TWI850775B - Sputtering target, surface treatment method thereof and target structure - Google Patents

Abstract

A sputtering target includes a working surface having a sputtering zone and a rough area. The sputtering zone has a first surface roughness. The rough area is adjacent to the sputtering area and has a second surface roughness. The second surface roughness is greater than the first surface roughness, and the first roughness area corresponds to an edge of a magnetic field line distribution.

Description

Sputtering target, surface treatment method and target structure

The present invention relates to a sputtering target, a surface treatment method of the sputtering target, and a target structure formed by the sputtering target.

It is known that particles sputtered from the sputter plating target may rebound onto the target or backing plate. The rebounded particles are called "back sputter particles". When the back sputter particles rebound back to the target, they are likely to rebound from the target surface again, which may eventually cause the back sputter particles to fall on the workpiece or fall into the environment, causing sputter plating contamination problems.

Therefore, the present invention proposes a sputtering target, its surface treatment method and target structure, which can improve the above-mentioned known problems.

An embodiment of the present invention provides a sputtering target. The sputtering target includes a sputtering zone and a rough zone on a working surface. The sputtering zone has a first surface roughness. The rough zone is adjacent to the sputtering zone and has a second surface roughness. The second surface roughness is greater than the first surface roughness, and the rough zone corresponds to the edge of a magnetic field line distribution.

Another embodiment of the present invention provides a sputtering target. The sputtering target includes a sputtering zone of a working surface, a first edge zone of the working surface, and a second edge zone of the working surface. The sputtering zone has a first surface roughness. The first edge zone is adjacent to the sputtering zone and has a second surface roughness. The second edge zone is adjacent to the sputtering zone and has a third surface roughness. The second surface roughness is greater than the first surface roughness and the third surface roughness.

Another embodiment of the present invention provides a target structure. The target structure includes a sputtering target and a backing plate. The sputtering target includes at least a working surface and a side surface. The working surface includes a sputtering area and a first edge area. The sputtering area has a first surface roughness. The first edge area is adjacent to the sputtering area, and the first edge area has a second surface roughness, wherein the second surface roughness is greater than the first surface roughness. The side surface is arranged around the working surface, and the side surface has a side surface roughness, wherein the side surface roughness is greater than the first surface roughness. The backing plate is arranged on a surface of the sputtering target to contact and support the sputtering target.

Another embodiment of the present invention provides a surface treatment method for a sputtering target. The surface treatment method includes the following steps: providing a sputtering target, the sputtering target having an initial working surface; performing a first surface treatment to surface treat the initial working surface of the sputtering target to form a working surface; and performing a second surface treatment to roughen a portion of the working surface, wherein the surface roughness of this portion is greater than the surface roughness of the working surface outside this portion.

In order to better understand the above and other aspects of the present invention, the following is a specific example and a detailed description with the attached drawings as follows:

100: Sputtering machine

105: Back panel

105u: Area

110,110’: Sputtering target

110s: Side

110s1: First sub-side

110s2: Second sub-side

110s3: The third sub-side

110s4: The fourth sub-side

110u: working surface

110u1: Splash plating area

110u2: The first marginal zone

110u21: First sub edge area

110u22: Second sub edge area

110u3: The second fringe area

110u31: Third sub marginal area

110u32: The fourth sub-edge area

120: First magnetic part

125: Second magnetic part

130: Workpiece carrier

140: Target carrier

M1: Magnetic field

P1: Backscatter particles

R1: First surface roughness

R2: Second surface roughness

R3: Third surface roughness

R4: Side surface roughness

S110~130: Steps

W1: Workpiece

Figure 1 shows a top view of a sputtering machine according to an embodiment of the present invention.

Figure 2 shows a cross-sectional view of the sputtering machine in Figure 1 along direction 2-2’.

Figure 3 shows a cross-sectional view of the sputtering machine in Figure 1 along direction 3-3’.

Figure 4 shows a flow chart of the surface treatment method of the sputtering target in Figure 1.

FIG. 5A is a schematic diagram of the sputtering target in step S110 of FIG. 4.

Figure 5B is a schematic diagram showing a portion of the roughened working surface in step S130 of Figure 4.

Please refer to Figures 1 to 3. Figure 1 shows a top view of a sputtering machine 100 according to an embodiment of the present invention, Figure 2 shows a cross-sectional view of the sputtering machine 100 in Figure 1 along direction 2-2', and Figure 3 shows a cross-sectional view of the sputtering machine 100 in Figure 1 along direction 3-3'. To avoid over-complexity, Figure 1 does not show the first magnetic member 120, the second magnetic member 125, the workpiece carrier 130, and the target carrier 140.

As shown in FIGS. 2 and 3 , the sputtering machine 100 includes at least one first magnetic member 120, at least one second magnetic member 125, a workpiece carrier 130, and a target carrier 140. The target carrier 140 can carry at least one backing plate 105, and a sputtering target 110 is disposed on the backing plate 105 to form a target structure. In one embodiment, the backing plate 105 is disposed on the lower surface of the sputtering target 110 to contact and support the sputtering target 110. The workpiece carrier 130 can carry a workpiece W1, and the workpiece W1 is, for example, a glass or substrate of a product, such as a display panel, a touch panel, a semiconductor wafer or other electronic components. The first magnetic member 120 and the second magnetic member 125 are disposed in the target carrier 140. The first magnetic member 120 and the second magnetic member 125 can generate a magnetic field M1. The first magnetic member 120 and the second magnetic member 125 are, for example, magnets, wherein one of the first magnetic member 120 and the second magnetic member 125 has, for example, an N pole, and the other of the first magnetic member 120 and the second magnetic member 125 has, for example, an S pole.

In the ion sputtering process, the magnetic field M1 generated by the first magnetic member 120 and the second magnetic member 125 passes through the sputtering target 110. Magnetron sputtering increases the plasma density and the sputtering rate by confining the charged particles (ionized particles of the sputtering target 110) by the magnetic field M1. The ionized particles of the sputtering target 110 fly toward the workpiece W1 to form a (sputtering) thin film on the workpiece W1.

In one embodiment, the sputtering target 110 is formed into a long strip plate. The working surface 110u includes an upper surface having a short side direction and a long side direction. The size of the sputtering target 110 is not particularly limited, and the length of the short side direction is, for example, 100 millimeters (mm) to 2000mm, preferably 150mm to 1500mm, and more preferably 200mm to 1000mm. Moreover, the length of the long side direction is, for example, 100mm to 4000mm, preferably 300mm to 3500mm, and more preferably 450mm to 3000mm. In addition, the length of the long side direction and the length of the short side direction can be the same or different. The back plate 105 is a long strip plate with no particular limitation on the length of the short side and the long side.

As for the target material, the material of the sputtering target 110 is, for example, metal, such as aluminum, titanium, copper, tin, indium or alloys thereof, or other materials, such as indium tin oxide; in addition, the back plate 105 can be made of metal, such as but not limited to oxygen-free copper or similar materials.

The sputtering target 110 includes a working surface 110u. The working surface 110u can face the workpiece W1. The working surface 110u includes a sputtering area 110u1 and a rough area. The rough area includes a first edge area 110u2 and a second edge area (non-spattering area) 110u3, wherein the first edge area 110u2 and the second edge area 110u3 are arranged around the sputtering area 110u1, and the first edge area 110u2 is arranged on opposite sides of the sputtering area 110u1. In one embodiment, the first edge area 110u2 is located at two short sides of the sputtering target 110, and the second edge area 110u3 is located at two long sides of the sputtering target 110.

In one embodiment, the sputtering region 110u1 has a first surface roughness R1, the first edge region 110u2 is adjacent to the sputtering region 110u1 and has a second surface roughness R2, and the second edge region 110u3 is adjacent to the sputtering region 110u1 and has a third surface roughness R3. In one embodiment, the second surface roughness R2 is greater than the first surface roughness R1 and the third surface roughness R3. Since the first edge region 110u2 provides a rough surface, the back-sputtering particles P1 between the sputtering target 110 and the workpiece W1 are easily attached thereto without rebounding, thereby improving the problem of sputtering contamination.

During the ion sputtering process, the material of the sputtering area 110u1 is ionized, so there will be material consumption, causing the surface of the sputtering area 110u1 to be concave. Since the materials of the first edge area 110u2 and the second edge area 110u3 are not ionized or only slightly ionized, there will be no material consumption or very little material consumption, so the first edge area 110u2 and the second edge area 110u3 can also be called non-spattering areas or anti-spattering areas. In another embodiment, according to different magnetic field settings, the second edge area 110u3 can be reduced or even not set. In another embodiment, the width of the second edge area 110u3 can be less than 10mm.

As shown in Figure 1, in one embodiment, the position of the first edge region 110u2 may correspond to the edge of the magnetic force lines distributed in the magnetic field M1, that is, the magnetic force lines are directed toward the first magnetic member 120 and the second magnetic member 125 to form a closed curve, and the magnetic force lines are correspondingly formed in the sputtering region 110u1, and the first edge region 110u2 and the second edge region 110u3 are formed outside the closed curve. Therefore, the back sputtering particles P1 between the first edge region 110u2 and the second edge region 110u3 and the workpiece W1 are not easily controlled by the magnetic field M1. However, by roughening the surface of the first edge region 110u2 (roughening is indicated by a dotted cross section in FIG. 1), the back sputtering particles P1 between the sputtering target 110 and the workpiece W1 are easily attached thereto, thereby avoiding the back sputtering particles P1 from rebounding and improving the problem of sputtering contamination. In addition, since the back sputtering particles P1 are not easy to rebound to the second edge region 110u3, the second edge region 110u3 may not be subjected to surface treatment. In another embodiment, the second edge region 110u3 may also be subjected to surface treatment.

In one embodiment, the back plate 105 may also be subjected to surface treatment. For example, the area 105u of the back plate 105 adjacent to the first edge area 110u2 may also be subjected to surface treatment (roughening is indicated by a dotted cross section in FIG. 1). The surface roughness of the area 105u may be the same as or similar to the second surface roughness R2. Similarly, the back-splash particles P1 are easily attached to the roughened area 105u, improving the problem of sputtering contamination.

In terms of the surface treatment process, the working surface 110u may be subjected to at least one surface treatment. In one embodiment, the surface treatment of the present invention is a grinding treatment. For example, in the first surface treatment, a first surface treatment component may be used to treat the entire working surface 110u, including the sputtering area 110u1, the first edge area 110u2 and the second edge area 110u3, so that the working surface 110u has a first surface roughness R1. In the second surface treatment, a second surface treatment component may be used to treat the first edge area 110u2 of the working surface 110u, so that the first edge area 110u2 has a second surface roughness R2. Since the second surface treatment is not performed on the splated area 110u1 and the second edge area 110u3, the splated area 110u1 and the second edge area 110u3 retain the first surface roughness R1 of the first surface treatment. In one embodiment, the surface roughness of the first surface treatment part is less than the surface roughness of the second surface treatment part, so the first surface roughness R1 obtained by the first surface treatment part is less than the second surface roughness R2 obtained by the second surface treatment part.

In one embodiment, the surface treatment material is not particularly limited and can be used as a surface treatment material coated with abrasive particles on a paper or fiber substrate, and preferably a surface treatment material in which abrasive particles are impregnated in a non-woven fabric of synthetic fibers such as nylon using Scotch Brite (manufactured by 3M Japan Co., Ltd.) or Kenmaron (manufactured by Sankyo Chemical Co., Ltd.). By using a surface treatment material with a high porosity and elastic substrate such as a non-woven fabric, scratches caused by abrasive particles falling off the surface treatment material can be prevented, and it is easy to adapt to the polishing surface, thereby making it easy to suppress uneven polishing.

In addition, in the present invention, the particle size distribution and particle size number (particle size) of the abrasive particles of the surface treatment part are based on JIS R 6001. Grinding is preferably performed while removing the grinding chips or fallen abrasive particles by suction or exhaust and air blowing. In this way, the sputtering target 110 can be polished without leaving grinding chips and fallen abrasive particles on the polishing surface, so that deep scratches or roughness of the polishing surface can be further prevented, and the uniformity of the surface roughness of each area of the working surface 110u can be further improved. The removal of grinding chips or fallen abrasive particles by suction can be carried out in a dust collector or near a dust collector or by using a grinder with a dust collection mechanism.

In addition to manual work, a grinder equipped with a surface treatment part can also be used. An orbital sander is preferably used as the grinder, but it is not limited to this. Any grinder such as a mini angle sander, a disc grinder, or a belt sander can also be used.

In one embodiment, the first surface treatment member is, for example, a non-woven fabric or the like, and the second surface treatment member is, for example, sandpaper or the like.

In terms of manufacturing process, the first surface treatment is, for example, polishing and grinding, while the second surface treatment is, for example, filing and grinding.

In terms of surface roughness values, the first surface roughness R1 is, for example, an arithmetic mean deviation (Ra) in the range of 0.8 micrometers to 2.0 micrometers (including end points), such as 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, etc. The second surface roughness R2 is, for example, an arithmetic mean deviation (Ra) in the range of 2.5 micrometers to 4.2 micrometers (including end points), such as 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, etc. In terms of the ratio of surface roughness, the ratio of the first surface roughness R1 to the second surface roughness R2 is, for example, between 1/2 and 1/4, but can also be larger or smaller.

In terms of area ratio, the sum of the first edge area 110u2 and the second edge area 110u3 accounts for a first ratio of the working surface 110u, and the first ratio is, for example, in the range of 5.6% to 12.7% (including the end point value), and the first edge area 110u2 accounts for a second ratio of the working surface 110u, and the second ratio is, for example, in the range of 0.75% to 1.5% (including the end point value), but the embodiment of the present invention is not limited thereto.

In another embodiment, three surface treatments may be performed. For example, in the first surface treatment, the entire working surface 110u, including the sputtering area 110u1, the first edge area 110u2 and the second edge area 110u3, may be treated with a first surface treatment component, such as a first surface treatment component, so that the working surface 110u has a first surface roughness R1. In the second surface treatment, the first edge area 110u2 and the second edge area 110u3 of the working surface 110u may be treated with a second surface treatment component, such as a second surface treatment component. In the third surface treatment, the first edge area 110u2 of the working surface 110u may be treated with a third surface treatment component, such as a third surface treatment component. In this embodiment, the surface roughness of the first surface treatment part is smaller than the surface roughness of the second surface treatment part, and the surface roughness of the second surface treatment part is smaller than the surface roughness of the third surface treatment part, so the surface roughness R1 of the sputtering area 110u1 is smaller than the surface roughness R3 of the second edge area 110u3, and the surface roughness R3 of the second edge area 110u3 is smaller than the surface roughness R2 of the first edge area 110u2.

In this embodiment, the first surface roughness R1 is, for example, an arithmetic mean deviation (Ra) in the range of 0.8 micrometers to 1.3 micrometers (including the end point values), such as 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, etc. The second surface roughness R2 is, for example, an arithmetic mean deviation (Ra) in the range of 2.5 micrometers to 4.2 micrometers (including the end point values), such as 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, etc. The third surface roughness R3 is greater than the first surface roughness R1. The third surface roughness R3 is, for example, the centerline average roughness (arithmetic mean deviation, Ra) in the range of 1.4 microns to 2.0 microns (including end point values), such as 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, etc.

As shown in FIGS. 1 to 3 , the working surface 110u is, for example, the entire upper surface of the sputtering target 110 facing the +Z axis. The first edge region 110u2 is a portion of the entire edge region of the working surface 110u, and the second edge region 110u3 is another portion of the entire edge region of the working surface 110u. The first edge region 110u2 and the second edge region 110u3 can define the entire edge region of the working surface 110u, which surrounds the sputtering region 110u1 in a closed manner, but the embodiment of the present invention is not limited thereto. In one embodiment, as shown in FIG. 5B , the working surface 110u is, for example, a long strip, the sputtering region 110u1 is located in the center, the first edge region 110u2 is located at both ends of the short side, and the second edge region 110u3 is located at both sides of the long side, and the first edge region 110u2 at the two ends and the second edge region 110u3 at the two sides alternately adjoin and surround the entire sputtering region 110u1.

As shown in FIG. 2, the first edge region 110u2 includes a first sub-edge region 110u21 and a second sub-edge region 110u22, and the first sub-edge region 110u21 and the second sub-edge region 110u22 are respectively located at or adjacent to the two opposite sides of the sputtering region 110u1. As shown in FIG. 3, the second edge region 110u3 includes a third sub-edge region 110u31 and a fourth sub-edge region 110u32, and the third sub-edge region 110u31 and the fourth sub-edge region 110u32 are respectively located at or adjacent to the other two opposite sides of the sputtering region 110u1. Although not shown in Figures 2-3, the first sub-edge area 110u21 is connected to the third sub-edge area 110u31 and the fourth sub-edge area 110u32, and the second sub-edge area 110u22 is also connected to the third sub-edge area 110u31 and the fourth sub-edge area 110u32.

As shown in FIGS. 2-3 , the sputtering target 110 further includes a side surface 110s, which defines the entire side interface of the sputtering target 110. The side surface 110s is disposed around the working surface 110u. Please also refer to FIG. 5B , where the side surface 110s includes a first sub-side surface 110s1 and a second sub-side surface 110s2 opposite to each other and a third sub-side surface 110s3 and a fourth sub-side surface 110s4 opposite to each other, wherein the first sub-side surface 110s1 and the second sub-side surface 110s2 are adjacent to the first edge region 110u2, and the third sub-side surface 110s3 and the fourth sub-side surface 110s4 are adjacent to the second edge region 110u3. The side surface 110s has a side surface area, and the side surface area is, for example, at least a portion of the entire side surface 110s. For example, the side surface area can be located at least a portion of at least one of the first sub-side surface 110s1, the second sub-side surface 110s2, the third sub-side surface 110s3, and the fourth sub-side surface 110s4. In one embodiment, the side surface area can be the entire side surface 110s. The side surface area has a side surface roughness R4. The side surface roughness R4 is greater than the first surface roughness R1 and/or the third surface roughness R3. The side surface roughness R4 is, for example, between 2.5 microns and 4.2 microns. The center line average roughness is, for example, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, etc. In one embodiment, the side surface roughness R4 can be achieved in the aforementioned second surface treatment.

Please refer to Figures 4 and 5A~5B. Figure 4 shows a flow chart of the surface treatment method of the sputtering target 110 in Figure 1, Figure 5A shows a schematic diagram of the sputtering target 110' in step S110 of Figure 4, and Figure 5B shows a partial schematic diagram of the roughened working surface 110u in step S130 of Figure 4.

In step S110, as shown in FIG. 5A, a sputtering target 110' is provided, and the sputtering target 110' has an initial working surface 110u'. The sputtering target 110' is formed, for example, by subjecting a metal ingot to a rolling process to form a rolled plate, and then cutting the plate to the required size. The initial working surface 110u' of the sputtering target 110' has not been surface treated, and the initial surface roughness R1' of the initial working surface 110u' is, for example, less than 1 micron.

In step S120, the first surface treatment is performed to treat the initial working surface 110u' of the sputter-plated target 110 to form the working surface 110u. For example, the first surface treatment component can be used to treat at least a portion of the initial working surface 110u' to form the working surface 110u. The working surface 110u has a centerline average roughness ranging from 0.8 microns to 2.0 microns (including end point values). The first surface treatment is, for example, polishing and grinding, and the first surface treatment component is, for example, a non-woven fabric or the like.

In step S130, a second surface treatment is performed to roughen a portion of the working surface 110u that has been subjected to the first surface treatment, and the surface roughness of this portion is greater than the surface roughness of the portion outside the working surface 110u, for example, in the range of 2.5 microns to 4.2 microns. The second surface treatment is, for example, filing and grinding, and the second surface treatment member is, for example, sandpaper or the like. In one embodiment, the aforementioned portion is, for example, a portion of the working surface 110u of FIG. 2 (for example, the first edge region 110u2) and/or at least a portion of the side surface 110s, or the aforementioned portion is, for example, the edge corresponding to the magnetic field line distribution.

In summary, the embodiments of the present invention provide a sputtering target. The sputtering target has a working surface. The surface roughness of a part of the working surface is greater than the surface roughness of other parts of the working surface, so it is easy to capture backsplash particles and improve the sputtering pollution problem. The aforementioned part is, for example, a part of the working surface and/or at least a part of the side surface, or, the aforementioned part is, for example, the edge corresponding to the distribution of magnetic field lines. In one embodiment, the working surface includes a rough area (the aforementioned "part"), a sputtering area and a non-spattering area, and the rough area is correspondingly distributed on two opposite sides of the working surface, or adjacent to two opposite sides of the sputtering area. In one embodiment, the non-spattering area is respectively connected to the sputtering area and the rough area. In one embodiment, the surface roughness of the non-sputtering area is less than the surface roughness of the roughening area. In one embodiment, the sputtering target may have a side surface, and the surface roughness of the side surface is greater than the surface roughness of the sputtering area. In one embodiment, the roughening area connection ring is arranged around the sputtering area.

In summary, although the present invention has been disclosed as above by the embodiments, it is not intended to limit the present invention. Those with common knowledge in the technical field to which the present invention belongs can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope defined in the attached patent application.

105: Back panel

105u: Area

110: Sputtering target

110s: Side

110s1: First sub-side

110s2: Second sub-side

110s3: The third sub-side

110s4: The fourth sub-side

110u: working surface

110u1: Splash plating area

110u2: The first marginal zone

110u21: First sub edge area

110u22: Second sub edge area

110u3: The second fringe area

110u31: Third sub marginal area

110u32: The fourth sub-edge area

W1: Workpiece

Claims (11)

A sputtering target material comprises: a sputtering area of a working surface, having a first surface roughness; a rough area of the working surface, wherein the rough area comprises: a first edge area, having a second surface roughness; and a second edge area, having a third surface roughness; wherein the working surface is an upper surface of the sputtering target material, and the first edge area and the second edge area are connected to form a closed annular ring. Around the sputtering area, the first edge area is a part of the closed ring, and the second edge area is the remaining part of the closed ring, and the second surface roughness is greater than the first surface roughness and the third surface roughness, and the third surface roughness is greater than the first surface roughness; wherein the area of the first edge area accounts for a proportion of the area of the working surface between 0.75% and 1.5%. The sputtering target as described in claim 1, wherein the first edge region and the second edge region are connected and arranged around the sputtering region. The sputtering target as described in claim 1, wherein the first surface roughness is a centerline average roughness between 0.8 microns and 2.0 microns and/or the second surface roughness is a centerline average roughness between 2.5 microns and 4.2 microns. A sputtering target as described in claim 1, wherein the sputtering target further includes a side surface having a side surface roughness, and the side surface roughness is greater than the first surface roughness and/or the third surface roughness. The sputter plating target as described in claim 4, wherein the side surface roughness is a centerline average roughness between 2.5 microns and 4.2 microns. The sputtering target material as described in claim 1, wherein the ratio of the total area of the first edge region and the second edge region to the area of the working surface is between 5.6% and 12.7%. A target structure includes at least: a sputtering target, at least including: a working surface, which is an upper surface of the sputtering target, and includes: a sputtering area, having a first surface roughness; and a first edge area, having a second surface roughness, wherein the second surface roughness is greater than the first surface roughness; and a second edge area, the second edge area has a third surface roughness, wherein the second surface roughness is greater than the third surface roughness, and the first edge area and the second edge area are connected to form a closed annular ring. The sputtering region, the first edge region is a part of the closed ring, and the second edge region is the remaining part of the closed ring; and a side surface, which is arranged around the working surface, and the side surface has a side surface roughness, wherein the side surface roughness is greater than the first surface roughness; and a back plate, which is arranged on a surface of the sputtering target material to contact and support the sputtering target material; wherein the area of the first edge region accounts for a proportion of the area of the working surface between 0.75% and 1.5%, and the third surface roughness is greater than the first surface roughness. A surface treatment method for a sputtering target comprises: providing a sputtering target, wherein the sputtering target has an initial working surface, the initial working surface is an upper surface of the sputtering target, the initial working surface has a sputtering area, a first edge area and a second edge area, the first edge area and the second edge area are connected to form a closed ring surrounding the sputtering area, the first edge area is a part of the closed ring, and the second edge area is the remaining part of the closed ring; performing a first surface treatment, surface treating the initial working surface of the sputtering target to form a working surface, the sputtering area of the working surface has a first surface roughness; and performing a second surface treatment to roughen the first edge region and the second edge region of the working surface that has undergone the first surface treatment, the second edge region having a third surface roughness; performing a third surface treatment to roughen the first edge region of the working surface that has undergone the second surface treatment, the first edge region having a second surface roughness; wherein the second surface roughness is greater than the first surface roughness and the third surface roughness, and the area of the first edge region accounts for a proportion of the area of the working surface between 0.75% and 1.5%, and the third surface roughness is greater than the first surface roughness. The surface treatment method as described in claim 8, wherein the first surface treatment is a polishing and grinding treatment and/or the second surface treatment is a filing and grinding treatment. A surface treatment method as described in claim 8, wherein the first surface treatment is performed with a non-woven fabric and the second surface treatment is performed with sandpaper. A surface treatment method as described in claim 8, wherein the second surface treatment further roughens a side surface around the working surface.

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