Surface treatment methods for pure titanium sputtering targets

Abstract

The application discloses a surface treatment method of a pure titanium sputtering target, and the treatment method comprises preliminary treatment, turning treatment, sandpaper treatment, canvas treatment and cloth treatment which are sequentially performed; the preliminary treatment is sequentially performed on the pure titanium target material and comprises oil removal, cleaning and drying treatment; the turning treatment is performed on the pure titanium target material after the preliminary treatment; the sandpaper treatment comprises 600# sandpaper treatment and 800# sandpaper treatment which are sequentially performed; the canvas treatment is performed on the pure titanium target material by using grinding paste with different particle sizes; and the cloth treatment is performed on the polishing disc by using cloth, and silica polishing liquid is added in the polishing process. The surface treatment method of the pure titanium sputtering target solves the problem that the existing surface treatment technology is prone to forming a deformation layer and generating a deformation twin, and the problem that the extreme difference of the surface roughness of the sputtering target is large.

Description

Technical Field

[0001] This invention belongs to the field of surface treatment technology, specifically relating to a surface treatment method for pure titanium sputtering targets. Background Technology

[0002] In sputtering deposition, the target is typically connected to the negative electrode, and the substrate is connected to the positive electrode. A high-voltage electric field is applied between the target and the substrate. The inert gas (usually argon) between the target and the substrate is ionized under the influence of the high-voltage electric field to form plasma. Positively charged ions bombard the target, causing atoms on the target surface to detach and deposit on the substrate surface, thus forming a coating. Excessive or uneven surface roughness can generate large particles during sputtering. Therefore, the surface roughness of the target has a significant impact on the uniformity of the coating, especially the extreme differences in surface roughness.

[0003] In existing technologies, the surface treatment of pure titanium sputtering targets typically involves first grinding and then polishing with a cloth. However, because pure titanium is soft and has good ductility, it easily forms a deformation layer during polishing, which contains deformation twins. The deformation layer and the formation of twins are significant reasons for the generation of large particles during sputtering. Furthermore, the surface roughness extreme differences commonly used in existing technologies are difficult to control and measure for pure titanium sputtering targets. Summary of the Invention

[0004] The purpose of this invention is to provide a surface treatment method for pure titanium sputtering targets, which solves the problem that existing surface treatment technologies easily form deformable layers and generate deformable twins, resulting in a large difference in the extreme values ​​of surface roughness of sputtering targets.

[0005] The technical solution adopted in this invention is a surface treatment method for a pure titanium sputtering target, which includes preliminary treatment, turning treatment, sandpaper treatment, canvas treatment and velvet cloth treatment performed in sequence.

[0006] The initial treatment involves sequentially degreasing, cleaning, and drying the pure titanium target material.

[0007] Turning is the process of turning the pre-treated pure titanium target.

[0008] The sandpaper treatment includes sequential application of 600# sandpaper and 800# sandpaper.

[0009] The canvas treatment involves applying abrasive paste of different particle sizes to the pure titanium target material to form a canvas.

[0010] The velvet treatment involves polishing with a velvet cloth on a polishing pad, with silica polishing slurry added during the polishing process.

[0011] The invention is further characterized by:

[0012] The specific process of the preliminary treatment is as follows: the pure titanium target is placed in NaOH solution for 5 min-15 min, then cleaned with hydrochloric acid solution for 5 min-15 min, and finally placed in a beaker containing anhydrous ethanol, cleaned with an ultrasonic vibrator for 2 min-5 min, and then dried.

[0013] The parameters for the turning process are: feed rate 0.1mm / r-0.2mm / r, turning speed 50m / min-150m / min, and turning depth 0.2mm-0.4mm; the surface roughness of the target material after turning is 0.5μm-1.2μm.

[0014] The total time for sandpaper treatment is 10-20 minutes, the time for 600# sandpaper treatment is 3-7 minutes, and the time for 800# sandpaper treatment is 7-13 minutes.

[0015] The total processing time for the canvas is 7-12 minutes. The specific process for canvas processing is as follows:

[0016] Step 1: Polish on a polishing pad using a canvas, adding diamond polishing paste W7 during the polishing process, for 4-6 minutes;

[0017] The second step is to polish the surface with a canvas on the polishing pad, adding diamond polishing paste W2.5 during the polishing process for 2-4 minutes.

[0018] The third step is to polish the surface with a canvas on the polishing pad, adding diamond polishing paste W1 during the polishing process for 1-2 minutes.

[0019] The parameters for the velvet cloth treatment are: polishing disc speed of 250r / min-600r / min, silica polishing slurry particle size of 0.05μm-0.15μm, and treatment time of 2min-8min.

[0020] The beneficial effects of this invention are:

[0021] The surface treatment method for pure titanium sputtering targets provided by this invention combines multiple surface treatment methods and further optimizes the process. The various steps work together to achieve optimal results, making the surface roughness of the target material more uniform and significantly reducing the extreme value difference, thereby improving sputtering uniformity. Furthermore, through multiple experiments, this invention has found that when the surface gloss is between 70 GU and 350 GU, the extreme value difference of roughness is between 0.02 and 0.06, which effectively solves the problem of the difficulty and inaccuracy in measuring the extreme value difference of roughness. The surface gloss is used to determine whether the surface roughness of the target material is uniform and the extreme value difference. Attached Figure Description

[0022] Figure 1 This is a flowchart of the surface treatment method for the pure titanium sputtering target of the present invention;

[0023] Figure 2 This is a test image of the surface roughness of the pure titanium sputtering target after surface treatment in Embodiment 4 of the present invention;

[0024] Figure 3 This is a curve showing the maximum surface roughness of the pure titanium sputtering target after surface treatment in Embodiment 4 of the present invention.

[0025] Figure 4 This is a microstructure diagram of the surface roughness of the pure titanium sputtering target after surface treatment in Embodiment 4 of the present invention;

[0026] Figure 5 This is a microstructure diagram of the pure titanium sputtering target after general surface treatment in Embodiment 4 of the present invention. Detailed Implementation

[0027] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0028] Example 1

[0029] The surface treatment method for a pure titanium sputtering target proposed in this embodiment includes preliminary treatment, turning treatment, sandpaper treatment, canvas treatment and velvet cloth treatment performed in sequence.

[0030] The initial treatment involves sequentially degreasing, cleaning, and drying the pure titanium target material.

[0031] The specific process of the preliminary treatment is as follows: the pure titanium target is placed in NaOH solution for 5 minutes, then in hydrochloric acid solution for 5 minutes, and finally in a beaker containing anhydrous ethanol, cleaned with an ultrasonic vibrator for 2 minutes and then dried.

[0032] Turning is the process of turning the pre-treated pure titanium target.

[0033] The turning parameters are: feed rate 0.1 mm / r, turning speed 50 m / min, and turning depth 0.2 mm; the surface roughness of the target material after turning is 0.5 μm.

[0034] The sandpaper treatment includes sequential application of 600# sandpaper and 800# sandpaper.

[0035] The total time for sandpaper treatment is 10 minutes, the time for 600# sandpaper treatment is 3 minutes, and the time for 800# sandpaper treatment is 7 minutes.

[0036] The canvas treatment involves applying abrasive paste of different particle sizes to the pure titanium target material to form a canvas.

[0037] The total time for canvas treatment is 7 minutes. The specific process for canvas treatment is as follows:

[0038] Step 1: Polish the pad with a canvas, adding diamond polishing paste W7 during the polishing process, for 4 minutes.

[0039] The second step is to polish the surface with a canvas on a polishing pad, adding diamond polishing paste W2.5 during the polishing process for 2 minutes.

[0040] Step 3: Polish with a canvas on the polishing pad, adding diamond polishing paste W1 during the polishing process for 1 minute.

[0041] The velvet treatment involves polishing with a velvet cloth on a polishing pad, with silica polishing slurry added during the polishing process;

[0042] The parameters for the velvet cloth treatment were: polishing disc rotation speed of 250 r / min, silica polishing slurry particle size of 0.05 μm, and treatment time of 2 min.

[0043] Example 2

[0044] The surface treatment method for a pure titanium sputtering target proposed in this embodiment includes preliminary treatment, turning treatment, sandpaper treatment, canvas treatment and velvet cloth treatment performed in sequence.

[0045] The initial treatment involves sequentially degreasing, cleaning, and drying the pure titanium target material.

[0046] The specific process of the preliminary treatment is as follows: the pure titanium target is placed in NaOH solution for 10 minutes, then in hydrochloric acid solution for 10 minutes, and finally in a beaker containing anhydrous ethanol, cleaned with an ultrasonic vibrator for 4 minutes and then dried.

[0047] Turning is the process of turning the pre-treated pure titanium target.

[0048] The turning parameters were: feed rate 0.15 mm / r, turning speed 100 m / min, and turning depth 0.3 mm; the surface roughness of the target material after turning was 0.8 μm.

[0049] The sandpaper treatment includes sequential application of 600# sandpaper and 800# sandpaper.

[0050] The total time for sandpaper treatment is 15 minutes, the time for 600# sandpaper treatment is 5 minutes, and the time for 800# sandpaper treatment is 10 minutes.

[0051] The canvas treatment involves applying abrasive paste of different particle sizes to the pure titanium target material to form a canvas.

[0052] The total time for canvas treatment is 9 minutes. The specific process for canvas treatment is as follows:

[0053] Step 1: Polish the surface with a canvas on a polishing pad, adding diamond polishing paste W7 during the polishing process for 5 minutes.

[0054] The second step is to polish the surface with a canvas on a polishing pad, adding diamond polishing paste W2.5 during the polishing process for 3 minutes.

[0055] Step 3: Polish with a canvas on the polishing pad, adding diamond polishing paste W1 during the polishing process for 1 minute.

[0056] The velvet treatment involves polishing with a velvet cloth on a polishing pad, with silica polishing slurry added during the polishing process;

[0057] The parameters for the velvet cloth treatment were: polishing disc rotation speed of 400 r / min, silica polishing slurry particle size of 0.1 μm, and treatment time of 5 min.

[0058] Example 3

[0059] The surface treatment method for a pure titanium sputtering target proposed in this embodiment includes preliminary treatment, turning treatment, sandpaper treatment, canvas treatment and velvet cloth treatment performed in sequence.

[0060] The initial treatment involves sequentially degreasing, cleaning, and drying the pure titanium target material.

[0061] The specific process of the preliminary treatment is as follows: the pure titanium target is placed in NaOH solution for 15 minutes, then cleaned with hydrochloric acid solution for 15 minutes, and finally placed in a beaker containing anhydrous ethanol, cleaned with an ultrasonic vibrator for 5 minutes, and then dried.

[0062] Turning is the process of turning the pre-treated pure titanium target.

[0063] The turning parameters were: feed rate 0.2 mm / r, turning speed 150 m / min, and turning depth 0.4 mm; the surface roughness of the target material after turning was 1.2 μm.

[0064] The sandpaper treatment includes sequential application of 600# sandpaper and 800# sandpaper.

[0065] The total time for sandpaper treatment is 20 minutes, the time for 600# sandpaper treatment is 7 minutes, and the time for 800# sandpaper treatment is 13 minutes.

[0066] The canvas treatment involves applying abrasive paste of different particle sizes to the pure titanium target material to form a canvas.

[0067] The total time for canvas treatment is 12 minutes. The specific process for canvas treatment is as follows:

[0068] Step 1: Polish the surface with a canvas on a polishing pad, adding diamond polishing paste W7 during the polishing process, for 6 minutes.

[0069] The second step is to polish the surface with a canvas on a polishing pad, adding diamond polishing paste W2.5 during the polishing process for 4 minutes.

[0070] Step 3: Polish with a canvas on the polishing pad, adding diamond polishing paste W1 during the polishing process for 2 minutes.

[0071] The velvet treatment involves polishing with a velvet cloth on a polishing pad, with silica polishing slurry added during the polishing process;

[0072] The parameters for the velvet cloth treatment were: polishing disc speed of 600 r / min, silica polishing slurry particle size of 0.15 μm, and treatment time of 8 min.

[0073] Example 4

[0074] The surface treatment method for a pure titanium sputtering target proposed in this embodiment includes preliminary treatment, turning treatment, sandpaper treatment, canvas treatment, and felt treatment performed sequentially. Figure 1 As shown;

[0075] The initial treatment involves rinsing the sample in a 400 ml / L 10% NaOH solution for 10 minutes to remove surface oil, followed by rinsing in a 400 ml / L hydrochloric acid solution for 10 minutes to remove the surface oxide film. Finally, the sample is placed in a beaker containing anhydrous ethanol, rinsed with an ultrasonic vibrator for 3 minutes, and then dried.

[0076] The turning process involved turning the pre-treated pure titanium target material. During turning, the feed rate was 0.15 mm / r, the turning speed was 100 m / min, and the depth of cut was 0.2 mm. The surface roughness of the target material after treatment was 0.8 μm.

[0077] The sandpaper treatment consists of sequential treatment with 600# sandpaper and 800# sandpaper; the total time for the sandpaper treatment is 15 minutes, with 5 minutes for the 600# sandpaper treatment and 10 minutes for the 800# sandpaper treatment.

[0078] The total time for canvas processing is 10 minutes, including three steps:

[0079] Step 1: Polish the surface with a canvas on a polishing pad, adding diamond polishing paste W7 during the polishing process for 5 minutes.

[0080] The second step is to polish the surface with a canvas on a polishing pad, adding diamond polishing paste W2.5 during the polishing process for 3 minutes.

[0081] Step 3: Polish with a canvas on the polishing pad, adding diamond polishing paste W1 during the polishing process for 2 minutes.

[0082] The velvet treatment involved polishing with a velvet cloth on a polishing pad. During the polishing process, a silica polishing slurry with a particle size of 0.05 μm was added. The treatment time was 6 min, and the rotation speed of the polishing pad was 450 r / min. The process parameters for the surface treatment in Example 4 are shown in Table 1.

[0083] Table 1 Surface Treatment Process Parameters

[0084]

[0085] When it is necessary to further improve the surface gloss or remove the deformed layer caused by cutting, the mechanically polished sample is placed in a vibratory polishing fixture with two counterweights, and then placed in a vibratory polishing tank containing a mixture of OP-S polishing fluid and hydrogen peroxide. Vibratory polishing is performed for 30 minutes, and then the sample is taken out and ultrasonically cleaned with anhydrous ethanol for 15 minutes.

[0086] The difference between Comparative Example 1 and Sample 1 of Example 4 is that the feed rate during turning was 0.25 mm / r, the turning speed was 100 m / min, and the turning depth was 0.2 mm. After turning, the surface roughness of the target material was 1.7 μm. Even after repeating the cloth treatment 5 times, the surface gloss was still 420 GU, and the extreme difference in roughness was 0.35 μm. Further increasing the number of cloth treatments had little effect on the surface gloss and the extreme difference in roughness because the surface roughness of the target material after turning was 1.5 μm, and the turning marks were too large to be eliminated in subsequent processing.

[0087] The difference between Comparative Example 2 and Sample 1 of Example 4 is that 600# sandpaper was not used; instead, 800# sandpaper was used directly for 14 minutes. Even after repeating the cloth treatment more than 4 times, the surface gloss was still 415 GU, and the extreme difference in roughness was 0.28 μm. Further increasing the number of cloth treatments did not have a significant impact on the surface gloss and the extreme difference in roughness.

[0088] The difference between Comparative Example 3 and Sample 1 of Example 4 is that Sample 1 was treated with 400# sandpaper for 3 minutes before being treated with 600# sandpaper. Even after repeating the cloth treatment more than 6 times, the surface gloss was still 520 GU and the extreme difference in roughness was 0.43 μm. Further increasing the number of cloth treatments did not have a significant impact on the surface gloss and the extreme difference in roughness. This is because the rough scratches and deformation layer produced by the 400# sandpaper are difficult to eliminate in the subsequent treatment.

[0089] The difference between Comparative Example 4 and Sample 1 of Example 4 is that no diamond polishing paste was used during the canvas treatment.

[0090] The difference between Comparative Example 5 and Sample 1 of Example 4 is that no silica polishing liquid was used during the fabric treatment.

[0091] The difference between Comparative Example 6 and Sample 1 of Example 4 is that the canvas was replaced with a scouring pad, specifically:

[0092] The total processing time with the scouring pad is 10 minutes, including three steps:

[0093] Step 1: Polish the polishing pad with a scouring pad, adding diamond polishing paste W7 during the polishing process, for 5 minutes.

[0094] The second step is to polish the surface with a scouring pad on the polishing pad, adding diamond polishing paste W2.5 during the polishing process for 3 minutes.

[0095] Step 3: Polish the surface with a scouring pad on the polishing pad, adding diamond polishing paste W1 during the polishing process for 2 minutes.

[0096] The difference between Comparative Example 7 and Sample 1 of Example 4 is that diamond polishing paste W1 was used during the fabric treatment.

[0097] The sputtering surfaces of the target materials after surface treatment in Examples 4 and Comparative Examples 1-7 are evaluated in Table 2. The gloss was measured according to the 20-degree gloss standard.

[0098] Table 2 Evaluation of sputtering surface of target material after surface treatment

[0099]

[0100] Existing surface treatment methods are not effective for pure titanium targets, especially since the extreme difference in surface roughness is difficult to control and measure. Through multiple experiments, this invention has found that when the surface gloss is between 70 GU and 350 GU, the extreme difference in roughness is between 0.02 and 0.06. Therefore, this invention can effectively solve the problem of the difficulty and inaccuracy in measuring the extreme difference in roughness. By detecting the surface gloss, it can determine whether the surface roughness of the target material tends to be uniform and the extreme difference.

[0101] A comparison of Sample 1 from Example 4 with Comparative Examples 1-6 reveals that the surface roughness of the target material after turning, the choice of sandpaper, and the selection of polishing cloth, polishing fluid, and polishing paste all significantly affect the final roughness. Taking Comparative Example 1 as an example, the surface roughness of the target material after turning is 1.7 μm. Even with subsequent increases in the number of abrasive cloth treatments, the impact on surface gloss and the difference in roughness extreme values ​​is minimal. This is because the turning marks are too large at 1.7 μm and difficult to eliminate in subsequent processing. Simultaneously, the surface roughness of Sample 1 from Example 4 was measured using a surface roughness meter. Figure 2 As shown, the calculated extreme difference in surface roughness is 0.058; the curve of the maximum roughness value in this test is shown below. Figure 3 As shown, the treated pure titanium surface exhibits less surface undulation and lower surface roughness. The SEM image of sample 1 in Example 4 is shown below. Figure 4 As shown, the SEM image of the sample in Comparative Example 1 is as follows. Figure 5 As shown in the figure, the surface of a pure titanium target material generally exhibits micropores and fine scratches after surface treatment. However, the surface of the pure titanium target material after the surface treatment proposed in this invention is smooth and clean, without micropores or scratches. It is evident that sample 1 in Example 4 achieved optimal results through the coordinated action of each step, resulting in a more uniform surface roughness and a significant reduction in extreme value differences.

Claims

1. A surface treatment method for a pure titanium sputtering target, characterized by, The processing method comprises sequentially performing preliminary processing, turning processing, sandpaper processing, canvas processing and velvet processing; The preliminary processing is sequentially performing oil removal, cleaning and drying processing on the pure titanium target material; The turning processing is turning the pure titanium target material after the preliminary processing; The sandpaper processing comprises sequentially performing 600# sandpaper processing and 800# sandpaper processing; The canvas processing is performing canvas processing on the pure titanium target material by using abrasive paste with different particle sizes; The velvet processing is polishing on the polishing disc by using velvet, and adding silica polishing liquid in the polishing process; The specific process of the preliminary processing is: cleaning the pure titanium target material in a NaOH solution for 5min-15min, then cleaning the pure titanium target material in a hydrochloric acid solution for 5min-15min, and finally cleaning the pure titanium target material in a beaker containing anhydrous ethanol by using an ultrasonic vibrator for 2min-5min, and then drying; The parameters of the turning processing are: a feed amount of 0.1mm / r-0.2mm / r, a turning speed of 50m / min-150m / min, and a turning depth of 0.2mm-0.4mm; the surface roughness of the target material after the turning processing is 0.5μm-1.2μm; The total time of the sandpaper processing is 10min-20min, the time of the 600# sandpaper processing is 3min-7min, and the time of the 800# sandpaper processing is 7min-13min; The total time of the canvas processing is 7min-12min, and the specific process of the canvas processing is: First step, polishing on the polishing disc by using canvas, adding diamond abrasive paste W7 in the polishing process, and the time is 4min-6min; Second step, polishing on the polishing disc by using canvas, adding diamond abrasive paste W2.5 in the polishing process, and the time is 2min-4min; Third step, polishing on the polishing disc by using canvas, adding diamond abrasive paste W1 in the polishing process, and the time is 1min-2min; The parameters of the velvet processing are: the rotation speed of the polishing disc is 250r / min-600r / min, the particle size of the silica polishing liquid is 0.05μm-0.15μm, and the processing time is 2min-8min.

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