Magnetic field scanning cylindrical cathode target

Abstract

The application relates to a magnetic field scanning cylindrical cathode target, which comprises a magnetic field module, a target material assembly sleeved outside the magnetic field module and a driving module for driving the magnetic field module to rotate; the magnetic field module comprises a rotating shaft, a magnetic base fixed outside the rotating shaft, a magnet assembly fixed on the magnetic base and a magnetic yoke sleeved outside the magnet assembly; the target material assembly comprises a target base connected with the magnetic field module through a bearing and a target material sleeved outside the target base; the target base has a water-cooling interlayer; the magnetic field module is used for generating a magnetic field; under the driving of the driving module, the magnetic field module generates a moving magnetic field, which scans the surface of the target material. The cathode target can solve the problems in the prior art, the magnet is not directly contacted with cooling water, and the service life of the magnet and the utilization rate of the target material are greatly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of magnetron sputtering technology, and particularly relates to a magnetic field scanning cylindrical cathode target for industrial vacuum ion sputtering coating. BACKGROUND

[0002] Magnetron sputtering is a kind of physical vapor deposition (PVD), which is a thin film preparation method developed in the 1970s. It can be used to prepare metal, semiconductor, insulator and other materials. Magnetron sputtering technology has the characteristics of high speed, low temperature, low damage, energy saving and environmental protection, simple equipment, easy control, large coating area and strong adhesion. Compared with general sputtering method, magnetron sputtering technology has the advantages of high gas ionization rate and sputtering rate. At present, the use of magnetron sputtering technology to prepare thin films at low cost, large area and high efficiency has gradually become the development direction of the coating field, and the demand for large size and high quality sputtering target materials is also increasing.

[0003] The utilization rate of the magnetron sputtering target material is an important parameter for the engineering design of the magnetron sputtering source and the cost accounting of the production process. However, the existing target for vacuum ion coating machine has many problems, such as low target material utilization rate (<50%), contact of cooling water with magnet will cause short service life of magnetic steel, and frequent replacement is required. SUMMARY

[0004] The purpose of the present application is to provide a magnetic field scanning cylindrical cathode target which can solve the problems in the prior art, and the magnetic field of the target does not directly contact with the cooling water, greatly improving the service life of the magnet and the utilization rate of the target material.

[0005] To achieve the above purpose, the present application adopts the following technical solutions:

[0006] A magnetic field scanning cylindrical cathode target, which comprises a magnetic field module, a target material assembly sleeved outside the magnetic field module, and a driving module for driving the magnetic field module to rotate;

[0007] The magnetic field module comprises a rotating shaft, a magnetic base fixedly arranged outside the rotating shaft, a magnet assembly fixedly arranged on the magnetic base, and a magnetic yoke sleeved outside the magnet assembly;

[0008] The target material assembly comprises a target base connected to the magnetic field module through a bearing, and a target material sleeved outside the target base; the target base has a water-cooled interlayer;

[0009] The magnetic field module is used for generating a magnetic field, and under the driving of the driving module, the magnetic field module generates a moving magnetic field which scans the surface of the target material, so as to realize uniform sputtering of the target surface and effectively improve the utilization rate of the target material.

[0010] Further, the driving module is an electric motor.

[0011] The electric motor is a servo motor.

[0012] Further, the magnet assembly comprises a plurality of strip-shaped magnetic steels arranged along the length direction of the rotating shaft; and a magnetic steel gap is arranged between adjacent magnetic steels.

[0013] The magnetic steels are made of NbFeB material.

[0014] The magnetic steels comprise N-pole magnetic steels and S-pole magnetic steels.

[0015] Further, the number of the magnet assemblies is multiple, and the magnet assemblies are sequentially arranged along the outer periphery of the magnet base.

[0016] The lengths of the magnetic steels in adjacent magnet assemblies are different.

[0017] The magnetic steel gaps in adjacent magnet assemblies are staggered.

[0018] Further, the water-cooled interlayer is a cooling circuit arranged in the middle of the target base.

[0019] The cooling circuit is connected with a cooling water inlet and a cooling water outlet.

[0020] Further, the cathode target further comprises a flange and a magnetic fluid sealing device.

[0021] The output shaft of the electric motor is connected with the output shaft of the magnetic fluid sealing device.

[0022] The output shaft of the magnetic fluid sealing device is further connected with the rotating shaft.

[0023] The flange is used for connecting the cathode target with the vacuum cavity.

[0024] Further, the output shaft of the electric motor is connected with the output shaft of the magnetic fluid sealing device through a speed reducer.

[0025] Further, the target material is a single metal pipe or a ceramic pipe.

[0026] Or, the target material is formed by splicing a plurality of metal pipes or ceramic pipes, and the interfaces of adjacent metal pipes or ceramic pipes are beveled.

[0027] Further, the target material and the target base are connected by indium-tin alloy.

[0028] Further, the cathode target further comprises a sputtering power supply.

[0029] The sputtering power supply is a direct current, pulse, radio frequency or intermediate frequency power supply, and the power density is 5-30 W / cm2.2 .

[0030] Compared with the prior art, the present application has the following advantages:

[0031] (1) The present application sets a rotatable magnetic field module, so that the magnetic field generated by the magnetic field module can move, realizing the rotation scanning of the magnetic field on the surface of the target material, ensuring uniform sputtering of the surface in the sputtering process, and effectively improving the utilization rate of the target material and the stability of the glow.

[0032] (2) The present application sets a target holder with a water-cooled interlayer, so that the cooling water flows in the water-cooled circuit inside the target holder to indirectly cool the magnetic field module, thereby avoiding the direct contact of the cooling water with the magnets, and greatly improving the utilization rate of the target material, the service life of the magnetic steel, and the stability of the plasma.

[0033] (3) The magnet assembly used in the magnetic field module of the present application has different lengths of magnetic steels in adjacent magnet assemblies, and the gaps between the magnetic steels in adjacent magnet assemblies are staggered. Since there is a gap between adjacent magnetic steels, if the length of each group of magnets is the same, there will be no magnetic field at the gap at the same position, which will result in no sputtering or low sputtering rate at some positions, uneven sputtering on the target surface, and reduced utilization rate of the target material. Therefore, by making the lengths of the magnetic steels in adjacent groups different, the gaps between adjacent magnets are staggered, so that there is no dead angle in the magnetic field, ensuring that each position can be sputtered during magnetron sputtering, and improving the utilization rate of the target material.

[0034] (4) The cathode target of the present application is composed of a plurality of metal pipes or ceramic pipes spliced together, and the interfaces of adjacent metal pipes or ceramic pipes are beveled during splicing. In this way, the part with material covers the part without material during rotation, thereby ensuring the uniformity of the film and ensuring that each position can be sputtered. BRIEF DESCRIPTION OF DRAWINGS

[0035] Figure 1 is a structural schematic diagram of the cylindrical cathode target in the present application;

[0036] Figure 2 is a sectional view of the cylindrical cathode target along the A-A' plane in the present application; Figure 1

[0037] Figure 3 is a sectional view of the cylindrical cathode target along the B-B' plane in the present application; Figure 1

[0038] Figure 4 is a schematic diagram of the magnetic field layout of the magnetic steel overlap;

[0039] Figure 5 is a schematic diagram of the target material of the cylindrical cathode target as a whole target and a spliced target;​​

[0040] Figure 6 is 4 groups of magnetic steel arrangement, Comsol simulation target surface etching profile magnetic field distribution schematic diagram;

[0041] Figure 7 is 8 groups of magnetic steel arrangement Comsol simulation target surface etching profile magnetic field distribution schematic diagram.

[0042] Wherein:

[0043] 1, servo motor, 2, flange, 3, cooling water inlet, 4, target material, 5, cooling water outlet, 6, rotating shaft, 7, target holder, 8, magnetic fluid sealing device, 9, magnetic base, 10, magnetic steel, 11, magnetic yoke, 12, sealing ring, 13, target material, 14, bearing. DETAILED DESCRIPTION

[0044] The application will be further described below in conjunction with the drawings:

[0045] As Figures 1-3 shown in a kind of magnetic field scanning cylindrical cathode target, the cathode target includes magnetic field module, target material subassembly of being set outside the magnetic field module and drive module of the magnetic field module rotation is driven.The magnetic field module includes rotating shaft, fixedly arranged on the rotating shaft outside magnetic base, fixedly arranged on the magnetic base magnet assembly and the magnetic yoke of being set outside the magnet assembly.The magnetic field module is used to generate magnetic field, under the drive of the drive module, the magnetic field module generates moving magnetic field, and the magnetic field is scanned to the target surface.The cathode target also includes sputtering power supply;The sputtering power supply is direct current, pulse, radio frequency or intermediate frequency power supply, and power density is 5-30W / cm 2 With speed reducer, PLC and touch screen, the rotation direction and rotational speed of the magnetic field module are controlled, the rotational speed of the magnetic field system is 5-30rpm, so that the magnetic field parallel to the target surface is scanned to the entire target. By setting the rotatable magnetic field module, uniform sputtering of the target surface can be realized, and the utilization rate of the target material is effectively improved.

[0046] As Figure 2 shown, the target material subassembly includes target holder connected with the magnetic field module by bearing and target material set outside the target holder. The number of bearings is two, and the two ends of the target material subassembly are connected with the magnetic field module by one bearing. The target material and the target holder are connected by indium-tin alloy.

[0047] As Figure 1As shown, the driving module is a motor; the motor is a servo motor. The cathode target also comprises a flange and a magnetic fluid sealing device; the output shaft of the motor is connected with the output shaft of the magnetic fluid sealing device; the output shaft of the magnetic fluid sealing device is also connected with the rotating shaft; the flange is used for connecting the cathode target with the vacuum cavity. The output shaft of the motor is connected with the output shaft of the magnetic fluid sealing device through a speed reducer. The magnetic fluid sealing device is a standard part, which plays a dynamic sealing role in the rotation of the magnetic field module. The speed reducer plays a role of adjusting the rotating speed of the magnetic field module. The motor rotates to drive the speed reducer, the speed reducer rotates to drive the magnetic fluid sealing device, the magnetic fluid sealing device rotates to drive the magnetic field module.

[0048] As shown in Figure 2 and Figure 3 shown, the magnet assembly comprises a plurality of strip-shaped magnetic steels arranged along the length direction of the rotating shaft; a magnetic steel gap is arranged between adjacent magnetic steels; the magnetic steels are made of NbFeB material; the magnetic steels comprise N-pole magnetic steels and S-pole magnetic steels. In each group of magnetic steels, the lengths of the N-pole magnetic steels and the S-pole magnetic steels are the same. The number of the magnet assemblies is multiple, and the magnet assemblies are arranged along the outer periphery of the magnetic seat in sequence. As shown in Figure 3 , a plurality of magnet assemblies are symmetrically distributed along the axis of the cylinder, and the distribution angles of 4 groups, 6 groups and 8 groups of magnetic steels are 90°, 60° and 45°, respectively. As shown in Figure 4 , the lengths of the magnetic steels in adjacent magnet assemblies are different; the magnetic steel gaps in adjacent magnet assemblies are staggered. Preferably, the lengths of the magnetic steels in any two adjacent magnet assemblies differ by 2 cm. There is a gap between adjacent magnetic steels. If the lengths of the magnetic steels in each group are the same, there is no magnetic field at the gap at the same position, which will cause the position to be not sputtered or sputtered at a low rate, the target surface is not sputtered uniformly, and the utilization rate of the target material is reduced. By making the lengths of the magnetic steels in adjacent groups different, the gaps between adjacent magnetic steels are staggered, so that there is no dead angle in the magnetic field, ensuring that each position can be sputtered during magnetron sputtering, and improving the utilization rate of the target material.

[0049] As shown in Figure 2 , the target seat has a water-cooled interlayer; the water-cooled interlayer is a cooling circuit arranged in the middle of the target seat; the cooling circuit is connected with a cooling water inlet and a cooling water outlet. In this embodiment, the cooling system of the cathode target is composed of a circulating water cooler, a water pressure gauge, a cooling water inlet, a cooling water outlet and a water-cooled circuit. The temperature of the cooling water flowing in the cooling circuit is 25-28 ℃, and the water pressure is 2-2.5 kg / cm 2, the flow rate is 10-15 L / min. If the magnet is directly in contact with the cooling water, the magnet will be corroded, affecting the performance of the magnet. The application sets a target seat with a water-cooled sandwich, and a water-cooled circuit is opened on the target seat, which can ensure the stability of cooling and avoid direct contact between the cooling water and the magnet, prolong the service life of the magnet and ensure the performance stability of the magnet.

[0050] As shown in Figure 5 , the target material is a single metal pipe or ceramic pipe as shown in Figure 5 a, or is spliced by multiple metal pipes or ceramic pipes, and the interfaces of adjacent metal pipes or ceramic pipes are beveled when splicing, as shown in Figure 5 b. If it is a cylindrical shape, there is a gap in the middle when rotating, without target material, affecting the uniformity of the film during preparation. In this embodiment, the target material is spliced with a beveled interface, so that the part with material covers the part without material during rotation, thereby ensuring the uniformity of the film and ensuring that each place can be sputtered.

[0051] The following describes the cathode target of the application in two specific embodiments:

[0052] Embodiment 1

[0053] In this embodiment, the magnetic steel in the magnetic field module is a strip-shaped NbFeB, as shown in Figure 3 , the magnetic steel is symmetrically distributed around the cylindrical axis, and the included angleƟ between adjacent two magnet assemblies is 90 o °. Corresponding to the special layout of 4 groups of magnetic steel right-angled distribution, it is formed by alternately arranging any two groups of magnetic steel with a length difference of 2 cm as shown in Figure 4 . The drive module controls the rotating speed of the magnetic field system to be 10 rpm to realize the scanning of the magnetic field parallel to the target surface on the entire target. The target material is spliced by 3 titanium pipes according to Figure 5 b; the indium-tin alloy is used to connect the target material and the base. The water temperature of the cooling water in the water cooling circuit is 28 o C, the water pressure is 2.5 kg / cm 2 , and the flow rate is 10 L / min. The power supply adopts a direct current sputtering power supply, the power density is 10 W / cm 2 , the working gas is Ar, the working gas pressure is 0.8 Pa, the ionization rate is 45%, the deposition rate is 2 µm / h, the target material utilization rate is 29 when the magnetic field does not rotate, and the etching track is shown in Figure 6 ; when the rotating speed of the magnetic field is 10 rpm, the target material utilization rate is 95%.

[0054] Embodiment 2

[0055] In this embodiment, the magnetic steel in the magnetic field module is a strip-shaped NbFeB, and the magnetic steel is symmetrically distributed around the cylindrical axis, as shown in Figure 3As shown, the included angle Ɵ between two adjacent magnet components is 45°. o The special layout corresponding to the 8 sets of magnets arranged at right angles is formed by alternating arrangements of two sets of magnets with a length difference of 2cm, such as... Figure 4 As shown. The drive module controls the rotation speed of the magnetic field module to 10 rpm, achieving a magnetic field parallel to the target surface scanning the entire target. The target material consists of three sections of titanium cylindrical tubes pressed together. Figure 5 The target and base are assembled using method b; an indium-tin alloy is used for connection between them. The cooling water temperature in the cooling system is 28°C. o C. Water pressure is 2.5 kg / cm² 2 The flow rate is 10 L / min. A DC sputtering power supply with a power density of 10 W / cm³ is used. 2 When the working gas is Ar and the working pressure is 0.8 Pa, the ionization rate is 61%, the deposition rate is 3 µm / h, and the target utilization rate is 38% when the magnetic field is not rotating (see etching track). Figure 7 When the magnetic field rotation speed is 10 rpm, the target material utilization rate is 96%.

[0056] In summary, this invention achieves rotating magnetic field scanning by incorporating a rotatable magnetic field module. Furthermore, by using a target holder with a water-cooled jacket, cooling water flows within the target holder's internal water-cooling circuit, indirectly cooling the magnetic field module. This avoids direct contact between the cooling water and the magnet, significantly improving the utilization rate of the target material, the lifespan of the magnet, and the stability of the plasma.

[0057] The above-described embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A magnetic field scanning cylindrical cathode target, characterized in that, The cathode target includes a magnetic field module, a target material assembly sleeved on the outside of the magnetic field module, and a drive module that drives the magnetic field module to rotate. The magnetic field module includes a rotating shaft, a magnetic base fixedly disposed on the outside of the rotating shaft, a magnet assembly fixedly disposed on the magnetic base, and a magnetic yoke sleeved on the outside of the magnet assembly. The target assembly includes a target base connected to the magnetic field module via a bearing and a target material sleeved on the outside of the target base; the target base has a water-cooled jacket. The magnetic field module is used to generate a magnetic field. Driven by the driving module, the magnetic field module generates a moving magnetic field that scans the surface of the target material. The magnet assembly includes multiple strip magnets arranged along the length of the rotation axis; a magnet gap is provided between adjacent magnets; there are multiple sets of magnet assemblies, arranged sequentially along the outer periphery of the magnet base; the magnets in adjacent magnet assemblies have different lengths; The magnets in adjacent magnet assemblies are arranged with staggered spacing.

2. The magnetic field scanning cylindrical cathode target according to claim 1, characterized in that, The drive module is a motor; the motor is a servo motor.

3. The magnetic field scanning cylindrical cathode target according to claim 1, characterized in that, The magnet is made of NbFeB material; The magnets include N-pole magnets and S-pole magnets.

4. The magnetic field scanning cylindrical cathode target according to claim 1, characterized in that, The water-cooled jacket is a cooling circuit located in the middle of the target base; the cooling circuit is connected to a cooling water inlet and a cooling water outlet.

5. The magnetic field scanning cylindrical cathode target according to claim 2, characterized in that, The cathode target also includes a flange and a magnetohydrodynamic sealing device; The output shaft of the motor is connected to the output shaft of the magnetohydrodynamic sealing device; The output shaft of the magnetohydrodynamic sealing device is also connected to the rotating shaft; The flange is used to connect the cathode target and the vacuum chamber.

6. The magnetic field scanning cylindrical cathode target according to claim 5, characterized in that, The output shaft of the motor is connected to the output shaft of the magnetohydrodynamic sealing device via a speed reducer.

7. The magnetic field scanning cylindrical cathode target according to claim 1, characterized in that, The target material is a single metal tube or a ceramic tube. Alternatively, it can be made of multiple metal or ceramic tubes joined together, with the joints of adjacent metal or ceramic tubes being beveled.

8. The magnetic field scanning cylindrical cathode target according to claim 1, characterized in that, The target material and the target holder are connected by an indium-tin alloy.

9. The magnetic field scanning cylindrical cathode target according to claim 1, characterized in that, The cathode target also includes a sputtering power source; The sputtering power supply is a DC, pulsed, radio frequency, or intermediate frequency power supply with a power density of 5-30 W / cm². 2 .

Images