Magnetron Sputtering Target System for Evaporation Coating on Inner Wall of Different-shaped Cavities

Abstract

The present invention relates to a magnetron sputtering target system for inner wall evaporation coating of a cavity with different shapes, which belongs to the field of high-energy pulsed magnetron sputtering for sputtering coating on the inner wall of a superconducting accelerating cavity. The present invention includes a vacuum mechanism suitable for loading a superconducting accelerating cavity, a magnetron sputtering target mechanism arranged in the inner cavity of the superconducting accelerating cavity, and a driving mechanism connected to the magnetron sputtering target mechanism. The present invention realizes the lifting of an annular target in the inner cavity of the 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. At the same time, the power of the negative electrode power supply and the sputtering time of the annular target can be controlled to achieve uniform coating, which is beneficial to controlling the uniformity and adhesion of the film thickness. In addition, the driving mechanism has a large moving range with a large stroke, which can meet the requirements for evaporating films on multi-cell superconducting accelerating cavities.

Description

Technical Field

[0001] The present invention relates to the field of high-energy pulsed magnetron sputtering for sputter coating the inner wall of a superconducting accelerating cavity, in particular to a magnetron sputtering target system for evaporative coating on the inner wall of a cavity with a special shape. Background Art

[0002] Superconducting radio frequency accelerating cavities, with their high unloaded quality factor, higher accelerating gradient, low energy loss, low surface resistance, long service life and high reliability, have gradually become the mainstream technology in high-energy physics, nuclear research and some industrial applications. They are widely used especially in large accelerators such as linear accelerators and circular accelerators. Compared with the first-generation pure niobium superconducting accelerating cavities, the next-generation superconducting accelerator technology comes from the copper cavity niobium film coating technology of the European Ion Accelerator Center. It significantly reduces the material cost, and at the same time has advantages such as higher thermal stability and mechanical stability, insensitivity to DC magnetic fields, and higher operating temperature, becoming the preferred technology for advanced light sources at home and abroad.

[0003] In a 1.3 GHz single-cell copper cavity, reference can be made to Figure 8 , where a structure with a relatively small volume and characteristic frequency wavelength is formed by combining a beam tube and an elliptical cell. The characteristics of this structure include the gradual change in the angle between the ellipsoidal surface and the beam tube, and the significant change in the distance between the cathode target and the accelerating cavity target, which poses great challenges during the coating process, mainly including a series of problems such as the uniformity of the film thickness, the increase in defects due to the shadow effect caused by oblique angle growth, the increase in film stress, and the decrease in the bonding force between the film and the substrate.

[0004] Currently, the mainstream sputtering method for the copper cavity niobium film technology is to place a long cylindrical target at the center of the symmetry axis of the copper cavity, and deposit a superconducting film isotropically on the surface of the copper cavity by ion evaporation by applying a voltage between the accelerating cavity and the niobium rod. This not only has low sputtering efficiency, poor film adhesion, but also uneven sputtering thickness, which seriously affects parameters such as the accelerating gradient and quality factor of the superconducting accelerating cavity, causing a great obstacle to large-scale applications.

[0005] In summary, to solve the 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 freedom, controllable position, controllable power, and controllable magnetic field to meet the sputtering requirements of superconducting accelerating cavities. Summary of the Invention

[0006] To solve the above problems, the present invention provides a magnetron sputtering target system for inner wall evaporation of a cavity with different shapes, which enables plasma to discharge in a specified area of a superconducting acceleration cavity to complete coating of the corresponding area, and 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 controlling the uniformity and adhesion of the film thickness.

[0007] The magnetron sputtering target system for inner wall evaporation of a cavity with different shapes provided by the present invention includes 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 includes an electrode lead-out rod, an electrode plate, an annular target, and a bottom support member connected in sequence from top to bottom; a cooling column is arranged in the inner cavity of the annular target, and 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 at intervals in sequence along the axial direction of the cooling column; the bottom of the annular target is connected to the bottom support member; an air passage plate is arranged on the top of the electrode plate, a top support member is arranged on the top of the air passage plate, and the air outlet of the air passage plate is located at the bottom of the air passage plate and outside the annular target; the electrode lead-out rod passes through the air passage plate and the top support member in sequence and extends to the outside of the vacuum mechanism.

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

[0009] In a feasible embodiment, a liquid inlet channel, a cooling cavity, and a liquid outlet channel are arranged in sequence and communicated with each other in the cooling column; the extending directions of the liquid inlet channel and the liquid outlet channel are both the same as the extending direction of the cooling column; a liquid inlet pipe communicated with the liquid inlet of the liquid inlet channel is arranged at the liquid inlet of the liquid inlet channel, a liquid outlet pipe communicated with the liquid outlet of the liquid outlet channel is arranged at the liquid outlet of the liquid outlet channel, and both the liquid inlet pipe and the liquid outlet pipe extend to the outside of the vacuum mechanism.

[0010] In a feasible embodiment, the driving mechanism includes a driving member, and a transfer block slidably connected to the driving shaft of the driving member is arranged on the driving shaft of the driving member, and the transfer block is connected to the electrode lead-out rod.

[0011] In a feasible embodiment, a multi-pass flange and a negative electrode power supply are further included; the top of the electrode lead-out rod passes through the multi-pass flange and is connected to the negative electrode power supply; the top of the air passage tube passes through the multi-pass flange and is suitable for being communicated with an external gas generating device, and the tops of both the liquid inlet pipe and the liquid outlet pipe pass through the multi-pass flange and are connected to an external pump body.

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

[0013] In a feasible embodiment, an insulating cushion layer is further provided between the gas path disk and the electrode disk; and / or, an insulating cushion layer is further provided between the electrode disk and the cooling column; and / or, an insulating cushion layer is further provided outside the bottom support member; and / or, an insulating cushion layer is provided on the part of the electrode lead rod exposed to the external environment.

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

[0015] In a feasible embodiment, the vacuum mechanism includes a vacuum chamber and a vacuum pump group 12 connected to the vacuum chamber, and the vacuum chamber is adapted to load a superconducting accelerating cavity; it further includes a bracket, and the vacuum chamber is arranged on the bracket.

[0016] The present invention also provides a method for using the magnetron sputtering target system for inner wall evaporation of a cavity with different shapes, which at least includes the following steps:

[0017] Step 1): Evacuate the air, and evacuate the vacuum degree in the vacuum mechanism to ≤ 2*10-8 Torr;

[0018] Step 2): Film sputtering, control the driving mechanism 3 to move the magnetron sputtering target mechanism 2 in the inner cavity of the superconducting accelerating cavity 100 until a uniform superconducting film is sputtered on all the superconducting accelerating cavities 100.

[0019] The magnetron sputtering target system for inner wall evaporation of a cavity with different shapes provided by the present invention has the following beneficial effects:

[0020] 1) The present invention realizes the lifting of the annular target material in the inner cavity of the superconducting accelerating cavity, so that the plasma can discharge in a specified area in the inner cavity of the superconducting accelerating cavity to complete the coating of the corresponding area. At the same time, the power of the negative electrode power supply and the sputtering time of the annular target material can be controlled to achieve uniform coating, which is beneficial to controlling the uniformity and adhesion of the film thickness; in addition, the driving mechanism has a large moving range of travel, which can meet the requirements of evaporating films on multi-cell superconducting accelerating cavities.

[0021] 2) In the present invention, permanent magnets are provided on the outer wall of the cooling column, and the permanent magnets are located inside the annular target. By constraining the behavior of electrons through the magnetic field, the collision probability between electrons and argon gas is increased, resulting in an increase in the film sputtering rate. At the same time, the permanent magnets can provide a magnetic field perpendicular to the target surface of the annular target with a strength of 400 - 600 Oe. Insulators are used to separate the permanent magnets from each other, so that the magnetic field does not dissipate at the joints of the magnets but diverges outward, increasing the magnetic field lines perpendicular to the annular target with higher efficiency and increasing the number of secondary electrons, thereby improving the sputtering efficiency.

[0022] 3) In the present invention, air holes exist in the air path plate within the range of 360°, enabling the working gas to be evenly distributed around the annular target, so as to achieve uniform glow discharge near the annular target and realize omnidirectional uniform glow discharge sputtering.

[0023] 4) In the present invention, a negative electrode power supply with adjustable high frequency, duty cycle, frequency, and pulse waveform is adopted. The power of the negative electrode power supply is 1.8 - 3.8 KW / cm 2 , and the current density is 2.4 - 4.4 A / cm 2 , the duty cycle is 0.1 - 0.99, the pulse frequency is 10 - 40 kHz, and the negative electrode power supply adopts the method of enhancing positive and negative pulses 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 an 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-pass flange, and negative electrode power supply in the present invention.

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

[0031] Figure 8 It is a cross-sectional view of the single Cell acceleration cavity in the present invention.

[0032] Figure 9 It is a schematic structural diagram of the air path plate in the present invention.

[0033] Figure 10 This 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 group 12

[0038] Magnetron sputtering target mechanism 2

[0039] Electrode lead-out rod 21

[0040] Electrode plate 22

[0041] Ring-shaped target 23

[0042] Cooling column 24

[0043] Cooling cavity 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 path plate 28

[0050] Ring-shaped gas path channel 28.1

[0051] Gas path pipe 28.2

[0052] Gas outlet hole 28.3

[0053] Top support 29

[0054] Drive mechanism 3

[0055] Driver 31

[0056] Adapter block 32

[0057] Multi-pass flange 4

[0058] Negative electrode power supply 5

[0059] Insulating cushion 6

[0060] Bracket 7

[0061] Acceleration cavity 100 Detailed implementation manners

[0062] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention. In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "left side", "right side", "upper side", "lower side", "above", "below", etc. is based on the orientation or positional relationship shown in the accompanying drawings. It 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 thus should not be construed as a limitation to the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0063] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "mounted", "connected" and "connected" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0064] In addition, in the description of the present invention, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0065] The present invention provides a magnetron sputtering target system for evaporating the inner wall of a cavity with different shapes. Refer to Figures 1 to 3 , which includes a vacuum mechanism 1 suitable for loading a superconducting accelerating cavity 100, a magnetron sputtering target mechanism 2 disposed in the superconducting accelerating cavity 100, and a driving mechanism 3 connected to the magnetron sputtering target mechanism 2. The magnetron sputtering target mechanism 2 is used for evaporating 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 lift and lower in the superconducting accelerating cavity 100. Continue to refer to Figure 4 , Figure 5 and Figure 10, the magnetron sputtering target mechanism 2 includes an electrode lead rod 21, an electrode plate 22, an annular target 23, and a bottom support 27 connected in sequence from top to bottom. The electrode lead rod 21 can introduce the negative electrode of an external power supply, causing the electrode plate 22 and the annular target 23 to carry negative charges. During evaporation coating, the superconducting acceleration cavity 100 is externally connected to a positive power supply and thus carries positive charges, and the material of the annular target 23 will be evaporated and coated on the inner wall of the superconducting acceleration cavity 100. In most cases, the material of the annular target 23 is the superconducting material niobium (Nb). In another specific embodiment, the residual resistivity of the annular target 23 ≥ 300. Continue to refer to Figure 4 , Figure 5 and Figure 10 , a cooling column 24 is provided in the inner cavity of the annular target 23. A plurality of permanent magnets 25 and a plurality of insulators 26 are arranged in a ring around the outer wall of the cooling column 24. The permanent magnets 25 and the insulators 26 are arranged at intervals in sequence 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 a space in the inner cavity of the annular target 23 for installing the permanent magnets 25 and the insulators 26. The permanent magnets 25 can provide a magnetic field perpendicular to the annular target 23, and the insulators 26 can prevent the magnetic field provided by the permanent magnets 25 from being consumed at the joints of the permanent magnets 25, but instead diverge outward, increasing the magnetic field lines perpendicular to the annular target 23 with greater efficiency and increasing the number of secondary electrons, thereby improving the sputtering efficiency during evaporation coating. In a 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 plate 22 by screws. That is to say, the annular target 23 is fixed between the electrode plate 22 and the bottom support 27; In another specific embodiment, permanent magnets 25, insulators 26, permanent magnets 25, and insulators 26 are sequentially arranged on the outer wall of the cooling column 24 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 ≥ 500 Oe. Continue to refer to Figure 4 , Figure 5 and Figure 10, a gas path plate 28 is provided on the top of the electrode plate 22, a top support 29 is provided on the top of the gas path plate 28, the air outlet of the gas path plate 28 is located at the bottom of the gas path plate 28 and outside the annular target 23, and the electrode lead-out rod 21 sequentially passes through the gas path plate 28 and the top support 29 and extends to the outside of the vacuum mechanism 1. Generally speaking, both the gas path plate 28 and the top support 29 are annular, and there is a space left in the middle for the electrode lead-out rod 21 to pass through. As an illustration: during evaporation coating, in addition to the superconducting acceleration cavity 100 carrying positive electricity and the annular target 23 carrying negative electricity, there is also a necessary condition that there is a working gas between the outer wall of the annular target 23 and the inner wall of the superconducting acceleration cavity 100. Therefore, the air outlet of the gas path plate 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 acceleration cavity 100 during evaporation coating. The present invention realizes the lifting of the annular target in the inner cavity of the superconducting acceleration cavity, so that the plasma can discharge in a specified area in the inner cavity of the superconducting acceleration cavity to complete the coating of the corresponding area. At the same time, the power of the negative electrode power supply and the sputtering time of the annular target can be controlled to achieve uniform coating, which is beneficial to controlling the uniformity and adhesion of the film thickness; in addition, the driving mechanism has a large stroke range of movement, which can meet the requirements for evaporating films on multi-cell superconducting acceleration cavities.

[0066] In the system for evaporating and magnetron sputtering a target on the inner wall of a different-shaped cavity provided in the embodiment of the present invention, referring to Figure 4 , Figure 5 and Figure 9 , a circular gas path channel 28.1 is provided in the gas path plate 28, and a gas path tube 28.2 that is connected to the circular gas path channel 28.1 and extends to the outside of the vacuum mechanism 1 is further provided on the gas path plate 28. Usually, only one gas path tube 28.2 is maintained. A plurality of air outlet holes 28.3 that are arranged in sequence along the circumferential direction of the circular gas path channel 28.1 and are all connected to the circular gas path channel 28.1 are provided at the bottom of the gas path plate 28, and the air outlet holes 28.3 are located outside the annular target 23. In a specific embodiment, the number of the air outlet holes 28.3 is 5 to 15, preferably 10, and the spacing angles between adjacent air outlet holes 28.3 are the same, that is, the air outlet holes 28.3 are evenly arranged in a ring at the bottom of the gas path plate 28, so that there are air outlet holes 28.3 in the range of 360° of the gas path plate 28, which can make the working gas evenly distributed around the annular target 23, so that uniform glow discharge can be achieved near the annular target 23, and omnidirectional uniform glow discharge sputtering can be realized.

[0067] In the system for evaporating and magnetron sputtering a target on the inner wall of a different-shaped cavity provided in the embodiment of the present invention, referring to Figure 4 , Figure 5 and Figure 10, a liquid inlet channel, a cooling cavity 24.1, and a liquid outlet channel that are sequentially connected are provided in the cooling column 24. The extending directions of the liquid inlet channel and the liquid outlet channel are both consistent with the extending direction of the cooling column 24. A liquid inlet pipe 24.2 communicating therewith is provided at the liquid inlet of the liquid inlet channel, and a liquid outlet pipe 24.3 communicating therewith is provided at the liquid outlet of the liquid outlet channel. Both the liquid inlet pipe 24.2 and the liquid outlet pipe 24.3 extend to the outside of the vacuum mechanism 1. As an illustration, when the annular target 23 is sputtered by argon ion bombardment, the ion kinetic energy is converted into heat energy, so that the surface temperature of the annular target 23 is very high. Therefore, the cooling liquid in the liquid inlet channel, the cooling cavity 24.1, and the liquid outlet channel can absorb and carry away the heat dissipated from the surface of the annular target 23, prevent the permanent magnet 25 from demagnetizing, and ensure the magnetron effect of the permanent magnet 25.

[0068] In the system for magnetron sputtering target for inner wall evaporation plating of a cavity with different shapes provided by the embodiment of the present invention, refer to Figures 4 to 7 , it further 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 electrode lead-out rod 21 penetrates into the multi-way flange 4 and is connected to the negative electrode power supply 5. The top of the gas pipeline 28.2 passes through the multi-way flange 4 and is adapted to communicate with an external gas generating device. The tops of both the liquid inlet pipe 24.2 and the liquid outlet pipe 24.3 pass through the multi-way flange 4 and are adapted to communicate with an external pump body. In a specific embodiment, refer to Figures 4 to 7 , the multi-way flange 4 is a four-way flange. The negative electrode power supply 5 is located above the interface at the topmost part of the four-way flange. The electrode lead-out rod 21 penetrates into the four-way flange from the interface at the bottommost part and passes out from the interface at the topmost part. After passing out, the electrode lead-out rod 21 usually penetrates into a corrugated pipe, and the top of the corrugated pipe is connected to the negative electrode power supply 5. The electrode lead-out rod 21 is connected to the negative electrode power supply 5 in the corrugated pipe; the top of the gas pipeline 28.2 passes out from the interface on the left side of the four-way flange and is externally connected to a gas generating device. The tops of the liquid inlet pipe 24.2 and the liquid outlet pipe 24.3 pass out from the interface on the right side of the four-way flange and are externally connected to a pump body. Usually, the tops of both the liquid inlet pipe 24.2 and the liquid outlet pipe 24.3 pass out from the same interface of the four-way flange, and the top of the gas pipeline 28.2 passes out from the opposite interface.

[0069] In the system for magnetron sputtering target for inner wall evaporation plating of a cavity with different shapes provided by the embodiment of the present invention, refer to Figure 1, the driving mechanism 3 includes a driving member 31. A transfer block 32 is slidably connected to the driving shaft of the driving member 31, 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 move up and down on the driving shaft of the driving member 31 (refer to the driving mode of a ball screw). Also, since 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. Therefore, the electrode lead-out rod 21 can move up and down synchronously with the transfer block 32. The bottom of the electrode lead-out rod 21 is connected to an electrode plate 22, the electrode plate 22 is connected downward to an annular target 23 and a bottom support 27, and upward to a gas path plate 28 and a top support 29. Therefore, when the electrode plate 22 moves up and down, the entire magnetron sputtering target mechanism 2 is lifted or lowered. In a specific embodiment, the electrode lead-out rod 21 passes through a multi-pass flange 4 and then penetrates into a bellows. 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 transfer block 32. When the transfer block 32 moves up and down on the driving shaft of the driving member 31, the top of the bellows will move up and down accordingly, but the bottom of the bellows will not move, and the bellows will be in a state of being shortened or elongated. Also, since the negative electrode power supply 5 is installed at the top of the bellows, the negative electrode power supply 5 will move up and down with the top of the bellows. The negative electrode power supply 5 drives the magnetron sputtering target mechanism 2 to move up and down 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 inner wall evaporation of a cavity with different shapes provided in the embodiments of the present invention, referring to Figure 4 , Figure 5 and Figure 10 , an insulating cushion layer 6 is further provided between the gas path plate 28 and the electrode plate 22; and / or, an insulating cushion layer 6 is further provided between the electrode plate 22 and the cooling column 24; and / or, an insulating cushion layer 6 is further provided outside the bottom support 27; and / or, an insulating cushion layer 6 is provided on the part of the electrode lead-out rod 21 exposed to the external environment.

[0071] In the magnetron sputtering target system for inner wall evaporation of a cavity with different shapes provided in the embodiments of the present invention, referring to Figure 1 , the vacuum mechanism 1 includes a vacuum chamber 11 and a vacuum pump group 12 connected to the vacuum chamber 11. The vacuum chamber 11 is adapted to load the superconducting acceleration cavity 100, and further includes a bracket 7. The vacuum chamber 11 is provided on the bracket 7.

[0072] The embodiments of the present invention further provide a method for using a magnetron sputtering target system for inner wall evaporation of a cavity with different shapes, which at least includes the following steps:

[0073] Step 1): Evacuate the air, and evacuate the vacuum degree in the vacuum mechanism 1 to ≤ 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 connected in sequence 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 arranged in sequence and spaced apart in the axial direction of the cooling column (24); and 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); 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); An annular air passage (28.1) is provided in the air path plate (28), and an air path pipe (28.2) is also provided on the air path plate (28) and is connected to the annular air passage (28.1) and extends to the outside of the vacuum mechanism (1); a plurality of air outlet holes (28.3) are arranged in sequence along the circumferential direction of the annular air passage (28.1) and are all connected to the annular air passage (28.1) at the bottom of the air path plate (28), and the air outlet holes (28.3) are located outside the annular target material (23); 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, and both the liquid inlet pipe (24.2) and the liquid outlet pipe (24.3) extend toward 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 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).

3. The magnetron sputtering target system for evaporation of the inner wall of a special-shaped cavity according to claim 1, 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; 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.

4. The magnetron sputtering target system for evaporation of the inner wall of a special-shaped cavity according to claim 3, 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 2.4~4.4 A / cm 2 ; and / or, the duty cycle of the negative electrode power supply (5) is 0.1~0.99; and / or, the pulse frequency of the negative electrode power supply (5) is 10~40 kHz.

5. 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 disk (28) and the electrode disk (22); and / or, an insulating cushion layer (6) is also provided between the electrode disk (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.

6. 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.

7. 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).

8. A method for using the special-shaped cavity inner wall evaporation magnetron sputtering target system according to any one of claims 1 to 7, 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 superconducting acceleration cavities (100) are sputtered with a uniform superconducting thin film.

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