A target material assembly with segmented pattern structure and knurling method thereof

Abstract

The present invention provides a target assembly with a segmented pattern structure and a knurling method thereof, wherein the target assembly comprises a stacked target and a back plate; the end face of the target has a first segmented pattern structure; the R angle at the connection between the end face and the side of the target has a second segmented pattern structure; the first segmented pattern structure and the second segmented pattern structure are independently at least two-segmented pattern structures. The knurling method comprises the following steps: (1) performing a first segmented knurling on the end face of the target; (2) performing a second segmented knurling on the R angle at the connection between the end face and the side of the target; (3) polishing the knurled area of ​​the target. Steps (1) and (2) are performed in no particular order. The present invention effectively prevents the fall-off of the back-sputtered objects of the target during the sputtering process, protects the wafer from damage, improves the coating quality, and prolongs the service life of the target assembly.

Description

Technical Field

[0001] The invention belongs to the technical field of magnetron sputtering coating, and relates to a target material component with a pattern structure, and in particular to a target material component with a segmented pattern structure and a knurling method thereof. Background Art

[0002] Magnetron sputtering coating is a very important thin film formation process in the manufacturing process of semiconductor devices. The typical magnetron sputtering coating process is to place the target assembly in a vacuum environment and fill it with inert gas argon, so that the target is at the positive pole and the silicon wafer is at the negative pole. Under the action of the electric field, the argon gas is ionized and decomposed into argon ions. The argon ions bombard the surface of the target material under the action of the electric field, so that the metal atoms of the target material are sputtered onto the surface of the silicon wafer. During the magnetron sputtering process, high-speed ions bombard the sputtering area of ​​the target material. In addition to being deposited on the surface of the wafer, the sputtered metal ions will also be deposited on other surfaces of the chamber, including the edges and sides of the target material. Due to the high energy of the plasma atmosphere, the atoms redeposited on the edges and sides of the target material will overflow again to form anti-sputtering objects, causing the anti-sputtering objects to fall off during the sputtering process, thereby damaging the wafer.

[0003] CN 108994525A discloses a knurling process for the end face of an ultra-high purity titanium sputtering target for semiconductors, including knurling the end face of the target material; knurling the side face of the target material; and knurling the R angle at the connection between the end face and the side face of the target material. The invention manufactures a special knurling tool head and tool handle, clamps the target material on a lathe, and realizes knurling patterns in the required area of ​​the target material through the operation of the processing equipment and the downward pressure of the tool on the target material, thereby increasing the surface adhesion of the target material and preventing the excess ions accumulated in the target material during the sputtering process from falling off, causing damage to the wafer. However, the end face of the target material of the invention has only one-stage knurling, and after long-term use, the phenomenon of excess ions falling off will still occur, so the adhesion strength of this pattern design is still greatly improved.

[0004] It can be seen that how to provide a target material assembly and a knurling method thereof to effectively prevent the fall-off of the back-sputtered materials during the sputtering process, protect the wafer from damage, improve the coating quality, and extend the service life of the target material assembly has become an urgent problem that technical personnel in this field need to solve. Summary of the invention

[0005] The object of the present invention is to provide a target material assembly with a segmented pattern structure and a knurling method thereof, wherein the knurling method effectively prevents the back-sputtering materials from falling off during the sputtering process of the target material, protects the wafer from damage, improves the coating quality, and prolongs the service life of the target material assembly.

[0006] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a target material assembly having a segmented pattern structure, wherein the target material assembly comprises a target material and a back plate that are stacked.

[0008] The end surface of the target material has a first segmented pattern structure.

[0009] The R angle at the connection between the end face and the side face of the target material has a second segmented pattern structure.

[0010] The first segmented pattern structure and the second segmented pattern structure are independently at least 2-segment pattern structures, for example, they can be 2-segment, 3-segment, 4-segment or 5-segment, but are not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0011] In the present invention, the end face of the target material specifically refers to the area where the edge and the side of the target material intersect, which is a part of the non-sputtering area of ​​the target material.

[0012] The present invention respectively arranges segmented pattern structures on the end face and R corner of the target material. Compared with the traditional one-stage pattern structure, the segmented pattern structure can significantly enhance the adhesion of the non-sputtering area of ​​the target material, thereby effectively preventing the fall-off of the back-sputtered materials of the target material during the sputtering process, protecting the wafer from damage, improving the coating quality, and extending the service life of the target material assembly.

[0013] Preferably, the first segmented pattern structure is a three-segment pattern structure.

[0014] Preferably, the width of each pattern segment in the first segmented pattern structure is 3-5 mm, for example, it can be 3 mm, 3.2 mm, 3.4 mm, 3.6 mm, 3.8 mm, 4 mm, 4.2 mm, 4.4 mm, 4.6 mm, 4.8 mm or 5 mm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0015] Preferably, each segment of the pattern in the first segmented pattern structure is arranged in an interlocking relationship with the adjacent pattern.

[0016] In the present invention, the specific manner of the interlocking arrangement is that two adjacent sections of the pattern are staggered in grooves, that is, the segmented pattern structure is not integrated, thereby avoiding the risk of large-area back-sputtering falling off.

[0017] Preferably, the engagement depth between each pattern and the adjacent pattern in the first segmented pattern structure is 0.8-1.2 mm, for example, it can be 0.8 mm, 0.85 mm, 0.9 mm, 0.95 mm, 1 mm, 1.05 mm, 1.1 mm, 1.15 mm or 1.2 mm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0018] Preferably, the second segmented pattern structure is a three-segment pattern structure.

[0019] Preferably, the angle between the perpendicular line in the plane of each pattern segment in the second segmented pattern structure and the target material plane is 30°-70°, for example, it can be 30°, 35°, 40°, 45°, 50°, 55°, 60°, 65° or 70°, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0020] Preferably, the first segmented pattern structure and the second segmented pattern structure are arranged in an interlocking manner.

[0021] Preferably, the engagement depth between the first segmented pattern structure and the second segmented pattern structure is 0.8-1.2 mm, for example, it can be 0.8 mm, 0.85 mm, 0.9 mm, 0.95 mm, 1 mm, 1.05 mm, 1.1 mm, 1.15 mm or 1.2 mm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0022] Preferably, the pattern models of the first segmented pattern structure and the second segmented pattern structure are independently 60-100TPI, for example, they can be 60TPI, 65TPI, 70TPI, 75TPI, 80TPI, 85TPI, 90TPI, 95TPI or 100TPI, but are not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0023] Compared with the traditional 50TPI pattern model, the 60-100TPI pattern model can significantly increase the adhesion of the knurled area, thereby greatly reducing the risk of back-sputtering falling off.

[0024] Preferably, the roughness of the first segmented pattern structure and the second segmented pattern structure is independently 10-15μm, for example, it can be 10μm, 10.5μm, 11μm, 11.5μm, 12μm, 12.5μm, 13μm, 13.5μm, 14μm, 14.5μm or 15μm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0025] In a second aspect, the present invention provides a knurling method for a target assembly as described in the first aspect, the knurling method comprising the following steps:

[0026] (1) performing a first segmented knurling on the end surface of the target material;

[0027] (2) performing a second segmented knurling on the R angle at the connection between the end face and the side face of the target;

[0028] (3) Polishing the knurled area of ​​the target material.

[0029] Wherein, the first segmented knurling in step (1) and the second segmented knurling in step (2) are independently at least two-segment knurlings; and steps (1) and (2) are performed in no particular order.

[0030] In the present invention, the first segmented knurling and the second segmented knurling are independently at least 2-segment knurling, for example, they can be 2-segment, 3-segment, 4-segment or 5-segment, but are not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0031] The present invention performs segmented knurling on the end face and R angle of the target material, thereby significantly enhancing the adhesion of the non-sputtering area of ​​the target material, thereby effectively preventing the back-sputtering of the target material from falling off during the sputtering process, protecting the wafer from damage, improving the coating quality, and extending the service life of the target material assembly.

[0032] Preferably, the first segmented knurling in step (1) and the second segmented knurling in step (2) are independently three-segment knurling.

[0033] Preferably, the rotational speed of the target material in the knurling process of the first segmented knurling in step (1) and the second segmented knurling in step (2) is independently 20-25 rpm, for example, it can be 20 rpm, 20.5 rpm, 21 rpm, 21.5 rpm, 22 rpm, 22.5 rpm, 23 rpm, 23.5 rpm, 24 rpm, 24.5 rpm or 25 rpm, but it is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0034] During the knurling process of the present invention, the target material keeps rotating at a uniform speed, while the tool of the fixed knurling wheel keeps stationary. The specifications of the knurling wheel and the inclination angle of the tool are adjusted according to the specific needs of the customer, thereby ensuring the stability of the knurling process and the qualified rate of the target material assembly.

[0035] Preferably, the pressure drop of the knurling wheel during the knurling process of the first segmented knurling in step (1) and the second segmented knurling in step (2) is independently 0.3-0.4 mm, for example, it can be 0.3 mm, 0.31 mm, 0.32 mm, 0.33 mm, 0.34 mm, 0.35 mm, 0.36 mm, 0.37 mm, 0.38 mm, 0.39 mm or 0.4 mm, but it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0036] In the present invention, the pressure drop is the depth of the knurling wheel pressed into the target surface, which needs to be kept within a reasonable range. When the pressure drop is less than 0.3 mm, the roughness of the knurling area is too low, the adhesion is too small, and the fall of the back-sputtering cannot be effectively avoided; when the pressure drop is greater than 0.4 mm, the energy consumption is increased while the risk of deformation of the target edge is increased.

[0037] Preferably, the polishing process in step (3) uses flocked sandpaper.

[0038] Preferably, the specification of the flocking sandpaper is 500-700#, for example, it can be 500#, 520#, 540#, 560#, 580#, 600#, 620#, 640#, 660#, 680# or 700#, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0039] Preferably, the rotation speed of the target material during the polishing process is 300-350rpm, for example, it can be 300rpm, 305rpm, 310rpm, 315rpm, 320rpm, 325rpm, 330rpm, 335rpm, 340rpm, 345rpm or 350rpm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0040] As a preferred technical solution of the second aspect of the present invention, the knurling method comprises the following steps:

[0041] (1) The end surface of the target material is knurled in three stages; during the knurling process, the rotation speed of the target material is 20-25 rpm, and the pressure drop of the knurling wheel is 0.3-0.4 mm;

[0042] (2) The R angle at the connection between the end face and the side face of the target is knurled in three stages; the rotation speed of the target during the knurling process is 20-25 rpm, and the pressure drop of the knurling wheel is 0.3-0.4 mm;

[0043] (3) The knurled area of ​​the target material is polished using flocked sandpaper of specification 500-700#; the rotation speed of the target material during the polishing process is 300-350rpm;

[0044] There is no particular order in which steps (1) and (2) are performed.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] (1) The target assembly provided by the present invention is provided with a segmented pattern structure on the end face and R corner of the target. Compared with the conventional one-segment pattern structure, the segmented pattern structure can significantly enhance the adhesion of the non-sputtering area of ​​the target, thereby effectively preventing the fall-off of the back-sputtered objects of the target during the sputtering process, protecting the wafer from damage, improving the coating quality, and extending the service life of the target assembly;

[0047] (2) The knurling method provided by the present invention is easy to operate, highly controllable, and can be applied to the setting of different pattern structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 It is a schematic diagram of the segmented pattern structure at the end face of the target material in the target material assembly provided by the present invention;

[0049] Figure 2 It is a schematic diagram of the segmented knurling operation at the end face of the target material in the knurling method provided by the present invention;

[0050] Figure 3 It is a schematic diagram of the segmented knurling operation at the R corner of the target material in the knurling method provided by the present invention.

[0051] Among them: 1-back plate; 2-target material; 3-knurling wheel; 4-tool; 5-first knurling area; 6-second knurling area; 7-third knurling area; α-first angle; β-second angle; γ-third angle; D-pattern width; d-embedded depth. DETAILED DESCRIPTION

[0052] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0053] Example 1

[0054] This embodiment provides a target material assembly with a segmented pattern structure (see Figure 1 ) and knurling method thereof (see Figure 2 and Figure 3 ), the target assembly comprises a stacked target 2 and a backing plate 1; the end surface of the target 2 has a three-segment pattern structure, such as Figure 1 As shown, the width D of each pattern is 4 mm, and the adjacent patterns are arranged in an interlocking manner, and the interlocking depth d is 1 mm; the R angle at the connection between the end face and the side face of the target material 2 has a 3-segment pattern structure, combined with Figure 2From the knurling method, it can be seen that the angle α between the perpendicular line of the plane of the outer segment of the pattern and the plane of the target material 2 is 30°, the angle β between the perpendicular line of the plane of the middle segment of the pattern and the plane of the target material 2 is 45°, and the angle γ between the perpendicular line of the plane of the inner segment of the pattern and the plane of the target material 2 is 70°. In addition, the three-segment pattern structure at the end face of the target material 2 and the three-segment pattern structure at the R angle are arranged in an interlocking manner, and the interlocking depth is 1mm. The pattern model is 80TPI and the roughness is 12.5μm.

[0055] In this embodiment, the knurling method comprises the following steps:

[0056] (1) The end surface of the target material 2 is knurled in three stages; during the knurling process, the rotation speed of the target material 2 is 22.5 rpm, and the pressure drop of the knurling wheel 3 is 0.35 mm; Figure 2 As shown, the first knurled area 5, the second knurled area 6 and the third knurled area 7 are obtained in sequence;

[0057] (2) The R angle at the connection between the end face and the side face of the target material 2 is knurled in three stages; during the knurling process, the rotation speed of the target material 2 is 22.5 rpm, and the pressure drop of the knurling wheel 3 is 0.35 mm; Figure 3 As shown, the angles between the tool 4 and the plane of the target 2 during the three-stage knurling process are α = 30°, β = 45°, and γ = 70°;

[0058] (3) The knurled area of ​​the target material 2 is polished using flocked sandpaper of specification 600#; the rotation speed of the target material 2 during the polishing process is 325 rpm.

[0059] Since the target material assembly obtained in this embodiment has a three-segment pattern structure, the adhesion of the non-sputtering area is strong, and no back-sputtering material falls off during the sputtering process, thereby protecting the wafer from damage and achieving good coating quality.

[0060] Example 2

[0061] This embodiment provides a target material assembly with a segmented pattern structure (see Figure 1 ) and knurling method thereof (see Figure 2 and Figure 3 ), the target assembly comprises a stacked target 2 and a backing plate 1; the end surface of the target 2 has a three-segment pattern structure, such as Figure 1 As shown, the width D of each pattern is 3 mm, and the adjacent patterns are interlocked and arranged, and the interlocking depth d is 0.8 mm; the R angle at the connection between the end face and the side face of the target material 2 has a 3-segment pattern structure, combined with Figure 2From the knurling method, it can be seen that the angle α between the perpendicular line of the plane of the outer segment of the pattern and the plane of the target material 2 is 35°, the angle β between the perpendicular line of the plane of the middle segment of the pattern and the plane of the target material 2 is 50°, and the angle γ between the perpendicular line of the plane of the inner segment of the pattern and the plane of the target material 2 is 65°. In addition, the three-segment pattern structure at the end face of the target material 2 and the three-segment pattern structure at the R angle are arranged in an interlocking manner, and the interlocking depth is 0.8mm. The pattern model is 60TPI and the roughness is 10μm.

[0062] In this embodiment, the knurling method comprises the following steps:

[0063] (1) The end surface of the target material 2 is knurled in three stages; during the knurling process, the rotation speed of the target material 2 is 20 rpm, and the pressure drop of the knurling wheel 3 is 0.3 mm; Figure 2 As shown, the first knurled area 5, the second knurled area 6 and the third knurled area 7 are obtained in sequence;

[0064] (2) The R angle at the connection between the end face and the side face of the target material 2 is knurled in three stages; during the knurling process, the rotation speed of the target material 2 is 20 rpm, and the pressure drop of the knurling wheel 3 is 0.3 mm; Figure 3 As shown, the angles between the tool 4 and the plane of the target 2 during the three-stage knurling process are α = 35°, β = 50°, and γ = 65°;

[0065] (3) The knurled area of ​​the target material 2 is polished using flocked sandpaper of specification 500#; the rotation speed of the target material 2 during the polishing process is 300 rpm.

[0066] Since the target material assembly obtained in this embodiment has a three-segment pattern structure, the adhesion of the non-sputtering area is strong, and no back-sputtering material falls off during the sputtering process, thereby protecting the wafer from damage and achieving good coating quality.

[0067] Example 3

[0068] This embodiment provides a target material assembly with a segmented pattern structure (see Figure 1 ) and knurling method thereof (see Figure 2 and Figure 3 ), the target assembly comprises a stacked target 2 and a backing plate 1; the end surface of the target 2 has a three-segment pattern structure, such as Figure 1 As shown, the width D of each pattern is 5 mm, and the adjacent patterns are arranged in an interlocking manner, and the interlocking depth d is 1.2 mm; the R angle at the connection between the end face and the side face of the target material 2 has a 3-segment pattern structure, combined with Figure 2From the knurling method, it can be seen that the angle α between the perpendicular line of the plane of the outer segment of the pattern and the plane of the target material 2 is 40°, the angle β between the perpendicular line of the plane of the middle segment of the pattern and the plane of the target material 2 is 50°, and the angle γ between the perpendicular line of the plane of the inner segment of the pattern and the plane of the target material 2 is 60°. In addition, the three-segment pattern structure at the end face of the target material 2 and the three-segment pattern structure at the R angle are interlocked and arranged with each other, and the interlocking depth is 1.2mm. The pattern model is 100TPI and the roughness is 15μm.

[0069] In this embodiment, the knurling method comprises the following steps:

[0070] (1) The end surface of the target material 2 is knurled in three stages; during the knurling process, the rotation speed of the target material 2 is 25 rpm, and the pressure drop of the knurling wheel 3 is 0.4 mm; Figure 2 As shown, the first knurled area 5, the second knurled area 6 and the third knurled area 7 are obtained in sequence;

[0071] (2) The R angle at the connection between the end face and the side face of the target material 2 is knurled in three stages; during the knurling process, the rotation speed of the target material 2 is 25 rpm, and the pressure drop of the knurling wheel 3 is 0.4 mm; Figure 3 As shown, the angles between the tool 4 and the plane of the target 2 during the three-stage knurling process are α = 40°, β = 50°, and γ = 60°;

[0072] (3) The knurled area of ​​the target material 2 is polished using flocked sandpaper of specification 700#; the rotation speed of the target material 2 during the polishing process is 350 rpm.

[0073] Since the target material assembly obtained in this embodiment has a three-segment pattern structure, the adhesion of the non-sputtering area is strong, and no back-sputtering material falls off during the sputtering process, thereby protecting the wafer from damage and achieving good coating quality.

[0074] Example 4

[0075] The present embodiment provides a target assembly with a segmented pattern structure and a knurling method thereof. In the target assembly, except that the pattern model of the three-segment pattern structure at the end face of the target 2 and the three-segment pattern structure at the R corner is 50TPI, the other conditions are the same as those in Example 1, so they are not repeated here.

[0076] Compared with Example 1, the adhesion of the non-sputtering area of ​​the target assembly obtained in this example is weakened to a certain extent, and the back-sputtered materials occasionally fall off during the sputtering process, but the wafer is not obviously damaged and the coating quality is also at a qualified level.

[0077] Example 5

[0078] The present embodiment provides a target material assembly having a segmented pattern structure and a knurling method thereof. The knurling method has the same conditions as those in Example 1 except that the pressure drop of the knurling wheel during the knurling process of the first segmented knurling and the second segmented knurling is 0.25 mm, and thus will not be described in detail here.

[0079] Compared with Example 1, the adhesion of the non-sputtering area of ​​the target assembly obtained in this example is weakened to a certain extent, and the back-sputtered materials occasionally fall off during the sputtering process, but the wafer is not obviously damaged and the coating quality is also at a qualified level.

[0080] Example 6

[0081] The present embodiment provides a target material assembly having a segmented pattern structure and a knurling method thereof. The knurling method has the same conditions as those in Example 1 except that the pressure drop of the knurling wheel during the knurling process of the first segmented knurling and the second segmented knurling is 0.45 mm, and thus will not be described in detail here.

[0082] Compared with Example 1, the edge of the target assembly obtained in this example is slightly deformed, which reduces the coating quality to a certain extent, and the excessive pressure drop causes increased energy consumption, which is not conducive to saving production costs.

[0083] Example 7

[0084] This embodiment provides a target assembly with a segmented pattern structure and a knurling method thereof. In the knurling method, except that step (2) is performed first and then step (1), the other conditions are the same as those in embodiment 1, so they are not described here.

[0085] Since the target material assembly obtained in this embodiment has a three-segment pattern structure, the adhesion of the non-sputtering area is strong, and no back-sputtering material falls off during the sputtering process, thereby protecting the wafer from damage and achieving good coating quality.

[0086] Comparative Example 1

[0087] This comparative example provides a target assembly with a one-stage pattern structure and a knurling method thereof, wherein the target assembly comprises a stacked target and a back plate; the end face of the target has a one-stage pattern structure, and the width of the pattern is 4 mm; the R angle at the connection between the end face and the side of the target has a one-stage pattern structure, and the angle between the perpendicular line of the pattern plane and the target plane is 45°. In addition, the one-stage pattern structure at the end face of the target and the one-stage pattern structure at the R angle are arranged in an interlocking manner, and the interlocking depth is 1 mm, the pattern model is 80TPI, and the roughness is 12.5μm.

[0088] In this comparative example, the knurling method comprises the following steps:

[0089] (1) performing one-stage knurling on the end surface of the target; during the knurling process, the rotation speed of the target is 22.5 rpm, and the pressure drop of the knurling wheel is 0.35 mm;

[0090] (2) performing one-step knurling on the R angle at the connection between the end face and the side face of the target; during the knurling process, the rotation speed of the target is 22.5 rpm, the pressure drop of the knurling wheel is 0.35 mm, and the angle between the tool and the target plane is 45°;

[0091] (3) The knurled area of ​​the target material is polished using flocked sandpaper of specification 600#; the rotation speed of the target material during the polishing process is 325 rpm.

[0092] Compared with Example 1, the adhesion of the non-sputtering area of ​​the target assembly obtained in this comparative example is significantly weakened, the back-sputtered materials often fall off during the sputtering process, and the wafer is significantly damaged, and the coating quality is significantly reduced.

[0093] It can be seen that the target assembly provided by the present invention arranges a segmented pattern structure on the end face and R corner of the target material respectively. Compared with the traditional one-stage pattern structure, the segmented pattern structure can significantly enhance the adhesion of the non-sputtering area of ​​the target material, thereby effectively preventing the fall-off of the back-sputtered materials of the target material during the sputtering process, protecting the wafer from damage, improving the coating quality, and extending the service life of the target assembly; in addition, the knurling method provided by the present invention is easy to operate, highly controllable, and can be applied to the setting of different pattern structures.

[0094] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A target assembly with a segmented pattern structure, characterized in that: The target material assembly comprises a target material and a back plate which are stacked; The end surface of the target material has a first segmented pattern structure; The R angle at the connection between the end face and the side face of the target material has a second segmented pattern structure; The first segmented pattern structure and the second segmented pattern structure are independently at least two-segmented pattern structures; The width of each segment of the first segmented pattern structure is 3-5 mm; Each segment of the pattern in the first segmented pattern structure is arranged in an interlocking manner with the adjacent pattern; The embedding depth between each segment of the pattern and the adjacent pattern in the first segmented pattern structure is 0.8-1.2 mm; The first segmented pattern structure and the second segmented pattern structure are arranged in an interlocking manner; The engagement depth between the first segmented pattern structure and the second segmented pattern structure is 0.8-1.2 mm; The roughness of the first segmented pattern structure and the second segmented pattern structure are independently 10-15 μm.

2. The target assembly according to claim 1, characterized in that: The first segmented pattern structure is a three-segmented pattern structure.

3. The target assembly according to claim 1, characterized in that: The second segmented pattern structure is a three-segmented pattern structure.

4. The target assembly according to claim 1, characterized in that: The angle between the perpendicular line of the plane of each pattern in the second segmented pattern structure and the target plane is 30°-70°.

5. The target assembly according to claim 1, characterized in that: The pattern models of the first segmented pattern structure and the second segmented pattern structure are independently 60-100 TPI.

6. A knurling method for a target assembly as claimed in any one of claims 1 to 5, characterized in that: The knurling method comprises the following steps: (1) performing a first segmented knurling on the end surface of the target material; (2) performing a second segmented knurling on the R angle at the connection between the end face and the side face of the target; (3) polishing the knurled area of ​​the target material; Wherein, the first segmented knurling in step (1) and the second segmented knurling in step (2) are independently at least two-segment knurlings; and steps (1) and (2) are performed in no particular order.

7. The knurling method according to claim 6, characterized in that: The first segmented knurling in step (1) and the second segmented knurling in step (2) are independently three-segment knurling.

8. The knurling method according to claim 6, characterized in that: The rotation speed of the target material during the knurling process of step (1) the first segmented knurling and step (2) the second segmented knurling is independently 20-25 rpm.

9. The knurling method according to claim 6, characterized in that: The pressure drop of the knurling wheel during the knurling process of step (1) the first segmented knurling and step (2) the second segmented knurling is independently 0.3-0.4 mm.

10. The knurling method according to claim 6, characterized in that: The polishing process in step (3) is performed using flocked sandpaper.

11. The knurling method according to claim 10, characterized in that: The specification of the flocking sandpaper is 500-700#.

12. The knurling method according to claim 6, characterized in that: The rotation speed of the target during the polishing process is 300-350 rpm.

13. The knurling method according to claim 6, characterized in that: The knurling method comprises the following steps: (1) The end surface of the target material is knurled in three stages; during the knurling process, the rotation speed of the target material is 20-25 rpm, and the pressure drop of the knurling wheel is 0.3-0.4 mm; (2) The R angle at the connection between the end face and the side face of the target is knurled in three stages; the rotation speed of the target during the knurling process is 20-25 rpm, and the pressure drop of the knurling wheel is 0.3-0.4 mm; (3) The knurled area of ​​the target material is polished using flocked sandpaper of specification 500-700#; the rotation speed of the target material during the polishing process is 300-350rpm; There is no particular order in which steps (1) and (2) are performed.

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