[0071] Molybdenum powder with a purity ≥4N and an average particle size of 5μm and titanium powder with a purity ≥3N5 and an average particle size of 150μm were selected, and 65 parts of molybdenum powder and 35 parts of titanium powder were divided into 6 equal parts. In a powder mixer under nitrogen atmosphere, each part of molybdenum powder and each part of titanium powder were first mixed for 12 hours at a speed of 12 r / min to obtain 6 equal parts of molybdenum-titanium mixed powder. Then, the 6 equal parts of the molybdenum-titanium mixed powder were second mixed for 8 hours at a speed of 9 r / min to obtain mixed powder.

[0072] The mixed powder is first subjected to cold isostatic pressing at 230 MPa for 20 minutes, and the resulting compact is then placed in a sleeve for degassing. The degassing process includes: firstly, evacuating the vacuum to a vacuum degree of 2.2 × 10⁻⁶. -3 Pa, then the temperature is raised to 200℃, then a vacuum is drawn to a vacuum degree of 1.3×10.-3 Pa, then the temperature is raised to 400℃ for the second time, followed by a third evacuation to a vacuum degree of 8×10. -4 Pa, then the temperature is increased to 700℃ for the third time, and finally a vacuum is drawn to a vacuum degree of 4.5×10. -4 Pa; then the degassed billet is held at 1400℃ and 180MPa for 12h for hot isostatic pressing; finally, the hot isostatic pressed billet is heated to 1300℃ at a heating rate of 10℃ / min and held for 8h for vacuum annealing, and then naturally cooled to room temperature (25℃) to obtain the molybdenum-titanium alloy target.

[0073] The molybdenum-titanium alloy target obtained in this embodiment contains only pure molybdenum phase and molybdenum-titanium alloy phase.

[0074] Example 4

[0075] This embodiment provides a method for preparing a molybdenum-titanium alloy target. The preparation method is the same as in Example 1, except that the molybdenum powder is 40 parts and the titanium powder is 60 parts.

[0076] Example 5

[0077] This embodiment provides a method for preparing a molybdenum-titanium alloy target. The preparation method is the same as in Example 1, except that the molybdenum powder is 70 parts and the titanium powder is 30 parts.

[0078] Example 6

[0079] This embodiment provides a method for preparing a molybdenum-titanium alloy target. Except for directly mixing 55 parts of molybdenum powder and 45 parts of titanium powder in the first mixing, the preparation method is the same as in Example 1.

[0080] Example 7

[0081] This embodiment provides a method for preparing a molybdenum-titanium alloy target, wherein the preparation method, except that the degassing treatment is performed by a single vacuuming to 4×10⁻⁶, involves... -4 Except for Pa, which was heated to 650°C in one go, everything else was the same as in Example 1.

[0082] Example 8

[0083] This embodiment provides a method for preparing a molybdenum-titanium alloy target. The preparation method is the same as in Embodiment 1, except that the degassing treatment does not involve the first vacuuming and the first heating.

[0084] Example 9

[0085] This embodiment provides a method for preparing a molybdenum-titanium alloy target. Except for the heating rate of 4°C / min during vacuum annealing, the preparation method is the same as in Example 1.

[0086] Example 10

[0087] This embodiment provides a method for preparing a molybdenum-titanium alloy target. Except for the heating rate of 12°C / min during vacuum annealing, the preparation method is the same as in Example 1.

[0088] II. Comparative Example

[0089] Comparative Example 1

[0090] This comparative example provides a method for preparing a molybdenum-titanium alloy target. The preparation method is the same as in Example 1, except that the average particle size of the titanium powder is 90 μm.

[0091] Comparative Example 2

[0092] This comparative example provides a method for preparing a molybdenum-titanium alloy target. The preparation method is the same as in Example 1, except that the average particle size of the titanium powder is 160 μm.

[0093] Comparative Example 3

[0094] This comparative example provides a method for preparing a molybdenum-titanium alloy target. The preparation method is the same as in Example 1, except that the average particle size of the molybdenum powder is 6 μm.

[0095] Comparative Example 4

[0096] This comparative example provides a method for preparing a molybdenum-titanium alloy target. The preparation method is the same as in Example 1, except that the average particle size of the molybdenum powder is 1 μm.

[0097] Comparative Example 5

[0098] This comparative example provides a method for preparing a molybdenum-titanium alloy target. The preparation method is the same as in Example 1, except that the average particle size of the molybdenum powder is 8 μm and the average particle size of the titanium powder is 20 μm.

[0099] III. Tests and Results

[0100] The density, proportion of molybdenum-titanium alloy phase, hydrogen content and oxygen content of the molybdenum-titanium alloy target obtained by the preparation method of the molybdenum-titanium alloy target provided in the above embodiments or comparative examples were tested or calculated, and the results are shown in Table 1.

[0101] Table 1

[0102]

[0103] The data in Table 1 shows that:

[0104] (1) As can be seen from Examples 1 to 3, the preparation method of molybdenum-titanium alloy target provided by the present invention, by selecting the specifications of raw materials and combining specific processes, produces a molybdenum-titanium alloy target with a density of over 99.9% and a molybdenum-titanium alloy phase ratio of over 50%, a hydrogen content as low as 3 ppm and an oxygen content as low as 576 ppm, which reduces the probability of abnormalities during sputtering.

[0105] (2) It can be seen from the comprehensive examples 1 and 4 to 6 that the content of molybdenum powder and titanium powder in example 4 or 5 is not within the preferred range, and in example 6 only one mixing is carried out, resulting in uneven mixing. All of these lead to a decrease in the proportion of molybdenum-titanium alloy phase, a decrease in density, and an increase in hydrogen and oxygen content. This indicates that the present invention further preferably includes mixing 45 to 65 parts of molybdenum powder and 35 to 55 parts of titanium powder (the sum of the contents is 100 parts), or further preferably the mixing method, which further improves the degree of alloying and improves the quality of the obtained molybdenum-titanium alloy target.

[0106] (3) As can be seen from the combined examples 1, 7 and 8, the present invention further optimizes the degassing process, that is, the degassing process includes a first vacuuming, a first heating, a second vacuuming, a second heating, a third vacuuming, a third heating and a fourth vacuuming in sequence. Compared with the method of one vacuuming and one heating or three vacuuming and two heating, the gas at the phase interface is removed more thoroughly, thereby reducing the hydrogen and oxygen impurity content of the obtained molybdenum-titanium alloy target.

[0107] (4) As can be seen from the combined examples 1, 9 and 10, the present invention further optimizes the heating rate of the vacuum treatment to 5-10℃ / min, which further enables the molybdenum-titanium alloy to be fully alloyed, and the pure titanium phase and gaseous impurities are fully eliminated, thereby further improving the quality of the obtained molybdenum-titanium alloy target.

[0108] (5) As can be seen from the comprehensive examples 1 and 1 to 4, whether the average particle size of the titanium powder in 1 or 2 is too small or too large, and the average particle size of the molybdenum powder is within 3 to 5 μm, or the average particle size of the titanium powder in 3 or 4 is too small or too large, and the average particle size of the titanium powder is within 100 to 150 μm, or neither the molybdenum powder nor the titanium powder in 5 are within the specific selection range, all result in a decrease in the quality of the obtained molybdenum-titanium alloy target. This shows that the present invention selects the average particle size of the molybdenum powder as 3 to 5 μm and the average particle size of the titanium powder as 100 to 150 μm. The combination of the two, along with specific processes, improves the degree of molybdenum-titanium alloying, and obtains a molybdenum-titanium alloy target containing only pure molybdenum phase and molybdenum-titanium alloy phase. This improves the density, reduces the hydrogen and oxygen content, thereby helping to reduce particle abnormalities during sputtering and improve product yield.

[0109] The applicant declares that the above description is only a specific embodiment 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 conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A method for preparing a molybdenum-titanium alloy target, characterized in that, The preparation method includes the following steps: Molybdenum powder and titanium powder are mixed in a protective gas atmosphere to obtain a mixed powder; the mixed powder is then subjected to cold isostatic pressing, degassing under a cladding, hot isostatic pressing and vacuum annealing to obtain a molybdenum-titanium alloy target. The molybdenum powder has an average particle size of 3–5 μm, and the titanium powder has an average particle size of 100–150 μm.

2. The preparation method according to claim 1, characterized in that, The protective gas atmosphere includes argon and / or nitrogen. Preferably, the purity of the molybdenum powder is ≥3N5; Preferably, the purity of the titanium powder is ≥3N.

3. The preparation method according to claim 1 or 2, characterized in that, The mixing, by weight, comprises mixing 25 to 70 parts of molybdenum powder and 30 to 75 parts of titanium powder, preferably 45 to 65 parts of molybdenum powder and 35 to 55 parts of titanium powder; Preferably, the mixing process includes first dividing the molybdenum powder and the titanium powder into n equal parts, then mixing each part of molybdenum powder with each part of titanium powder in a first mixing process to obtain n equal parts of molybdenum-titanium mixed powder, and then mixing the n equal parts of molybdenum-titanium mixed powder in a second mixing process to obtain mixed powder, wherein n≥2, preferably 3 to 6.

4. The preparation method according to claim 3, characterized in that, The mixing is carried out in a powder mixer; Preferably, the rotation speed of the mixer during the first mixing is 10-12 r / min; Preferably, the first mixing time is 12-18 hours; Preferably, the rotation speed of the mixer during the second mixing is 7-9 r / min; Preferably, the second mixing time is 8 to 12 hours.

5. The preparation method according to any one of claims 1 to 4, characterized in that, The pressure of the cold isostatic pressing is 160–230 MPa; Preferably, the holding time for cold isostatic pressing is 20 to 25 minutes.

6. The preparation method according to any one of claims 1 to 5, characterized in that, The degassing process involves placing the cold isostatically pressed compact in a sleeve for degassing. Preferably, the degassing process includes sequentially performing a first vacuuming, a first heating, a second vacuuming, a second heating, a third vacuuming, a third heating, and a fourth vacuuming.

7. The preparation method according to claim 6, characterized in that, The first vacuuming includes evacuating to a vacuum level ≤ 3 × 10⁻⁶. -3 Pa; Preferably, the endpoint temperature of the first heating is 100–200°C; Preferably, the second vacuuming includes evacuating to a vacuum level ≤ 2 × 10⁻⁶. -3 Pa; Preferably, the endpoint temperature of the second heating is 300–400°C; Preferably, the third vacuuming includes evacuating to a vacuum level < 1 × 10⁻⁶. -3 Pa; Preferably, the final temperature of the third heating step is 600–700°C; Preferably, the fourth vacuuming includes evacuating to a vacuum level of <5×10⁻⁶. -4 Pa.

8. The preparation method according to any one of claims 1 to 7, characterized in that, The temperature of the hot isostatic pressing is 1200–1400℃; Preferably, the pressure of the hot isostatic pressing is 160–180 MPa; Preferably, the heat preservation and pressure holding time for hot isostatic pressing is 5 to 12 hours.

9. The preparation method according to any one of claims 1 to 8, characterized in that, The vacuum annealing temperature is 1100–1300℃; Preferably, the heating rate of the vacuum annealing is 5–10 °C / min; Preferably, the holding time for vacuum annealing is 8 to 12 hours.

10. The preparation method according to any one of claims 1 to 9, characterized in that, The preparation method includes the following steps: Molybdenum powder with a purity ≥3N5 and an average particle size of 3-5 μm, and titanium powder with a purity ≥3N and an average particle size of 100-150 μm are selected. 25-70 parts of molybdenum powder and 30-75 parts of titanium powder are divided into n equal parts, where n ≥ 2. In a powder mixer under a protective gas atmosphere, each part of molybdenum powder and each part of titanium powder are first mixed at a speed of 10-12 r / min for 12-18 h to obtain n equal parts of molybdenum-titanium mixed powder. Then, the n equal parts of the molybdenum-titanium mixed powder are second mixed at a speed of 7-9 r / min for 8-12 h to obtain mixed powder. First, the mixed powder is subjected to cold isostatic pressing at a pressure of 160–230 MPa for 20–25 min. The resulting compact is then placed in a sleeve for degassing. The degassing process includes: firstly, evacuating the vacuum to a vacuum degree ≤ 3 × 10⁻⁶. -3 Pa, then heat to 100-200℃, then evacuate to a vacuum level ≤2×10. -3 Pa, then raise the temperature a second time to 300-400℃, followed by a third evacuation to a vacuum level <1×10⁻⁶. -3 Pa, then raise the temperature a third time to 600-700℃, and finally evacuate to a vacuum level of <5×10⁻⁶. -4 Pa; subsequently, the degassed compact is subjected to hot isostatic pressing at 1200-1400℃ and 160-180MPa for 5-12 hours; finally, the hot isostatic pressed compact is heated to 1100-1300℃ at a heating rate of 5-10℃ / min and held for 8-12 hours for vacuum annealing to obtain the molybdenum-titanium alloy target.

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