JP2017002348A - Rotation type cathode unit for magnetron sputtering apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotation type cathode unit simply attached and detached from a component for rotating and driving a target in a vacuum chamber and constituted so as to prevent deposition to the component in the vicinity of the target.SOLUTION: A rotation type cathode unit for magnetron sputtering apparatuses comprises: targets Tg, Tghaving cylindrical backing tubes 41 and target materials 42 externally inserted thereinto; and drive blocks Db, Dbarranged at one ends of the targets in the axial line directions and for rotating and driving the targets. The drive block includes a rotating member 13 rotated and driven by drive means 2, and the one end of the backing tube is combined with a flange 17 provided in the rotating member and the target is coupled by a clamp Cp. First deposition preventing means Psfor preventing sputtered particles from being scattered on the clamp and the drive block is provided at the end of the backing tube.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a rotary cathode unit used in a sputtering apparatus, and more particularly to a magnetron type.

  This type of rotary cathode unit is known from Patent Document 1, for example. This is a cylindrical target that is set in a vacuum chamber where a substrate to be processed exists, a drive block that is arranged at one end in the axial direction of the target and rotationally drives the target, and is arranged at the other end in the axial direction of the target. And a support block for rotatably supporting the target. In addition, a magnet unit is provided in the internal space of the target, and leaks from the target surface so that a line passing through the position where the vertical component of the magnetic field becomes zero extends along the bus of the target and closes in a racetrack shape on the substrate side. To generate a magnetic field.

  The target is made of a material appropriately selected from metals and metal compounds (metal oxide, metal nitride, etc.) according to the composition of the thin film to be deposited on the substrate. Here, when the target is sputtered to form a film on the substrate, the target is eroded. For this reason, the target is periodically replaced. However, in consideration of the workability of target replacement, a configuration in which the target can be easily attached to and detached from the drive block and the support block is desired. Therefore, the target is fixed using a clamp in combination with components for rotationally driving the target provided on the support block and the drive block, respectively, and the target can be detached from the drive block and the support block with a simple operation. It is proposed.

  By the way, at the time of sputtering, the sputtered particles from the target are not only directed to the substrate but also scattered and adhered to components (drive block and support block) existing in the vicinity thereof. For this reason, it is necessary to adopt a configuration that prevents adhesion (deposition) to components so as not to hinder good film formation on the substrate. In particular, as described above, when a target is attached to a support block or drive block using a clamp, the clamp is positioned in the vicinity of the target. Therefore, depending on the thin film attached to the clamp surface, electrons are charged during sputtering. There is a risk of causing problems that induce abnormal discharge.

JP 2012-132039 A

  In view of the above points, the present invention is configured so that it can be easily detached from a component for rotationally driving a target in a vacuum chamber, and film formation on a component near the target can be prevented. An object of the present invention is to provide a rotary cathode unit for a sputtering apparatus.

  In order to solve the above problems, a rotary cathode unit for a sputtering apparatus according to the present invention includes a target having a cylindrical backing tube and a target material extrapolated thereto, and a target disposed at one end in the axial direction of the target. A drive block for rotating the drive block, the drive block having a rotary member that is driven to rotate by a drive means, and a flange is provided on the rotary member, and one end of a backing tube is combined with the flange and a target is connected by a clamp. The first anti-sticking means for preventing scattering of sputtered particles to the clamp and the drive block is provided in a portion of the backing tube extending from one side in the axial direction of the target.

  According to the present invention, since the flange provided on the rotating member of the drive block and the backing tube of the target are combined and fixed by the clamp, the drive block and the target can be attached and detached with a simple operation. And by providing an adhesion prevention means in the portion of the backing tube extending from the target and positioning it in the vicinity of the target material to be sputtered at the time of sputtering, it is possible to reliably prevent spattering of the sputtered particles to the clamp. Note that the target material and the backing tube can be configured separately or can be configured integrally with the same material.

  In the present invention, further comprising a support block that is disposed at the other axial end of the target and rotatably supports the target, the target is coupled by a clamp by combining one end of a backing tube with a driven shaft provided in the support block, What is necessary is just to employ | adopt the structure by which the 2nd adhesion prevention means which prevents scattering of the sputter | spatter particle | grains to a clamp and a support block is just provided in the part of the backing tube extended from the axial direction other side of a target.

  By the way, in order to effectively increase the sputtering rate, a magnet unit is provided in the internal space of the target, and a line passing through a position where the vertical component of the magnetic field becomes zero extends along the bus of the target and closes in a racetrack shape. As described above, sputtering may be performed by generating a leakage magnetic field on the target surface on the substrate side (magnetron method). In this case, when a sputtering gas such as a rare gas is introduced into the vacuum chamber and power is supplied to the target, plasma is generated along the racetrack. At this time, the electron density in the plasma tends to increase locally at the corner of the racetrack. For this reason, normally, the magnetic field strength at both ends of the target respectively facing the corner is locally weakened. On the other hand, the rotationally driven target is mainly sputtered and eroded at the rotational position where the leakage magnetic field acts, while the sputtered particles reattach at other rotational positions of the target. In this case, the reattachment of sputtered particles tends to be dominant at both ends of the target where the electron density is low. As a result, erosion at both ends of the target is difficult to proceed, and abnormal discharge may be induced by the reattached sputtered particles.

  In the present invention, the anti-adhesion means includes a ring-shaped base portion that is extrapolated to a portion of the backing tube, a plate-shaped portion that extends radially outward from the base portion, and an axial line of the target material extending from the base portion in the axial direction. A cylindrical part covering the directional end part, and a notch recessed in the axial direction is formed in the cylindrical part so as to locally expose the axial end part of the target material from which the magnetic field leaks. Is preferred. According to this, by providing the notch, while the target rotates once, the target is eroded at the position where the leakage magnetic field acts, while the adhesion of sputtered particles is prevented at the position where the leakage magnetic field does not act. . Therefore, both ends of the target can be eroded, and the target can be eroded almost uniformly over the entire length in the axial direction, and the induction of abnormal discharge can be reliably prevented. Note that the length of the cylindrical portion covering the end of the target and the area where the target is exposed (the width of the notch) are appropriately set according to the configuration of the magnet unit (leakage magnetic field), and the height of the plate-like portion. Is appropriately set according to the target type, the input power of the target, and the like so that the sputter particles are not scattered on the clamp, the drive block, and the support block.

The perspective view explaining the structure of the rotation cathode unit for sputtering devices of this invention. The fragmentary sectional view of a rotation cathode unit. Sectional drawing which expands and shows the drive block of the rotating cathode unit shown in FIG. The figure explaining the structure of a clamp. Sectional drawing which follows the VV line | wire of FIG. The perspective view explaining an adhesion prevention means.

  Hereinafter, an embodiment of a rotary cathode unit for a magnetron sputtering apparatus of the present invention will be described with reference to the drawings. In the following, as shown in FIG. 2, the rotary cathode unit is assumed to be placed in a vacuum chamber (not shown) in a horizontal posture, and “up”, “down” as a vertical direction and an axial direction as a reference with respect to this. The terms indicating the direction such as “right” and “left” are used. In the present embodiment, one side in the axial direction corresponds to the right side in FIG. 2, and the other side in the axial direction corresponds to the left side in FIG.

Referring to FIGS. 1 and 2, RC is a rotary cathode unit according to an embodiment of the present invention. Two RCs are disposed to face a substrate W, which is a film formation target, in a vertical direction in a vacuum chamber outside the figure. The cylindrical targets Tg ₁ and Tg ₂ are provided. Together with the drive block _Db 1, Db ₂ at the right end of the target _Tg 1, Tg ₂ installed on the cradle St are respectively connected, the left end of the target _Tg 1, Tg ₂ support block _Sb 1, Sb ₂ Are connected to each other. Then, the rotary cathode unit RC is detachably attached to a predetermined position of a vacuum chamber (not shown) via a support plate Sp connected to the right end of the pedestal St.

Here, since each target Tg ₁ , Tg ₂ , drive block Db ₁ , Db ₂ and support block Sb ₁ , Sb ₂ have the same form, one drive block Db ₁ is also referred to with reference to FIG. As an example, the drive block Db ₁ includes a housing 11, and an inner cylinder 12 having a circular cross section extending in the left-right direction is provided in the housing 11. An outer cylindrical body 13 having a circular cross section is disposed concentrically with the inner cylindrical body 12 around the fixed inner cylinder 12, and the outer cylindrical body 13 constitutes the rotating member of the present embodiment. An annular recess 13a that is recessed in the radial direction is provided on the inner circumferential surface of the outer cylinder 13, and a brush 14 that conducts the inner cylinder 12 and the outer cylinder 13 through the recess 13a is provided. Yes. The outer cylinder 13 is rotatably supported by a support member 16 inserted into the housing 11 via a plurality of bearings 15a. An oil seal 15b is externally inserted into the outer cylinder 13 so as to be positioned on both sides of the bearing 15a in the left-right direction. The drive block Db ₁ is provided with drive means 2 that rotationally drives the outer cylinder 13 and rotationally drives the target Tg ₁ coupled thereto.

The driving means 2 includes a motor 21 stored in the pedestal St, and a belt 23 wound around a pulley 22 provided on a driving shaft of the motor 21 and an outer peripheral surface of the outer cylinder 13. A conductive flange 17 and a regulating plate 18 that regulates the flow of cooling water are attached to the left end of the outer cylinder 13 in a liquid-tight manner. The fitted via an O-ring 17a on the outer peripheral surface of the backing to the inner right end flange of the tube 17 to be described later (i.e., a combination of one end and the flange 17 of the backing tube), and backing tube by the clamp Cp _1, flanges 17, As a result, the outer cylinder 13 as a rotating member of the drive block Db ₁ is connected.

The clamp Cp ₁ is not particularly limited as long as it can be easily attached and detached, and a known one can be used. For example, the inner end of the backing tube is inserted into the outer peripheral surface of the flange 17 as shown in FIG. A semicircular upper frame portion C11 surrounding and enclosing the upper half of the portion, a semicircular lower frame portion C12 surrounding and enclosing the lower half of the portion, and an upper frame portion C11 A bolt C15 is provided for fastening the flanges C13 and C14 provided to the lower frame portion C12 in a state of being joined to each other. Then, when rotating the outer cylinder 13 by driving the motor 21, the outer cylindrical body 13 and clamp Cp ₁ and the target Tg ₁ together it is rotated at a predetermined rotational speed. Further, the inner cylinder 12 is electrically connected to the outer cylinder 13 via the brush 14, and the outer cylinder 13 is electrically connected to the backing tube 41 and eventually the target material 42 via the flange 17 and the clamp Cp ₁ . (That is, the inner cylinder 12 and the target material 42 have the same potential).

The housing 11 is provided with a conductive main pipe 19 having a forward path 19a and a return path 19b therein, and one end extends through the housing 11 to the inner cylindrical body 12, and the forward path 19a is formed inside. The original return path 19 b communicates with the space 13 b between the inner cylinder 12 and the outer cylinder 13, and communicates with the internal space 12 a of the cylinder 12. The other end of the main pipe 19 is connected to a chiller unit Ch having a known structure. Further, an output cable Pk from a sputter power source (not shown) is connected to the main tube 19. Thereby, for example, a predetermined electric power having a negative potential is applied to the target Tg ₁ via the output cable Pk from the sputtering power supply while the outer cylinder 13 is driven to rotate by the motor 21 and the target Tg ₁ is driven to rotate. be able to.

The support block Sb ₁ is provided with a driven shaft 32 that is rotatably supported by a bearing 31 so as to rotatably support one end of the target Tg ₁ . In this case, the flange 32a is provided on the right end of the driven shaft 32, the same, fitted via an O-ring (not shown) the inner left edge of the backing tube 41 on the outer peripheral surface of the flange 32a, the backing by a clamping Cp ₂ tube 41 is connected to the support block Sb _1. Thus, the target _Tg 1, Tg ₂ can be detached by a simple operation from the driving block _Db 1, Db ₂ and the support block _Sb 1, Sb _2. The clamp Cp ₂ is the same as the clamp Cp ₁ on the drive block Db ₁ side.

The targets Tg ₁ and Tg ₂ are constituted by a cylindrical backing tube 41 and a cylindrical target material 42 joined to the backing tube 41 via a bonding material (not shown) such as indium or tin. . In this case, the length in the left-right direction (axial direction) of the backing tube 41 and the target material 42 is fixed so that the backing tube 41 protrudes from both ends of the target material 42, respectively. As the target material 42, a material appropriately selected from metals and metal compounds according to the composition of the film to be deposited on the substrate W is used. Depending on the target type, the backing tube 41 and the target material 42 are integrated. Can be formed.

A tubular body 43 is inserted into the backing tube 41, and the right end thereof is connected to the left end of the inner cylindrical body 12. In this case, the internal space of the tube body 43 constitutes the forward path 44 when the refrigerant is circulated, and the right end of the forward path 44 communicates with the internal space 12 a of the inner cylindrical body 12. On the other hand, the space between the tube body 43 and the backing tube 41 constitutes a return path 45 when the refrigerant circulates, and the return path 45 communicates with the space 13b between the inner cylinder body 12 and the outer cylinder body 13. Yes. Thus, reaching forward 44 through the internal space 12a of the original forward 19a and the inner cylindrical body 12 of Motokan 19 from a chiller unit Ch, support block _Sb 1, Sb ₂ side end this backward back to return 45 A refrigerant circulation passage that reaches the space 13b from 45 and returns from the return path 19b of the main pipe 19 to the chiller unit Ch is formed, and the target material 42 can be cooled by heat exchange with the refrigerant during sputtering.

Further, in the backing tube 41, a line passing through the position where the vertical component of the magnetic field is zero between the targets Tg ₁ and Tg ₂ and the substrate W, supported by the tube 43, is the target Tg ₁ and Tg ₂ . A magnet unit Mu that generates a magnetic field (not shown) that leaks from the surfaces of the targets Tg ₁ and Tg ₂ is incorporated so as to extend along the bus and close in a racetrack shape. The magnet unit Mu includes a yoke 51 having a length that covers substantially the entire length of the target. In the present embodiment, the yoke 51 is substantially equally divided into four parts, and each part of the yoke 51 is supported by a column 52 penetrating the tubular body 43. Each part of the yoke 51 is composed of a plate member made of a magnetic material, which has a top surface 51a parallel to the substrate W and an inclined surface 51b inclined downward from the top surface 51a. A central magnet 53 is disposed on the top surface 51a of the yoke 51, and peripheral magnets 54 are disposed on both inclined surfaces 51b. Although not specifically illustrated and described, corner magnets (see FIG. 5) are formed at both ends of the top surface 51a of the yoke 51 so as to bridge between the peripheral magnets 54 so as to surround the end of the central magnet 53. (Not shown) is arranged. In this case, as the central magnet 53, the peripheral magnet 54, and the corner magnet, neodymium magnets having the same magnetization are used. For example, a bar-shaped one having a substantially square cross section formed integrally can be used.

By the way, when the rotary cathode unit RC is installed in a vacuum chamber, a sputtering gas such as a rare gas is introduced into the vacuum chamber, and power is supplied to the targets Tg ₁ and Tg ₂ , plasma is generated along a racetrack-like magnetic field. The target material 42 is sputtered and eroded over substantially the entire length in the axial direction. At this time, the sputtered particles from the target material 42 are not only scattered toward the substrate W but also to the clamps Cp ₁ , Cp ₂ , drive blocks Db ₁ , Db ₂ , support blocks Sb ₁ , Sb _2, etc. in the vicinity thereof. Scatter and adhere. For this reason, it is necessary to employ a configuration that prevents the sputtered particles from scattering to these components so as not to hinder good film formation on the substrate W. In particular, since the conductive clamps Cp ₁ and Cp ₂ are positioned in the vicinity of the targets Tg ₁ and Tg ₂ , the thin film attached to the surfaces of the clamps Cp ₁ and Cp ₂ induces abnormal discharge due to the charging of electrons. It is necessary to configure so that it can be prevented.

In the present embodiment, first and second preventing spattering of the sputtered particles from the target material 42 to the clamps Cp ₁ and Cp ₂ at predetermined intervals in portions of the backing tube 41 extending outward in the left-right direction. Both prevention means Ps ₁ and Ps ₂ were provided. Since the adhesion preventing means Ps ₁ and Ps ₂ have the same configuration, the first adhesion preventing means Ps ₁ on the drive block Db ₁ side will be described with reference to FIG. 6. The adhesion preventing means Ps ₁ is a backing tube. A ring-shaped base 71 having an inner diameter larger than the outer diameter of 41 and extending from the target material 42 to the portion of the backing tube 41 extending rightward (or leftward), and a plate extending radially outward from the base 71 And a cylindrical portion 73 extending from the base portion 71 in the left-right direction and covering the right end portion of the target material 42 (see FIG. 3). The cylindrical portion 73 is formed with a notch 74 that is recessed in the left-right direction so as to locally expose the right end portion of the target material 42 from which the magnetic field leaks.

The length of the cylindrical portion 73 covering the right end portion of the target material 42 and the area where the target material 42 is exposed (the length of the cutout 74 in the arc direction) are appropriately set according to the leakage magnetic field from the magnet unit Mu. The length of the plate-like portion 72 in the radial direction is determined by the clamps Cp ₁ , Cp ₂ , the drive blocks Db ₁ , Db _2, and the support block Sb according to the target type and the input power to the targets Tg ₁ , Tg ₂ . ₁ and Sb ₂ are set appropriately so that the sputtered particles are not scattered. The anti-adhesion means Ps ₁ is divided into two parts in the vertical direction in consideration of attachment / detachment with respect to the backing tube 41, and the two targets Tg ₁ and Tg ₂ are erected on the pedestal St so as to be positioned radially outward. The two struts 75 are attached via fastening means such as screws.

According to the above embodiment, the flanges 17 and 32a provided on the outer cylindrical body 13 and the driven shaft 32, which are parts for rotationally driving the targets Tg ₁ and Tg ₂ , and the backing tube 41 are combined to provide the clamps Cp ₁ and Cp. ₂ , the targets Tg ₁ and Tg ₂ can be attached to and detached from the drive blocks Db ₁ and Db ₂ and the support blocks Sb ₁ and Sb ₂ by a simple operation. Then, by disposing the adhesion preventing means Ps ₁ and Ps ₂ in the vicinity of the target material 42, it is possible to reliably prevent scattering of sputtered particles generated by sputtering of the target material 42 to the clamps Cp ₁ and Cp ₂ . Moreover, by providing the cylindrical portion 73 with the notch 74, the target material 42 is eroded at the position where the leakage magnetic field acts while the target material 42 rotates once, while the target material 42 is sputtered at the position where the leakage magnetic field does not act. Particle adhesion is prevented. Accordingly, both end portions of the target material 42 can be eroded, and the target material 42 can be eroded almost uniformly over the entire length in the busbar direction, and the induction of abnormal discharge can be reliably prevented.

As mentioned above, although embodiment of this invention was described, this invention is not limited to said thing. In the above-described embodiment, the example including the support blocks Sb ₁ and Sb ₂ has been described as an example. However, the support blocks Sb ₁ and Sb ₂ can be omitted, and the anti-adhesion means Ps ₁ and Ps ₂ are divided into two parts, and two targets Tg ₁ , In the above description, the Tg ₂ is disposed through the two struts 75 erected on the pedestal St so as to be positioned radially outward. However, the present invention is not limited to this, and obstructs the rotation of the target. If it can arrange | position so that it may not, the attachment method does not ask | require.

RC: Rotary cathode unit, Cp ₁ , Cp ₂ ... Clamp, Db ₁ , Db ₂ ... Drive block, Ps ₁ , Ps ₂ ... Prevention means, Tg ₁ , Tg ₂ ... Target, Sb ₁ , Sb ₂ ... Support block , 12 ... Inner cylinder, 13 ... Outer cylinder, 17, 32a ... Flange, 2 ... Driving means, 41 ... Backing tube (target component), 42 ... Target material (target component), 71 ... Base ( Anti-adhesion means), 72 ... plate-like part, 73 ... cylindrical part, 74 ... notch, Mu ... magnet unit.

Claims (3)

A target having a cylindrical backing tube and a target material extrapolated thereto, and a drive block arranged at one end in the axial direction of the target to drive the target to rotate;
The driving block has a rotating member that is driven to rotate by driving means, a flange is provided on the rotating member, and a target is connected by a clamp by combining one end of a backing tube to the flange,
A rotary cathode unit for a sputtering apparatus, wherein a first adhesion preventing means for preventing scattering of sputtered particles to a clamp and a drive block is provided at a portion of a backing tube extending from one side in the axial direction of the target. It further includes a support block that is disposed at the other end in the axial direction of the target and rotatably supports the target, and the target is connected by a clamp by combining one end of a backing tube with a driven shaft provided in the support block,
2. The rotary type for a sputtering apparatus according to claim 1, wherein second backing means for preventing scattering of sputtered particles to the clamp and the support block is provided in a portion of the backing tube extending from the other side in the axial direction of the target. Cathode unit. The rotary cathode unit for a sputtering apparatus according to claim 1 or 2, wherein a line that passes through the position where the vertical component of the magnetic field is zero and extends in the internal space of the target extends along the bus of the target. In further comprising a magnet unit that generates a magnetic field that leaks from the target surface so as to close in a racetrack shape,
The first and second anti-adhesion means include a ring-shaped base portion that is externally inserted into a portion of the backing tube, a plate-shaped portion that extends radially outward from the base portion, and a target material that extends from the base portion in the axial direction. And a cylindrical portion that covers the axial end, and a notch that is recessed in the axial direction is formed in the cylindrical portion so as to locally expose the axial end of the target material from which the magnetic field leaks. A rotary cathode unit for a sputtering apparatus.

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