CN116057200A

CN116057200A - Driving block for rotary cathode unit

Info

Publication number: CN116057200A
Application number: CN202180058390.6A
Authority: CN
Inventors: 织井雄一; 吉田大介; 立川晋辅
Original assignee: Ulvac Inc
Current assignee: Ulvac Inc
Priority date: 2020-09-16
Filing date: 2021-06-11
Publication date: 2023-05-02
Also published as: TW202214888A; JPWO2022059278A1; JP7303393B2; WO2022059278A1; TWI831022B; KR20220139382A

Abstract

The invention provides a driving block of a rotary cathode unit, which can supply power to inner parts of an inner pipe without performing waterproof processing. A Drive Block (DB) for a rotary cathode unit (Rc) having a 1 st drive device (92) for rotationally driving a target (Tg) about an axis is provided with a hollow tube (4), and the hollow tube (4) has a straight line portion extending from an inner tube (3) in the axis direction; a 1 st inner cylinder (5) which is sleeved on the straight line part of the hollow pipe and defines a 1 st channel (Fp 3) communicated with the refrigerant circulating channel (Fp 2) in the inner pipe; a 2 nd inner cylinder (6) which is sleeved on the 1 st inner cylinder and defines a 2 nd channel (Fp 4) communicated with the refrigerant circulating channel (Fp 1) between the target and the inner tube; an outer cylinder (7) which is externally fitted to the 2 nd inner cylinder via a bearing (Br 2) and is connected to one end of the target in the axial direction, and transmits power from the drive device; further, there are isolation means (Sv 1-Sv 3) for isolating the inner space of the inner tube and the hollow tube, which are in communication with each other, from a vacuum atmosphere in a state where one end of the inner tube is connected to the hollow tube.

Description

Driving block for rotary cathode unit

Technical Field

The present invention relates to a drive block for a rotary cathode unit, which is connected to one end of a target of the rotary cathode unit in an axial direction and drives the target to rotate around the axis, wherein the rotary cathode unit comprises: a cylindrical target disposed in a vacuum atmosphere; and an inner tube inserted into the target to form a space isolated from a vacuum atmosphere; a refrigerant circulation passage is provided between the target and the inner tube and in the inner tube.

Background

A rotary cathode unit used in a sputtering apparatus in the past is known, for example, from patent document 1. The rotary cathode unit has a drive block with a drive means for rotationally driving the target about an axis. The driving block is provided with: an inner cylinder fixedly arranged; and an outer cylinder disposed around the inner cylinder; a brush for conducting the inner cylinder and the outer cylinder is arranged between the inner cylinder and the outer cylinder. The outer cylinder coupled to the target is rotationally driven by a gear or a belt as a motor of a driving device wound around the outer cylinder.

The inner space of the inner cylinder is communicated with the 1 st channel of the refrigerant circulating channel in the inner tube, and the space between the inner cylinder and the outer cylinder is communicated with the 2 nd channel of the refrigerant circulating channel between the target and the inner tube. When a predetermined electric power is applied to the target via the brush to sputter the target, the cooling water as the coolant is circulated in the coolant circulation passage so that the target is not heated to exceed a predetermined temperature. The inner tube is provided with: a magnet unit that generates a leakage magnetic field on an outer surface of the target; and an electric moving device such as a motor that moves the magnet unit in a direction approaching and separating from the outer surface of the target.

In the device of the above-described conventional example, since the inner space of the inner cylinder of the drive block communicates with the 1 st passage in the inner tube, electric wiring is performed through the inner cylinder of the drive block when electric power is supplied to the motor located in the inner tube. In this case, since the cooling water flows through the inner space of the inner tube, it is necessary to perform waterproof processing for electric wiring, connectors, and the like, and thus, there is a problem that the wiring process is complicated, the number of components increases, and the cost increases.

Prior art literature

Patent literature

[ patent document 1 ] International publication No. 2016/185714

Disclosure of Invention

Technical problem to be solved by the invention

In view of the above, an object of the present invention is to provide a driving block for a rotary cathode unit, which does not impair the function of cooling a target during sputtering, and which can supply electric power without performing special waterproofing work on an electric-powered member provided in an inner tube, for example.

Means for solving the technical problems

In order to solve the above-described problems, a rotary cathode unit driving block according to the present invention is a rotary cathode unit driving block connected to one end of a target of a rotary cathode unit in an axial direction, the rotary cathode unit including: a cylindrical target disposed in a vacuum atmosphere; and an inner tube inserted into the target to form a space isolated from a vacuum atmosphere; a cooling medium circulation channel is arranged between the target and the inner tube and in the inner tube, the driving block is also provided with a 1 st driving device for applying a rotation force to the target, and the driving block is characterized in that the driving block is provided with: a hollow tube having a straight portion extending in the axial direction from the inner tube; the 1 st inner cylinder is sleeved on the straight line part of the hollow pipe, and defines a 1 st channel communicated with the refrigerant circulation channel in the inner pipe; a 2 nd inner cylinder which is sleeved on the 1 st inner cylinder and defines a 2 nd channel communicated with the refrigerant circulating channel between the target and the inner tube; an outer cylinder body externally embedded on the 2 nd inner cylinder body through a bearing and connected with one end of the target in the axial direction, and transmitting power from the driving device; and an isolation device for isolating the internal space of the hollow tube and the inner tube communicating with each other from the vacuum atmosphere in a state that the hollow tube is connected to one end of the inner tube.

In the present invention, the driving block is configured such that, when sputtering the target, a hollow tube is hermetically connected to one end of the inner tube of the rotary cathode unit inside the passages (1 st passage and 2 nd passage) for supplying and discharging cooling water (refrigerant) to and from the refrigerant circulation passage in the target required for cooling the target, and therefore, the cooling water does not need to flow through the hollow tube. Therefore, for example, the inner space of the inner tube and the hollow tube can be an atmosphere communicating with each other, and the function of cooling the target at the time of sputtering is not impaired.

In the present invention, there is a case where there is: a magnet unit that generates a leakage magnetic field on an outer surface of the target; and an electric moving device for moving the magnet unit in a direction approaching and separating from the outer surface of the target, wherein the inner tube and the inner space of the hollow tube are preferably in an atmosphere communicating with each other, and the members necessary for the movement of the magnet unit and the position detection thereof are electrically wired through the hollow tube. Thus, electrical wiring can be performed through the hollow tube in the air atmosphere, and thus, it is unnecessary to perform waterproof processing on the cable, the connector, and the like which are laid in the hollow tube, which is advantageous.

Here, when an electric mobile device such as a motor is provided in the inner tube, heat associated with the operation thereof is accumulated in the inner tube, and the operation of the mobile device may be failed. In the present invention, it is preferable that a gas introduction pipe for introducing gas into the inner pipe is provided in the hollow pipe. Thus, by supplying gas (compressed air or the like) into the inner tube and discharging the gas through the hollow tube, for example (in this case, it is only necessary to provide a supply passage and a discharge passage for the gas in the hollow tube), the heat accumulated in the inner tube can be discharged from the inner tube, and the operation failure of the mobile device due to the heat can be suppressed.

In addition, when sputtering the target in a state where the leakage magnetic field is generated by the rotary cathode unit, if, for example, a race track-shaped plasma is generated in a space between the target and the substrate to be processed, the outer surface of the target is sputtered as if the plasma shape is transferred. Then, on the target substrate disposed in opposition to the target in the vacuum atmosphere, sputtered particles scattered by sputtering according to a predetermined cosine law from the outer surface of the target are attached. In this case, if the film thickness distribution and the film mass distribution of the thin film formed on the surface of the substrate to be processed are to be adjusted, it is preferable that the magnet unit be inclined in the circumferential direction of the target to change the posture. In the present invention, a structure may be adopted in which the 2 nd drive means rotates the hollow tube about its axis within a predetermined rotation angle. Accordingly, if the hollow tube is rotated within a predetermined rotation angle range, the inner tube is rotated together with the rotation, and therefore, the posture of the magnet unit fixedly disposed therein can be advantageously changed with a simple configuration.

Drawings

Fig. 1 is a partial cross-sectional view showing a state in which a rotary cathode unit having a driving block of the present invention is mounted to a sputtering apparatus.

Fig. 2 is an enlarged cross-sectional view of a key part of the rotary cathode unit of fig. 1.

Fig. 3 is a partial cross-sectional view illustrating a modification of the rotary cathode unit.

Detailed Description

Hereinafter, an embodiment of the present invention will be described by taking a rectangular glass substrate (hereinafter referred to as "substrate S") as a substrate to be processed, and applying the driving block DB of the present invention to a rotary cathode unit Rc for a magnetron sputtering apparatus for forming a predetermined thin film on one surface of the substrate S, as an example.

Referring to fig. 1, the rotary cathode unit Rc has a cylindrical target Tg disposed opposite to the substrate S in a vacuum atmosphere Vp. Hereinafter, the direction of the generatrix of the target Tg is referred to as the X-axis direction, the direction in which the driving block DB is provided is referred to as the X-axis direction (right side in fig. 1), and the opposite direction is referred to as the X-axis direction (left side in fig. 1). The target Tg has: a cylindrical back tube 11; and a cylindrical target 12 bonded to the outer cylindrical surface of the backing tube 11 via an adhesive material (not shown) such as indium or tin. The target 12 may be appropriately selected from metals and metal compounds according to the composition of a thin film to be formed on the substrate S. In addition, a product formed by directly cutting a base metal may be used as the target Tg, and the backing tube 11 may be omitted.

The magnet box 3, which is an inner tube defining a space isolated from the vacuum atmosphere Vp, is inserted into the backing tube 11 across substantially the entire length of the target Tg. A refrigerant passage 31 extending over substantially the entire length thereof is formed in the magnet case 3. Further, although not particularly illustrated, at the rear end of the magnetic cartridge 3 in the X-axis direction, a gap 32 between the outer peripheral surface of the magnetic cartridge 3 and the inner peripheral surface of the back pipe 11 communicates with the refrigerant passage 31, and a refrigerant circulation passage Fp is formed by the refrigerant passage 31 and the gap 32. In the present embodiment, the gap 32 forms an outgoing path Fp1 of the refrigerant circulation passage Fp, and the refrigerant passage 31 forms a circuit Fp2 of the refrigerant circulation passage Fp.

The magnetic cassette 3 is fixedly provided with: a magnet unit 33 that causes a leakage magnetic field to act on the outer surface of the target 12; and an electric moving device 34 that moves the magnet unit 33 in a direction approaching and separating from the outer surface of the target 12. The magnet unit 33 has a yoke 33a having the same length as the X-axis direction length of the target Tg. Although not particularly illustrated, the yoke 33a is formed of a plate-like member made of a magnetic material, the plate-like member having a top surface parallel to the substrate S and a pair of inclined surfaces inclined downward from the top surface, a rod-like center magnet 33b is disposed on the top surface, and rod-like peripheral magnets 33c are disposed on the two inclined surfaces, respectively, so that the leakage magnetic field is generated such that a line passing through a position where the vertical component of the leakage magnetic field is zero extends in the X-axis direction and is closed in a track shape. Since a well-known product can be used as the magnet unit 33, further description is omitted.

The moving device 34 has a linear motor 34a disposed in the magnet case 3, and a drive shaft 34b of the linear motor 34a is coupled to a surface of the yoke 33a opposite to the disposition surfaces of the center magnet 33b and the peripheral magnet 33c via a support frame 34 c. Thus, by operating the linear motor 34a, the magnet unit 33 is free to move in the approaching and separating direction with respect to the outer surface of the target 12 in the direction orthogonal to the X-axis direction (up-down direction in fig. 1). At this time, a detection device 34d such as a sensor or an encoder is attached to the linear motor 34a, and detects the position of the magnet unit 33 with respect to the surface of the target 12. In the present embodiment, the case where the magnet unit 33 is integrally moved by using the single linear motor 34a has been described as an example, but the present invention is not limited to this, and for example, when the magnet unit 33 is divided into a plurality of portions in the X-axis direction, the plurality of linear motors 34a are provided corresponding to the respective portions. The driving block DB of the present embodiment is included to rotatably support the rotary cathode unit Rc in the vacuum chamber. In this case, although not particularly illustrated, a support block for rotatably supporting the rear end side of the target Tg in the X axis direction is disposed in the vacuum atmosphere Vp, and a known product itself may be used, so that a detailed description thereof is omitted here.

Referring again to fig. 2, the driving blocks DB disposed at the front end in the X-axis direction of the target Tg have a configuration concentric with each other: a hollow tube 4; a 1 st inner cylinder 5 sleeved on the hollow tube 4; a 2 nd inner cylinder 6 sleeved on the 1 st inner cylinder 5; and an outer cylinder 7. The hollow tube 4 is formed to extend linearly from the front end of the magnet case 3 in the X-axis direction toward the front in the X-axis direction. Although the hollow tube 4 and the magnetic cassette 3 may be integrally formed, the hollow tube 4 may be coupled to the magnetic cassette 3 via a coupling member Lm arranged at a fixed interval in the X-axis direction, for example, and may be provided so as to integrally rotate the hollow tube 4 and the magnetic cassette 3. Further, since a known method can be used as the connecting member Lm, further description is omitted. In the present embodiment, the internal space in the magnet case 3 where the magnet unit 33 and the moving device 34 are disposed and the internal space in the hollow tube 4 are always in an atmosphere. Further, a power cable K1 for supplying power to the linear motor 34a and a communication cable K2 for communicating with the detection device 34d are wired from outside the driving block DB through the hollow tube 4.

The 1 st inner tube 5 has a thick portion 51 at the front end side in the X axis direction, and a bearing Br1 is provided between the thick portion 51 and the hollow tube 4. At this time, a servo motor 42 as a 2 nd driving device is provided at the front end portion of the hollow tube 4 via a gear mechanism 41, and the hollow tube 4 and thus the magnet unit 33 in the magnet case 3 are provided so as to be rotatable about the X axis within a predetermined rotation angle range (for example, a range of ±several tens of degrees or less). Further, a belt mechanism may be used instead of the gear mechanism 41. The rear end of the 1 st inner cylinder 5 in the X-axis direction is externally fitted to the front end of the magnet case 3 in the X-axis direction via a ring Sw3 made of a resin material. The ring Sw3 made of resin has a function of a bearing and a function of sealing cooling water. A seal Sw1 for cooling water is provided between the thick portion 51 and the hollow tube 4 at the rear side in the X axis direction from the bearing Br1. The gap between the hollow tube 4 and the 1 st inner tube body 5 located at the rear side of the cooling water seal Sw1 in the X-axis direction defines a 1 st passage Fp3 communicating with the circuit Fp2 of the refrigerant circulation passage Fp.

The 2 nd inner cylinder 6 has a flange wall portion 61 extending in a direction orthogonal to the X-axis direction at the front end side thereof, and a gap between the 1 st inner cylinder 5 and the 2 nd inner cylinder 6 defines a 2 nd passage Fp4 communicating with the outgoing path Fp1 of the refrigerant circulation passage Fp. The mounting member Ap is mounted to a mounting hole Ih formed in a partition wall Ip (e.g., a wall surface of a vacuum chamber) defining a vacuum atmosphere Vp. At this time, the mounting member Ap is formed of a tubular member having a flange portion Ap1 provided at one end, and vacuum seals Sv1 such as O-rings are mounted on the front and rear surfaces of the flange portion Ap1 in the X-axis direction, respectively, and both the seals Sv1 are pressure-bonded to the outer surface of the partition wall Ip and the end surface of the 2 nd inner cylinder 6 in the X-axis direction, and are kept airtight. In addition, 2

joint portions

8a and 8b having shaft portions extending in the X-axis direction are provided in the space between the flange wall portion 61 and the material thickness portion 51 in the atmosphere, and an off-drawing water suction pipe and a drain pipe from an off-drawing cooling unit are connected to each of the

joint portions

8a and 8 b. By circulating cooling water having a predetermined temperature through the coolant circulation passage Fp by the cooling means, the target 12 can be cooled during sputtering of the target Tg.

The outer cylinder 7 is provided via a bearing Br2 externally fitted to a linear portion 62 extending in the X-axis direction of the 2 nd inner cylinder 6. At this time, a small-diameter mounting stepped portion 11a is provided at one end of the back tube 11 in the X-axis direction, and the rear end of the outer tube 7 in the X-axis direction is fitted to the mounting stepped portion 11a via a vacuum seal Sv2 such as an O-ring, and in this state, the outer tube 7 and the back tube 11 are connected by a clip Cp. Further, since a known product can be used as the clip Cp used for the above-described connection, further description is omitted. When the target Tg is replaced by erosion of the target 12 due to sputtering, the target Tg is detached from the support block on the rear side in the X-axis direction, and after the jig Cp is removed, the target Tg is pulled toward the rear in the X-axis direction, whereby the target Tg can be removed.

A vacuum seal Sv3 composed of an oil seal, a double lip seal, or a magnetic fluid seal is provided between the outer peripheral surface of the outer cylinder 7 and the inner peripheral surface of the mounting member Ap, which allows rotation of the outer cylinder 7 and maintains airtight of the space inside the outer cylinder 7. In the present embodiment, the vacuum seals Sv1 to Sv3 constitute an insulating device that insulates the inner space of the magnetic cassette 3 and the hollow tube 4, which are inner tubes, from the vacuum atmosphere Vp. Further, the straight portion 62 and the portion of the 1 st inner cylinder 5 protruding from the straight portion 62 toward the X-axis direction rear end side are covered by the outer cylinder 7, so that the outgoing path Fp1 and the 2 nd passage Fp4 are completely communicated in a fluid-tight manner. At this time, a seal Sw2 for cooling water is also provided between the linear portion 62 located closer to the magnet box 3 than the bearing Br2 and the outer tube portion 7.

Teeth 71 are provided on the outer cylinder surface of the outer cylinder 7 on the atmosphere side of the partition wall Ip, and a gear 91 engaged with the teeth is disposed. The gear 91 is connected to a drive shaft 92a of a motor 92, and the gear 91 is rotated by a predetermined number of rotations by the motor 92 to rotationally drive the outer cylinder 7, so that the target Tg connected thereto can be rotated by a predetermined number of rotations during sputtering of the target Tg. In the present embodiment, they constitute the 1 st driving means for applying a rotational force to the target Tg. The outer cylinder 7 is connected to an output cable (not shown) from an external sputtering power supply, and a predetermined electric power, for example, a negative potential, can be applied to the target 12.

In the above embodiment, the driving block DB is configured such that the cooling water (cooling medium) is supplied to and discharged from the cooling medium circulation passages Fp2 and Fp1 in the target Tg required for cooling the target Tg at the time of sputtering (the 1 st passage Fp3 and the 2 nd passage Fp 4) and the hollow pipe 4 is further provided inside, so that the cooling water does not need to flow through the hollow pipe 4. Further, since the inner space of the magnetic case 3 and the hollow tube 4 is set to be an atmosphere communicating with each other, and electric wiring is performed through the hollow tube 4, it is not necessary to perform waterproof processing for the cables K1 and K2 and the connector and the like laid in the hollow tube 4, and the function of cooling the target Tg at the time of sputtering is not impaired. Further, since the servo motor 42 is provided to rotate the hollow tube 4 around the axis thereof within a predetermined rotation angle range, the magnet unit 33 fixedly disposed therein can be tilted in the circumferential direction of the target Tg with a simple configuration to change the posture thereof, and the film thickness distribution and the film mass distribution of the thin film formed on the surface of the substrate S can be adjusted.

The embodiments of the present invention have been described above, but various modifications are possible without departing from the scope of the technical idea of the present invention. In the above embodiment, the hollow tube 4 having a straight overall length has been described as an example, but the present invention is not limited thereto, and the hollow tube may be straight from the magnet box 3 to a place where at least the 1 st inner cylinder 5 is externally fitted.

Further, when the linear motor 34a is provided in the magnet case 3, heat associated with the operation thereof is accumulated in the magnet case 3, and an operation failure of the linear motor 34a may be caused. As shown in fig. 3, a flexible tubular gas introduction pipe 10 may be disposed in the hollow pipe 4 in the atmosphere, and a gas such as compressed air or nitrogen may be introduced into the magnetic cassette 3. As a result, compressed air or the like is supplied into the magnet case 3 through the gas introduction pipe 10 provided in the hollow pipe 4, and the heat accumulated in the magnet case 3 can be discharged from the magnet case 3 by discharging the compressed air or the like through the discharge passage 10a, and an operation failure of the linear motor 34a due to the heat can be suppressed.

Description of the reference numerals

DB. drive block, br2.bearing, fp.refrigerant circulation passage, fp 3.1 th passage, fp 4.2 nd passage, K1. power cable (electric wiring), K2. communication cable (electric wiring), rc. rotary cathode unit, tg. target, vp. vacuum atmosphere, 3. Magnet case (inner tube), 33 magnet unit, 31 refrigerant passage (refrigerant circulation passage in inner tube), 32. Gap (refrigerant circulation passage between target and inner tube), 34. Moving device (electric moving device), 4. Hollow tube, 42. Servomotor (2 nd driving device), 5. 1 st inner tube, 6. 2 nd inner tube, 7. Outer tube, 92. Motor (1 st driving device), sv 1-Sv 3. Vacuum seal (isolating device), 10. Gas inlet tube.

Claims

1. A rotary cathode unit driving block connected to one end of a rotary cathode unit in an axial direction of a target, the rotary cathode unit including: a cylindrical target disposed in a vacuum atmosphere; and an inner tube inserted into the target to form a space isolated from a vacuum atmosphere; a cooling medium circulation channel is arranged between the target and the inner tube and in the inner tube, the driving block is also provided with a 1 st driving device for applying a rotation force to the target, and the driving block is characterized in that the driving block is provided with:

a hollow tube having a straight portion extending in the axial direction from the inner tube;

the 1 st inner cylinder is sleeved on the straight line part of the hollow pipe, and defines a 1 st channel communicated with the refrigerant circulation channel in the inner pipe;

a 2 nd inner cylinder which is sleeved on the 1 st inner cylinder and defines a 2 nd channel communicated with the refrigerant circulating channel between the target and the inner tube; and

an outer cylinder externally embedded on the 2 nd inner cylinder through a bearing and connected with one end of the target in the axial direction, and transmitting power from the driving device;

and an isolation device for isolating the inner space of the inner tube and the hollow tube, which are communicated with each other, from a vacuum atmosphere in a state that one end of the inner tube is connected with the hollow tube.

2. The drive block for a rotary cathode unit according to claim 1, wherein:

the inner tube has: a magnet unit that generates a leakage magnetic field on an outer surface of the target; and an electric moving device for moving the magnet unit in a direction approaching and separating from the outer surface of the target,

the inner tube and the hollow tube have an inner space that is an atmosphere communicating with each other, and the hollow tube is used to electrically wire components necessary for detecting the movement of the magnet unit and the position thereof.

3. The drive block for a rotary cathode unit according to claim 2, wherein:

a gas introduction pipe for introducing gas into the inner pipe is provided in the hollow pipe.

4. A driving block for a rotary cathode unit according to any one of claims 1 to 3, wherein:

the device is provided with a 2 nd driving device which rotates the hollow tube around the axis thereof within a prescribed rotation angle range.