Molybdenum-titanium target material and preparation method and application thereof

Abstract

The invention provides a molybdenum-titanium target material as well as a preparation method and application thereof. The preparation method comprises the following steps: carrying out hot isostatic pressing on a green body, removing a sheath, and milling; and then wrapping and rolling. According to the method, after hot isostatic pressing densification, a sheath is removed, six faces of a pressed ingot are milled, vacuum annealing is carried out, and then the sheath is re-wrapped for rolling. By means of sheathing rolling, the temperature of the blank can be kept, the blank is prevented from being oxidized in high-temperature air, edge crack extension can be restrained, the rolling yield is increased, and the final oxygen content of the target material is effectively reduced.

Description

Technical Field

[0001] This application relates to the field of target technology, and in particular to a molybdenum-titanium target, its preparation method and application. Background Technology

[0002] Molybdenum-titanium alloy sputtering targets are widely used in TFT-LCD and semiconductor manufacturing due to their excellent diffusion barrier properties and good compatibility with copper interconnect processes. Existing molybdenum-titanium sputtering target preparation typically involves powder mixing, cold isostatic pressing (CIP), hot isostatic pressing (HIP), and subsequent hot rolling / rolling. However, during the hot rolling process after HIP, the molybdenum alloy is usually heated in a hydrogen atmosphere. Titanium, however, is prone to hydrogenation in a hydrogen atmosphere, producing brittle titanium hydride. Therefore, titanium is usually heated in the atmosphere. Molybdenum, however, is easily oxidized and nitrided when heated in the atmosphere, and molybdenum oxide is prone to sublimation above 650°C, leading to surface defects in the billet, rapid temperature loss, and frequent cracking during rolling deformation, resulting in low yield. Furthermore, the final target material has a high oxygen content, which is detrimental to the performance of the sputtered film. Therefore, an improved process is needed to reduce oxygen content while maintaining density, thereby improving the workability and yield of the billet. Summary of the Invention

[0003] This application is made in view of the above-mentioned problems, and its purpose is to provide a molybdenum-titanium target material with low oxygen content.

[0004] The first aspect of this application provides a molybdenum-titanium target material, wherein the relative density of the molybdenum-titanium target material is above 99%; The oxygen content of the molybdenum-titanium target is below 800 ppm.

[0005] According to one of the technical solutions of the target material in this application, at least the following beneficial effects are achieved: The target material used in this application has a low oxygen content, which can improve the performance of sputtered thin films.

[0006] According to some embodiments of this application, the molar fraction of molybdenum in the molybdenum-titanium target is 30% to 70%.

[0007] According to some embodiments of this application, the molar fraction of titanium in the molybdenum-titanium target is 30% to 70%. According to some embodiments of this application, the relative density of the molybdenum-titanium target is 99% to 100%.

[0008] According to some embodiments of this application, the relative density of the molybdenum-titanium target is 99%~99.9%.

[0009] According to some embodiments of this application, the relative density of the molybdenum-titanium target is 99%~99.8%.

[0010] According to some embodiments of this application, the relative density of the molybdenum-titanium target is 99%~99.6%.

[0011] According to some embodiments of this application, the oxygen content of the molybdenum-titanium target is 0.1ppm to 800ppm.

[0012] According to some embodiments of this application, the oxygen content of the molybdenum-titanium target is 1ppm to 800ppm.

[0013] According to some embodiments of this application, the oxygen content of the molybdenum-titanium target is 100ppm to 800ppm.

[0014] According to some embodiments of this application, the oxygen content of the molybdenum-titanium target is 200ppm to 800ppm.

[0015] According to some embodiments of this application, the oxygen content of the molybdenum-titanium target is 300ppm to 800ppm.

[0016] According to some embodiments of this application, the oxygen content of the molybdenum-titanium target is 400ppm to 800ppm.

[0017] According to some embodiments of this application, the oxygen content of the molybdenum-titanium target is 500ppm to 800ppm.

[0018] According to some embodiments of this application, the oxygen content of the molybdenum-titanium target is 600ppm to 800ppm.

[0019] According to some embodiments of this application, the oxygen content of the molybdenum-titanium target is 600ppm to 780ppm.

[0020] According to some embodiments of this application, the oxygen content of the molybdenum-titanium target is 680ppm to 760ppm.

[0021] The second aspect of this application provides a method for preparing the above-mentioned molybdenum-titanium target, comprising the following steps: After hot isostatic pressing of the green billet, the cladding is removed and the billet is milled flat. Vacuum annealing; Then roll it in a sheath.

[0022] According to one of the technical solutions of the preparation method in this application, at least the following beneficial effects are achieved: After hot isostatic pressing densification, the cladding is removed and the six sides of the ingot are milled flat. Then, dehydrogenation and deoxidation treatment is carried out in a vacuum, and then the ingot is re-clad and rolled.

[0023] Encasing rolling can maintain the billet temperature, preventing oxidation in high-temperature air, inhibit crack propagation, improve the rolling yield, and effectively reduce the final oxygen content of the target material. According to some embodiments of this application, the preparation of the green billet includes mixing molybdenum powder and titanium powder followed by cold isostatic pressing.

[0024] According to some embodiments of this application, the particle size of the molybdenum powder is 2μm to 10μm.

[0025] According to some embodiments of this application, the average particle size of the molybdenum powder is 2 μm to 10 μm.

[0026] According to some embodiments of this application, the average particle size of the molybdenum powder is 2 μm to 8 μm.

[0027] According to some embodiments of this application, the particle size of the titanium powder is 20μm~150μm.

[0028] According to some embodiments of this application, the average particle size of the titanium powder is 20 μm to 100 μm.

[0029] According to some embodiments of this application, the average particle size of the titanium powder is 20 μm to 80 μm.

[0030] According to some embodiments of this application, the relative density of the green body is 60% to 80%.

[0031] According to some embodiments of this application, the pressure of the cold isostatic pressing is 100MPa~200MPa.

[0032] According to some embodiments of this application, the pressure of the cold isostatic pressing is 140MPa~180MPa.

[0033] According to some embodiments of this application, the temperature of the hot isostatic pressing is 800°C to 1400°C.

[0034] According to some embodiments of this application, the temperature of the hot isostatic pressing is 1000℃~1300℃.

[0035] According to some embodiments of this application, the pressure of the hot isostatic pressing is 50MPa~300MPa.

[0036] According to some embodiments of this application, the pressure of the hot isostatic pressing is 100MPa~200MPa.

[0037] According to some embodiments of this application, the pressure of the hot isostatic pressing is 140MPa~160MPa.

[0038] According to some embodiments of this application, the hot isostatic pressing time is 2h to 8h.

[0039] According to some embodiments of this application, the milled ingot is vacuum heated.

[0040] According to some embodiments of this application, the vacuum degree of the vacuum heating is 1×10⁻⁶. -2 Below Pa.

[0041] According to some embodiments of this application, the temperature of the vacuum heating is 700℃~1200℃.

[0042] According to some embodiments of this application, the temperature of the vacuum heating is 900℃~1000℃.

[0043] According to some embodiments of this application, the vacuum heating time is 2h to 12h.

[0044] According to some embodiments of this application, the rolling temperature is 700°C to 900°C.

[0045] According to some embodiments of this application, the rolling process further includes inter-fire annealing.

[0046] According to some embodiments of this application, the temperature of the secondary annealing is 400°C to 700°C.

[0047] According to some embodiments of this application, the inter-annealing time is 0.5h to 3h.

[0048] According to some embodiments of this application, the total deformation during rolling is 40% to 80%.

[0049] According to some embodiments of this application, the vacuum annealing temperature is 400℃~700℃.

[0050] According to some embodiments of this application, the vacuum annealing time is 0.5h to 3h.

[0051] According to some embodiments of this application, the rolling process is followed by heat treatment.

[0052] According to some embodiments of this application, the temperature of the heat treatment is 800℃~1400℃.

[0053] According to some embodiments of this application, the temperature of the heat treatment is 800℃~1000℃.

[0054] According to some embodiments of this application, the heat treatment time is 2h to 12h.

[0055] The third aspect of this application provides the application of the aforementioned molybdenum-titanium sputtering targets in TFT-LCD and / or semiconductor manufacturing. Attached Figure Description

[0056] To more clearly illustrate the technical solutions in the embodiments of this drawing or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this drawing. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0057] Figure 1 This is a photograph of the actual product of the molybdenum-titanium target rolling process in Example 1.

[0058] Figure 2 This is a picture of the actual product of the molybdenum-titanium target rolling process in Comparative Example 1.

[0059] Figure 3 This is a picture of the actual product of the molybdenum-titanium target rolling process in Comparative Example 1.

[0060] Figure 4 This is a picture of the actual product of the molybdenum-titanium target rolling process in Comparative Example 1.

[0061] The purpose, features, and advantages of this accompanying drawing will be further explained in conjunction with the embodiments and with reference to the accompanying drawing. Detailed Implementation

[0062] To make the objectives, technical solutions, and advantages of this application clearer, the following description and illustration are provided in conjunction with embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application. All other embodiments obtained by those skilled in the art based on the embodiments provided in this application without inventive effort are within the scope of protection of this application.

[0063] Obviously, the following description is merely some examples or embodiments of this application. Those skilled in the art can apply this application to other similar scenarios without any inventive effort. Furthermore, it is understood that although the effort involved in such development may be complex and lengthy, for those skilled in the art related to the content disclosed in this application, any changes to design, manufacturing, or production based on the technical content disclosed in this application are merely conventional technical means and should not be construed as insufficient disclosure of the content of this application.

[0064] Unless otherwise specified, the terms "comprising" and "including" as used in this application can be open-ended or closed-ended. For example, "comprising" and "including" can mean that other components not listed may also be included, or that only the listed components may be included.

[0065] Unless otherwise specified, the term "or" is inclusive in this application. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, the condition "A or B" is satisfied by any of the following conditions: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0066] This application relates to a method for preparing molybdenum-titanium alloy sputtering targets, which aims to solve the problems of rapid temperature loss of billets, easy oxidation, high cracking rate, low yield and high oxygen content of final products in traditional rolling processes.

[0067] This application involves removing the outer sheath after hot isostatic pressing (HIP) densification and milling the six sides of the ingot flat. Then, it undergoes vacuum heating for dehydrogenation and deoxidation treatment, followed by re-sheathing and sheath rolling. Sheath rolling can maintain the billet temperature, effectively avoid oxidation and edge cracking, thereby significantly improving the yield, reducing the oxygen content of the product, and obtaining a molybdenum-titanium alloy target with uniform structure, high density, and good plasticity, which is suitable for the preparation of large-size sputtering targets.

[0068] This application involves hot isostatic pressing densification followed by removal of the cladding and milling of the six sides of the billet. Then, dehydrogenation and deoxidation are performed in a vacuum, followed by re-cladding and rolling. Clad rolling maintains the billet temperature, preventing oxidation in high-temperature air, inhibits edge crack propagation, increases the rolling yield, and effectively reduces the final oxygen content of the target material.

[0069] A method for manufacturing a molybdenum-titanium alloy target includes the following steps: (a) Molybdenum powder and titanium powder are mixed under inert gas protection and then formed by CIP. (b) The green blank is subjected to HIP sintering to obtain a high-density pressed ingot; (c) Remove the HIP sleeve and mill the ingot on all six sides; (d) The pressed ingot is subjected to heating dehydrogenation and deoxygenation treatment under vacuum conditions; (e) The vacuum-treated ingot is re-encased and then hot-rolled or rolled to obtain a molybdenum-titanium sheet. (f) The plate is subjected to recrystallization heat treatment and machining to obtain a molybdenum-titanium alloy target.

[0070] According to some embodiments of this application, the vacuum heating dehydrogenation and deoxygenation conditions are: vacuum degree ≤ 1×10 -2 Pa, temperature 700℃~1200℃, heat preservation for 2h~12h.

[0071] According to some embodiments of this application, the rolling temperature range of the cladding is 700℃~900℃, and vacuum annealing of 400℃~700℃ for 0.5h~3h can be performed after rolling.

[0072] According to some embodiments of this application, the cladding material is low-carbon steel or stainless steel, which is removed after rolling.

[0073] According to some embodiments of this application, swag rolling effectively maintains billet temperature, prevents oxidation, reduces edge cracking, and improves yield.

[0074] The method described in this application includes the following steps: 1) Powder preparation: Select molybdenum powder (average particle size 2μm~10μm) and titanium powder (spherical, particle size 20μm~150μm), and mix them evenly under inert gas protection.

[0075] 2) Cold isostatic pressing (CIP): The mixed powder is pressed into shape to obtain a green body with a relative density of 60%~80% of the theoretical density.

[0076] 3) Hot Isostatic Pressing (HIP): The green billet is subjected to HIP sintering at a temperature range of 1000℃~1400℃, a pressure of 50MPa~300MPa, and a time of 2h~8h to obtain a high-density pressed ingot.

[0077] 4) Remove the HIP casing and mill the six sides of the die to eliminate surface contamination and uneven areas.

[0078] 5) Vacuum heating dehydrogenation and deoxidation treatment: The milled ingot is heated under vacuum conditions (vacuum degree ≤ 1×10⁻⁶). -2 Heating (Pa) at 700℃~1200℃ and holding for 2h~12h removes residual hydrogen and surface / internal oxygen, improving material purity.

[0079] 6) Re-coating and Coating Rolling: Re-coating the ingot under vacuum or inert atmosphere and then hot rolling / rolling it.

[0080] The rolling temperature is controlled at 700℃~900℃. The cladding can effectively maintain the billet temperature, prevent oxidation, and reduce edge cracks.

[0081] Furthermore, after each rolling, annealing is performed to remove work hardening (400℃~700℃, 0.5h~3h) to ensure plasticity and uniformity of microstructure.

[0082] 7) Final heat treatment and processing: The rolled sheet is subjected to recrystallization heat treatment (800℃~1400℃, 2h~12h, vacuum degree ≤1×10). -2 Pa), then machining to the target size and inspecting.

[0083] This application introduces a process route after HIP (High-Intensity Interval) – decoating – six-sided milling – vacuum dehydrogenation and deoxidation – recoating and rolling, which enables: Significantly reduces the oxygen content of the target material and improves the performance of the sputtered film; By using a sheathing rolling process to maintain the billet temperature, avoid oxidation, reduce edge cracks, and improve the yield; To obtain large-size molybdenum-titanium alloy targets with uniform structure, high density, and good plasticity; Reduce scrap rate and lower overall production costs.

[0084] Example 1 This embodiment describes a method for preparing a molybdenum-titanium target, which consists of the following steps: Mo powder with an average particle size of 4 μm and Ti powder with an average particle size of 45 μm, and an atomic ratio of Mo to Ti of 60:40, were mixed uniformly under inert gas protection to obtain a mixed powder. The mixed powder was cold isostatically pressed (CIP pressure 150 MPa) to obtain a green body with a relative density of 70%.

[0085] High-density ingots are obtained by hot isostatic pressing of green billets. HIP conditions: 1200 ℃, 150 MPa, 4 h.

[0086] After removing the cladding from the high-density ingot and milling it flat on all six sides, it is subjected to a vacuum of 10... -3 The milled and flattened ingot was prepared by holding it at 900 ℃ for 6 h.

[0087] After milling and pressing, the ingot is wrapped and rolled at 800 °C with a total deformation rate of 40%. After each rolling, it is annealed at 500 °C for 1 h to obtain the rolled material.

[0088] The rolled material was subjected to vacuum heat treatment at 1000℃ for 4 h to obtain molybdenum-titanium sputtering target.

[0089] Tests showed that the target material had a relative density of ≥99% and an oxygen content of ≤800 ppm (see Table 1 for specific data); the material had a uniform structure and good plasticity.

[0090] Example 2 This embodiment describes a method for preparing a molybdenum-titanium target, which consists of the following steps: Mo powder with an average particle size of 2 μm and Ti powder with an average particle size of 30 μm, and an atomic ratio of Mo to Ti of 50:50, were mixed uniformly under inert gas protection to obtain a mixed powder. The mixed powder was cold isostatically pressed (CIP pressure 140 MPa) to obtain a green body with a relative density of 65%.

[0091] High-density ingots are obtained by hot isostatic pressing of green billets. HIP conditions: 1000 ℃, 140 MPa, 4 h.

[0092] After removing the cladding from the high-density ingot and milling it flat on all six sides, it is subjected to a vacuum of 10... -3 The milled and flattened ingot was prepared by holding it at 900 ℃ for 4 h.

[0093] After milling and pressing, the ingot is wrapped and rolled at 700 °C with a total deformation rate of 60%. After each rolling, it is annealed at 600 °C for 1 h to obtain the rolled material.

[0094] The rolled material was subjected to vacuum heat treatment at 1000℃ for 4 h to obtain molybdenum-titanium sputtering target.

[0095] Tests showed that the target material had a relative density of ≥99% and an oxygen content of ≤800 ppm (see Table 1 for specific data); the material had a uniform structure and good plasticity.

[0096] Example 3 This embodiment describes a method for preparing a molybdenum-titanium target, which consists of the following steps: Mo powder with an average particle size of 8 μm and Ti powder with an average particle size of 80 μm, and an atomic ratio of Mo to Ti of 30:70, were mixed uniformly under inert gas protection to obtain a mixed powder. The mixed powder was cold isostatically pressed (CIP pressure 150 MPa) to obtain a green body with a relative density of 70%.

[0097] High-density ingots are obtained by hot isostatic pressing of green billets. HIP conditions: 1200 ℃, 150 MPa, 4 h.

[0098] After removing the cladding from the high-density ingot and milling it flat on all six sides, it is subjected to a vacuum of 10... -3 The milled and flattened ingot was prepared by holding it at 900 ℃ for 6 h.

[0099] After milling and pressing, the ingot is wrapped and rolled at 800 °C with a total deformation rate of 80%. After each rolling, it is annealed at 700 °C for 1 h to obtain the rolled material.

[0100] The rolled material was subjected to vacuum heat treatment at 1000℃ for 4 h to obtain molybdenum-titanium sputtering target.

[0101] Tests showed that the target material had a relative density of ≥99% and an oxygen content of ≤800 ppm (see Table 1 for specific data); the material had a uniform structure and good plasticity.

[0102] Example 4 Mo powder with an average particle size of 5 μm and Ti powder with an average particle size of 60 μm, and an atomic ratio of Mo to Ti of 70:30, were mixed uniformly under inert gas protection to obtain a mixed powder. The mixed powder was cold isostatically pressed (CIP pressure 180 MPa) to obtain a green body with a relative density of 75%.

[0103] High-density ingots are obtained by hot isostatic pressing of green billets. HIP conditions: 1300 ℃, 160 MPa, 5 h.

[0104] After removing the cladding from the high-density ingot and milling it flat on all six sides, it is subjected to a vacuum of 10... -3 The milled and flattened ingot was prepared by holding it at 1000 ℃ for 6 h.

[0105] After milling and pressing, the ingot is wrapped and rolled at 900 °C with a total deformation rate of 60%. After each rolling, it is annealed at 700 °C for 1 h to obtain the rolled material.

[0106] The rolled material was subjected to vacuum heat treatment at 900℃ for 2 h to obtain molybdenum-titanium sputtering target.

[0107] Tests showed that the target material had a relative density of ≥99% and an oxygen content of ≤800 ppm (see Table 1 for specific data); the material had a uniform structure and good plasticity.

[0108] Comparative Example 1 Comparative Example 1 provides a method for preparing a molybdenum-titanium alloy target, the steps of which are basically the same as those in Example 1, except that: The six sides were not milled flat after the molybdenum-titanium hot isostatic pressing process removed the cladding.

[0109] Comparative Example 2 Comparative Example 2 provides a method for preparing a molybdenum-titanium alloy target, the steps of which are basically the same as those in Example 1, except that: The molybdenum-titanium hot isostatic pressing process was not followed by vacuum dehydrogenation and deoxidation after the cladding was removed.

[0110] Comparative Example 3 Comparative Example 3 provides a method for preparing a molybdenum-titanium alloy target, the steps of which are basically the same as those in Example 1, except that: After hot isostatic pressing of molybdenum-titanium alloys, the cladding was removed but not re-clad before hot rolling.

[0111] To verify the advancement of the molybdenum-titanium alloy target and its preparation method provided in this embodiment of the invention, the relative density and oxygen content of the molybdenum-titanium alloy targets prepared in this embodiment and the comparative example of the invention were tested, and the results are shown in Table 1 below.

[0112] Using Example 1 and Comparative Examples 1-3 as examples, physical images of the molybdenum-titanium alloy target are provided as follows: Figures 1 to 4 As shown.

[0113] Table 1

[0114] From Table 1 above, at least the following conclusions can be drawn: This invention provides a molybdenum-titanium target material, its preparation method, and its application. Comparative Example 1, due to the failure to mill the six sides of the molybdenum-titanium billet after heat treatment and decoating, has surface defects before rolling. During rolling, these defects expand into cracks, such as... Figure 2 As shown; In Comparative Example 2, oxygen accumulation at the phase interface of the untreated molybdenum-titanium target material led to interface embrittlement, resulting in cracking during subsequent rolling. Figure 3 As shown; In Comparative Example 3, the molybdenum-titanium billet was not re-coated, which caused the molybdenum to oxidize and sublimate during heating, forming defects on the billet surface and subsequently cracking during rolling.

[0115] This application proposes a process route for preparing molybdenum-titanium sputtering targets. By combining a HIP process with decoating milling, vacuum dehydrogenation and deoxidation, and recoating rolling, the purity, yield, and final performance of the target material are significantly improved. This method is suitable for the industrial preparation of high-generation, large-size sputtering targets.

[0116] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. A molybdenum titanium target material, characterized by, The relative density of the Mo-Ti target is above 99%; The oxygen content of the Mo-Ti target is below 800ppm.

2. The molybdenum titanium target material of claim 1, wherein, The mole fraction of Mo in the Mo-Ti target is 30% to 70%; And / or, the mole fraction of Ti is 30% to 70%.

3. A method of producing a molybdenum titanium target according to claim 1 or 2, characterized in that, The method comprises the following steps: Milling the green compact after hot isostatic pressing and removing the package; Vacuum annealing; Re-packaging and rolling.

4. The production method according to claim 3, characterized by, The preparation of the green compact comprises mixing Mo powder and Ti powder and then cold isostatic pressing; And / or, the particle size of the Mo powder is 2μm to 10μm; And / or, the particle size of the Ti powder is 20μm to 150μm; And / or, the relative density of the green compact is 60% to 80%; And / or, the pressure of the cold isostatic pressing is 100MPa to 200MPa.

5. The preparation method according to claim 3, characterized in that, The temperature of the hot isostatic pressing is 800℃ to 1400℃; And / or, the pressure of the hot isostatic pressing is 50MPa to 300MPa; And / or, the time of the hot isostatic pressing is 2h to 8h.

6. The preparation method according to claim 3, characterized in that, Vacuum heating the milled ingot; And / or, the vacuum heating has a vacuum degree of 1 x 10 -2 Pa or below; And / or, the temperature of the vacuum heating is 700℃ to 1200℃; And / or, the time of the vacuum heating is 2h to 12h.

7. The preparation method according to claim 3, characterized in that, The temperature of the rolling is 700℃ to 900℃.

8. The preparation method according to claim 3, characterized in that, The rolling further comprises vacuum annealing; And / or, the temperature of the vacuum annealing is 400℃ to 700℃; And / or, the time of the vacuum annealing is 0.5h to 3h.

9. The preparation method according to claim 3, characterized in that, Heat treatment after the rolling is completed; And / or, the temperature of the heat treatment is 800℃ to 1400℃; And / or, the time of the heat treatment is 2h to 12h; And / or, the heat treatment is performed under vacuum or in an inert gas atmosphere.

10. Use of the Mo-Ti target according to claim 1 or 2 in TFT-LCD and / or semiconductor manufacturing.

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