Sputtering target diffusion bonded assembly and method

Abstract

This invention discloses a diffusion welding assembly and method for sputtering targets. The diffusion welding assembly includes a target component and a cover plate. The target component includes a target and a back plate. At least one of the upper and lower surfaces of the back plate has a recessed groove. The target is embedded in the groove and flush with the back plate. The cover plate covers the grooved surface of the back plate, and the contact surface or outer periphery of the back plate and the cover plate is sealed, thereby sealing the target component and the cover plate as a whole. The target is sealed within a sealed cavity formed by the back plate and the cover plate. The diffusion welding method for sputtering targets includes: laying the cover plate on the grooved surface of the back plate, sealing the contact surface or outer periphery of the cover plate and the back plate; stacking at least two diffusion welding assemblies in a hot isostatic pressing furnace for hot isostatic diffusion welding. The sputtering target diffusion welding assembly and method of this invention omit the processes of encapsulation and vacuuming, resulting in a simple structure and low manufacturing cost.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing technology, and more specifically to a sputtering target diffusion bonding assembly and method. Background Technology

[0002] Currently, existing magnetron sputtering target assemblies are manufactured by placing the target assembly inside a casing with a pre-drained degassing port. A degassing tube is then led out from the casing and connected to a vacuum system for degassing the casing. While this degassing process prevents airborne impurities from negatively impacting the quality of the resulting target assembly during subsequent hot isostatic pressing (HIP), the entire process is complex, involves numerous steps, and is costly. Summary of the Invention

[0003] The purpose of this invention is to provide a sputtering target diffusion welding assembly and method to solve the problems of complex processes, numerous steps, and high manufacturing costs associated with the use of encapsulation + vacuum technology in the prior art.

[0004] To achieve the above objectives, the present invention provides the following technical solution:

[0005] On one hand, the present invention provides a sputtering target diffusion welding assembly, the diffusion welding assembly including a target assembly and a cover plate, the target assembly including a target and a back plate, at least one of the upper and lower surfaces of the back plate having a recessed groove, the target being flush with the back plate after being embedded in the groove;

[0006] The grooved side of the back plate is covered with a cover plate, and the contact surface or outer periphery of the back plate and the cover plate are sealed, thereby sealing the target assembly and the cover plate into a closed whole, and the target is sealed in the closed receiving cavity formed by the back plate and the cover plate.

[0007] Furthermore, the cover plate is a target assembly, and the targets of the two target assemblies abut against each other.

[0008] Furthermore, the gap between the contact surfaces of the back plate and the cover plate is filled with adhesive, thereby sealing the target assembly with the cover plate.

[0009] Furthermore, the adhesive is a silver-tin alloy or indium.

[0010] Furthermore, the outer periphery of the contact surface between the back plate and the cover plate is welded and sealed.

[0011] Furthermore, the welding is friction stir welding or electron beam welding.

[0012] Furthermore, a partition is embedded between the cover plate and the target material.

[0013] Furthermore, the target material is made of titanium or tungsten; the backing plate is made of aluminum, copper, aluminum alloy, or copper alloy; the separator is made of stainless steel, graphite, or mica; the separator thickness is 0.1-4 mm; and the separator surface roughness is 0.3-1.0 μm.

[0014] On the other hand, the present invention also provides a diffusion welding method for sputtering targets, the method employing the above-mentioned diffusion welding assembly for sputtering targets, the method comprising the following steps:

[0015] Step 1: Lay a cover plate on the grooved surface of the back plate to seal the contact surface or outer perimeter of the cover plate with the back plate;

[0016] Step 2: Stack at least two diffusion welded assemblies in a hot isostatic pressing furnace and perform hot isostatic diffusion welding.

[0017] Compared with the prior art, the beneficial effects of the present invention are:

[0018] 1. The sputtering target diffusion welding assembly of the present invention seals the target within a closed cavity formed by the cover plate and the back plate by sealing the contact surface or outer periphery between the cover plate and the target assembly. Compared with the prior art's method of using a sleeve + vacuuming, the sputtering target diffusion welding assembly of the present invention, on the one hand, omits the sleeve and reduces the vacuuming process; on the other hand, it saves on processing and manufacturing costs.

[0019] 2. The sputtering target diffusion welding assembly of the present invention, by opening grooves at the top and bottom of the back plate and embedding the target material, stacking multiple target material components one on top of the other, and welding the outer periphery of two adjacent target material components to form a whole, and then placing it in a hot isostatic pressing furnace, on the one hand, multiple target material components are simultaneously subjected to hot isostatic pressing diffusion welding, which improves the efficiency of hot isostatic pressing diffusion welding, and the products in the same batch have the same quality and performance, with good uniformity; on the other hand, welding multiple target material components into a whole improves the utilization efficiency of the hot isostatic pressing furnace.

[0020] 3. The sputtering target diffusion welding method of the present invention involves stacking multiple target components welded together into a hot isostatic pressing furnace for hot isostatic diffusion welding. After cooling, the welded positions are then separated, which improves production efficiency, ensures good product quality uniformity, and is simple and convenient to operate, which is conducive to mass production. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the target assembly.

[0022] Figure 2 This is a top view of the back panel;

[0023] Figure 3A schematic diagram of the sputtering target diffusion welding assembly in Example 1;

[0024] Figure 4 A schematic diagram of the sputtering target diffusion welding assembly in Example 2;

[0025] Figure 5 A schematic diagram of the sputtering target diffusion welding assembly in Example 3.

[0026] In the figure, 1-target assembly; 11-target; 12-backplate; 13-groove; 2-cover plate; 3-partition. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," "front," and "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. In this invention, it should also be noted that the terms "installation" and "connection" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, mechanical connections, indirect connections through intermediate media, or electrical connections. The specific meaning of the terms in this invention can be understood according to the specific circumstances.

[0029] Example 1

[0030] This embodiment discloses a sputtering target diffusion welding assembly, such as Figure 3 As shown, the diffusion welding assembly includes a target assembly 1, such as Figure 1-2 As shown, the target assembly includes a target 11 and a back plate 12. Preferably, both the target 11 and the back plate 12 are cylindrical structures. A recessed groove 13 is formed on the top of the back plate 12, and the target 11 is embedded in the groove 13. Preferably, the groove 13 is cylindrical, and the top of the target 11 is flush with the top of the back plate 12.

[0031] The diffusion welding assembly includes a target assembly 1 and a cover plate 2 welded to the top of the target assembly 1. Specifically, friction stir welding is used to weld a ring around the outer periphery of the contact surface between the target assembly 1 and the cover plate 2, thereby sealing the target 11 in a sealed cavity formed by the cover plate 2 and the back plate 12.

[0032] The material of cover plate 2 and back plate 12 can be the same or different.

[0033] To avoid diffusion welding between the target 11 and the cover plate 2 and to facilitate the subsequent separation of the target 11 and the cover plate 2, preferably, a partition plate 3 is embedded between the cover plate 2 and the target 11.

[0034] The target material 11 is made of titanium or tungsten, preferably titanium.

[0035] The back plate 12 is made of aluminum, copper, aluminum alloy, or copper alloy. Preferably, the back plate 12 is made of aluminum alloy 6061.

[0036] The partition 3 is made of one of stainless steel, graphite, and mica, preferably stainless steel.

[0037] The thickness of the partition 3 is 0.1-4 mm. If the thickness of the partition 3 is less than 0.1 mm, the expansion of the cover plate 2 and the target material 11 during the subsequent hot isostatic diffusion welding process will compress it, which may easily cause the partition 3 to break. If the thickness of the partition 3 is greater than 4 mm, the gap between the cover plate 2 and the back plate 12 will be too large, making it difficult to achieve a seal between the cover plate 2 and the back plate 12 through welding. Preferably, the thickness of the partition 3 is 2 mm.

[0038] The lower the surface roughness of the partition 3, that is, the smoother the surface of the partition 3, the more difficult it is for atomic diffusion to occur between the partition 3, the cover plate 2, and the target material 11 during the subsequent diffusion welding process. Therefore, the surface roughness of the partition 3 is designed to be 0.3-1.0 μm, preferably 1 μm.

[0039] The sputtering target diffusion welding assembly of the present invention seals the target within a closed cavity formed by welding a ring around the outer periphery of the contact surface between the cover plate and the target assembly. Compared with the prior art's method of using a sleeve and vacuuming, the sputtering target diffusion welding assembly of the present invention, on the one hand, omits the sleeve and reduces the vacuuming process; on the other hand, it saves on processing and manufacturing costs.

[0040] Example 2

[0041] Unlike Example 1, this example discloses a sputtering target diffusion welding assembly, such as... Figure 4As shown, the diffusion welding assembly includes a target assembly 1, such as Figure 1-2 As shown, the target assembly includes a target 11 and a back plate 12. Preferably, both the target 11 and the back plate 12 are cylindrical structures. A recessed groove 13 is formed on the top of the back plate 12, and the target 11 is embedded in the groove 13. Preferably, the groove 13 is cylindrical, and the top of the target 11 is flush with the top of the back plate 12.

[0042] The diffusion welding assembly consists of two target material components 1 placed one above the other, so that the two targets of the two target material components 1 abut against each other, and an electron beam welding is used to weld a circle around the outer periphery of the contact surface of the two target material components 1, that is, to weld a circle around the outer periphery of the contact surface of the two back plates 12, thereby connecting the two target material components 1 into a whole, so that the two targets 11 are sealed in the sealed cavity formed by the two back plates 12.

[0043] To avoid diffusion welding between the two targets 11, preferably, a partition 3 is embedded between the cover plate 2 and the target 11.

[0044] Example 3

[0045] Unlike Example 1, this example discloses a sputtering target diffusion welding assembly, such as... Figure 5 As shown, the diffusion welding assembly includes a target assembly 1, which includes a target 11 and a back plate 12. Preferably, both the target 11 and the back plate 12 are cylindrical structures. The back plate 12 has recessed grooves 13 at its top and bottom. The two targets 11 are respectively embedded in the two grooves 13. Preferably, the grooves 13 are cylindrical, and the top of the target 11 is flush with the top of the back plate 12.

[0046] The diffusion welding assembly consists of two target material components 1 placed one above the other, such that the two targets of the two target material components 1 abut against each other. By filling the gap between the contact surfaces of the back plate and the cover plate with adhesive, the target material components are sealed to the cover plate. The adhesive is a silver-tin alloy or indium, that is, the contact surfaces of the two back plates 12 are bonded together, thereby connecting the two target material components 1 into a whole, so that the two targets 11 are sealed in the sealed cavity formed by the two back plates 12.

[0047] To avoid diffusion welding between the two targets 11, preferably, a partition 3 is embedded between the cover plate 2 and the target 11.

[0048] In this embodiment, by opening grooves 13 at the top and bottom of the back plate and embedding target materials 11, stacking multiple target material components 1 one after another, and welding the outer periphery of two adjacent target material components 1, a whole can be formed. Then, it is placed in a hot isostatic pressing furnace. On the one hand, multiple target material components 1 are simultaneously subjected to hot isostatic diffusion welding, which improves the efficiency of hot isostatic diffusion welding, and the quality and performance of products in the same batch are the same, with good uniformity. On the other hand, welding multiple target material components 1 into a whole improves the utilization efficiency of the hot isostatic pressing furnace.

[0049] Example 4

[0050] This embodiment provides a sputtering target diffusion welding method, which uses the sputtering target diffusion welding assembly described in Embodiment 1, and includes the following steps:

[0051] Step 1: Cover the upper surface of the target assembly 1 with the cover plate 2, and weld a ring around the outer periphery of the contact surface between the cover plate 2 and the target assembly 1.

[0052] Step 2: Stack at least two diffusion welded assemblies in a hot isostatic pressing furnace and perform hot isostatic diffusion welding.

[0053] The sputtering target diffusion welding method of the present invention involves stacking multiple target components welded together into a single unit and placing them into a hot isostatic pressing furnace for hot isostatic diffusion welding. After cooling, the welded parts are then separated, which improves production efficiency, ensures good product quality uniformity, and is simple and convenient to operate, which is conducive to mass production.

[0054] Example 5

[0055] This embodiment provides a sputtering target diffusion welding method, which uses the sputtering target diffusion welding assembly described in Embodiment 2, and includes the following steps:

[0056] Step 1: Place the two target components 1 one above the other, insert the partition 3 between the two targets 11, and make the two targets 11 abut against each other. Weld a ring around the outer perimeter of the contact surface of the two target components 1.

[0057] Step 2: Stack at least two diffusion welded assemblies in a hot isostatic pressing furnace and perform hot isostatic diffusion welding.

[0058] Example 6

[0059] This embodiment provides a sputtering target diffusion welding method, which uses the sputtering target diffusion welding assembly described in Embodiment 3. The method includes the following steps:

[0060] Step 1: Place multiple target material assemblies 1 one on top of the other, insert a partition 3 between two adjacent target materials 11, and make the two target materials 11 abut against each other. Adhesive is used to bond the contact surfaces of two adjacent target material assemblies 1.

[0061] Step 2: Stack at least two diffusion welded assemblies in a hot isostatic pressing furnace and perform hot isostatic diffusion welding.

[0062] Comparative Example 1

[0063] In this embodiment, a sleeve + vacuum method is used for sputtering target diffusion welding. Specifically, the target assembly is placed in a sealed sleeve, the sleeve is evacuated and degassed, and then it is placed in a hot isostatic pressing furnace for diffusion welding. After diffusion welding is completed, it is cooled and then the sleeve is removed.

[0064] Effect Example

[0065] The sputtering target diffusion-welded assemblies of Examples 1-3, after undergoing hot isostatic diffusion welding, can be separated at the weld joint to obtain the diffusion-welded target assembly. The diffusion-welded target assembly has a smooth surface, uniform atomic diffusion, and good product performance.

[0066] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0067] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A sputtering target diffusion welding assembly, characterized in that, The diffusion welding assembly includes a target assembly (1) and a cover plate (2). The target assembly (1) includes a target (11) and a back plate (12). At least one of the upper and lower surfaces of the back plate (12) has a recessed groove (13). The target (11) is embedded in the groove (13) and is flush with the back plate (12). The surface of the back plate (12) with the groove (13) is covered by the cover plate (2). The contact surface or outer periphery of the back plate (12) and the cover plate (2) are sealed, thereby sealing the target assembly (1) and the cover plate (2) into a sealed whole. The target (11) is sealed in the sealed cavity formed by the back plate (12) and the cover plate (2). The diffusion welding assembly can also be a structure of two target components (1) stacked on top of each other. Each target component (1) includes a target (11) and a back plate (12). The back plate (12) has recessed grooves (13) at the top and bottom. The two targets (11) are respectively embedded in the two grooves (13). The top of the target is flush with the top of the back plate (12). The targets of the two target components stacked on top of each other abut against each other. The sealing of the back plate (12) and the cover plate (2) can be achieved by filling the gap between the contact surfaces with silver-tin alloy or indium adhesive to seal the target assembly (1) and the cover plate (2), or by welding the outer periphery of the contact surfaces through friction stir welding or electron beam welding; and a partition plate (3) is embedded between the cover plate (2) and the target (11). The partition plate (3) is made of stainless steel, graphite, or mica, with a thickness of 0.1-4 mm and a surface roughness of 0.3-1.0 µm. The target (11) is made of titanium or tungsten. The back plate (12) is made of aluminum, copper, aluminum alloy, or copper alloy.

2. A method for diffusion welding of sputtering targets, characterized in that, This method uses the sputtering target diffusion welding assembly as described in claim 1, and includes the following steps: Step 1: Lay a cover plate (2) on the surface of the groove (13) on the back plate (12) and seal the contact surface or outer periphery of the cover plate (2) with the back plate (12); Step 2: Stack at least two diffusion welded assemblies in a hot isostatic pressing furnace and perform hot isostatic diffusion welding.

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