Central magnetic field rotatable target cathode and magnetron sputtering coating device

Abstract

The present invention discloses a target cathode with a rotatable central magnetic field and a magnetron sputtering coating device, relating to the field of magnetron sputtering technology. The target cathode with a rotatable central magnetic field comprises: a target material, a first column magnet, a second column magnet, and a rotation drive device. The front surface of the target material is used for colliding with charged particles to cause sputtering. A plurality of first column magnets are provided, and the plurality of first column magnets are sequentially arranged on the back side of the target material along a first circumference. The first circumference and the target material are coaxial, and the magnetic poles of all the first column magnets on the side close to the target material are the same. A single second column magnet is provided, and the second column magnet is arranged on the back side of the target material. The second column magnet is eccentrically arranged within the first circumference, and the magnetic poles of the second column magnet on the side close to the target material are opposite to the magnetic poles of the first column magnet on the side close to the target material. The rotation drive device is used to drive the second column magnet to rotate around the central axis of the first circumference. This improves the utilization rate of the target material and the sputtering rate.

Description

Technical Field

[0001] The present invention relates to the technical field of magnetron sputtering, in particular to a target cathode with a rotatable central magnetic field and a magnetron sputtering coating device. Background Art

[0002] Magnetron sputtering is a coating technology that uses the coating material as the target cathode, bombards the target material with argon ions, generates cathode sputtering, and sputters the target atoms onto the workpiece to form a deposited layer. The coating material remains solid and does not form a molten pool. As an important surface treatment technology, magnetron sputtering will play an increasingly important role in future scientific and technological development. It has become an important means of depositing wear-resistant, corrosion-resistant, decorative, optical and other functional films. Magnetron sputtering will continue to incorporate more advanced scientific and technological elements to meet more complex and high-precision coating needs.

[0003] Due to the magnetic field distribution factor, the existing target cathode has low target material utilization and low sputtering rate, and cannot achieve large-area uniform and rapid thin film deposition. Summary of the Invention

[0004] The purpose of the present invention is to provide a target cathode with a rotatable central magnetic field and a magnetron sputtering coating device to solve the problems existing in the above-mentioned prior art and improve the utilization rate of the target material and the sputtering rate.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The present invention provides a target cathode with a rotatable central magnetic field, comprising: a target material, a first column magnet, a second column magnet and a rotation drive device, wherein the front side of the target material is used for colliding with charged particles for sputtering; a plurality of first column magnets are provided, and the plurality of first column magnets are sequentially arranged on the back side of the target material along a first circumference, the first circumference and the target material are coaxial, and the magnetic poles of all the first column magnets on the side close to the target material are the same; a single second column magnet is provided, and the second column magnet is arranged on the back side of the target material; the second column magnet is eccentrically arranged within the first circumference, and the magnetic pole of the second column magnet on the side close to the target material is opposite to the magnetic pole of the first column magnet on the side close to the target material; the rotation drive device is used to drive the second column magnet to rotate around the central axis of the first circumference.

[0007] Preferably, a cooling cavity is constructed on the back side of the target material, and the cooling cavity is connected to a water inlet and a water outlet, and cooling water is circulated in the cooling cavity to cool the target material.

[0008] Preferably, the second column magnet is arranged perpendicular to the target surface of the target material, and the first column magnet gradually extends from one end away from the target material to the other end toward the direction close to the central axis of the first circle.

[0009] Preferably, it also includes a target seat connecting and fixing sleeve and a magnetic rail seat, the magnetic rail seat is arranged on the back side of the target material, the front side of the magnetic rail seat is arranged in contact with the back side of the target material, the target seat connecting and fixing sleeve is arranged on the back side of the magnetic rail seat and connected to each other, the back side of the magnetic rail seat is provided with a groove extending from the back side toward the front side, the first column magnet is arranged inside the magnetic rail seat and arranged in sequence around the groove, the target seat connecting and fixing sleeve seals the groove and forms the cooling cavity, the target seat connecting and fixing sleeve is electrically connected to the magnetic rail seat, the target seat connecting and fixing sleeve is used to be connected to the negative pole of an external power supply, the second column magnet is arranged in the cooling cavity, the middle part of the target seat connecting and fixing sleeve is provided with an axial hole, the rotating shaft of the rotation drive device is passed through the axial hole, the free end of the rotating shaft is fixedly connected to the second column magnet, and the axis of the rotating shaft is coaxial with the central axis of the first circle.

[0010] Preferably, it also includes a rear washer, which is annular and is arranged on the back of the magnetic rail seat. A plurality of accommodating cavities are provided on the back of the magnetic rail seat. The plurality of accommodating cavities are arranged in sequence around the groove. One end of the first column magnet extends into the accommodating cavity, and the other end is connected to the rear washer.

[0011] Preferably, it also includes an annular mounting flange, which is arranged on the back side of the target base connecting and fixing sleeve, an insulating gasket is sandwiched between the target base connecting and fixing sleeve and the mounting flange, and the rotating shaft is passed through the mounting flange, the target base connecting and fixing sleeve and the rear washer.

[0012] Preferably, it also includes a shielding cover, the front side end of the shielding cover is open, and the back side end is constructed with an annular extension plate, the magnetic rail seat, the rear washer and the target seat connection and fixing sleeve are all located in the shielding cover, the extension plate and the mounting flange, the first circumference and the target seat connection and fixing sleeve are all coaxially arranged, the extension plate is located between the mounting flange and the insulating pad, the mounting flange, the extension plate, the insulating pad and the target seat connection and fixing sleeve are all fixedly connected by the same set of mounting bolts, during installation, the screw of each mounting bolt passes through the through holes on the mounting flange, the extension plate and the insulating pad in turn and is threadedly connected to the threaded hole on the back side of the target seat connection and fixing sleeve, and the outer cover of the mounting bolt is provided with an insulating sleeve.

[0013] Preferably, the target material is pressed and fixed to the front surface of the magnetic rail seat by an annular pressure cover, the pressure cover is detachably connected to the magnetic rail seat, and the pressure cover is pressed against the outer edge of the front surface of the target material.

[0014] Preferably, the gland is mounted on the front of the magnetic rail seat via gland mounting bolts, and the magnetic rail seat is mounted on the front of the target seat connection fixing sleeve via magnetic rail seat mounting bolts.

[0015] The present invention also provides a magnetron sputtering coating device, comprising the above-mentioned central magnetic field rotatable target cathode.

[0016] Compared with the prior art, the present invention has achieved the following technical effects:

[0017] The second column magnet in the central magnetic field rotatable target cathode provided by the present invention can be driven by a rotation drive device to rotate around the central axis of the first circle. During the rotation of the second column magnet, due to the different distances between the second column magnet and different first column magnets, it can generate magnetic fields of different ranges, and the areas of the target surface sputtering runway formed are also different, thereby achieving the purpose of increasing the target surface sputtering runway area and improving the utilization rate of the target material and the sputtering rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 A cross-sectional view in a first direction of the central magnetic field rotatable target cathode provided by the present invention;

[0020] Figure 2 A cross-sectional view in a second direction of the central magnetic field rotatable target cathode provided by the present invention;

[0021] Figure 3 A schematic diagram of the structure of the electrical connection threaded hole of the central magnetic field rotatable target cathode provided by the present invention;

[0022] Figure 4 A schematic structural diagram of the water inlet pipe, water outlet pipe and flow guide pipe of the central magnetic field rotatable target cathode provided by the present invention;

[0023] Figure 5 The arrangement diagram of the first column magnet and the second column magnet;

[0024] Figure 6 is the target magnetic field analysis diagram;

[0025] In the figure: 1-mounting bolt; 2-insulating sleeve; 3-mounting flange; 4-first vacuum sealing O-ring; 5-second vacuum sealing O-ring; 6-shielding cover; 7-insulating pad; 8-target base connecting fixing sleeve; 81-water inlet pipe; 82-water outlet pipe; 83-guide pipe; 84-electrical threaded hole; 9-rear washer; 10-first column magnet; 11-first cooling water pressure sealing O-ring; 12-magnetic rail seat; 121-cooling chamber; 13-magnetic rail seat mounting bolt; 14-target material; 15-pressure cover; 16-pressure cover mounting bolt; 17-second column magnet; 18-locating pin; 19-center rotating seat; 20-rotating shaft; 21-first bearing; 22-second cooling water pressure sealing O-ring; 23-second bearing; 24-circlip; 25-adapter shaft; 26-rotating motor; 27-motor seat; 28-first bolt; 29-second bolt. DETAILED DESCRIPTION

[0026] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0027] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] In this specification, the front and positive side of each component are viewed from the perspective of charged particles. Specifically, the side of the component facing the charged particles is the front or positive side, and the other side is the back or back side.

[0029] The following combination Figures 1 to 6 , describing embodiments of the present invention.

[0030] The present invention provides a target cathode with a rotatable central magnetic field, comprising: a target material 14, a first column magnet 10, a second column magnet 17 and a rotation drive device, wherein the front surface of the target material 14 is used for colliding with charged particles for sputtering; a plurality of first column magnets 10 are provided, and the plurality of first column magnets 10 are sequentially arranged on the back side of the target material 14 along a first circumference, the first circumference and the target material 14 are coaxial, and the magnetic poles of all the first column magnets 10 on the side close to the target material 14 are the same; a single second column magnet 17 is provided, and the second column magnet 17 is arranged on the back side of the target material 14; the second column magnet 17 is eccentrically arranged within the first circumference, and the magnetic pole of the second column magnet 17 on the side close to the target material 14 is opposite to the magnetic pole of the first column magnet 10 on the side close to the target material 14; the rotation drive device is used to drive the second column magnet 17 to rotate around the central axis of the first circumference.

[0031] The second column magnet 17 in the central magnetic field rotatable target cathode provided by an embodiment of the present invention can be driven by a rotation drive device to rotate around the central axis of the first circle. During the rotation of the second column magnet 17, due to the different distances between the second column magnet 17 and different first column magnets 10, magnetic fields of different ranges can be generated, and the areas of the target surface sputtering runways formed are also different, thereby achieving the purpose of increasing the target surface sputtering runway area and improving the utilization rate of the target material 14.

[0032] In some embodiments, a cooling cavity 121 is configured on the back side of the target 14 . The cooling cavity 121 is connected to a water inlet and a water outlet. Cooling water circulates in the cooling cavity 121 to cool the target 14 .

[0033] This embodiment can reduce the probability of the target material 14 being damaged due to high temperature and improve the stability of sputtering.

[0034] In some embodiments, the second pillar magnet 17 is disposed perpendicular to the target surface of the target 14 , and the first pillar magnet 10 gradually extends from one end away from the target 14 to the other end toward the central axis of the first circle.

[0035] In this embodiment, the first column magnet 10 is tilted toward the second column magnet 17, thereby optimizing the magnetic field distribution and improving sputtering efficiency. In a more preferred embodiment, the first column magnet 10 is tilted at an angle of 30 degrees, that is, the angle between the axis of the first column magnet 10 and the axis of the second column magnet 17 is 30 degrees.

[0036] In some embodiments, the second column magnet 17 may be an elliptical cylindrical magnet or a cylindrical magnet. The purpose of setting it as an elliptical cylindrical magnet is to utilize the special shape and surface of the elliptical magnet to have a very high uniform magnetic field. The magnetic field strength and direction can be adjusted according to the major and minor axes and polarization direction of the ellipse to control the motion trajectory of the charged particles, which can ensure that the charged particles do not produce unnecessary deviations during the acceleration process, thereby improving the acceleration efficiency and accuracy.

[0037] In some embodiments, the embodiments of the present invention further include a target base connecting and fixing sleeve 8 and a magnetic rail seat 12, the magnetic rail seat 12 is arranged on the back of the target material 14, the front of the magnetic rail seat 12 is arranged to fit the back of the target material 14, the target base connecting and fixing sleeve 8 is arranged on the back of the magnetic rail seat 12 and connected to each other, the back of the magnetic rail seat 12 is provided with a groove extending from the back toward the front, the first column magnet 10 is arranged inside the magnetic rail seat 12, and is arranged in sequence around the groove, the target base connecting and fixing sleeve 8 seals the groove and forms a cooling chamber 121, the target base connecting and fixing sleeve 8 is electrically connected to the magnetic rail seat 12, the target base connecting and fixing sleeve 8 is used to be connected to the negative pole of an external power supply, the second column magnet 17 is arranged in the cooling chamber 121, the middle part of the target base connecting and fixing sleeve 8 is provided with an axial hole, the rotating shaft 20 of the rotary drive device is passed through the axial hole, the free end of the rotating shaft 20 is fixedly connected to the second column magnet 17, and the axis of the rotating shaft 20 is coaxial with the central axis of the first circle.

[0038] This embodiment achieves the purpose of forming a cooling cavity 121 on the back of the target material 14. In addition, during use, it is necessary to apply a negative voltage to the target material 14. The embodiment of the present invention applies voltage to the target base connecting and fixing sleeve 8 and transmits it to the target material 14 through the magnetic rail seat 12. Specifically, the back side end of the target base connecting and fixing sleeve 8 is provided with an electrical threaded hole 84, which is used to install a wire nose for connecting the wire.

[0039] In some examples, the water inlet and the water outlet are arranged on the target base connecting and fixing sleeve 8, that is, two channels are provided on the target base connecting and fixing sleeve 8, which serve as the water inlet and the water outlet respectively. In order to better inlet and outlet water, a stainless steel pipe is welded at the port of the water inlet on the back of the target base connecting and fixing sleeve 8 as the water inlet pipe 81, and a stainless steel pipe is welded at the port of the water outlet on the back of the target base connecting and fixing sleeve 8 to make a water pipe 82. A stainless steel pipe is welded at the other port of the water outlet as a guide pipe 83. The gap distance between the outlet end face of the guide pipe 83 and the back of the magnetic rail seat 12 is preferably 1 mm. In use, the cooling cavity 121 is horizontally arranged, that is, the target material 14 is horizontally arranged, and the cooling water enters the cooling cavity 121 from the water inlet pipe 81, and then enters the water outlet pipe 82 from the guide pipe 83 and flows out, so that the cooling water completely fills the cooling cavity 121, thereby improving the cooling effect.

[0040] Some examples, such as Figure 1 As shown, the rotating shaft 20 is rotatably connected to the shaft hole via a first bearing 21 and a second bearing 23. A retaining spring 24 limits axial movement of the second bearing 23. A second cooling water pressure seal O-ring 22 is provided between the outer wall of the rotating shaft 20 and the shaft hole to prevent water leakage from the cooling chamber 121. The arrangement of the bearings ensures that the rotating shaft 20 is concentric with the magnetic rail seat 12 and that the rotating shaft 20 does not swing, ensuring stable rotation. This ensures that the central magnetic field on the target surface rotates stably without excessive fluctuations.

[0041] In some examples, an adapter shaft 25 is also included. The rotation driving device is a rotating motor 26. The adapter shaft 25 is directly connected to the rotating motor 26. The adapter shaft 25 is coaxially connected to the rotating shaft 20. In order to prevent the rotating shaft 20 from conducting electricity to the rotating motor 26, the adapter shaft 25 can be set as an insulating shaft to achieve insulation purposes.

[0042] In some embodiments, the second column magnet 17 is mounted on the central rotating seat 19 in the cooling cavity 121 and sealed with waterproof glue. The central rotating seat 19 and the rotating shaft 20 are fixedly connected by a positioning pin 18. The waterproof glue seal is to prevent the second column magnet 17 from rusting and corroding due to long-term immersion in cooling water.

[0043] In some examples, a deep groove for fixing the second column magnet 17 is provided on the front side of the central rotating seat 19, so that the second column magnet 17 is not easy to fall off and works stably.

[0044] In some embodiments, the embodiments of the present invention further include a rear washer 9, which is annular and is arranged on the back of the magnetic rail seat 12. The back of the magnetic rail seat 12 is provided with multiple accommodating cavities, which are arranged in sequence around the groove. One end of the first column magnet 10 extends into the accommodating cavity, and the other end is connected to the rear washer 9.

[0045] The rear shim 9 in this embodiment converts all the magnetic quantities of the first column magnets 10 into a magnetic ring, thereby optimizing the magnetic field distribution so that the front surface of the target 14 can form a ring shape.

[0046] In some embodiments, a first cooling water pressure sealing O-ring 11 is provided between the rear washer 9 and the magnetic rail seat 12 and between the rear washer 9 and the target seat connection fixing sleeve 8 .

[0047] In some examples, the rear washer 9 and the central rotating seat 19 are made of Q235 material with good magnetic conductivity and a thickness of 5 mm.

[0048] In some embodiments, the embodiments of the present invention further include an annular mounting flange 3, which is arranged on the back side of the target base connecting and fixing sleeve 8, an insulating gasket 7 is sandwiched between the target base connecting and fixing sleeve 8 and the mounting flange 3, and the rotating shaft 20 is passed through the mounting flange 3, the target base connecting and fixing sleeve 8 and the rear washer 9.

[0049] This embodiment facilitates the connection of the cathode target and the coating device via the mounting flange 3 . It is understandable that the mounting flange 3 is provided with a plurality of through holes or threaded holes for passing bolts.

[0050] In some embodiments, the present invention further includes a shielding cover 6 having an open front end and an annular extension plate formed on the back end. The magnetic rail seat 12, rear washer 9, and target base connection and fixing sleeve 8 are all located within the shielding cover 6. The extension plate is coaxially arranged with the mounting flange 3, the first circumference, and the target base connection and fixing sleeve 8. The extension plate is located between the mounting flange 3 and the insulating gasket 7. The mounting flange 3, the extension plate, the insulating gasket 7, and the target base connection and fixing sleeve 8 are all fixedly connected by a common set of mounting bolts 1. During installation, the screw of each mounting bolt 1 sequentially passes through a through-hole in the mounting flange 3, the extension plate, and the insulating gasket 7, and then is threadedly connected to a threaded hole on the back of the target base connection and fixing sleeve 8. The mounting bolts 1 are covered with an insulating sleeve 2. The use of the insulating sleeve 2 and the insulating gasket 7 can prevent the experimenter from being electrocuted by contact with the mounting bolts 1 or the mounting flange 3 during target operation, thereby protecting the experimenter's safety.

[0051] The shielding cover 6 in this embodiment is used to connect to the ground, which can shield the radiation and heat of high-energy particles generated by the experiment, reduce the radiation dose received by the operator and the surrounding environment, and ensure the safety of the experiment. At the same time, the shielding cover 6 can also intercept recoil matter and debris to prevent damage to equipment and experimenters, thereby ensuring the safety of the experiment and protecting the safety of experimenters, equipment and the environment.

[0052] Preferably, since the turning point distance of the secondary electron cycloid trajectory is generally no more than 3 mm, the side gap between the shielding cover 6 and the magnetic track seat 12 is set to no more than 2.5 mm, which can make the shielding cover 6 and the magnetic track seat 12 in an open circuit state, thereby saving energy and reducing energy consumption.

[0053] Specifically, in magnetron sputtering coating technology, for a planar cathode, the trajectory of secondary electrons (the distance between the electrons and the turning point) is a crucial factor. After being emitted from the cathode target, electrons follow a complex path under the combined influence of the electric and magnetic fields. This path can be described by a cycloid, a mathematical curve that represents the trajectory of electrons in magnetic and electric fields. This distance has a decisive influence on the electron path during magnetron sputtering and can be determined by a specific formula. The formula can be referenced in existing technology and will not be elaborated here.

[0054] The insulating pad 7 is made of insulating materials such as polytetrafluoroethylene and has a thickness of 5-10 mm. The insulating pad 7 is provided with a sealing groove and circular evenly distributed mounting holes for the insulating sleeve 2 and the mounting bolts 1 to pass through. A gap is provided between the mounting hole of the insulating pad 7 and the insulating sleeve 2 to facilitate the installation of the insulating sleeve 2.

[0055] In some embodiments, the embodiments of the present invention also include a first vacuum sealing O-ring 4 and a second vacuum sealing O-ring 5, the second vacuum sealing O-ring 5 is arranged between the mounting flange 3 and the extension plate, and the first vacuum sealing O-ring 4 is arranged on the surface of the mounting flange 3 in contact with the coating equipment.

[0056] In some embodiments, the magnetic rail seat 12 is made of copper material with good conductivity, and the distance between the bottom of the cooling cavity 121 and the front of the magnetic rail seat 12 is 2 mm, that is, the thickness of the part of the magnetic rail seat 12 corresponding to the cooling cavity 121 is 2 mm.

[0057] In some embodiments, the target 14 is pressed and fixed to the front surface of the magnetic rail base 12 by an annular pressure cap 15. The pressure cap 15 is detachably connected to the magnetic rail base 12 and is pressed against the outer edge of the front surface of the target 14. Specifically, the pressure cap 15 is mounted to the front surface of the magnetic rail base 12 via pressure cap mounting bolts 16, and the magnetic rail base 12 is mounted to the front surface of the target base connection and fixing sleeve 8 via magnetic rail base mounting bolts 13.

[0058] This embodiment uses bolts to install the components, abandoning the existing gluing, which improves the working stability and service life.

[0059] According to the different thicknesses of the target material 14, the pressure caps 15 of different sizes are selected for fixed installation, so that the gap between the target surface and the magnet surface of the second column magnet 17 is 2 mm, thereby improving the coating quality.

[0060] In some embodiments, the rotating motor 26 is connected to the flange via a motor base 27 . The rotating motor 26 is connected to the motor base 27 via a first bolt 28 , and the motor base 27 is connected to the flange via a second bolt 29 .

[0061] The present invention also provides a magnetron sputtering coating device, comprising the above-mentioned central magnetic field rotatable target cathode.

[0062] This embodiment has all the advantages of the above embodiments, which will not be described in detail here.

[0063] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A target cathode with a rotatable central magnetic field, characterized in that: include: A target material, wherein the front surface of the target material is used for collision with charged particles to perform sputtering; A plurality of first column magnets are provided, wherein the plurality of first column magnets are sequentially arranged on the back side of the target along a first circumference, the first circumference and the target are coaxial, and the magnetic poles of all the first column magnets on the side close to the target are the same; A second column magnet is provided, wherein the second column magnet is provided on the back side of the target; the second column magnet is eccentrically provided within the first circumference, and the magnetic pole of the second column magnet on the side close to the target is opposite to the magnetic pole of the first column magnet on the side close to the target; as well as a rotation driving device for driving the second column magnet to rotate around the central axis of the first circle; The back side of the target material is constructed with a cooling cavity, which is connected to a water inlet and a water outlet, and the cooling cavity is used to circulate cooling water to cool the target material; the second column magnet is arranged perpendicular to the target surface of the target material, and the first column magnet gradually extends from one end away from the target material to the other end toward the direction of the central axis of the first circle; it also includes a target seat connecting and fixing sleeve and a magnetic rail seat, the magnetic rail seat is arranged on the back side of the target material, the front side of the magnetic rail seat is arranged in contact with the back side of the target material, the target seat connecting and fixing sleeve is arranged on the back side of the magnetic rail seat and is connected to each other, the back side of the magnetic rail seat is provided with a groove extending from the back side toward the front side, and the first column magnet is arranged The interior of the magnetic rail seat is arranged in sequence around the groove, the target seat connection and fixing sleeve seals the groove and forms the cooling chamber, the second column magnet is arranged in the cooling chamber, the middle part of the target seat connection and fixing sleeve is provided with an axial hole, the rotating shaft of the rotary drive device is passed through the axial hole, the free end of the rotating shaft is fixedly connected to the second column magnet, the axis of the rotating shaft is coaxial with the central axis of the first circle; a guide pipe is provided at the inner port of the water outlet, the gap between the water outlet end face of the guide pipe and the back side of the magnetic rail seat is 1 mm, so that the cooling chamber is arranged horizontally in the use state; the outer cover of the magnetic rail seat is provided with a shielding cover, and the gap between the shielding cover and the side of the magnetic rail seat is set to be no more than 2.5 mm.

2. The central magnetic field rotatable target cathode according to claim 1, characterized in that: The target base connection fixing sleeve is electrically connected to the magnetic rail seat, and the target base connection fixing sleeve is used to be connected to the negative pole of an external power supply.

3. The central magnetic field rotatable target cathode according to claim 2, characterized in that: It also includes a rear washer, which is annular and is arranged on the back of the magnetic rail seat. The back of the magnetic rail seat is provided with multiple accommodating cavities, and the multiple accommodating cavities are arranged in sequence around the groove. One end of the first column magnet extends into the accommodating cavity, and the other end is connected to the rear washer.

4. The central magnetic field rotatable target cathode according to claim 3, characterized in that: It also includes an annular mounting flange, which is arranged on the back side of the target base connection and fixing sleeve, an insulating gasket is sandwiched between the target base connection and fixing sleeve and the mounting flange, and the rotating shaft is passed through the mounting flange, the target base connection and fixing sleeve and the rear washer.

5. The central magnetic field rotatable target cathode according to claim 4, characterized in that: The front side end of the shielding cover is open, and the back side end is constructed with an annular extension plate. The magnetic rail seat, the rear washer and the target base connection and fixing sleeve are all located in the shielding cover. The extension plate and the mounting flange, the first circumference and the target base connection and fixing sleeve are all coaxially arranged. The extension plate is located between the mounting flange and the insulating pad. The mounting flange, the extension plate, the insulating pad and the target base connection and fixing sleeve are all fixedly connected by the same set of mounting bolts. During installation, the screw of each mounting bolt passes through the through holes on the mounting flange, the extension plate and the insulating pad in sequence and is threadedly connected to the threaded hole on the back side of the target base connection and fixing sleeve. The outer cover of the mounting bolt is provided with an insulating sleeve.

6. The central magnetic field rotatable target cathode according to claim 5, characterized in that: The target material is pressed and fixed on the front face of the magnetic rail seat by an annular pressure cover, the pressure cover is detachably connected to the magnetic rail seat, and the pressure cover is pressed on the outer edge of the front face of the target material.

7. The central magnetic field rotatable target cathode according to claim 6, characterized in that: The gland is mounted on the front of the magnetic rail seat via gland mounting bolts, and the magnetic rail seat is mounted on the front of the target seat connection and fixing sleeve via magnetic rail seat mounting bolts.

8. A magnetron sputtering coating device, characterized in that: The invention comprises the target cathode with central magnetic field rotation according to any one of claims 1 to 7.

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