Preparation method of aluminum rotating target material

Abstract

The invention belongs to the technical field of sputter coating, and particularly relates to a preparation method of an aluminum rotating target material, which comprises the following steps: preparing an aluminum and aluminum alloy tube target and two mounting ends; carrying out hard oxidation treatment on the mounting end; processing the to-be-welded positions of the mounting end subjected to hard oxidation, the aluminum and aluminum alloy pipe target and the aluminum and aluminum alloy pipe target, so that the mounting end and the aluminum and aluminum alloy pipe target are subsequently welded and connected through a lock bottom joint; pickling the welding positions of the processed mounting end and the aluminum and aluminum alloy pipe target; the welding position is cleaned after acid pickling; the aluminum and aluminum alloy pipe target with the cleaned welding position and the mounting end are placed in a cavity of vacuum electron beam welding equipment to be vacuumized; and welding the vacuumized aluminum and aluminum alloy pipe target and the welding position of the mounting end by adopting an electron beam to obtain the aluminum rotating target material. According to the invention, the installation problem and the binding problem of the back tube can be solved, and the problems of In leakage and unbinding in the target material binding coating process can be solved.

Description

Technical Field

[0001] The invention belongs to the technical field of sputtering coating, and in particular relates to a method for preparing an aluminum rotating target material. Background Art

[0002] Adding an appropriate amount of element Cu to high-purity aluminum can improve the aluminum's resistance to electromigration, so AlCu alloy is the most common conductive interconnect material; adding an appropriate amount of rare earth element Nd to high-purity aluminum makes the AlNd alloy target have the characteristics of low resistivity, high heat resistance and high sputtering.

[0003] like Figure 1 As shown, the aluminum or aluminum alloy tubular target 11 is typically used by being bound to a backing tube 12. Backing tube 12 is used to bear the load and is typically made of 304 stainless steel or titanium. The aluminum or aluminum alloy tubular target 11 itself performs the coating and sputtering tasks. The aluminum or aluminum alloy tubular target 11 is then bound to backing tube 12, either in its entirety or in sections. Backing tube 12 is typically made of 304 stainless steel or titanium, and the binding material is typically Indium or its alloy. Due to the significant differences in the coefficients of expansion between backing tube 12, aluminum or aluminum alloy, and Indium or its alloy, the binding efficiency of such aluminum or aluminum alloy tubular targets 11 cannot reach 98% or higher. Consequently, Indium leakage and unbinding often occur during the coating process.

[0004] To this end, the present invention proposes a new method for preparing an aluminum rotary target. Summary of the Invention

[0005] The present invention proposes a method for preparing an aluminum rotating target, which aims to solve the problems of In leakage and unbinding during the coating process of the bound target. The present invention provides the following technical solutions:

[0006] A method for preparing an aluminum rotary target, the method comprising:

[0007] S1. Prepare an aluminum or aluminum alloy tube target and two mounting ends, the mounting ends being made of aluminum alloy tubes; the mounting ends serve as the ends of the aluminum or aluminum alloy tube target for assembly with the coating equipment;

[0008] S2. Hard-oxidize the mounting end;

[0009] S3. The mounting end after hard anodizing, as well as the aluminum and aluminum alloy tube target, the two positions to be welded are processed so that the aluminum and aluminum alloy tube target serves as the upper end of the lock bottom, the mounting end serves as the lower end of the lock bottom, and the mounting end and the aluminum and aluminum alloy tube target are subsequently welded together by a lock bottom joint;

[0010] S4. The welding position of the processed mounting end and the aluminum and aluminum alloy tube target is pickled; after pickling, the welding position is cleaned;

[0011] S5. Place the aluminum and aluminum alloy tube target and the mounting end after cleaning the welding position in the chamber of a vacuum electron beam welding device and evacuate the chamber; use an electron beam to weld the welding position of the vacuumed aluminum and aluminum alloy tube target and the mounting end, so that the mounting end and the aluminum and aluminum alloy tube target are welded together through a lock bottom joint to obtain an aluminum rotating target material.

[0012] Furthermore, in step S1, the aluminum and aluminum alloy tube target is made of an AlNd alloy with a Nd content of 0.1-3.5 wt.%, or an AlCu alloy with a Cu content of 0.1-3 wt.%, and the alloy purity is ≥99.9%.

[0013] Furthermore, in step S1, the mounting end is made of 6063, 6061 or 6082 aluminum alloy.

[0014] Furthermore, in step S1, the 6063, 6061 or 6082 aluminum alloy is in the extruded T6 state.

[0015] Furthermore, in step S2, the mounting end is hard-oxidized, and the hard-oxidized areas are the inner diameter and both end faces of the aluminum alloy tube.

[0016] Furthermore, the water temperature for hard oxidation is -5 to 3°C, and the oxidation liquid is a mixture of 10 to 20 wt.% sulfuric acid and 6 to 12 wt.% oxalic acid.

[0017] Furthermore, the thickness of the oxide film formed after hard oxidation is 30-50 μm, and the surface hardness of the mounting end after hard oxidation is Hv300-380.

[0018] Furthermore, in step S3, the parameters at the welding position of the processed mounting end and the aluminum and aluminum alloy tube target meet the following requirements: roughness ≤ Ra1.6um, weld step < 0.2mm, weld gap < 0.3mm; and the step height at the lower end of the lock bottom is 3-5mm.

[0019] Furthermore, in step S4, the welding position between the mounting end and the aluminum or aluminum alloy tube target is pickled, and the pickling agent used is a mixture of 3-5 wt.% hydrochloric acid and 5-20 wt.% phosphoric acid.

[0020] Furthermore, step S4 also includes wrapping the cleaned welding position with a stretch film.

[0021] Furthermore, the vacuum degree in the chamber of the vacuum electron beam welding equipment is less than 5×10 -2Pa; the relevant parameters of the vacuum electron beam welding equipment are set as: working distance of 400-550 mm, acceleration voltage of 70 kV, electron beam current of 40-45 uA, focusing current of 800-850 uA, welding speed of 900-1100 mm / min, welding position: flat welding, electron gun vertical.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] (1) The present invention proposes a method for preparing an aluminum rotary target. The mounting end is hard-oxidized, and then the aluminum or aluminum alloy tube target and the mounting end are welded together by electron beam welding. The bottom joints are then welded together to form an aluminum rotary target. This method solves the problems of back tube installation and binding, as well as the problems of In leakage and unbinding during the coating process of the bound target.

[0024] (2) Compared with traditional methods, the method of the present invention is safer and has the advantages of simple process operation, high stability and low cost. The structural strength of the prepared aluminum rotating target is the same as that of the binding, the size of the prepared target nozzle is precise, and the surface hardness of the aluminum alloy after hard oxidation is even higher than that of ordinary 304 stainless steel, and the corrosion resistance is better.

[0025] (3) There will be no indium leakage or debonding during the coating process, and the service life is longer. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural schematic diagram of the aluminum rotary target material involved in the background technology;

[0027] Figure 2 Schematic diagram of the structure of the aluminum rotary target of the present invention.

[0028] Reference numerals:

[0029] Figure 1 : 11 is an aluminum or aluminum alloy tube target; 12 is a back tube;

[0030] Figure 2 : 21 is the aluminum and aluminum alloy tube target; 22 is the mounting end; 23 is the welding position. DETAILED DESCRIPTION

[0031] The technical solution of the present invention will be clearly described below in conjunction with the accompanying drawings. Obviously, the described embodiments are not all embodiments of the present invention. All other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0032] Example 1:

[0033] like Figure 2 As shown, the present invention provides a method for preparing an aluminum rotary target, comprising the following steps:

[0034] S1. Aluminum and aluminum alloy tube target 21, the material can be selected as, 0.5wt.% Nd content AlNd alloy, alloy purity ≥ 99.9%, select national standard aluminum alloy tube 6061 as the welding mounting end material, the mounting end material is extruded T6 state;

[0035] S2. The mounting end 22 is hard-oxidized. The hard-oxidized areas are the inner wall and end faces of the pipe. The water temperature for hard oxidation is -5°C. The oxidation liquid is a mixture of 10 wt.% sulfuric acid and 12 wt.% oxalic acid. The oxide film thickness is 30 μm. The surface hardness after hard oxidation is Hv338.

[0036] S3. Process the welding position 23 between the aluminum or aluminum alloy tube target 21 and the mounting end 22. The roughness of the welding position 23 is Ra0.8um. The welding connection method is a lock bottom joint connection. The aluminum or aluminum alloy tube target 21 serves as the upper end of the lock bottom, and the mounting end 22 serves as the lower end of the lock bottom. The weld step is less than 0.2mm, the weld gap is less than 0.3mm, and the step height at the lower end of the lock bottom is 3mm.

[0037] S4. Pickle the welding position 23 between the aluminum and aluminum alloy tube target 21 and the mounting end 22 with a pickling agent of 5 wt.% hydrochloric acid and 10 wt.% phosphoric acid. After pickling, blow dry with an air gun, polish the welding position 23 and clean it. After cleaning, wrap it with a stretch film to prevent oxidation of the welding position 23.

[0038] S5. The aluminum and aluminum alloy tube target 21 and the mounting end 22 are placed in a vacuum electron beam chamber and evacuated to a vacuum degree of 1×10 -2 Pa, working distance is 400mm, acceleration voltage is 70kV, electron beam current is 45uA, focusing current is 800uA, welding speed is 900mm / min, welding position 23: flat welding, electron gun is vertical.

[0039] S6. The aluminum and aluminum alloy tube target 21 after welding is machined to the corresponding size according to the drawing. The surface of the welding position 23 is smooth after machining, without pores and cracks, and the helium test leak rate of the tube target is less than 1.0*10 -10 mbar.L / sec, with excellent air tightness.

[0040] Example 2:

[0041] like Figure 2 As shown, the present invention provides a method for preparing an aluminum rotary target, comprising the following steps:

[0042] S1. Aluminum and aluminum alloy tube target 21, the material can be selected as, 2wt.% Cu content AlCu alloy, alloy purity ≥ 99.9%, select national standard aluminum alloy tube 6063 as the welding mounting end material, the mounting end material is extruded T6 state;

[0043] S2. The mounting end 22 is hard-oxidized. The hard-oxidized areas are the inner diameter of the pipe and the end faces at both ends. The water temperature for hard oxidation is 2°C. The oxidation liquid is a mixture of 20wt.% sulfuric acid and 6wt.% oxalic acid. The oxide film thickness is 45μm. The surface hardness after hard oxidation is Hv365.

[0044] S3. Process the welding position 23 between the aluminum or aluminum alloy tube target 21 and the mounting end 22. The roughness of the welding position 23 is Ra1.2 μm. The welding connection method is a lock bottom joint connection. The aluminum or aluminum alloy tube target 21 serves as the upper end of the lock bottom, and the mounting end 22 serves as the lower end of the lock bottom. The weld step is less than 0.2 mm, the weld gap is less than 0.3 mm, and the step height at the lower end of the lock bottom is 5 mm.

[0045] S4. Pickle the welding position 23 between the aluminum and aluminum alloy tube target 21 and the mounting end 22 with a pickling agent of 3 wt.% hydrochloric acid and 20 wt.% phosphoric acid. After pickling, blow dry with an air gun, polish the welding position 23 and clean it. After cleaning, wrap it with a stretch film to prevent oxidation of the welding position 23.

[0046] S5. Place the aluminum and aluminum alloy tube target 21 and the mounting end 22 in a vacuum electron beam chamber and evacuate the chamber to a vacuum degree of 2×10 -2 Pa, working distance is 550mm, acceleration voltage is 70kV, electron beam current is 40uA, focusing current is 850uA, welding speed is 1100mm / min, welding position 23: flat welding, electron gun is vertical.

[0047] S6. The aluminum and aluminum alloy tube target 21 after welding is machined to the corresponding size according to the drawing. The surface of the welding position 23 is smooth after processing, without pores and cracks, and the helium test leak rate of the tube target is less than 1.0*10 -10 mbar.L / sec, with excellent air tightness.

[0048] Comparative Example 1:

[0049] Comparative Example 1 provides a method for preparing an aluminum rotary target, comprising:

[0050] S1. Metallization: Clean the inner wall of the AlCu tube target, select an aluminum foil of the same size as the AlCu tube target and fix the aluminum foil on the outer surface of the tube target for indium coating and shielding. Cover both ends of the AlCu tube target with aluminum foil for shielding. Coat the inner wall of the tube target and the outer diameter of the back tube with indium. The coating amount is 1.2kg / m and the coating thickness is 0.15mm.

[0051] S2. Binding: Insert the AlCu tube target into the backing tube. The backing tube is made of 304 stainless steel. A 0.3mm thick gap sheet is placed between every two sections of the tube target. The sections are inserted into the outside of the backing tube in sequence.

[0052] S3. Heating: Use an external heating device to heat the AlCu tube target and back tube at a heating temperature of 200°C for 1.2 hours.

[0053] S4. Cooling: Cool slowly at a rate of 40°C / h. After cooling to 60°C, it can be naturally cooled to room temperature.

[0054] S5. Grinding: Remove the heating device, remove the gap between the AlCu tube targets, clear the foreign matter in the gap, and grind the surface with 400-grit sandpaper to obtain the bound AlCu alloy target.

[0055] The data comparison of Example 1, Example 2 and Comparative Example 1 is shown in Table 1:

[0056] Table 1: Key parameters and product performance test results

[0057]

[0058]

[0059] The above technical features constitute the best embodiment of the present invention, which has strong adaptability and best implementation effect. Non-essential technical features can be added or removed according to actual needs to meet the needs of different situations.

[0060] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions of the technical solution of the present invention by ordinary technicians in this field do not deviate from the essence and scope of the technical solution of the present invention.

Claims

1. A method for preparing an aluminum rotary target, characterized in that: The preparation method comprises: S1. Prepare an aluminum or aluminum alloy tube target and two mounting ends, the mounting ends being made of aluminum alloy tubes; S2. Hard-oxidize the mounting end; S3. The mounting end after hard anodizing, as well as the aluminum and aluminum alloy tube target, the two positions to be welded are processed so that the aluminum and aluminum alloy tube target serves as the upper end of the lock bottom, the mounting end serves as the lower end of the lock bottom, and the mounting end and the aluminum and aluminum alloy tube target are subsequently welded together by a lock bottom joint; S4. The welding position of the processed mounting end and the aluminum and aluminum alloy tube target is pickled; after pickling, the welding position is cleaned; S5. Place the aluminum and aluminum alloy tube target and the mounting end after cleaning the welding position in the chamber of a vacuum electron beam welding device and evacuate the chamber; use an electron beam to weld the welding position of the vacuumed aluminum and aluminum alloy tube target and the mounting end, so that the mounting end and the aluminum and aluminum alloy tube target are welded together through a lock bottom joint to obtain an aluminum rotating target material.

2. The preparation method according to claim 1, characterized in that In step S1, the aluminum or aluminum alloy tube target is made of an AlNd alloy with a Nd content of 0.1-3.5 wt.%, or an AlCu alloy with a Cu content of 0.1-3 wt.%, and the alloy purity is ≥99.9%.

3. The preparation method according to claim 1, characterized in that In step S1, the mounting end is made of 6063, 6061 or 6082 aluminum alloy.

4. The preparation method according to claim 1, characterized in that In step S2, the mounting end is hard-oxidized, and the hard-oxidized areas are the inner diameter and both end faces of the aluminum alloy tube.

5. The preparation method according to claim 4, characterized in that The water temperature of hard oxidation is -5 to 3°C, and the oxidation liquid is a mixture of 10 to 20 wt.% sulfuric acid and 6 to 12 wt.% oxalic acid.

6. The preparation method according to claim 5, characterized in that The thickness of the oxide film formed after hard oxidation is 30 to 50 μm, and the surface hardness of the mounting end after hard oxidation is Hv300 to 380.

7. The preparation method according to claim 1, characterized in that In step S3, the parameters of the welding position of the processed mounting end and the aluminum and aluminum alloy tube target meet the following requirements: roughness ≤ Ra1.6um, weld step < 0.2mm, weld gap < 0.3mm; the step height of the lower end of the lock bottom is 3-5mm.

8. The preparation method according to claim 1, characterized in that In step S4, the welding position between the mounting end and the aluminum or aluminum alloy tube target is pickled, and the pickling agent used is a mixture of 3-5 wt.% hydrochloric acid and 5-20 wt.% phosphoric acid.

9. The preparation method according to claim 1, characterized in that Step S4 also includes wrapping the cleaned welding position with a stretch film.

10. The preparation method according to claim 1, characterized in that The vacuum degree in the chamber of the vacuum electron beam welding equipment is less than 5×10 -2 Pa; the relevant parameters of the vacuum electron beam welding equipment are set as: working distance of 400-550 mm, acceleration voltage of 70 kV, electron beam current of 40-45 uA, focusing current of 800-850 uA, welding speed of 900-1100 mm / min, welding position: flat welding, electron gun vertical.

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