Nickel-platinum alloy target blank and copper back plate welding method and nickel-platinum alloy target material

Abstract

The invention belongs to the technical field of semiconductor devices, and provides a welding method for a nickel-platinum alloy target blank and a copper back plate, which comprises the following steps of: (1) performing rolling treatment on a welding surface of the nickel-platinum alloy target blank subjected to surface treatment; (2) copper film plating treatment is conducted on the welding face of the nickel-platinum alloy target blank; (3) the nickel-platinum alloy target blank and the copper back plate are assembled and then put into a sheath, and the sheath is heated and degassed; (4) performing hot isostatic pressing on the degassed sheath in an environment at the temperature of 250-300 DEG C; and (5) the sheath is removed, and the nickel-platinum alloy target blank is obtained. According to the method, the welding surface of the nickel-platinum alloy target blank is rolled and then plated with the copper film, and the hot isostatic pressing temperature is controlled, so that after welding is completed, the welding binding rate of the nickel-platinum alloy target blank and the copper back plate is high, and the magnetic permeability of the nickel-platinum alloy target blank is not influenced. In addition, the invention further provides the nickel-platinum alloy target blank welded through the welding method.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductor devices, and specifically relates to a welding method for a nickel-platinum alloy target blank and a copper back plate, and a nickel-platinum alloy target material. Background Art

[0002] In the production of large-scale integrated circuits, the target blank assembly is composed of a target blank that meets the sputtering performance and a back plate with a certain strength. The back plate is mainly used for installation, fixation, electrical conduction, heat conduction, and support. The back plate and the target blank are connected by welding, and the magnetic permeability (PTF) of the nickel-platinum target blank will be affected by temperature during the welding process.

[0003] CN201410424946.0 discloses a method for preparing a nickel-platinum alloy target blank with a copper alloy backing plate, comprising the following steps in sequence: mechanically processing the surface of a nickel-platinum alloy target blank with a platinum content of 5 to 20 at%, and then chemically cleaning it; sequentially loading the copper alloy slab and the nickel-platinum alloy target blank into a sheath container, then sealing the sheath container, and welding an air outlet pipe to the sheath container; evacuating the sheath container through the air outlet pipe, and then welding the air outlet pipe; then performing hot isostatic pressing; then removing the sheath container, and machining the nickel-platinum alloy target blank and the copper alloy slab welded together, so as to obtain a nickel-platinum alloy target blank with a copper alloy backing plate.

[0004] In the above technical scheme, the surfaces of the nickel-platinum alloy target blank and the copper alloy plate blank are cleaned after mechanical processing, and then they are placed in a package for vacuum evacuation and hot isostatic pressing. Since the temperature of hot isostatic pressing is 575°C to 800°C, the meshing platinum target blank and the copper backing plate are welded in this high temperature environment, and the magnetic permeability of the nickel-platinum alloy target blank will be significantly reduced. Summary of the invention

[0005] The purpose of the present invention is to solve the above problems, and a method for welding a nickel-platinum alloy target blank and a copper back plate is provided. The method performs a copper film coating treatment on the welding surface of the nickel-platinum alloy target blank after rolling, and controls the hot isostatic pressing temperature, so that after welding, the nickel-platinum alloy target blank and the copper back plate have a high welding bonding rate, and have no effect on the magnetic permeability of the nickel-platinum alloy target blank. In addition, the present invention also provides a nickel-platinum alloy target material welded by the welding method.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] A method for welding a nickel-platinum alloy target blank and a copper back plate comprises the following steps:

[0008] Step (1): rolling the welding surface of the nickel-platinum alloy target blank after the surface treatment;

[0009] Step (2): performing copper plating treatment on the welding surface of the nickel-platinum alloy target blank;

[0010] Step (3): assembling the nickel-platinum alloy target blank and the copper backing plate and placing them in a sheath, heating the sheath and degassing it;

[0011] Step (4): hot isostatic pressing the degassed package at a temperature of 250° C. to 300° C. to complete the welding of the nickel-platinum alloy target blank and the copper backing plate;

[0012] Step (5): remove the sheath to obtain a nickel-platinum alloy target blank.

[0013] The temperature in step (4) can be 250°C, 275°C, or 300°C, but is not limited to the listed values. Other values ​​not listed within this numerical range are applicable.

[0014] In the above-mentioned method for welding a nickel-platinum alloy target blank and a copper backing plate, in step (1), a diamond rolling cutter is used, the cutter head diameter is 0.5 mm to 5 mm, the cutter head speed is 200 r / min to 500 r / min, the thickness pass feed is 0.01 mm to 0.02 mm, the total thickness feed is 0.05 mm to 0.15 mm, and the end face feed is 0.005 to 0.01 mm / r.

[0015] The diameter of the cutter head in step (1) can be 0.5 mm, 3 mm, or 5 mm, but is not limited to the listed values. Other values ​​not listed within this numerical range are applicable.

[0016] The rotation speed of the cutter head in step (1) can be 200 r / min, 350 r / min, 500 r / min, but is not limited to the listed values. Other values ​​not listed within this numerical range are applicable.

[0017] The thickness feed in step (1) can be 0.01 mm, 0.015 mm, or 0.02 mm, but is not limited to the listed values. Other values ​​not listed within this numerical range are applicable.

[0018] The total thickness feed in step (1) can be 0.05 mm, 0.01 mm, or 0.15 mm, but is not limited to the listed values. Other values ​​not listed within this numerical range are applicable.

[0019] The end face feed in step (1) can be 0.005mm / r, 0.0075mm / r, 0.01mm / r, but is not limited to the listed values. Other unlisted values ​​within this numerical range are applicable.

[0020] In the above-mentioned method for welding a nickel-platinum alloy target blank and a copper back plate, in step (2), the thickness of the copper film is 5um to 10um.

[0021] The thickness of the copper film in step (2) can be 5um, 7.5um, or 10um, but is not limited to the listed values. Other values ​​not listed within this numerical range are applicable.

[0022] In the above-mentioned method for welding a nickel-platinum alloy target blank and a copper back plate, in step (2), the welding surface of the nickel-platinum alloy target blank is plated with a copper film by electroplating or chemical plating.

[0023] In the above-mentioned method for welding a nickel-platinum alloy target blank and a copper back plate, the sheath material is A1060 aluminum alloy.

[0024] In the above-mentioned method for welding a nickel-platinum alloy target blank and a copper back plate, in step (4), the hot isostatic pressing time is 4 hours to 5 hours, and the hot isostatic pressing pressure is at least 110 MPa.

[0025] Among them, in step (4), the time of hot isostatic pressing can be 4h, 4.5h, or 5h, but is not limited to the listed values, and other unlisted values ​​within this numerical range are applicable.

[0026] In step (4), the hot isostatic pressing pressure can be 110 MPa, 120 MPa, or 130 MPa, but is not limited to the listed values. Other values ​​not listed within this numerical range are applicable.

[0027] In the above-mentioned method for welding a nickel-platinum alloy target blank and a copper back plate, in step (4), the sheath is degassed in a temperature environment of 200° C. to 250° C., and the degassing vacuum is less than 2.0×E-3Pa.

[0028] The degassing temperature in step (4) can be 200°C, 225°C, or 250°C, but is not limited to the listed values. Other values ​​not listed within this numerical range are applicable.

[0029] In step (4), the vacuum degree can be 0.5×E-3Pa, 1.0×E-3Pa, 1.5E-3Pa, but is not limited to the listed values. Other values ​​not listed within this numerical range are applicable.

[0030] In the above-mentioned method for welding a nickel-platinum alloy target blank and a copper backing plate, the surface treatment in step (1) specifically involves cleaning and degreasing the nickel-platinum alloy target blank and the copper backing plate.

[0031] At the same time, the present invention also provides a nickel-platinum alloy target material, including a nickel-platinum alloy target blank and a copper backing plate, and the nickel-platinum alloy target blank and the copper backing plate are prepared by the above preparation method.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] The present invention performs copper film coating treatment on the welding surface of the nickel-platinum alloy target blank after rolling, and controls the hot isostatic pressing temperature, so that after welding, the welding bonding rate of the nickel-platinum alloy target blank and the copper back plate is high, and the magnetic permeability of the nickel-platinum alloy target blank is slightly affected. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] It should be noted here that the specifications of the copper back plate used can be TU1, C18200, C46400, and TU1 is used in the following embodiments; wherein the platinum atomic content of nickel in the nickel-platinum alloy target blank is 1at% to 30at%.

[0036] Example 1

[0037] A method for welding a nickel-platinum alloy target blank and a copper back plate comprises the following steps:

[0038] Step (1): rolling the nickel-platinum alloy target blank after surface treatment with a cutter head diameter of 0.5 mm, a cutter head speed of 200 r / min, a thickness pass feed of 0.01 mm, a total thickness feed of 0.05 mm, and an end face feed of 0.005 mm / r;

[0039] Step (2): plating a copper film with a thickness of 5 μm on the welding surface of the nickel-platinum alloy target blank;

[0040] Step (3): assembling the nickel-platinum alloy target blank and the copper backing plate and placing them in a package, heating the package to 200° C. and degassing, wherein the vacuum degree of the degassing is 0.5×E-3Pa;

[0041] Step (4): hot isostatic pressing the degassed package at a temperature of 200° C. and a pressure of 110 MPa for 4 h to complete the welding of the nickel-platinum alloy target blank and the copper backing plate;

[0042] Step (5): remove the sheath to obtain a nickel-platinum alloy target.

[0043] Example 2

[0044] It is basically the same as Example 1, except that in step (1), the cutter head diameter is 3 mm, the cutter head rotation speed is 350 r / min, the thickness pass feed is 0.015 mm, the total thickness feed is 0.01 mm, and the end face feed is 0.0075 mm / r.

[0045] Example 3

[0046] It is basically the same as Example 1, except that in step (1), the cutter head diameter is 5 mm, the cutter head rotation speed is 500 r / min, the thickness pass feed is 0.02 mm, the total thickness feed is 0.15 mm, and the end face feed is 0.01 mm / r.

[0047] Example 4

[0048] It is basically the same as Example 1, except that the thickness of the copper film in step (2) is 7.5 um.

[0049] Example 5

[0050] It is basically the same as Example 1, except that the thickness of the copper film in step (2) is 10 um.

[0051] Example 6

[0052] The method is basically the same as Example 1, except that in step (3), the package is heated to 225°C and then degassed, and the vacuum degree of degassing is 1.0×E-3Pa.

[0053] Example 7

[0054] In step (3), the package is heated to 250°C and then degassed. The package is heated to 250°C and then degassed. The vacuum degree of degassing is 1.5×E-3Pa.

[0055] Example 8

[0056] The method is basically the same as Example 1, except that the hot isostatic pressing pressure in step (4) is 120 MPa and the time is 4.5 h.

[0057] Example 9

[0058] The method is basically the same as Example 1, except that the hot isostatic pressing pressure in step (4) is 130 MPa and the time is 5 h.

[0059] Comparative Example 1

[0060] It is basically the same as Example 1, except that the welding surface of the nickel-platinum alloy target blank is plated with a Ti film.

[0061] Comparative Example 2

[0062] It is basically the same as Example 1, except that the welding surface of the nickel-platinum alloy target blank is plated with a Ni film.

[0063] Comparative Example 3

[0064] It is basically the same as Example 1, except that only the welding surface of the nickel-platinum alloy target blank is rolled, and the welding surface of the platinum alloy target blank is not coated.

[0065] Comparative Example 4

[0066] The method is basically the same as Example 1, except that in step (4), the temperature of hot isostatic pressing is 150°C.

[0067] Comparative Example 5

[0068] The method is basically the same as Example 1, except that in step (4), the temperature of hot isostatic pressing is 350°C.

[0069] Test method:

[0070] 1. Before carrying out the preparation method, the PTF test of the nickel-platinum alloy target blank was carried out using ASTM F-1761-00, and the PTF of the nickel-platinum alloy target blank was measured to be 71%.

[0071] 2. The same test method was used to perform PTF test on the nickel-platinum alloy target materials welded by the welding method of the nickel-platinum alloy target blanks and the copper backing plate of Examples 1 to 9 and Comparative Examples 1 to 4, and the bonding strength of the nickel-platinum alloy target blanks and the backing plate was tested by a tensile testing machine. The test results are shown in Table 1.

[0072] Table 1 Welding results of nickel-platinum alloy target blank and copper backing plate

[0073] Welding bonding rate PTF Results Welding strength / MPa Example 1 100％ 71％ 50 Example 2 100％ 71％ 51 Example 3 100％ 71％ 51 Example 4 100％ 71％ 52 Example 5 100％ 71％ 53 Example 6 100％ 71％ 52 Example 7 100％ 71％ 52 Example 8 100％ 71％ 51 Example 9 100％ 71％ 52 Comparative Example 1 0 71％ Disconnected, not welded Comparative Example 2 0 71％ Disconnected, not welded Comparative Example 3 0 71％ Disconnected, not welded Comparative Example 4 0 71％ Disconnected, not welded Comparative Example 5 100％ 50％ 70

[0074] Result analysis:

[0075] 1. Comparing the results of Example 1, Example 2 and Example 3, the welding surface of the nickel-platinum alloy is rolled, mainly to gradually refine the coarse grains on the welding surface of the nickel-platinum alloy through repeated severe plastic deformation, so that a nanostructured layer with a gradient change of grains along the thickness direction is formed in the material, thereby increasing the surface energy storage. When the parameters are gradually increased, there is no effect on the PTF of the nickel-platinum alloy target blank, but it is beneficial to the subsequent low-temperature diffusion of the nickel-platinum alloy target blank and the copper backing plate.

[0076] 2. From the results of Example 1, Example 4 and Example 5, it can be seen that increasing the thickness of the copper film has no effect on the PTF of the nickel-platinum alloy target blank, but has a slight improvement in the welding strength between the nickel-platinum alloy target blank and the copper backing plate. However, during the coating, it usually takes 1 hour to coat a 1um copper film on the welding surface of the nickel-platinum alloy target blank. The thicker the film, the longer the time. The method of increasing the thickness of the copper film to improve the welding strength is very inconsistent with production efficiency.

[0077] 3. By comparing Example 1, Example 6 and Example 7, when the temperature and the vacuum degree are gradually increased within the range, there is no effect on the PTF of the nickel-platinum alloy target blank and the bonding rate between the nickel-platinum alloy target blank and the copper backing plate. Generally speaking, the vacuum state of the sheath is mainly to avoid oxidation during the welding process, thereby affecting the bonding rate between the nickel-platinum alloy target blank and the copper backing plate. Usually, the lower the vacuum state, the better the welding effect, while if it is too high, the effect will deteriorate.

[0078] 4. It can be seen from the results of Example 1, Example 8 and Example 9 that when the temperature of hot isostatic pressing is the same, the PTF of the nickel-platinum alloy target blank has no effect due to the same welding temperature, and the welding strength after welding will have slight fluctuations. However, the greater the pressure of hot isostatic pressing, the greater the damage to the equipment. Increasing equipment damage in exchange for a slight improvement in welding strength is not economically efficient. Generally speaking, increasing the temperature and pressure of hot isostatic pressing at the same time will significantly improve the strength of the welding, but high temperature will reduce PTF. Therefore,

[0079] 5. By comparing the results of Example 1, Comparative Example 1, Comparative Example 3 and Comparative Example 4, Ni film and Ti film were respectively plated on the welding surface of the nickel-platinum welding target blank. After the nickel-platinum alloy target blank and the copper back plate were welded, the magnetic permeability of the nickel-platinum alloy was not affected. However, the nickel-platinum alloy target blank and the copper back plate were separated. This proves that the same material as the copper back plate is selected as the intermediate layer and plated on the welding surface of the nickel-platinum alloy target blank, which can better improve the welding bonding rate. This is because when the intermediate film layer and the copper back plate are made of the same material and hot isostatic pressing is performed, the principle of similar compatibility can be used to improve the bonding rate; when no coating is performed and the temperature is low, the nickel-platinum alloy target blank and the copper back plate will be more easily separated, and the bonding rate will be worse.

[0080] 6. Comparing the results of Example 1, Comparative Example 4 and Comparative Example 5, firstly, in Comparative Example 4, the nickel-platinum alloy target blank and the copper backing plate were welded at a temperature outside the range and at a lower temperature. Although the PTF of the nickel-platinum alloy target did not decrease after welding, the welding temperature was not enough, and the target was separated, resulting in poor welding effect.

[0081] Comparative Example 5 uses a higher temperature for welding, which provides more heat for fusion and flow, and improves the bonding rate of the nickel-platinum alloy target blank and the copper backing plate. However, when the nickel-platinum alloy target is tested after welding, the PTF drops to only 50%, and the high temperature affects the PTF.

[0082] The above are only preferred embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements or modifications can be made without departing from the principles of the present invention. These improvements or modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for welding a nickel-platinum alloy target blank and a copper backing plate, characterized in that: The steps include: Step (1): rolling the welding surface of the nickel-platinum alloy target blank after the surface treatment; Step (2): performing copper plating treatment on the welding surface of the nickel-platinum alloy target blank; Step (3): assembling the nickel-platinum alloy target blank and the copper backing plate and placing them in a sheath, heating the sheath and degassing it; Step (4): hot isostatic pressing the degassed package at a temperature of 250° C. to 300° C. to complete the welding of the nickel-platinum alloy target blank and the copper backing plate; Step (5): remove the sheath to obtain a nickel-platinum alloy target.

2. The method for preparing a nickel-platinum alloy target blank according to claim 1, characterized in that: In step (1), a diamond rolling cutter is used, with a cutter head diameter of 0.5 mm to 5 mm, a cutter head rotation speed of 200 r / min to 500 r / min, a thickness pass feed of 0.01 mm to 0.02 mm, a total thickness feed of 0.05 mm to 0.15 mm, and an end face feed of 0.005 mm / r to 0.01 mm / r.

3. The method for preparing a nickel-platinum alloy target blank according to claim 1, characterized in that: In step (2), the thickness of the copper film is 5um to 10um.

4. The method for preparing a nickel-platinum alloy target blank according to claim 1, characterized in that: In step (2), the welding surface of the nickel-platinum alloy target blank is plated with a copper film by electroplating or chemical plating.

5. The method for preparing a nickel-platinum alloy target blank according to claim 1, characterized in that: The material of the package sleeve is A1060 aluminum alloy.

6. The method for preparing a nickel-platinum alloy target blank according to claim 1, characterized in that: In step (4), the hot isostatic pressing time is 4 h to 5 h, and the hot isostatic pressing pressure is at least 110 MPa.

7. The method for preparing a nickel-platinum alloy target blank according to claim 1, characterized in that: In step (4), the package is degassed at a temperature of 200°C to 250°C, and the degassing vacuum is less than 2.0×E-3Pa.

8. The method for preparing a nickel-platinum alloy target blank according to claim 1, characterized in that: The surface treatment in step (1) specifically involves cleaning and degreasing the nickel-platinum alloy target blank and the copper backing plate.

9. A nickel-platinum alloy target, characterized in that: The invention comprises a nickel-platinum alloy target blank and a copper back plate, wherein the nickel-platinum alloy target blank and the copper back plate are welded by using the welding method of the nickel-platinum alloy target blank as claimed in any one of claims 1 to 8.