High-purity copper-aluminum alloy target material and preparation method thereof

Abstract

The embodiment of the invention discloses a high-purity copper-aluminum alloy target material and a preparation method thereof. The method comprises the following steps: S1, mixing copper and aluminum raw materials according to a set proportion, smelting in an inert atmosphere, and casting to obtain a high-purity copper-aluminum alloy cast ingot; the mass content of aluminum in the high-purity copper-aluminum alloy cast ingot is 0.1-1%, and the total mass content of copper and aluminum is not less than 99.9999%; s2, the high-purity copper aluminum alloy cast ingot is sequentially subjected to longitudinal forging and transverse forging; the forging temperature is not greater than 80 DEG C, and the forging deformation is 30-50%; s3, the forged high-purity copper aluminum alloy is subjected to cross rolling; the cross rolling temperature is not higher than 80 DEG C, and the rotation angle of each pass is 15-135 degrees; the deformation of each pass is 5-20%, and the total deformation is 70-95%; and S4, the high-purity copper aluminum alloy obtained after cross rolling is subjected to heat treatment, and a high-purity copper aluminum alloy target blank is obtained after water cooling.

Description

Technical Field

[0001] The invention belongs to the technical field of sputtering target materials, and in particular relates to a high-purity copper-aluminum alloy target material and a preparation method thereof. Background Art

[0002] In modern industry, with the rapid development of high-tech fields such as electronic information technology, optoelectronic display, and semiconductor manufacturing, sputtering targets have been widely used as important materials for producing thin films in the process of physical vapor deposition (PVD).

[0003] Copper-aluminum alloy targets are widely used in the manufacturing process of integrated circuits, microelectronic packaging and display devices due to their good electrical conductivity, corrosion resistance and excellent physical properties during thin film deposition. However, existing copper-aluminum alloy targets usually have the following problems: (1) Low material purity: During the sputtering process, targets with high impurity content may cause the quality of the film to deteriorate, affecting the performance of the end product; (2) Uneven grain structure: Traditional copper-aluminum alloy target preparation methods often result in coarse and unevenly distributed grains inside the material, affecting the stability of the target during sputtering and the uniformity of the film; (3) Unsatisfactory mechanical properties: The existing target preparation process usually cannot simultaneously ensure the strength, toughness and processing performance of the target, which to a certain extent limits the wide application of the target. Summary of the invention

[0004] In view of this, some embodiments disclose a method for preparing a high-purity copper-aluminum alloy target, comprising the steps of:

[0005] S1. Copper and aluminum raw materials are mixed according to a set ratio, vacuumed and filled with inert gas, smelted in an inert atmosphere, and cast to obtain a high-purity copper-aluminum alloy ingot; the mass content of aluminum in the high-purity copper-aluminum alloy ingot is 0.1-1%, and the total mass content of copper and aluminum is not less than 99.9999%;

[0006] S2. The high-purity copper-aluminum alloy ingot is subjected to longitudinal forging and transverse forging in sequence; the forging temperature is not greater than 80°C, and the forging deformation is 30-50%;

[0007] S3, the forged high-purity copper-aluminum alloy is cross-rolled; the cross-rolling temperature is not more than 80°C, the rotation angle of each pass is 15-135°; the deformation amount of each pass is 5-20%, and the total deformation amount is 70-95%;

[0008] S4. The high-purity copper-aluminum alloy after cross rolling is heat treated and water-cooled to obtain a high-purity copper-aluminum alloy target.

[0009] Furthermore, in the method for preparing a high-purity copper-aluminum alloy target disclosed in some embodiments, in step S4, the heat treatment temperature is 300-450° C., and the heat treatment time is 15-60 min.

[0010] In the method for preparing a high-purity copper-aluminum alloy target disclosed in some embodiments, in step S1, the inert atmosphere is argon gas, and the vacuum degree is 5 to 10 -3 Pa.

[0011] In some embodiments, the method for preparing a high-purity copper-aluminum alloy target disclosed in step S1 specifically comprises:

[0012] According to the set ratio, copper and aluminum raw materials are loaded into the crucible;

[0013] The crucible is placed in a vacuum induction melting furnace, evacuated and filled with argon;

[0014] Heating and melting in an argon atmosphere;

[0015] A high-purity copper-aluminum alloy ingot is obtained by casting.

[0016] In the preparation method of the high-purity copper-aluminum alloy target disclosed in some embodiments, the mass content of aluminum in the high-purity copper-aluminum alloy ingot is 0.1-0.5%.

[0017] In the method for preparing a high-purity copper-aluminum alloy target disclosed in some embodiments, during the cross-rolling process, the rotation angle of each pass is 15 to 135°.

[0018] In the preparation method of the high-purity copper-aluminum alloy target disclosed in some embodiments, during the cross-rolling process, the deformation amount of each pass is 5-15%, and the total deformation amount is 85-95%.

[0019] In the preparation method of the high-purity copper-aluminum alloy target disclosed in some embodiments, the cross-rolling temperature is 30-40°C.

[0020] The method for preparing the high-purity copper-aluminum alloy target disclosed in some embodiments also includes the step of machining the prepared high-purity copper-aluminum alloy target.

[0021] On the other hand, some embodiments disclose high-purity copper-aluminum alloy targets, which are obtained by the preparation method of the high-purity copper-aluminum alloy targets disclosed in the embodiments of the present invention. In the high-purity copper-aluminum alloy targets, the mass content of aluminum is 0.1-1%, the total mass content of copper and aluminum is not less than 99.9999%, and the average grain size is not more than 80μm.

[0022] The method for preparing a high-purity copper-aluminum alloy target disclosed in an embodiment of the present invention comprises the following steps: multi-directional forging a high-purity copper-aluminum alloy ingot to transform a coarse dendrite structure into fine and uniform grains, and eliminate internal defects of the ingot, thereby greatly improving the structure and performance of the alloy ingot material, and facilitating subsequent processing of the alloy ingot material; after multi-directional forging, the high-purity copper-aluminum alloy ingot is cross-rolled, and the cross-rolling and heat treatment processes make the internal grain structure of the ingot finer and more uniform, and the heat treatment process releases the internal stress of the high-purity copper-aluminum alloy billet, thereby obtaining a high-performance high-purity copper-aluminum alloy target. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the cross rolling (45° and 135°) process;

[0024] Figure 2 is a microstructure diagram of the internal grains of the copper-aluminum alloy target material of Example 1;

[0025] Figure 3 is a microstructure diagram of the internal grains of the copper-aluminum alloy target material of Example 2;

[0026] Figure 4 This is the microstructure diagram of the internal grains of the copper-aluminum alloy target material of Example 3. DETAILED DESCRIPTION

[0027] The word "embodiment" used herein as an "exemplary" does not necessarily mean that any embodiment described is superior or better than other embodiments. Performance index tests in the embodiments of the present invention are performed using conventional test methods in the art unless otherwise specified. It should be understood that the terms described in the embodiments of the present invention are only used to describe specific implementation methods and are not intended to limit the contents disclosed in the embodiments of the present invention.

[0028] Unless otherwise specified, the technical and scientific terms used herein have the same meanings as commonly understood by ordinary technicians in the technical field to which the embodiments of the present invention belong; other experimental methods and technical means not specifically specified in the embodiments of the present invention refer to experimental methods and technical means commonly used by ordinary technicians in the field.

[0029] The terms "substantially" and "approximately" used herein are used to describe small fluctuations. For example, they can refer to less than or equal to ±5%, such as less than or equal to ±2%, such as less than or equal to ±1%, such as less than or equal to ±0.5%, such as less than or equal to ±0.2%, such as less than or equal to ±0.1%, such as less than or equal to ±0.05%. The numerical data represented or presented in the range format herein are used only for convenience and brevity, and should therefore be flexibly interpreted as including not only the values ​​clearly listed as the limits of the range, but also all independent values ​​or sub-ranges contained in the range. For example, the numerical range of "1-5%" should be interpreted as including not only the clearly listed values ​​of 1% to 5%, but also the independent values ​​and sub-ranges within the range shown. Therefore, independent values ​​such as 2%, 3.5% and 4% and sub-ranges such as 1%-3%, 2%-4% and 3%-5% are included in this numerical range. This principle also applies to the range of only one numerical value. In addition, such an interpretation applies regardless of the width of the range or the characteristics described.

[0030] In this document, including in the claims, transitional words such as "comprises," "includes," "with," "having," "containing," "involving," "accommodating," etc. are understood to be open-ended, i.e., meaning "including but not limited to." Only the transitional words "consisting of" and "composed of" are closed transitional words.

[0031] In order to better illustrate the present invention, numerous specific details are provided in the specific examples below. It should be understood by those skilled in the art that the present invention can be implemented without certain specific details. In the embodiments, some methods, means, instruments, equipment, etc. well known to those skilled in the art are not described in detail in order to highlight the gist of the present invention.

[0032] Under the premise of no conflict, the technical features disclosed in the embodiments of the present invention may be arbitrarily combined, and the resulting technical solutions belong to the contents disclosed in the embodiments of the present invention.

[0033] In some embodiments, the method for preparing a high purity copper-aluminum alloy target comprises the steps of:

[0034] S1. Copper and aluminum raw materials are mixed according to a set ratio, smelted in an inert atmosphere, and cast to obtain a high-purity copper-aluminum alloy ingot; the mass content of aluminum in the high-purity copper-aluminum alloy ingot is 0.1-1%, and the total mass content of copper and aluminum is not less than 99.9999%; generally, the inert atmosphere is argon, and the vacuum degree is 5-10 -3 Pa;

[0035] In some embodiments, the method for preparing a high-purity copper-aluminum alloy ingot comprises:

[0036] According to the set ratio, copper and aluminum raw materials are loaded into the crucible;

[0037] The crucible is placed in a vacuum induction melting furnace, evacuated and filled with argon;

[0038] Heating and melting in an argon atmosphere;

[0039] Casting to obtain a high-purity copper-aluminum alloy ingot;

[0040] S2. The high-purity copper-aluminum alloy ingot is subjected to longitudinal forging and transverse forging in sequence; the forging temperature is not greater than 80°C, and the forging deformation is 30-50%;

[0041] In some embodiments, the forging temperature is 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, etc.;

[0042] In some embodiments, the forging deformation is 30%, 40%, 50%, etc.;

[0043] S3, the forged high-purity copper-aluminum alloy is cross-rolled; the cross-rolling temperature is not more than 80°C, the rotation angle of each pass is 15-135°; the deformation amount of each pass is 5-20%, and the total deformation amount is 70-95%;

[0044] In some embodiments, the cross-rolling temperature is 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, etc.;

[0045] In some embodiments, the rotation angle of each pass is 15°, 30°, 45°, 60°, 75°, 90°, 135°, etc.;

[0046] S4. The high-purity copper-aluminum alloy after cross rolling is heat treated and water-cooled to obtain a high-purity copper-aluminum alloy target. Generally, the heat treatment temperature is 300-450° C. and the heat treatment time is 15-60 minutes.

[0047] Some embodiments disclose a method for preparing a high-purity copper-aluminum alloy target, wherein the mass content of aluminum in the high-purity copper-aluminum alloy ingot is 0.1-0.5%, for example, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, etc.

[0048] In the preparation method of the high-purity copper-aluminum alloy target disclosed in some embodiments, during the cross-rolling process, the rotation angle of each pass is 45° to 135°, such as 45°, 90°, 135°, etc.

[0049] In the preparation method of high-purity copper-aluminum alloy target disclosed in some embodiments, during the cross-rolling process, the deformation of each pass is 5-15%, for example, 5%, 10%, 15%, etc.; the total deformation is 85-95%, for example, 85%, 90%, 95%, etc.

[0050] In the preparation method of the high-purity copper-aluminum alloy target disclosed in some embodiments, the cross-rolling temperature is 30-40°C, for example, 30°C, 35°C, 40°C, etc.

[0051] The method for preparing the high-purity copper-aluminum alloy target disclosed in some embodiments also includes the step of machining the prepared high-purity copper-aluminum alloy target.

[0052] The high-purity copper-aluminum alloy target disclosed in some embodiments is obtained by the preparation method of the high-purity copper-aluminum alloy target disclosed in the embodiments of the present invention. In the high-purity copper-aluminum alloy target, the mass content of aluminum is 0.1-1%, the total mass content of copper and aluminum is not less than 99.9999%, and the average grain size is not more than 80μm.

[0053] The technical details are further illustrated below in conjunction with embodiments.

[0054] Example 1

[0055] In Example 1, the preparation method of the high-purity copper-aluminum alloy target comprises:

[0056] Weigh copper and aluminum with a mass ratio of 99.9:0.1 into a crucible, put it into a vacuum induction melting furnace, and evacuate to 10 -3 After Pa, argon gas is filled in, and the mixture is heated and melted in an argon atmosphere, and then cast to obtain a high-purity copper-aluminum alloy ingot with an aluminum content of 0.1wt%;

[0057] The obtained high-purity copper-aluminum alloy ingot is subjected to multi-directional forging, and the temperature is maintained at 80° C. and the deformation amount is 50% during the forging process;

[0058] Then, cross rolling is performed at 40°C, during which the rotation angle of each pass is controlled to be 45°, the deformation of each pass is 10%, and the total deformation is 90%;

[0059] Then, the target was treated at 300°C for 60 minutes, water-cooled and machined to obtain a high-purity copper-aluminum alloy target.

[0060] The microstructure and grain size of the high-purity copper-aluminum alloy target obtained in Example 1 were tested, and the results are as follows: Figure 1 and Table 1, grain size tested by EBSD, and grain size statistics by Aztec. Figure 1 A schematic diagram of the cross-rolling direction is illustrated. The left figure shows that the rotation angle of each cross-rolling pass is 45°; for example, the angle between the second pass RD2 and the first pass RD1 is 45°; the right figure shows that the rotation angle of each cross-rolling pass is 135°, for example, the angle between the second pass RD2 and the first pass RD1 is 135°.

[0061] Example 2

[0062] In Example 2, the preparation method of the high-purity copper-aluminum alloy target includes:

[0063] Weigh copper and aluminum with a mass ratio of 99.7:0.3 into a crucible, put it into a vacuum induction melting furnace, and evacuate to 10 -3 After Pa, argon gas is filled in, and the mixture is heated and melted in an argon atmosphere, and after melting, a high-purity copper-aluminum alloy ingot with an aluminum content of 0.3wt% is cast;

[0064] The obtained high-purity copper-aluminum alloy ingot is subjected to multi-directional forging, and the temperature is maintained at 80° C. during the forging process, and the deformation amount is 30%;

[0065] Then, cross rolling was performed at 30°C, during which the rotation angle of each pass was controlled to be 90°, the deformation of each pass was 15%, and the total deformation was 85%;

[0066] Then, the target was treated at 350°C for 30 minutes, water-cooled and machined to obtain a high-purity copper-aluminum alloy target.

[0067] The microstructure and grain size of the high-purity copper-aluminum alloy target obtained in Example 2 were tested, and the results were as follows: Figure 2 and Table 1, grain size tested by EBSD, and grain size statistics by Aztec.

[0068] Example 3

[0069] In Example 3, the preparation method of the high-purity copper-aluminum alloy target includes:

[0070] Weigh copper and aluminum with a mass ratio of 99.5:0.5 into a crucible, put it into a vacuum induction melting furnace, and evacuate to 10 -3 After Pa, argon gas is filled in, and the mixture is heated and melted in an argon atmosphere, and then cast to obtain a high-purity copper-aluminum alloy ingot with an aluminum content of 0.5wt%;

[0071] The obtained high-purity copper-aluminum alloy ingot is subjected to multi-directional forging, and the temperature is maintained at 80° C. during the forging process, and the deformation amount is 40%;

[0072] Then, cross rolling was performed at 35°C, during which the rotation angle of each pass was controlled to be 135°, the deformation of each pass was 5%, and the total deformation was 95%;

[0073] Then, the target was treated at 450°C for 15 minutes, water-cooled and machined to obtain a high-purity copper-aluminum alloy target.

[0074] The microstructure and grain size of the high-purity copper-aluminum alloy target obtained in Example 3 were tested, and the results are as follows: Figure 3 and Table 1, grain size tested by EBSD, and grain size statistics by Aztec.

[0075] It can be seen from Table 1 that the grain sizes of the high-purity copper-aluminum alloy targets obtained in Examples 1, 2, and 3 are all less than 80 μm.

[0076] Table 1 Test results of high purity copper-aluminum alloy targets prepared in Examples 1 to 3

[0077] Serial number Average grain size (μm) Grain size deviation (%) Example 1 75 13 Example 2 46 13 Example 3 60 16

[0078] The method for preparing a high-purity copper-aluminum alloy target disclosed in an embodiment of the present invention comprises the following steps: multi-directional forging a high-purity copper-aluminum alloy ingot to transform a coarse dendrite structure into fine and uniform grains, and eliminating internal defects of the ingot, thereby greatly improving the structure and performance of the alloy ingot material, and facilitating subsequent processing of the alloy ingot material; cross-rolling the high-purity copper-aluminum alloy ingot after multi-directional forging, and making the internal grain structure of the ingot finer and more uniform through cross-rolling and heat treatment processes, and the heat treatment process can release the internal stress of the high-purity copper-aluminum alloy billet, thereby obtaining a high-performance high-purity copper-aluminum alloy target material, and the target material has a small grain size, which meets the requirements of a sputtering copper-aluminum alloy target material.

[0079] The technical solutions disclosed in the embodiments of the present invention and the technical details disclosed in the embodiments are merely illustrative of the inventive concept of the present invention and do not constitute a limitation on the technical solutions of the embodiments of the present invention. Any conventional changes, replacements or combinations of the technical details disclosed in the embodiments of the present invention have the same inventive concept as the present invention and are within the protection scope of the claims of the present invention.

Claims

1. A method for preparing a high-purity copper-aluminum alloy target, characterized in that: Includes steps: S1, copper and aluminum raw materials are mixed according to a set ratio, vacuumed and filled with inert gas, smelted in an inert atmosphere, and cast to obtain a high-purity copper-aluminum alloy ingot; the mass content of aluminum in the high-purity copper-aluminum alloy ingot is 0.1-1%, and the total mass content of copper and aluminum is not less than 99.9999%; S2. The high-purity copper-aluminum alloy ingot is subjected to longitudinal forging and transverse forging in sequence; the forging temperature is not greater than 80°C, and the forging deformation is 30-50%; S3, the forged high-purity copper-aluminum alloy is cross-rolled; the cross-rolling temperature is not more than 80°C, the rotation angle of each pass is 15-135°; the deformation amount of each pass is 5-20%, and the total deformation amount is 70-95%; S4. The high-purity copper-aluminum alloy after cross rolling is heat treated and water-cooled to obtain a high-purity copper-aluminum alloy target.

2. The method for preparing a high-purity copper-aluminum alloy target according to claim 1, characterized in that: In step S4, the heat treatment temperature is 300-450° C., and the heat treatment time is 15-60 min.

3. The method for preparing a high-purity copper-aluminum alloy target according to claim 1, characterized in that: In step S1, the inert atmosphere is argon gas, and the vacuum degree is 5 to 10 -3 Pa.

4. The method for preparing a high-purity copper-aluminum alloy target according to claim 1, characterized in that: Step S1 specifically includes: According to the set ratio, copper and aluminum raw materials are loaded into the crucible; The crucible is placed in a vacuum induction melting furnace, evacuated and filled with argon; Heating and melting in an argon atmosphere; A high-purity copper-aluminum alloy ingot is obtained by casting.

5. The method for preparing a high-purity copper-aluminum alloy target according to claim 1, characterized in that: The mass content of aluminum in the high-purity copper-aluminum alloy ingot is 0.1-0.5%.

6. The method for preparing a high-purity copper-aluminum alloy target according to claim 1, characterized in that: During the cross-rolling process, the rotation angle of each pass is 15 to 135°.

7. The method for preparing a high-purity copper-aluminum alloy target according to claim 1, characterized in that: During the cross-rolling process, the deformation of each pass is 5-15%, and the total deformation is 85-95%.

8. The method for preparing a high-purity copper-aluminum alloy target according to claim 1, characterized in that: The cross rolling temperature is 30-40°C.

9. The method for preparing a high-purity copper-aluminum alloy target according to claim 1, characterized in that: The method also includes a step of machining the prepared high-purity copper-aluminum alloy target material.

10. High purity copper-aluminum alloy target, characterized in that: The high-purity copper-aluminum alloy target is obtained by the preparation method of any one of claims 1 to 9, wherein the mass content of aluminum in the high-purity copper-aluminum alloy target is 0.1-1%, the total mass content of copper and aluminum is not less than 99.9999%, and the average grain size is not more than 80μm.

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