CN113897572A

CN113897572A - Target assembly and manufacturing method thereof

Info

Publication number: CN113897572A
Application number: CN202111183200.1A
Authority: CN
Inventors: 姚力军; 边逸军; 潘杰; 王学泽; 王少平
Original assignee: Ningbo Jiangfeng Electronic Material Co Ltd
Current assignee: Ningbo Jiangfeng Electronic Material Co Ltd
Priority date: 2021-10-11
Filing date: 2021-10-11
Publication date: 2022-01-07

Abstract

The present disclosure relates to the field of semiconductor manufacturing, and more particularly, to a target assembly and a method for manufacturing the target assembly. According to the invention, the arc-shaped chamfer of the edge of the target is subjected to sand blasting treatment, so that the arc-shaped chamfer of the edge of the target is uneven, a rough surface is provided for the subsequent adhesion of a reverse sputtering layer, and the adsorption force between the arc-shaped chamfer and the reverse sputtering layer is enhanced. Because the arc-shaped chamfer has a larger stress concentration coefficient than the plane, when the radius of the arc-shaped chamfer is smaller, the stress concentration coefficient is larger, so that the adsorption force between the arc-shaped chamfer and the reverse sputtering layer is enhanced by performing sand blasting on the arc-shaped chamfer, and the problem of larger stress concentration coefficient caused by smaller part of the arc-shaped chamfer is solved, thereby effectively avoiding stripping of the reverse sputtering layer, reducing the thickness of the edge of a non-sputtering area of the target, reducing the cost of the target and reducing the use cost of the target.

Description

Target assembly and manufacturing method thereof

Technical Field

The present disclosure relates to the field of semiconductor manufacturing, and more particularly, to a target assembly and a method for manufacturing the target assembly.

Background

In the field of semiconductor device manufacturing, the film prepared by using a Physical Vapor Deposition (PVD) method has the advantages of simple technical process, no environmental pollution, uniform and compact film formation, less required consumables, strong bonding force with a substrate and the like, so the PVD method is widely applied. The method for realizing physical vapor deposition mainly comprises the following steps: magnetron sputtering, ion plating, vacuum thermal evaporation and the like, wherein the magnetron sputtering and the ion plating both require a target material as a sputtering source.

Fig. 1 is a schematic cross-sectional view of a target assembly used in the prior art, which comprises a target 10 and a target backing plate 20, as shown in fig. 1. In the film forming process, high-speed nuclear energy particles bombard the surface of the target 10, the bombarded metal particles on the surface of the target 10 are separated from the target 10 to form free particles, and the free particles migrate to a substrate opposite to the target to be condensed and formed into a film. However, a small portion of the sputtered free particles are deposited at the connection part of the target 10 and the target backing plate 20 and the vicinity 11 under the action of the magnetic field, the free particles deposited at the connection part of the target 10 and the target backing plate 20 and the vicinity 11 are called as the anti-sputtering substances, and after the target is sputtered for multiple times, the anti-sputtering substances deposited at the connection part and the vicinity 11 are increased to form the anti-sputtering layer 30. However, due to the existence of stress between the reverse sputtering materials, between the reverse sputtering materials and the blank 10 to be sputtered, and between the reverse sputtering materials and the target backing plate 20, when the reverse sputtering materials are accumulated to a certain degree, the reverse sputtering materials will peel off from the target due to stress concentration, forming abnormal discharge, affecting the sputtering environment and attaching abnormal particles on the surface of the wafer, and affecting the subsequent film deposition, electrical test and chip yield.

The reverse sputtering material is easy to peel off from the target material after being accumulated for a certain time, so that abnormal particles of the wafer are higher more easily at the middle and later stages of the target material use, and when the abnormal particles exceed a certain threshold value, the service life of the target material is ended. But only a thin layer of the target material is consumed at this time, and most of the target material can be discarded, which is very wasteful. Therefore, if the falling-off amount of the reverse sputtering material in the later period of the use of the target material is reduced, the service life of the target material can be greatly prolonged, which is very important for reducing the use cost of the target material.

Disclosure of Invention

Accordingly, there is a need to provide a target assembly and a method for manufacturing the same, which can greatly reduce the falling off of the anti-sputtering material in the middle and later stages of the target material.

The embodiment of the invention provides a target assembly manufacturing method, which comprises the following steps:

providing a target assembly, wherein the target assembly comprises a target and a target back plate, the target is combined with the target back plate, and the edge of the target is provided with an arc-shaped chamfer and an inward concave inclined surface positioned on the lower side of the arc-shaped chamfer;

performing sand blasting treatment on the edge of the target sputtering surface and the position, close to the joint, of the target back plate, forming a sand blasting area on the edge of the target, wherein the sand blasting area is positioned from the top end of the arc-shaped chamfer to the joint of the target and the target back plate, and the sand blasting area is also formed at the position, close to the joint, of the target back plate;

and carrying out fusion jetting treatment on the sand blasting area of the inwards recessed inclined plane at the edge of the target material and the position of the target material back plate close to the joint to form a fusion jetting layer.

Optionally, the radius of the arc-shaped chamfer is 2 mm-4 mm.

Optionally, the target is a titanium target or a tantalum target.

Optionally, the upper edge of the spray layer is close to the arc-shaped chamfer, so that the whole inward concave inclined surface of the target material edge covers the spray layer.

Optionally, the surface roughness formed by the sand blasting area is 5 μm to 10 μm, and the specific sand blasting process includes: the sprayed sand is No. 46 white corundum, the air pressure range of the sand blasting machine is controlled to be 0.441 MPa-0.539 MPa, the distance range from the gun nozzle of the sand blasting gun to the surface of the target material is 150 mm-200 mm, and the linear motion direction of the sand sprayed by the nozzle of the sand blasting gun forms an included angle of 40-70 degrees with the surface of the target material.

Optionally, the specific process for blasting the arc area at the edge of the sputtering surface comprises the following steps: the sand blasting gun and the surface of the target material form an included angle of 50-70 degrees, and the nozzle does small-amplitude uniform-speed swing during sand blasting, so that the surface of the arc area is guaranteed to be uniformly blasted.

Optionally, the spray layer is a uniform aluminum film layer of 10 μm to 22 μm, and the specific process of the spray treatment includes: the melting shot powder of the melting shot treatment is aluminum powder, the supply amount is set to be 40-150 g/min, the temperature of the melting shot treatment is controlled to be 1200-1350 ℃, and the melting shot distance of the melting shot treatment is 60-300 mm.

An embodiment of the present invention further provides a target assembly, including:

the target material is combined with the target material back plate, and the edge of the target material is provided with an arc-shaped chamfer and an inward concave inclined plane positioned on the lower side of the arc-shaped chamfer; the circular arc chamfer angle of the edge of the target material forms a sand blasting area; and a meltallizing layer is formed at the position of the inwards recessed inclined plane of the target material edge and the position of the target material back plate close to the joint.

Optionally, the radius of the arc-shaped chamfer is 2 mm-4 mm.

Optionally, the surface roughness formed by the sand blasting area is 5 μm to 10 μm.

Has the advantages that: according to the invention, the arc-shaped chamfer of the edge of the target is subjected to sand blasting treatment, so that the arc-shaped chamfer of the edge of the target is uneven, a rough surface is provided for the subsequent adhesion of a reverse sputtering layer, and the adsorption force between the arc-shaped chamfer and the reverse sputtering layer is enhanced. Because the arc-shaped chamfer has a larger stress concentration coefficient than the plane, when the radius of the arc-shaped chamfer is smaller, the stress concentration coefficient is larger, so that the adsorption force between the arc-shaped chamfer and the reverse sputtering layer is enhanced by performing sand blasting on the arc-shaped chamfer, and the problem of larger stress concentration coefficient caused by smaller part of the arc-shaped chamfer is solved, thereby effectively avoiding stripping of the reverse sputtering layer, reducing the thickness of the edge of a non-sputtering area of the target, reducing the cost of the target and reducing the use cost of the target. When the radius of the arc-shaped chamfer is larger, the reverse sputtering layer positioned on the arc-shaped chamfer is more difficult to peel off through sand blasting treatment, and the use cost of the target is effectively reduced.

Furthermore, in the invention, the height of the spray layer is close to that of the arc chamfer, and the whole side wall of the target is covered with the spray layer, so that the reverse sputtering substances possibly generated in the sputtering process of the target can be fully adsorbed, and the probability of abnormal particles is reduced.

Drawings

FIG. 1 is a schematic cross-sectional view of a target assembly used in the prior art;

FIG. 2 is a schematic cross-sectional view of a target assembly prior to grit blasting in accordance with an embodiment of the present invention;

fig. 3 is an enlarged cross-sectional view of an edge of a target assembly after bead blasting in accordance with an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

An embodiment of the present invention first provides a method for manufacturing a target assembly, please refer to fig. 1, which includes:

step S10, providing a target assembly, wherein the target assembly comprises a target and a target back plate, the target bonding surface is combined with the target back plate, and the edge of the target sputtering surface is provided with an arc-shaped chamfer and an inward concave inclined surface positioned on the lower side of the arc-shaped chamfer;

step S20, performing sand blasting treatment on the target edge and the position, close to the joint, of the target back plate, forming a sand blasting area on the target edge, wherein the sand blasting area is positioned from the top end of the circular arc chamfer to the joint of the target and the target back plate, and the sand blasting area is also formed at the position, close to the joint, of the target back plate;

and step S30, carrying out fusion jetting treatment on the sand blasting area of the inwards concave inclined plane of the target edge and the position of the target back plate close to the joint to form a fusion jetting layer.

Specifically, referring to fig. 2, the target assembly includes a target 110 and a target backing plate 120, and the bonding surface of the target 110 is bonded to the target backing plate 120. The target 110 includes a sputtering region 111 at the center and a non-sputtering region 112 outside the sputtering region 111, and the non-sputtering region 112 is located at the edge of the target 110 and is an edge region of the sputtering surface of the target 110. Although referred to herein as a non-sputtering region 112, because the distribution of the electric field affects less sputtering.

In a specific embodiment, the target may be a titanium target or a tantalum target. In the present embodiment, the target 110 is a 200mm titanium target for semiconductor vacuum sputtering. Without limitation, in other embodiments, the target may be other sizes, types of targets.

The edge of the sputtering surface of the target, namely the outermost edge of the non-sputtering region 112, is provided with an arc-shaped chamfer 112 and an inward concave inclined surface 114 positioned on the lower side of the arc-shaped chamfer 113, the lower side is a position between the arc-shaped chamfer 112 and the joint of the target and the target back plate, and the inward concave inclined surface 114 on the edge of the target is concave inwards, so that a subsequent spray layer can be conveniently formed and cannot be sputtered.

When the reverse sputtering layer is formed on the edge of the sputtering surface of the target in the subsequent sputtering process, the edge of the sputtering surface of the target is provided with the arc-shaped chamfer 112, so that the problems of stress mismatching and stress concentration of the reverse sputtering layer caused by the difference of the thermal expansion coefficients can be effectively relieved, and the problems of stripping of the reverse sputtering layer and plasma tip discharge are effectively avoided. However, since the size of the circular arc chamfer 112 is large in the prior art, and is often 6mm or more, the thickness of the edge of the sputtering surface of the target is affected by the size of the circular arc chamfer 112, and the edge of the non-sputtering region 112 cannot be made thin. The non-sputtering area is less likely to be sputtered, and in consideration of cost, the thickness of the non-sputtering area is generally smaller than that of the sputtering area 111, and the thickness of the non-sputtering area is lower closer to the edge.

Therefore, referring to fig. 3, the present invention performs sand blasting on the target edge and the target backing plate near the joint, so as to form a sand blasting region 115 at the target edge, where the sand blasting region is located from the top end of the circular arc chamfer to the joint between the target and the target backing plate, and the sand blasting region is also formed at the target backing plate near the joint.

The sand blasting is to form a high-speed spray beam by using compressed air as power to spray blasting materials (copper ore sand, quartz sand, carborundum, iron sand and Hainan sand) to the surface of a workpiece to be treated at a high speed, so that the appearance or the shape of the outer surface of the workpiece is changed, and the surface of the workpiece obtains certain cleanliness and different roughness due to the impact and the cutting action of the blasting materials on the surface of the workpiece. The surface of the edge of the target material is subjected to sand blasting treatment, so that the mechanical property of the surface of the edge of the target material can be improved, the fatigue resistance of the surface of the edge of the target material can be improved, and the target material is applied to vacuum sputtering, so that the damage of sputtered target material atoms to the surface of the edge of the target material can be avoided. Meanwhile, the surface of the edge of the target material is subjected to sand blasting treatment, the surface of the edge of the target material is uneven, an attached rough surface is provided for the spray powder, and the adsorption force between the surface of the edge of the target material and the spray film layer is enhanced.

Most importantly, the arc-shaped chamfer at the edge of the target is subjected to sand blasting treatment, so that the arc-shaped chamfer at the edge of the target is uneven, a rough surface is provided for the adhesion of a subsequent anti-sputtering layer, and the adsorption force between the arc-shaped chamfer and the anti-sputtering layer is enhanced. Because the arc-shaped chamfer has a larger stress concentration coefficient than the plane, when the radius of the arc-shaped chamfer is smaller, the stress concentration coefficient is larger, so that the adsorption force between the arc-shaped chamfer and the reverse sputtering layer is enhanced by performing sand blasting on the arc-shaped chamfer, and the problem of larger stress concentration coefficient caused by smaller part of the arc-shaped chamfer is solved, thereby effectively avoiding stripping of the reverse sputtering layer, reducing the thickness of the edge of a non-sputtering area of the target, reducing the cost of the target and reducing the use cost of the target.

In this embodiment, the radius of the circular arc chamfer is 2mm to 4 mm. In other embodiments, the radius of the circular arc chamfer may be larger than 4mm, for example, 5mm, 6mm, etc., and the reverse sputtering layer on the circular arc chamfer is less likely to be peeled off by the sand blasting, thereby effectively reducing the use cost of the target.

In particular embodiments, the main factors affecting the quality of blasting are: sand material, sand size, sand weight, air pressure, spray angle, spray distance. Variations in either parameter can affect the effectiveness of the blasting to varying degrees. The following describes in detail a method for performing sand blasting in this embodiment, which is used to treat the edge surface of the target, so that the roughness of the edge surface of the target is uniform and the color difference is small.

In this embodiment, the blasting sand in the blasting process is 46 # white corundum, that is, 46 grains of white corundum are contained in each square foot. Pouring about 1 kg of No. 46 white corundum into a sand blasting machine, controlling the air pressure range of the sand blasting machine to be 0.441 MPa-0.539 MPa, and if the air pressure is more than 0.539MPa, ensuring that the power of sand blasting is too sufficient, so that the average depth of pits formed by surface impact or cutting of a non-sputtering area is increased, and the binding force between a subsequent sprayed film layer and a rough surface is influenced. If the air pressure is less than 0.441MPa, the power of sand blasting is insufficient, so that the average depth of the anti-sticking pits of the anti-sticking plate is too small, and the bonding force between the subsequent melt-blasted film layer and the rough surface is also influenced.

In a specific embodiment, the distance from the nozzle of the sand blasting gun to the surface of the non-sputtering area in the sand blasting process is adjustable and can be adjusted according to different roughness to be formed. In the embodiment, the distance from the nozzle of the sand blasting gun to the surface of the non-sputtering area at the edge of the target material ranges from 150mm to 200 mm. And the included angle between the linear motion direction of the sand sprayed by the sand spraying gun nozzle and the edge surface of the target material is 40-60 degrees, so that the sand moves at a constant speed on the premise that the sand spraying gun nozzle is fixed, the surface roughness and uniformity of the edge surface of the target material after sand spraying are consistent, and the uniformity of sand spraying and the preset coverage range can be ensured. After the sand blasting treatment, a uniform rough layer with the roughness of 5.08-7.62 mu m is formed on the surface of the edge of the target material, and the formation of the uniform rough layer is favorable for the subsequent formation of a meltallizing layer.

When the arc-shaped chamfer of the non-sputtering area is subjected to sand blasting, the sand blasting gun and the surface of the target material form a 50-70 degree angle, and the nozzle does small-amplitude uniform swing during sand blasting, so that the uniform sand blasting of the surface of the arc area is ensured. Because the subsequent meltallizing layer that does not form of convex chamfer of non-sputtering district, consequently adopt the more wide-angle nozzle to do the uniform velocity swing of small-amplitude, can fully guarantee the even sandblast of convex chamfer surface, be more favorable to the later stage to the absorption on anti-sputtering layer.

In this embodiment, the target edge and the target backing plate are subjected to sand blasting at the position close to the joint; in other embodiments, only the edge of the target may be sandblasted, that is, the part from the top end of the circular arc chamfer to the connection between the target and the target backing plate may be sandblasted.

After the surface of the non-sputtering region is subjected to sand blasting, the sand-blasted rough surface may be cleaned. In this embodiment, the rough surface is cleaned with purified water or deionized water, and the sandblasted sand grains are cleaned, wherein the cleaning time is about 5min to 10 min. In other embodiments, if the rough surface after the sand blasting process has no sand blasting sand remaining, or the remaining sand blasting sand does not affect the subsequent meltallizing process, the cleaning process may not be performed.

The basic principle of the thermal spraying is that the material (powder or wire) is heated and melted, and the material is impacted and attached to the surface of a substrate (or workpiece) at high speed under the conveying of a gas belt, and is accumulated and solidified to form a film thickness or a coating, so that the purposes of corrosion resistance, rust resistance, wear resistance, lubrication, surface roughening, adsorption, insulation, heat insulation and the like are achieved. In the spray treatment process of this embodiment, the spray material is liquid after melting, and because the rough surface after the sandblast treatment is uneven, the rough surface can "catch up" the liquid spray material more, and the liquid spray material solidifies at the rough surface and forms the spray layer. Due to the fact that the rough surface is uneven, the spray layer is also uneven, and the adhesion of the subsequent reverse sputtering layer on the rough spray layer is stronger.

In this example, the shot material in the shot process is a welding material powder made of an aluminum powder or an aluminum-silicon alloy, or may be a mixed powder of an aluminum powder and a silicon powder (the silicon content is maintained at 5 wt% to 50 wt%).

In order to allow the contact of the above-mentioned thermal spraying powder on the surface of the blasting region and to allow the thermal spraying powder to smoothly pass through the fine nozzle of the thermal spraying gun, it is necessary to keep 50% or more of the shape of the thermal spraying powder in a spherical shape. The particle size of the thermal spraying powder is preferably in the range of 20 μm to 100. mu.m, provided that the particle size of the thermal spraying powder is larger than 100. mu.m. Gaps can be formed between adjacent particles, so that the surface of a spray layer after spray treatment is too rough; if the particle size of the thermal spraying powder is less than 20 μm, the thermal spraying powder is easily melted during thermal spraying, which is disadvantageous to adhesion of the thermal spraying layer.

In a specific embodiment, the temperature for performing the spray treatment on the rough surface is controlled to be 1200 ℃ to 1350 ℃, and if the temperature for performing the spray treatment on the surface of the non-sputtering area is less than 1200 ℃, the melting of the spray powder is insufficient, and the adhesion between the spray layer and the surface of the sand blasting area is poor. If the temperature of the blasting process in the blasting zone exceeds 1350 c, the powder will be completely melted inside and a hard oxide layer will be formed on the roughened surface, which will prevent the adhesion of the blasted layer to the surface of the blasting zone.

In a specific embodiment, the spray distance of the spray treatment on the rough surface, namely the distance from the spray gun head to the surface of the sand blasting area, is 60 mm-300 mm, and if the spray distance is less than 60mm, not only is the spray powder excessively melted, so that the surface of the rough surface is oxidized, but also the surface of the sand blasting area is subjected to shape and tissue changes due to heating. In addition, if the spray distance exceeds 300mm, the sprayed powder may be re-solidified in the process of reaching the surface of the non-sputtering region, resulting in a decrease in the amount of adhesion of the sprayed layer.

In a specific embodiment, the supply amount of the shot powder is set to 40 to 150 g/min. If the supply amount of the shot powder is less than 40g/min, the adhesion of the film layer to the rough surface is lowered, and if the supply amount of the shot powder is more than 150g/min, the adhesion layer of the rough surface becomes thick, and the shrinkage during cooling is poor, so that the adhesion is lowered and the cost is increased.

In the course of the thermal spraying treatment of the rough surface, it is preferable to form a non-oxidizing atmosphere of nitrogen gas in the environment of the thermal spraying treatment of the rough surface in order to prevent oxidation of the rough surface and oxidation of the powder particles.

In the current target design, the height of the meltallizing layer is far lower than that of the chamfer of the arc area, and the flat surface between the meltallizing layer and the chamfer of the arc area is not subjected to any protection treatment. During the sputtering process of the target material, the unprotected surface of the side wall still has a certain probability of adsorbing reverse sputtering particles. When the unprotected area accumulates and adsorbs the reverse sputtering particles to the limit in the end period of the target material use, the reverse sputtering materials cannot be continuously adsorbed, and the number of abnormal particles on the surface of the wafer is increased sharply.

In the invention, the position of the upper edge of the spray layer is close to the arc-shaped chamfer, and the whole side wall of the target material covers the spray layer, so that the reverse sputtering substances possibly generated in the sputtering process of the target material can be fully adsorbed, and the probability of abnormal particles is reduced. And because the side wall of the target material is an inward concave slope, the sputtering effect cannot be influenced even if the whole side wall of the target material is covered with the meltallizing layer.

After the thermal spraying, a uniform thermal spraying layer with the roughness of 10-25 mu m is formed on the surface of the non-sputtering area. And the fusion-jetting layer formed on the surface of the target after sand blasting and fusion-jetting treatment has strong adhesion with the surface of the non-sputtering area. The target material of this embodiment is applied to vacuum sputtering for a long time, even target material atom forms and piles up, the rete can not drop yet, the particulate matter that can not appear prior art drops and causes the problem that the parameter of sputtering is not up to standard, keeps the sputtering parameter stable. Moreover, this significantly improves the target lifetime, which can ultimately increase the target lifetime by more than 50%.

An embodiment of the present invention further provides a target assembly, please refer to fig. 2 and fig. 3, including:

the target 110 and the target back plate 120, the target 110 bonding surface is bonded with the target back plate 120, and the edge of the target sputtering surface is provided with an arc-shaped chamfer 113 and an inward concave inclined surface 114 positioned on the lower side of the arc-shaped chamfer 113; the circular arc chamfer of the edge of the target material is provided with a sand blasting area 115; and a spray layer 116 is formed at the position of the inward concave inclined plane of the target edge and the position of the target back plate close to the joint, and the position of the upper edge of the spray layer is close to the arc-shaped chamfer. Wherein the radius of the arc chamfer is 2-4 mm. The surface roughness formed by the sand blasting area is 5-10 μm, and the surface roughness of the meltallizing layer 116 is 10-25 μm.

The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A method for manufacturing a target assembly, comprising:

providing a target assembly, wherein the target assembly comprises a target and a target back plate, the bonding surface of the target is combined with the target back plate, and the edge of the sputtering surface of the target is provided with an arc-shaped chamfer and an inward concave inclined surface positioned on the lower side of the arc-shaped chamfer;

performing sand blasting treatment on the target edge and the position of the target back plate close to the joint, forming a sand blasting area on the target edge, wherein the sand blasting area is positioned from the top end of the arc-shaped chamfer to the joint of the target and the target back plate, and the sand blasting area is also formed on the position of the target back plate close to the joint;

2. The method of claim 1, wherein the radius of the circular arc chamfer is 2mm to 4 mm.

3. The method of claim 1, wherein the target is a titanium target or a tantalum target.

4. The method of claim 1, wherein the upper edge of the meltblown layer is substantially adjacent to the rounded chamfer such that the entire inward concave slope of the target edge covers the meltblown layer.

5. The method according to claim 1, wherein the surface roughness of the sandblasted region is 5 μm to 10 μm, and the specific sandblasting process comprises: the sand blasting machine is white corundum, the air pressure range of the sand blasting machine is controlled to be 0.441 MPa-0.539 MPa, the distance range from a gun nozzle of the sand blasting gun to the surface of the target material is 150 mm-200 mm, and the included angle between the linear motion direction of the sand blasting of the nozzle of the sand blasting gun and the surface of the target material is 40-70 degrees.

6. The method of claim 5, wherein the step of blasting the arc region of the edge of the sputtering surface comprises: the sand blasting gun and the surface of the target material form an included angle of 50-70 degrees, and the nozzle does small-amplitude uniform-speed swing during sand blasting, so that the surface of the arc area is guaranteed to be uniformly blasted.

7. The method for manufacturing the target assembly according to claim 1, wherein the spray layer is a uniform aluminum film layer of 10 μm to 22 μm, and the specific process of the spray treatment comprises: the melting shot powder of the melting shot treatment is aluminum powder, the supply amount is set to be 40-150 g/min, the temperature of the melting shot treatment is controlled to be 1200-1350 ℃, and the melting shot distance of the melting shot treatment is 60-300 mm.

8. A target assembly, comprising:

9. The target assembly of claim 8, wherein the radius of the rounded chamfer is 2mm to 4 mm.

10. The target assembly of claim 8, wherein the upper edge of the meltblown layer is proximate to the rounded chamfer such that the entire inward concave slope of the target edge covers the meltblown layer.