JP7303393B2 - Drive block for rotating cathode unit - Google Patents

Description

The present invention has a cylindrical target placed in a vacuum atmosphere and an inner tube inserted in the target to form a space isolated from the vacuum atmosphere, and The present invention relates to a drive block for a rotary cathode unit, which is connected to one axial end of a target of a rotary cathode unit in which a coolant circulation path is provided in a tube, and drives the target to rotate about the axis.

Conventionally, a rotary cathode unit used in a sputtering apparatus is known, for example, from Japanese Unexamined Patent Application Publication No. 2002-200012. This comprises a drive block having drive means for driving the target in rotation about its axis. The drive block is provided with a fixed inner cylindrical body and an outer cylindrical body disposed around the inner cylindrical body, and brushes are provided between the inner cylindrical body and the outer cylindrical body to conduct them. is provided. An outer cylindrical body connected to the target is driven to rotate by a gear or belt from a motor as a driving means wound around the outer cylinder.

The inner space of the inner cylinder communicates with the first passage of the refrigerant circuit inside the inner pipe, and the space between the inner cylinder and the outer cylinder is the second passage of the refrigerant circuit between the target and the inner pipe. Connected to the aisle. When the target is sputtered by supplying a predetermined electric power to the target through the brush, cooling water as a coolant is circulated in the coolant circulation path so that the target is not heated to a temperature exceeding a predetermined temperature. Further, the inner tube is provided with a magnet unit for generating a leakage magnetic field on the outer surface of the target, and an electric moving means such as a motor for moving the magnet unit toward and away from the outer surface of the target. ing.

Here, in the above conventional example, the internal space of the inner cylindrical body of the drive block communicates with the first passage in the inner pipe. Electrical wiring is to be carried out through the inner cylindrical body. In such a case, since cooling water is passed through the inner space of the inner cylinder, it is necessary to waterproof the electrical wiring and connectors. However, there is a problem in that the number of units increases and the cost increases.

WO2016/185714

In view of the above points, the present invention is designed to enable electric power to be supplied to electrically driven parts provided in the inner tube without impairing the function of cooling the target during sputtering, for example, without special waterproofing. The object is to provide a drive block for a rotary cathode unit with a reduced pressure.

In order to solve the above problems, the present invention has a cylindrical target placed in a vacuum atmosphere, and an inner tube inserted in the target to form a space isolated from the vacuum atmosphere, the target A drive block for a rotary cathode unit which is connected to one axial end of a target of a rotary cathode unit provided with a coolant circulation path between the inner tube and the inner tube, and drives the target to rotate around the axis, , further comprising a first driving means for applying a rotational force to the target, wherein the direction from one end of the target in the axial direction to the other end in the axial direction is the rearward direction in the X-axis direction, and the direction from the other end in the axial direction of the target to the one end in the axial direction is the X-axis direction. A straight that extends forward in the X-axis direction and is inserted into the inner pipe to form a refrigerant circulation path in the inner pipe in a gap between it and the inner peripheral surface of the inner pipe, and extends forward from the inner pipe in the X-axis direction . and a hollow tube having a straight portion, which is inserted over the straight portion of the hollow tube and connected to the inner tube at its rear end in the axial direction, so that the coolant circulates in the inner tube in the gap between the hollow tube and the hollow tube. A gap between the target and the inner pipe is formed between a first inner cylindrical body that defines a first passage that communicates with the passage, and an outer peripheral surface of the first inner cylindrical body that is externally inserted into the first inner cylindrical body. a second inner cylindrical body that defines a second passage that communicates with the refrigerant circulation path between the second inner cylindrical body and a second inner cylindrical body that is fitted onto the second inner cylindrical body via a bearing and is connected to one end of the target in the axial direction so as to provide power from the driving means; an outer cylindrical body to which power is transmitted, and further comprising isolating means for isolating an internal space between the inner tube and the hollow tube from a vacuum atmosphere.

According to the present invention, the driving block includes passages (first passage and second passage) for supplying and discharging cooling water (coolant) to and from a refrigerant circulation passage in the target required for cooling the target during sputtering of the target. passage) further includes a hollow tube hermetically connected to one end of the inner tube of the rotary cathode unit, so there is no particular need to pass cooling water through the hollow tube. For this reason, for example, it is possible to make the inner space of the inner tube and the hollow tube communicate with each other in an atmospheric atmosphere, and furthermore, the function of cooling the target during sputtering is not impaired.

In the present invention, the inner tube is provided with a magnet unit for generating a leakage magnetic field on the outer surface of the target, and an electric moving means for moving the magnet unit in the direction of approaching and separating from the outer surface of the target. In this case, it is preferable that the internal spaces of the inner tube and the hollow tube are communicated with each other in an atmospheric atmosphere, and electrical wiring is provided to parts necessary for movement of the magnet unit and detection of its position through the hollow tube. According to this, electrical wiring can be carried out through the hollow tube in the atmosphere, which is advantageous because it is not necessary to apply waterproofing to cables, connectors, etc., which are wired inside the hollow tube.

Here, when an electric moving means such as a motor is provided in the inner pipe, there is a fear that the heat associated with the operation of the motor stays inside the inner pipe and causes a malfunction of the moving means. In the present invention, it is preferable that a gas introduction pipe for introducing gas toward the inner pipe is provided in the hollow pipe. According to this, by supplying gas (compressed air, etc.) into the inner tube and discharging it through, for example, a hollow tube (in this case, a gas supply passage and a discharge passage may be provided in the hollow tube), the inner The heat trapped in the pipe can be discharged from the inner pipe, and it is possible to suppress malfunction of the moving means due to heat.

By the way, when the target is sputtered with a leakage magnetic field applied by the rotary cathode unit, for example, if a racetrack-shaped plasma is generated in the space between the target and the substrate to be processed, the shape of the plasma changes. The outer surface of the target is sputtered as if it were being transferred. Sputtered particles scattered from the outer surface of the target according to a predetermined cosine law by sputtering adhere to the substrate to be processed, which is arranged opposite to the target in a vacuum atmosphere. At this time, when trying to adjust the film thickness distribution and film quality distribution of the thin film formed on the surface of the substrate to be processed, it is preferable to change the orientation of the magnet unit by tilting it in the circumferential direction of the target. In the present invention, a configuration including a second driving means for rotating the hollow tube about its axis within a predetermined rotation angle range can be employed. According to this, when the hollow tube is rotated within a predetermined rotation angle range, the inner tube is also rotated accordingly, so that the orientation of the magnet unit fixedly arranged inside can be changed with a simple configuration. It is possible and advantageous.

FIG. 4 is a partial cross-sectional view showing a state in which a rotary cathode unit having a drive block of the present invention is attached to a sputtering apparatus; FIG. 2 is a cross-sectional view showing an enlarged main part of the rotary cathode unit of FIG. 1; FIG. 5 is a partial cross-sectional view for explaining a modification of the rotary cathode unit;

Hereinafter, with reference to the drawings, a substrate to be processed is a rectangular glass substrate (hereinafter referred to as "substrate S"), and a rotating type magnetron sputtering apparatus for forming a predetermined thin film on one surface of the substrate S is used. An embodiment will be described by taking as an example a case where the drive block DB of the present invention is applied to the cathode unit Rc.

Referring to FIG. 1, the rotary cathode unit Rc includes a cylindrical target Tg arranged to face the substrate S in a vacuum atmosphere Vp. In the following, the generatrix direction of the target Tg is defined as the X-axis direction, the direction in which the drive block DB is provided is defined as the front side of the X-axis direction (right in FIG. 1), and the opposite direction is defined as the rear side of the X-axis direction (left in FIG. 1). . The target Tg has a cylindrical backing tube 11 and a cylindrical target material 12 bonded to the outer cylindrical surface of the backing tube 11 via a bonding material (not shown) such as indium or tin. As the target material 12, one appropriately selected from metals and metal compounds according to the composition of the film to be formed on the substrate S is used. As the target Tg, one formed by directly cutting a base metal can be used, in which case the backing tube 11 is omitted.

A magnet case 3 as an inner tube defining a space isolated from the vacuum atmosphere Vp is inserted in the backing tube 11 over substantially the entire length of the target Tg. A coolant passage 31 is formed in the magnet case 3 so as to extend over substantially the entire length of the magnet case 3 . Although not shown and described, the coolant passage 31 at the rear end of the magnet case 3 in the X-axis direction communicates with the gap 32 between the outer peripheral surface of the magnet case 3 and the inner peripheral surface of the backing tube 11. A refrigerant circuit Fp is formed by the refrigerant passage 31 and the gap 32 . In the present embodiment, the gap 32 constitutes the outward route Fp1 of the refrigerant circuit Fp, and the refrigerant passage 31 constitutes the return route Fp2 of the refrigerant circuit Fp.

In the magnet case 3, there are a magnet unit 33 for applying a leakage magnetic field to the outer surface of the target material 12, and an electric moving means 34 for moving the magnet unit 33 toward and away from the outer surface of the target material 12. is fixedly placed. The magnet unit 33 has a yoke 33a having a length equivalent to the length of the target Tg in the X-axis direction. The yoke 33a is a plate-shaped member made of a magnetic material, which is not particularly illustrated and described, but has a top surface parallel to the substrate S and a pair of slanted surfaces slanted downward from the top surface. A bar-shaped central magnet 33b is arranged on the top surface, and bar-shaped peripheral magnets 33c are arranged on both inclined surfaces, respectively. A leakage magnetic field is applied so as to close the track. Since a known unit can be used as the magnet unit 33, further explanation is omitted.

The moving means 34 includes a direct-acting motor 34a arranged in the magnet case 3, and the driving shaft 34b of the direct-acting motor 34a is connected to the surface on which the central magnet 33b and the peripheral magnets 33c are arranged via the support frame 34c. is connected to the surface of the yoke 33a facing away from the . As a result, by operating the direct-acting motor 34a, the magnet unit 33 can freely move toward and away from the outer surface of the target material 12 in a direction perpendicular to the X-axis direction (vertical direction in FIG. 1). becomes. In this case, the direct-acting motor 34 a is provided with a detection means 34 d such as a sensor or encoder for detecting the position of the magnet unit 33 with respect to the surface of the target material 12 . In the present embodiment, an example in which the magnet units 33 are integrally moved by a single direct-acting motor 34a is described, but the present invention is not limited to this. When it is divided into a plurality of parts, a plurality of direct-acting motors 34a are provided corresponding to each part. A drive block DB of this embodiment is provided to rotatably support the rotary cathode unit Rc within the vacuum chamber. In this case, although not shown and described, a support block for rotatably supporting the rear end side of the target Tg in the X-axis direction is arranged in the vacuum atmosphere Vp. Therefore, detailed description is omitted here.

Referring also to FIG. 2 , the drive block DB provided at the front end of the target Tg in the X-axis direction includes a hollow tube 4 concentrically arranged with each other, and a first inner cylindrical body 5 externally inserted into the hollow tube 4 . , a second inner cylindrical body 6 externally inserted into the first inner cylindrical body 5 , and an outer cylindrical body 7 . The hollow tube 4 is formed to extend straight 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 magnet case 3 can be integrally formed, the hollow tube 4 is connected to the magnet case 3 via, for example, connecting members Lm arranged at predetermined intervals in the X-axis direction. The hollow tube 4 and the magnet case 3 are made to be rotated integrally. Since a known method can be used for the connecting member Lm, further explanation is omitted. In this embodiment, the internal space in the magnet case 3 where the magnet unit 33 and the moving means 34 are arranged and the internal space in the hollow tube 4 are always in the atmosphere. A power cable K1 for supplying power to the direct-acting motor 34a and a communication cable K2 for communicating with the detection means 34d are wired through the hollow tube 4 from the outside of the drive block DB. .

The first inner cylindrical body 5 has a thick portion 51 on the front end side in the X-axis direction, and a bearing Br<b>1 is provided between the thick portion 51 and the hollow tube 4 . In this case, a servomotor 42 as a second driving means is provided at the front end of the hollow tube 4 via a gear mechanism 41 to move the hollow tube 4 and, by extension, the magnet unit 33 in the magnet case 3 along the X-axis. It is designed to be able to rotate within a predetermined rotation angle range (for example, a range of ±several tens of degrees or less). A belt mechanism may be used instead of the gear mechanism 41 . The rear end of the first inner cylindrical body 5 in the X-axis direction is fitted onto the front end of the magnet case 3 in the X-axis direction via a resin ring Sw3. This resin ring Sw3 has a function of a bearing and a function of sealing the cooling water. Between the thick portion 51 and the hollow tube 4, a cooling water seal Sw1 is provided on the rear side of the bearing Br1 in the X-axis direction. A gap between the hollow tube 4 located on the rear side of the cooling water seal Sw1 in the X-axis direction and the first inner cylindrical body 5 defines a first passage Fp3 that communicates with the return passage Fp2 of the refrigerant circulation passage Fp. It's like

The second inner cylindrical body 6 has a flange wall portion 61 extending in a direction perpendicular to the X-axis direction on its front end side in the X-axis direction. The gap defines a second passage Fp4 communicating with the outward path Fp1 of the refrigerant circulation path Fp. Then, it is attached via an attachment part Ap to an attachment hole Ih formed in a partition wall Ip (for example, a wall surface of a vacuum chamber) that defines the vacuum atmosphere Vp. In this case, the attachment part Ap is composed of a cylindrical member having a flange portion Ap1 at one end, and a vacuum seal Sv1 such as an O-ring is attached to each of the front and rear surfaces of the flange portion Ap1 in the X-axis direction, Both seals Sv1 are in pressure contact with the outer surface of the partition wall Ip and the end surface of the second inner cylindrical body 6 in the X-axis direction to hold them airtight. Two 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 thick portion 51 positioned in the atmosphere. 8b is connected to a water intake pipe and a drain pipe (not shown) from a chiller unit (not shown). As a result, the target material 12 can be cooled during the sputtering of the target Tg by circulating cooling water of a predetermined temperature in the coolant circulation path Fp by the chiller unit.

The outer cylindrical body 7 is provided via a bearing Br2 externally fitted to a straight portion 62 extending in the X-axis direction of the second inner cylindrical body 6 . In this case, a mounting step portion 11a having a small diameter is provided at one end of the backing tube 11 in the X-axis direction, and the rear end of the outer cylindrical body 7 in the X-axis direction is attached to the mounting step portion 11a via a vacuum seal Sv2 such as an O-ring. In this state, the outer cylindrical body 7 and the backing tube 11 are connected by the clamp Cp. Since a known clamp Cp can be used for the connection, further explanation is omitted. In addition, when replacing the target Tg due to corrosion of the target material 12 due to sputtering, the target Tg is detached from the support block on the rear side in the X-axis direction, and after removing the clamp Cp, it is directed toward the rear in the X-axis direction. The target Tg can be removed by pulling out the target Tg.

Between the outer peripheral surface of the outer cylindrical body 7 and the inner peripheral surface of the mounting part Ap, an oil seal, a double lip seal, or a A vacuum seal Sv3 is provided which is composed of a magnetic fluid seal. In this embodiment, the vacuum seals Sv1 to Sv3 constitute isolation means for isolating the inner space between the magnet case 3 as the inner tube and the hollow tube 4 from the vacuum atmosphere Vp. The outer cylindrical body 7 covers the straight portion 62 and the portion of the first inner cylindrical body 5 that protrudes from the straight portion 62 toward the rear end in the X-axis direction, and liquid-tightly seals the outward path Fp1 and the second passage Fp4. is in full communication with the In this case, a cooling water seal Sw2 is also provided between the straight portion 62 located closer to the magnet case 3 than the bearing Br2 and the outer cylindrical portion 7 .

The outer cylinder surface of the outer cylinder body 7 is provided with teeth 71 positioned on the atmosphere side of the partition wall Ip, and gears 91 meshing with the teeth 71 are arranged. A drive shaft 92a of a motor 92 is connected to the gear 91, and the motor 92 rotates the gear 91 at a predetermined number of revolutions to rotate the outer cylindrical body 7, thereby connecting to the target Tg during sputtering. The target Tg can be rotated at a predetermined rotation speed. In this embodiment, these constitute the first drive means for applying a rotational force to the target Tg. An output cable (not shown) from a sputtering power supply (not shown) is connected to the outer cylindrical body 7 so that a predetermined power having a negative potential, for example, can be applied to the target material 12 .

According to the above embodiment, the drive block DB is provided with passages (second Since the configuration in which the hollow pipe 4 is further present inside the first passage Fp3 and the second passage Fp4), it is not particularly necessary to pass the cooling water through the hollow pipe 4). Since the inner spaces of the magnet case 3 and the hollow tube 4 are made into an atmospheric atmosphere communicating with each other and electrical wiring is performed through the hollow tube 4, the cables K1, K2 and This eliminates the need for waterproofing the connector or the like, and does not impair the function of cooling the target Tg during sputtering. In addition, since the configuration including the servomotor 42 that rotates the hollow tube 4 around its axis within a predetermined rotation angle range is adopted, the magnet unit 33 that is fixedly arranged therein can be rotated in the circumferential direction of the target Tg with a simple configuration. By tilting to change the posture, the film thickness distribution and film quality distribution of the thin film formed on the surface of the substrate S can be adjusted.

Although the embodiments of the present invention have been described above, 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 has a straight shape over its entire length. It is not limited to this.

By the way, when the direct-acting motor 34a is provided in the magnet case 3, there is a possibility that the heat associated with the operation of the direct-acting motor 34a stays in the magnet case 3 and causes malfunction of the direct-acting motor 34a. As shown in FIG. 3, even if a flexible tube-shaped gas introduction pipe 10 is arranged in the hollow pipe 4 in the atmosphere so that a gas such as compressed air or nitrogen gas can be introduced into the magnet case 3. good. According to this, compressed air or the like is supplied into the magnet case 3 through the gas introduction pipe 10 provided in the hollow tube 4 and discharged through the discharge passage 10a, thereby removing the heat trapped in the magnet case 3. 3, and it is possible to suppress malfunction of the direct-acting motor 34a due to heat.

DB... Drive block, Br2... Bearing, Fp... Refrigerant circulation path, Fp3... First passage, Fp4... Second passage, K1... Power supply cable (electrical wiring), K2... Communication cable (electrical wiring), Rc... Rotary cathode Unit, Tg... Target, Vp... Vacuum atmosphere, 3... Magnet case (inner tube), 33... Magnet unit, 31... Refrigerant passage (refrigerant circulation path in inner tube), 32... Gap (between target and inner tube Refrigerant circuit), 34 moving means (electrically driven moving means), 4 hollow tube, 42 servo motor (second driving means), 5 first inner cylindrical body, 6 second inner cylindrical body, 7 outer cylindrical body 92 motor (first driving means) Sv1 to Sv3 vacuum seals (separating means) 10 gas introducing pipe.

Claims (4)

It has a cylindrical target placed in a vacuum atmosphere and an inner tube inserted in the target to form a space isolated from the vacuum atmosphere, and a coolant circulates between the target and the inner tube and in the inner tube. A drive block for a rotary cathode unit connected to one axial end of the target of the rotary cathode unit provided with the path to drive the target to rotate about the axis, the drive block providing a rotational force to the target. in the one further comprising
The direction from one end of the target in the axial direction to the other end in the axial direction is defined as the rear in the X-axis direction, and the direction from the other end in the axial direction of the target to the one end in the axial direction is defined as the front in the X-axis direction,
A hollow body that is inserted into the inner pipe and has a straight portion that extends forward in the X-axis direction from the inner pipe so that a coolant circulation path is formed in the gap between the inner pipe and the inner peripheral surface of the inner pipe . and a second pipe that is inserted over the straight portion of the hollow pipe and connected to the inner pipe at its rear end in the axial direction so that the gap between the pipe and the hollow pipe communicates with the refrigerant circulation path in the inner pipe. a first inner cylinder defining one passage;
A second inner cylinder that is fitted around the first inner cylinder and defines a second passage that communicates with the refrigerant circulation path between the target and the inner pipe at a gap between the first inner cylinder and the outer peripheral surface of the first inner cylinder. a cylinder;
an outer cylindrical body that is externally fitted to the second inner cylindrical body via a bearing, is connected to one end of the target in the axial direction, and receives power from a driving means;
A drive block for a rotary cathode unit, further comprising isolation means for isolating an interior space of the inner tube and the hollow tube from a vacuum atmosphere.
A drive block for a rotating cathode unit according to claim 1, comprising:

In the apparatus comprising, in the inner tube, a magnet unit for generating a leakage magnetic field on the outer surface of the target, and an electric moving means for moving the magnet unit in a direction toward or away from the outer surface of the target,

A rotary cathode, characterized in that the inner space of the inner tube and the hollow tube are communicated with each other in an atmospheric atmosphere, and electrical wiring is provided to parts necessary for moving the magnet unit and detecting its position through the hollow tube. Drive block for the unit.

3. The drive block for a rotary cathode unit according to claim 2, wherein a gas introduction pipe is provided in said hollow tube for introducing gas toward said inner tube.

A driving block for a rotary cathode unit according to any one of claims 1 to 3, further comprising second driving means for rotating the hollow tube about its axis within a predetermined rotation angle range. .

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