Special-shaped cavity inner wall evaporation magnetron sputtering target system

Abstract

The invention discloses an evaporation magnetron sputtering target system for the inner wall of a special-shaped cavity, and relates to the field of high-energy pulse magnetron sputtering for sputtering coating of the inner wall of a superconducting acceleration cavity. The device comprises a vacuum mechanism suitable for loading a superconducting acceleration cavity, a magnetron sputtering target mechanism arranged in an inner cavity of the superconducting acceleration cavity, and a driving mechanism connected with the magnetron sputtering target mechanism. According to the invention, the lifting of the annular target material in the inner cavity of the superconducting acceleration cavity is realized, so that plasmas can discharge in a specified area in the inner cavity of the superconducting acceleration cavity to finish the coating of a corresponding area, and meanwhile, the power of a negative electrode power supply and the sputtering time of the annular target material can be controlled to realize uniform coating; the uniformity and the adhesion of the thickness of the thin film are favorably controlled; in addition, the driving mechanism has a large-stroke moving range, and the requirement for thin film evaporation of the multi-cell superconducting acceleration cavity can be met.

Description

Technical Field

[0001] The invention relates to the field of high-energy pulse magnetron sputtering for sputtering coating on the inner wall of a superconducting acceleration cavity, in particular to a magnetron sputtering target system for evaporating the inner wall of a special-shaped cavity. Background Art

[0002] Superconducting radio frequency accelerating cavities have gradually become mainstream technologies in high-energy physics, nuclear research and some industrial applications due to their high no-load quality factor, higher acceleration gradient, low energy loss, low surface resistance, long service life and high reliability. They are especially widely used in large accelerators such as linear accelerators and circular accelerators. Compared with the first generation of pure niobium superconducting accelerating cavities, the next generation of superconducting accelerator technology comes from the copper cavity niobium film technology of the European Center for Ion Accelerators, which greatly reduces material costs, and has the advantages of higher thermal and mechanical stability, insensitivity to DC magnetic fields and increased operating temperature, making it the preferred technology for advanced light sources at home and abroad.

[0003] In a 1.3GHz single-cell copper cavity, see Figure 8 , a small structure with a characteristic frequency wavelength is formed by combining a beam tube and an elliptical cell. The structural features include the gradual angle between the ellipsoidal surface and the beam tube, and the significant change in the distance between the cathode target and the acceleration cavity target. This poses great challenges in the coating process, mainly including a series of problems such as uniformity of film thickness, increased defects caused by the shadow effect due to oblique growth, increased film stress, and decreased bonding between the film and the substrate.

[0004] At present, the mainstream sputtering method of copper cavity niobium film coating technology is to place a longer cylindrical target at the center of the copper cavity symmetry axis, apply voltage between the acceleration cavity and the niobium rod, and isotropically deposit superconducting film on the copper cavity surface by ion evaporation. This not only has low sputtering efficiency and poor film adhesion, but also uneven sputtering thickness, which seriously affects the acceleration gradient and quality factor of the superconducting acceleration cavity and creates a major obstacle to large-scale applications.

[0005] In summary, in order to solve coating problems such as low sputtering efficiency, poor adhesion, and uneven thickness, it is very necessary to design a local magnetron sputtering target with high degree of freedom, controllable position, controllable power, and controllable magnetic field to meet the sputtering needs of the superconducting acceleration cavity. Summary of the invention

[0006] In order to solve the above problems, the present invention provides a magnetron sputtering target system for evaporation on the inner wall of a special-shaped cavity, which can enable plasma to discharge in a specified area in a superconducting acceleration cavity to complete the coating of the corresponding area, and at the same time can control the power of the negative electrode power supply and the sputtering time of the annular target material to achieve uniform coating, which is beneficial to control the uniformity and adhesion of the film thickness.

[0007] The present invention provides a magnetron sputtering target system for evaporating a special-shaped cavity inner wall, comprising a vacuum mechanism suitable for loading a superconducting acceleration cavity, a magnetron sputtering target mechanism arranged in the superconducting acceleration cavity, and a driving mechanism connected to the magnetron sputtering target mechanism; the magnetron sputtering target mechanism comprises an electrode lead-out rod, an electrode disk, an annular target material and a bottom support member connected in sequence from top to bottom; a cooling column is provided in the inner cavity of the annular target material, a plurality of permanent magnets and a plurality of insulators are arranged around the outer wall of the cooling column, and the permanent magnets and insulators are arranged in sequence along the axial direction of the cooling column; the bottom of the annular target material is connected to the bottom support member; a gas path disk is provided on the top of the electrode disk, a top support member is provided on the top of the gas path disk, and an air outlet of the gas path disk is located at the bottom of the gas path disk and outside the annular target material; the electrode lead-out rod passes through the gas path disk and the top support member in sequence and extends to the outside of the vacuum mechanism.

[0008] In a feasible embodiment, an annular air path channel is provided in the air path plate, and an air path pipe connected to the annular air path channel and extending to the outside of the vacuum mechanism is also provided on the air path plate; a plurality of air outlet holes are arranged in sequence along the circumferential direction of the annular air path channel and are all connected to the annular air path channel at the bottom of the air path plate, and the air outlet holes are located outside the annular target material.

[0009] In a feasible embodiment, the cooling column is provided with a liquid inlet channel, a cooling cavity and a liquid outlet channel which are connected in sequence; the extension direction of the liquid inlet channel and the liquid outlet channel are consistent with the extension direction of the cooling column; the liquid inlet of the liquid inlet channel is provided with a liquid inlet pipe connected thereto, and the liquid outlet of the liquid outlet channel is provided with a liquid outlet pipe connected thereto, and the liquid inlet pipe and the liquid outlet pipe both extend to the outside of the vacuum mechanism.

[0010] In a feasible implementation manner, the driving mechanism includes a driving member, a driving shaft of the driving member is provided with an adapter block slidably connected thereto, and the adapter block is connected to the electrode lead-out rod.

[0011] In a feasible embodiment, it also includes a multi-way flange and a negative electrode power supply, the top of the electrode lead-out rod passes through the multi-way flange and is connected to the negative electrode power supply; the top of the gas circuit pipe passes through the multi-way flange and is suitable for connecting with an external gas generating device, and the top of the liquid inlet pipe and the top of the liquid outlet pipe both pass through the multi-way flange and are suitable for connecting with an external pump body.

[0012] In one feasible implementation, the power of the negative electrode power supply is 1.8 to 3.8 KW / cm 2 ; and / or, the current density of the negative electrode power supply is 2.4 to 4.4 A / cm 2 ; and / or, the duty cycle of the negative electrode power supply is 0.1 to 0.99; and / or, the pulse frequency of the negative electrode power supply is 10 to 40 kHz.

[0013] In a feasible embodiment, an insulating pad layer is provided between the gas circuit plate and the electrode plate; and / or, an insulating pad layer is provided between the electrode plate and the cooling column; and / or, an insulating pad layer is provided on the outside of the bottom support member; and / or, an insulating pad layer is provided on the portion of the electrode lead-out rod exposed to the external environment.

[0014] In a feasible implementation manner, the residual resistivity of the target material is ≥300; and / or the material of the permanent magnet is neodymium iron boron; and / or the magnetic field provided by the permanent magnet is ≥500 Oe.

[0015] In a feasible implementation manner, the vacuum mechanism includes a vacuum cavity and a vacuum pump group 12 connected to the vacuum cavity, wherein the vacuum cavity is suitable for loading a superconducting acceleration cavity; and further includes a bracket, wherein the vacuum cavity is arranged on the bracket.

[0016] The present invention also provides a method for using a system for evaporating a magnetron sputtering target on the inner wall of a special-shaped cavity, which comprises at least the following steps:

[0017] Step 1): Evacuate the vacuum mechanism to a vacuum degree of ≤2*10-8Torr;

[0018] Step 2): Thin film sputtering, controlling the driving mechanism 3 to move the magnetron sputtering target mechanism 2 in the inner cavity of the superconducting accelerating cavity 100 until all the superconducting accelerating cavities 100 are sputtered with uniform superconducting thin films.

[0019] The magnetron sputtering target system for evaporating the inner wall of a special-shaped cavity provided by the present invention has the following beneficial effects:

[0020] 1) The present invention realizes the lifting and lowering of the annular target in the inner cavity of the superconducting accelerating cavity, so that the plasma can discharge in the specified area in the inner cavity of the superconducting accelerating cavity to complete the coating of the corresponding area, and at the same time can control the power of the negative electrode power supply and the sputtering time of the annular target to achieve uniform coating, which is beneficial to control the uniformity and adhesion of the film thickness; in addition, the driving mechanism has a large range of movement, which can meet the needs of multi-cell superconducting accelerating cavity evaporation film.

[0021] 2) In the present invention, a permanent magnet is provided on the outer wall of the cooling column, and the permanent magnet is located inside the annular target. By constraining the behavior of electrons through the magnetic field, the collision probability of electrons and argon gas can be increased, resulting in an increase in the sputtering rate of the thin film; at the same time, the permanent magnet can provide a magnetic field of 400 to 600 Oe perpendicular to the target surface of the annular target. The permanent magnets are separated by insulators so that the magnetic field will not be dissipated at the junction of the magnets, but diverge outward, thereby more efficiently increasing the magnetic lines of force perpendicular to the annular target, increasing the number of secondary electrons, and thus improving the sputtering efficiency.

[0022] 3) The gas path plate of the present invention has gas outlets in a range of 360°, which can evenly distribute the working gas around the annular target, so that the annular target is evenly ignited near the target, thus achieving all-round even ignition sputtering.

[0023] 4) The present invention adopts a high frequency negative electrode power supply with adjustable duty cycle, frequency and pulse waveform, and the power of the negative electrode power supply is 1.8-3.8KW / cm 2 , current density is 2.4~4.4A / cm 2 , the duty cycle is 0.1 to 0.99, the pulse frequency is 10 to 40 kHz, and the negative electrode power supply adopts positive and negative pulse enhancement to reduce the secondary electron emission coefficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a side view of the present invention.

[0025] Figure 2 It is the overall structure diagram of the present invention.

[0026] Figure 3 It is a front view of the present invention.

[0027] Figure 4 It is a cross-sectional view of the magnetron sputtering target mechanism in the present invention.

[0028] Figure 5 It is a cross-sectional view of the magnetron sputtering target mechanism in the present invention.

[0029] Figure 6 It is a schematic structural diagram of the magnetron sputtering target mechanism, multi-way flange and negative electrode power supply in the present invention.

[0030] Figure 7 It is a schematic diagram of the structure of the magnetron sputtering target mechanism, various pipelines, multi-way flange and negative electrode power supply in the present invention.

[0031] Figure 8 It is a cross-sectional view of a single-cell accelerating chamber in the present invention.

[0032] Fig. 9 It is a schematic diagram of the structure of the gas circuit plate in the present invention.

[0033] Fig.10 It is a cross-sectional view of the magnetron sputtering target mechanism in the present invention.

[0034] Reference numerals

[0035] Vacuum mechanism 1

[0036] Vacuum chamber 11

[0037] Vacuum pump set 12

[0038] Magnetron sputtering target mechanism 2

[0039] Electrode lead rod 21

[0040] Electrode disk 22

[0041] Ring target 23

[0042] Cooling column 24

[0043] Cooling chamber 24.1

[0044] Liquid inlet pipe 24.2

[0045] Liquid outlet pipe 24.3

[0046] Permanent magnet 25

[0047] Insulator 26

[0048] Bottom support 27

[0049] Gas circuit board 28

[0050] Annular gas channel 28.1

[0051] Gas pipe 28.2

[0052] Vent 28.3

[0053] Top support 29

[0054] Driving mechanism 3

[0055] Driving member 31

[0056] Transfer block 32

[0057] Multi-way flange 4

[0058] Negative electrode power supply 5

[0059] Insulation pad 6

[0060] Bracket 7

[0061] Acceleration chamber 100 DETAILED DESCRIPTION

[0062] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without creative work belong to the scope of protection of the present invention. In the description of the present invention, it should be noted that the orientation or position relationship indicated by the terms "left side", "right side", "upper side", "lower side", "above", "below" and the like is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0063] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0064] Furthermore, in the description of the present invention, unless otherwise specified, “plurality” means two or more.

[0065] The present invention provides a system for evaporating magnetron sputtering targets on the inner wall of a special-shaped cavity, referring to Figure 1 to Figure 3 , comprising a vacuum mechanism 1 suitable for loading a superconducting accelerating cavity 100, a magnetron sputtering target mechanism 2 arranged in the superconducting accelerating cavity 100, and a driving mechanism 3 connected to the magnetron sputtering target mechanism 2, wherein the magnetron sputtering target mechanism 2 is used for performing vapor deposition on the inner wall of the superconducting accelerating cavity 100, and the driving mechanism 3 is used for driving the magnetron sputtering target mechanism 2 to rise and fall in the superconducting accelerating cavity 100. Figure 4 , Figure 5 and Fig.10The magnetron sputtering target mechanism 2 includes an electrode lead-out rod 21, an electrode disk 22, an annular target material 23 and a bottom support 27 connected in sequence from top to bottom. The electrode lead-out rod 21 can introduce the negative electrode of an external power source, and make the electrode disk 22 and the annular target material 23 carry negative electricity. During evaporation, the superconducting acceleration cavity 100 will be connected to an external positive power source to carry positive electricity, and the material of the annular target material 23 will be evaporated on the inner wall of the superconducting acceleration cavity 100. In most cases, the material of the annular target material 23 is the superconducting material niobium (Nb). In another specific embodiment, the residual resistivity of the annular target material 23 is ≥300. Continue to refer to Figure 4 , Figure 5 and Fig.10 A cooling column 24 is provided in the inner cavity of the annular target 23, and a plurality of permanent magnets 25 and a plurality of insulators 26 are arranged around the outer wall of the cooling column 24. The permanent magnets 25 and the insulators 26 are arranged in sequence and spaced apart along the axial direction of the cooling column 24. The bottom of the annular target 23 is connected to the bottom support 27. Generally speaking, the outer diameter of the cooling column 24 is smaller than the inner diameter of the annular target 23, so that there is space in the inner cavity of the annular target 23 for installing the permanent magnets 25 and the insulators 26. The permanent magnet 25 can provide a magnetic field perpendicular to the annular target 23, and the insulator 26 can prevent the magnetic field provided by the permanent magnet 25 from being consumed at the intersection of the permanent magnets 25, but diverge outward, thereby more efficiently increasing the magnetic lines of force perpendicular to the annular target 23, increasing the number of secondary electrons, and thus improving the sputtering efficiency during evaporation. In one specific embodiment, the annular target 23 is connected and fixed to the bottom support 27 by screws, and the annular target 23 is also connected and fixed to the electrode disk 22 by screws, that is, the annular target 23 is fixed between the electrode disk 22 and the bottom support 27; in another specific embodiment, the outer wall of the cooling column 24 is provided with a permanent magnet 25, an insulator 26, a permanent magnet 25 and an insulator 26 in sequence from bottom to top; in another specific embodiment, the material of the permanent magnet 25 is neodymium iron boron, and the magnetic field provided by the permanent magnet 25 is ≥500Oe. Continue reading Figure 4 , Figure 5 and Fig.10, a gas path disk 28 is provided on the top of the electrode disk 22, a top support 29 is provided on the top of the gas path disk 28, the gas outlet of the gas path disk 28 is located at the bottom of the gas path disk 28 and outside the annular target 23, the electrode lead-out rod 21 passes through the gas path disk 28 and the top support 29 in sequence and extends to the outside of the vacuum mechanism 1, generally speaking, the gas path disk 28 and the top support 29 are both annular, and a space is left in the middle for the electrode lead-out rod 21 to pass through. As an illustration: during evaporation, in addition to the superconducting accelerating cavity 100 carrying positive electricity and the annular target 23 carrying negative electricity, there is another necessary condition that there is working gas between the outer wall of the annular target 23 and the inner wall of the superconducting accelerating cavity 100, so the gas outlet of the gas path disk 28 must be located outside the annular target 23 to ensure that the working gas can be injected between the outer wall of the annular target 23 and the inner wall of the superconducting accelerating cavity 100 during evaporation. The present invention realizes the lifting and lowering of the annular target in the inner cavity of a superconducting accelerating cavity, so that plasma can discharge in a specified area in the inner cavity of the superconducting accelerating cavity to complete the coating of the corresponding area, and at the same time can control the power of the negative electrode power supply and the sputtering time of the annular target to achieve uniform coating, which is beneficial to control the uniformity and adhesion of the film thickness; in addition, the driving mechanism has a large range of movement, which can meet the needs of multi-cell superconducting accelerating cavity evaporation film.

[0066] In the magnetron sputtering target system for evaporating the inner wall of a special-shaped cavity provided by an embodiment of the present invention, refer to Figure 4 , Figure 5 and Fig. 9 The gas path plate 28 is provided with an annular gas path channel 28.1, and the gas path plate 28 is also provided with an gas path pipe 28.2 which is connected with the annular gas path channel 28.1 and extends to the outside of the vacuum mechanism 1. Normally, only one gas path pipe 28.2 is required. The bottom of the gas path plate 28 is provided with a plurality of gas outlet holes 28.3 which are arranged in sequence along the circumferential direction of the annular gas path channel 28.1 and are all connected with the annular gas path channel 28.1, and the gas outlet holes 28.3 are located outside the annular target material 23. In a specific embodiment, the number of the gas outlet holes 28.3 is 5 to 15, preferably 10, and the spacing angles between adjacent gas outlet holes 28.3 are the same, that is, the gas outlet holes 28.3 are evenly arranged in a ring at the bottom of the gas path plate 28, so that the gas path plate 28 has gas outlet holes 28.3 within a range of 360°, which can make the working gas evenly distributed around the annular target 23, so that uniform ignition can be achieved near the annular target 23, and all-round uniform ignition sputtering can be achieved.

[0067] In the magnetron sputtering target system for evaporating the inner wall of a special-shaped cavity provided by an embodiment of the present invention, refer to Figure 4 , Figure 5 and Fig.10, the cooling column 24 is provided with a liquid inlet channel, a cooling cavity 24.1 and a liquid outlet channel which are connected in sequence, the extension direction of the liquid inlet channel and the liquid outlet channel are consistent with the extension direction of the cooling column 24, the liquid inlet of the liquid inlet channel is provided with a liquid inlet pipe 24.2 which is connected thereto, the liquid outlet of the liquid outlet channel is provided with a liquid outlet pipe 24.3 which is connected thereto, and the liquid inlet pipe 24.2 and the liquid outlet pipe 24.3 are both extended to the outside of the vacuum mechanism 1. As an illustration, when the annular target 23 is sputtered by argon ion impact, the kinetic energy of the ions is converted into heat energy, so that the surface temperature of the annular target 23 is very high, so the coolant in the liquid inlet channel, the cooling cavity 24.1 and the liquid outlet channel can absorb and take away the heat emitted from the surface of the annular target 23, prevent the permanent magnet 25 from demagnetizing, and ensure the magnetocontrol effect of the permanent magnet 25.

[0068] In the magnetron sputtering target system for evaporating the inner wall of a special-shaped cavity provided by an embodiment of the present invention, refer to Figure 4 to Figure 7 , further comprising a multi-way flange 4 and a negative electrode power supply 5, the top of the electrode lead-out rod 21 passes through the multi-way flange 4 and is connected to the negative electrode power supply 5; the top of the electrode lead-out rod 21 passes through the multi-way flange 4 and is connected to the negative electrode power supply 5, the top of the gas circuit pipe 28.2 passes through the multi-way flange 4 and is suitable for communicating with an external gas generating device, the top of the liquid inlet pipe 24.2 and the top of the liquid outlet pipe 24.3 both pass through the multi-way flange 4 and are suitable for communicating with an external pump body. In a specific embodiment, refer to Figure 4 to Figure 7 The multi-way flange 4 is a four-way flange, the negative electrode power supply 5 is located above the top interface of the four-way flange, the electrode lead-out rod 21 penetrates from the bottom interface of the four-way flange and passes out from the top interface, and the electrode lead-out rod 21 usually penetrates into the bellows after passing out, and the top of the bellows is connected to the negative electrode power supply 5, and the electrode lead-out rod 21 is connected to the negative electrode power supply 5 in the bellows; the top of the gas circuit pipe 28.2 penetrates from the interface on the left side of the four-way flange and is externally connected to the gas generating device, the top of the liquid inlet pipe 24.2 and the top of the liquid outlet pipe 24.3 penetrate from the interface on the right side of the four-way flange and are externally connected to the pump body. Normally, the top of the liquid inlet pipe 24.2 and the top of the liquid outlet pipe 24.3 both penetrate from the same interface of the four-way flange, and the top of the gas circuit pipe 28.2 penetrates from another opposite interface.

[0069] In the magnetron sputtering target system for evaporating the inner wall of a special-shaped cavity provided by an embodiment of the present invention, refer to Figure 1The driving mechanism 3 includes a driving member 31, and a transfer block 32 slidably connected to the driving shaft of the driving member 31 is provided, and the transfer block 32 is connected to the electrode lead-out rod 21. When the driving mechanism 3 is in use, the transfer block 32 can be raised and lowered on the driving shaft of the driving member 31 (refer to the driving mode of the ball screw), and because the transfer block 32 is connected to the top of the electrode lead-out rod 21, generally speaking, the transfer block 32 is a clamping block that can clamp the electrode lead-out rod 21, so the electrode lead-out rod 21 can be raised and lowered synchronously with the transfer block 32, and the bottom of the electrode lead-out rod 21 is connected to the electrode disk 22, and the electrode disk 22 is connected to the annular target material 23 and the bottom support 27 downwardly, and is connected to the gas path disk 28 and the top support 29 upwardly, so when the electrode disk 22 is raised and lowered, the entire magnetron sputtering target mechanism 2 is raised and lowered. In a specific embodiment, the electrode lead-out rod 21 is inserted into the bellows after passing through the multi-way flange 4. A negative electrode power supply 5 is provided at the top of the bellows. The electrode lead-out rod 21 is connected to the negative electrode power supply 5 in the bellows. The bottom of the bellows is fixed, and the top of the bellows is connected to the adapter block 32. When the adapter block 32 is lifted or lowered on the driving shaft of the driving member 31, the top of the bellows will move up and down, but the bottom of the bellows will not move, and the bellows will appear to be shortened or elongated. Because the negative electrode power supply 5 is installed at the top of the bellows, the negative electrode power supply 5 will rise and fall with the top of the bellows, and the negative electrode power supply 5 will drive the magnetron sputtering target mechanism 2 to rise and fall in the inner cavity of the superconducting acceleration cavity 100 through the electrode lead-out rod 21.

[0070] In the magnetron sputtering target system for evaporating the inner wall of a special-shaped cavity provided by an embodiment of the present invention, refer to Figure 4 , Figure 5 and Fig.10 An insulating cushion layer 6 is further provided between the gas path disk 28 and the electrode disk 22; and / or, an insulating cushion layer 6 is further provided between the electrode disk 22 and the cooling column 24; and / or, an insulating cushion layer 6 is further provided on the outside of the bottom support member 27; and / or, an insulating cushion layer 6 is provided on the portion of the electrode lead-out rod 21 exposed to the external environment.

[0071] In the magnetron sputtering target system for evaporating the inner wall of a special-shaped cavity provided by an embodiment of the present invention, refer to Figure 1 The vacuum mechanism 1 includes a vacuum cavity 11 and a vacuum pump group 12 connected to the vacuum cavity 11 , wherein the vacuum cavity 11 is suitable for loading a superconducting acceleration cavity 100 , and further includes a bracket 7 , on which the vacuum cavity 11 is disposed.

[0072] The embodiment of the present invention further provides a method for using a system for evaporating a magnetron sputtering target on the inner wall of a special-shaped cavity, which comprises at least the following steps:

[0073] Step 1): Vacuum the vacuum mechanism 1 to a vacuum degree of ≤2*10-8 Torr, that is, the vacuum degree of the vacuum chamber 11 is reduced to ≤2*10 -8 Further, the mechanical pump is turned on to roughly pump the vacuum chamber 11, and the vacuum degree of the vacuum chamber 11 is waited until it reaches 5*10 -1 Torr, turn on the molecular pump, and perform high vacuum extraction on the vacuum chamber 11, so that the vacuum degree is ≤2*10 -8 Torr.

[0074] Step 2): Thin film sputtering, controlling the driving mechanism 3 to move the magnetron sputtering target mechanism 2 in the inner cavity of the superconducting accelerating cavity 100 until all the superconducting accelerating cavities 100 are sputtered with uniform superconducting thin films.

[0075] Before step 1, the method may also include: fixing the special-shaped single-cell and 9-cell superconducting radio frequency cavities in the vacuum chamber of the vacuum mechanism 1, fixing the top and bottom of the superconducting acceleration cavity 100 with screws, fixing the middle part in a specific slot, and winding the heating wire around the surface of the special-shaped cavity.

[0076] Between step 1 and step 2, the following may also be included: 1) Leak detection: when the vacuum degree of the vacuum chamber 11 changes at a low rate, a small amount of acetone or alcohol is dripped from the gap of the opening. If the vacuum gauge reading does not change significantly, it indicates that the sealing is good and there is no leakage. 2) Baking: after the vacuum gauge reading stabilizes, the vacuum chamber 11 is wrapped with a heating belt and baked for about 24 hours, and then the baking is stopped. 3) Washing: when the vacuum degree is less than ≤2*10 -8 Torr, evacuate the air inlet pipe, add working gas, and repeat the operation three times. 4) Control the growth pressure, close the vacuum gauge, set the flow meter to a specific flow, and control the vacuum degree of the vacuum chamber 11 to stabilize at a specific condition through the gate valve switch size.

[0077] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

Claims

1. A magnetron sputtering target system for evaporation of the inner wall of a special-shaped cavity, characterized in that: It comprises a vacuum mechanism (1) suitable for loading a superconducting accelerating cavity (100), a magnetron sputtering target mechanism (2) arranged in the inner cavity of the superconducting accelerating cavity (100), and a driving mechanism (3) connected to the magnetron sputtering target mechanism (2); The magnetron sputtering target mechanism (2) comprises an electrode lead-out rod (21), an electrode disk (22), an annular target material (23) and a bottom support member (27) which are sequentially connected from top to bottom; a cooling column (24) is provided in the inner cavity of the annular target material (23); a plurality of permanent magnets (25) and a plurality of insulators (26) are arranged around the outer wall of the cooling column (24); the permanent magnets (25) and the insulators (26) are sequentially spaced apart along the axial direction of the cooling column (24); the bottom of the annular target material (23) is connected to the bottom support member (27); An air path disk (28) is provided on the top of the electrode disk (22), a top support member (29) is provided on the top of the air path disk (28), and an air outlet of the air path disk (28) is located at the bottom of the air path disk (28) and outside the annular target material (23); the electrode lead-out rod (21) passes through the air path disk (28) and the top support member (29) in sequence and extends to the outside of the vacuum mechanism (1).

2. The magnetron sputtering target system for evaporation of the inner wall of a special-shaped cavity according to claim 1, characterized in that: The gas path plate (28) is provided with an annular gas path channel (28.1), and the gas path plate (28) is also provided with an gas path pipe (28.2) which is connected to the annular gas path channel (28.1) and extends to the outside of the vacuum mechanism (1); the bottom of the gas path plate (28) is provided with a plurality of gas outlet holes (28.3) which are arranged in sequence along the circumferential direction of the annular gas path channel (28.1) and are all connected to the annular gas path channel (28.1), and the gas outlet holes (28.3) are located outside the annular target material (23).

3. The magnetron sputtering target system for evaporation of the inner wall of a special-shaped cavity according to claim 1, characterized in that: The cooling column (24) is provided with a liquid inlet channel, a cooling cavity (24.1) and a liquid outlet channel which are connected in sequence; the extension direction of the liquid inlet channel and the liquid outlet channel are consistent with the extension direction of the cooling column (24); A liquid inlet pipe (24.2) in communication with the liquid inlet of the liquid inlet channel is provided at the liquid inlet, and a liquid outlet pipe (24.3) in communication with the liquid outlet of the liquid outlet channel is provided at the liquid outlet. Both the liquid inlet pipe (24.2) and the liquid outlet pipe (24.3) extend toward the outside of the vacuum mechanism (1).

4. The magnetron sputtering target system for evaporation of the inner wall of a special-shaped cavity according to claim 1, characterized in that: The driving mechanism (3) comprises a driving member (31), a driving shaft of the driving member (31) is provided with an adapter block (32) slidably connected thereto, and the adapter block (32) is connected to the electrode lead-out rod (21).

5. The magnetron sputtering target system for evaporation of the inner wall of a special-shaped cavity according to claim 3, characterized in that: It also includes a multi-way flange (4) and a negative electrode power supply (5), the top of the electrode lead-out rod (21) passes through the multi-way flange (4) and is connected to the negative electrode power supply (5); the top of the gas circuit pipe (28.2) passes through the multi-way flange (4) and is suitable for communicating with an external gas generating device, and the top of the liquid inlet pipe (24.2) and the top of the liquid outlet pipe (24.3) both pass through the multi-way flange (4) and are suitable for communicating with an external pump body.

6. The magnetron sputtering target system for evaporation of the inner wall of a special-shaped cavity according to claim 5, characterized in that: The power of the negative electrode power supply (5) is 1.8-3.8 KW / cm 2 ; and / or, the current density of the negative electrode power supply (5) is 2.4 to 4.4 A / cm 2 ; and / or, the duty cycle of the negative electrode power supply (5) is 0.1 to 0.99; and / or, the pulse frequency of the negative electrode power supply (5) is 10 to 40 kHz.

7. The magnetron sputtering target system for evaporation of the inner wall of a special-shaped cavity according to claim 1, characterized in that: An insulating cushion layer (6) is also provided between the gas path plate (28) and the electrode plate (22); and / or, an insulating cushion layer (6) is also provided between the electrode plate (22) and the cooling column (24); and / or, an insulating cushion layer (6) is also provided on the outside of the bottom support member (27); and / or, an insulating cushion layer (6) is provided on the portion of the electrode lead-out rod (21) exposed to the external environment.

8. The magnetron sputtering target system for evaporation of the inner wall of a special-shaped cavity according to claim (1), characterized in that: The residual resistivity of the target material is ≥300; and / or the material of the permanent magnet (25) is neodymium iron boron; and / or the magnetic field provided by the permanent magnet (25) is ≥500 Oe.

9. The magnetron sputtering target system for evaporation of the inner wall of a special-shaped cavity according to claim 1, characterized in that: The vacuum mechanism (1) comprises a vacuum cavity (11) and a vacuum pump group (12) connected to the vacuum cavity (11), wherein the vacuum cavity (11) is suitable for loading a superconducting acceleration cavity (100); and further comprises a bracket (7), wherein the vacuum cavity (11) is arranged on the bracket (7).

10. A method for using the special-shaped cavity inner wall evaporation magnetron sputtering target system according to any one of claims 1 to 9, characterized in that: At least the following steps are included: Step 1): Evacuate the vacuum mechanism (1) to a vacuum degree of ≤2*10 -8 Torr; Step 2): Thin film sputtering, controlling the driving mechanism (3) to move the magnetron sputtering target mechanism (2) in the inner cavity of the superconducting acceleration cavity (100) until all the superconducting acceleration cavities (100) are sputtered with uniform superconducting thin films.

Images