Coating apparatus and process for target replacement

Abstract

The invention relates to a coating device for coating a substrate by means of cathode sputtering and to a method for replacing a target in such a coating device.

Description

Technical Field

[0001] The invention relates to a coating system for coating a substrate by means of sputtering and to a process for changing a target in such a coating system. Background Art

[0002] When coating by means of cathode sputtering, the target material of the cathode must be replaced regularly due to the sputtering process occurring at the target. Generally speaking, such a target cannot be removed because it is fixed to a so-called target backing plate or target support plate. In addition, the target is usually surrounded by a dark space or a so-called dark space shield connected to the ground. The target and the components around it usually have a large weight and must be mounted on the chamber elements of the equipment, for example, they are mounted on the chamber cover or chamber wall in a suspended position. However, for safety reasons, it is necessary to avoid operating under the cathode. In addition, the operation should be completed by one person. In this context, it is expected that the target and its surrounding components and their assembly can be easily accessed. The industry requires a simple, fast and safe replacement process in order to minimize the equipment downtime of the equipment.

[0003] According to the solution commonly used today, the target backing plate is screwed against an insulator mounted in the coating chamber. Subsequently, the dark space shield is set above the target backing plate and fixed to the coating chamber using screws. Before final fixing, the dark space shield must be aligned relative to the target.

[0004] Examples of coating devices with exchangeable targets are described, for example, in US Pat. No. 6,494,999 B1, DE 197 32 002 A1, DE 41 33 564 A1, DE 25 13 216 A1, DE 22 53 879 A and DE 195 25 007 A1. Summary of the invention

[0005] An object of the present invention is to provide a coating device with a target structure which allows a simple, fast and safe replacement of the target material. This object is achieved by a coating device according to claim 1. Preferred embodiments of the coating device according to the invention are described in the dependent claims. The invention further relates to a method for replacing a target in such a coating device.

[0006] Therefore, the present invention relates to a coating device for coating a substrate by sputtering. The coating device comprises at least a magnet system having one or more magnets, a dark space shield, a target and a target backing plate (or a target support plate), wherein the dark space shield, the target and the target backing plate form a preassembled unit (without the magnet system), which can be introduced into the coating device (including the magnet system) and replaced as a unit, wherein the target and the dark space shield are electrically insulated from each other. The coating device further comprises a coupling mechanism, which allows the preassembled unit (without the magnet system) to be attached to the coating device (including the magnet system). The coupling mechanism is fixed to the dark space shield or interacts with the dark space shield. The combination of the target and the target backing plate is also referred to as a "cathode" hereinafter.

[0007] The preassembled unit consisting of dark space shield, target and target backing plate allows simple handling and safe installation of the unit, so that a change of target material can be performed quickly in the coating apparatus of the invention without long apparatus downtimes.

[0008] Preferably, the coupling mechanism comprises one (or more) eccentric shafts. The eccentric shaft may be a tube or a round rod having one or more eccentrically formed inner sections, wherein at least one opening for receiving a coupling element is provided at each eccentrically formed inner section in the eccentrically formed inner sections. Preferably, the dark space shield or the section of the coating device to which the preassembled unit can be attached comprises one or more coupling elements, which are adapted to engage with the eccentric shaft, in particular with the opening of the eccentric shaft. Preferably, the rotation of the eccentric shaft moves the unit consisting of the dark space shield, the target and the target backing plate toward the magnet system and remains in a defined position. In particular, the rotation of the eccentric shaft causes the unit of the dark space shield, the target and the target backing plate to be clamped or secured to a portion of the chamber, such as a chamber cover or a chamber wall.

[0009] The solution based on the eccentric shaft makes the handling of the pre-assembled unit simpler and safer. In particular, with the solution, the coupling mechanism can be arranged in the processing area (ie vacuum) so that no additional openings are required. The eccentric shaft can be driven directly and manually without motors or other components.

[0010] According to a particularly preferred embodiment of the coating device of the present invention, the pre-assembled unit of the dark area shield, the target and the target backing plate further includes a positioning sleeve and / or a clamping bolt. The pre-assembled unit can be moved to the coating device using, for example, an auxiliary device. Then, the auxiliary device is guided to a stopper, which is placed in the coating chamber, and the pre-assembled unit is lifted in the coating chamber. During the lifting process, two positioning pins (for example, threaded to the chamber cover) enter the positioning sleeve of the pre-assembled unit and are accurately aligned in the coating chamber. Before the lifting process is about to be completed, the clamping bolts installed on the dark area shield are, for example, engaged in the eccentric shaft of the coupling mechanism. For example, four clamping bolts can be engaged in an eccentric shaft with a milled eccentric groove. By rotating the two eccentric shafts, the clamping bolts are clamped to the eccentric shaft. This causes the dark area shield to be clamped against a chamber element (for example, a chamber cover or a chamber wall). The spring element mounted on the dark space shield is pressed against the chamber cover when clamped and ensures defined contact and equipotential bonding relative to the chamber. One or more screws are used to ensure defined contact between the power connection and the target backing plate and compression of the sealing ring. The auxiliary device can then be removed.

[0011] By providing a pre-assembled unit, alignment between the target and the dark space shield can be performed before maintenance work is performed at the coating equipment in the workshop. This reduces maintenance time at the equipment and significantly simplifies and shortens maintenance work, thereby increasing the production capacity of the equipment.

[0012] Instead of the above arrangement, an inverted structure may also be considered in which the clamping bolt is installed in the coating chamber and the eccentric shaft is attached to the dark space shield.

[0013] The pre-assembled unit of dark space shield, target and target backing plate preferably has a longitudinal extension, wherein the eccentric axis extends along said longitudinal extension. This enables the coating system of the invention to be easily adapted to different target lengths.

[0014] The eccentric shaft preferably allows a maximum stroke of at most 10 mm, more preferably at most 5 mm, and particularly preferably at most 2 mm. Preferably, the eccentric shaft is directly rotatable manually.

[0015] The coating device preferably comprises a vacuum region which can be evacuated for the coating process, wherein the coupling mechanism is located completely within the vacuum region.Preferably, the vacuum region must be opened in order to allow manual operation of the coupling mechanism.

[0016] The magnet system is preferably displaceable in three spatial directions relative to the pre-assembled unit of dark space shield, target and target backing plate and optionally tiltable relative to the pre-assembled unit. This allows an exact alignment of the magnet system with the target.

[0017] Preferably, the coating device further comprises a connection section, via which current and / or coolant can be supplied to the pre-assembled unit of the dark space shield, the target and the target backing plate. Preferably, at least one additional threaded connection is arranged in the region of the connection section. The opening of the connecting medium is preferably located outside the coating area. The medium connection block is mounted on the chamber in an insulating position and is located in the region of the opening of the connecting medium. The connection is preferably designed to be flat, so that only a small installation stroke or eccentric stroke is required.

[0018] The invention further relates to a method for replacing a target in a coating plant as described above. In the method according to the invention, the preassembled unit of the dark space shield, the target and the target backing plate is first detached from the remaining coating plant by operating a coupling mechanism. Subsequently, the preassembled unit of the dark space shield, the target and the target backing plate is removed from the coating plant. Then, a new preassembled unit of the dark space shield, the target and the target backing plate can be introduced into the coating plant and the preassembled unit can be attached to the remaining coating plant by operating the coupling mechanism.

[0019] Preferably, the coupling mechanism comprises an eccentric shaft, wherein the detachment and attachment of the pre-assembled unit is preferably performed manually by rotating an operating section of the eccentric shaft, preferably by a maximum of 330°, more preferably by a maximum of 180°. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Hereinafter, preferred embodiments of the present invention are described in more detail with reference to the accompanying drawings.

[0021] - Figure 1 Shown: a perspective view of a section of a coating device according to the invention;

[0022] - Figure 2 Shown: Passing through Figure 1 (inverted) cross section;

[0023] - Figure 3 Shown are: a schematic cross-sectional view illustrating the operating principle of an eccentric shaft;

[0024] - Figure 4 Shown are: a schematic cross-sectional view illustrating the operating principle of an eccentric shaft;

[0025] - Figure 5 Shown: Passing through Figure 1 (inverted) cross section;

[0026] and

[0027] - Figure 6 Shown is a longitudinal section through a section of a coating device according to a particularly preferred embodiment. DETAILED DESCRIPTION

[0028] Figure 1 is a perspective view of a section of a coating apparatus according to a preferred embodiment of the present invention. Figure 2 and Figure 5 Corresponding cross-sectional views are shown. Figure 1 , Figure 2 and Figure 5 In particular, a preassembled unit of the dark space shield 4, target 8a and target backing plate 8b of the present invention is shown. Target 8a and target backing plate 8b together form cathode 8. According to the present invention, such a preassembled unit can be introduced into a coating device as a unit and can be replaced as a unit, wherein cathode 8 (consisting of target 8a and target backing plate 8b) and dark space shield 4 are electrically insulated from each other. The coating device (the rest is not shown) further includes a coupling mechanism, which attaches the preassembled unit of dark space shield 4, target 8a and target backing plate 8b to a component of the coating device, wherein the coupling mechanism can be fixed to the dark space shield 4 or interact with the dark space shield 4. In accordance with Figure 1 , Figure 2 and Figure 5 In the embodiment of the present invention, the coupling mechanism comprises two eccentric shafts 2 extending along the longitudinal extension of the preassembled unit. In the embodiment shown, the two eccentric shafts 2 are each rotatably mounted in a bearing block 14.

[0029] The principle of the eccentric shaft 2 is Figure 3 and Figure 4 The eccentric shaft 2 can be designed as a tube or a round rod with one or more eccentrically formed inner sections 2a, wherein at least one opening for receiving a coupling element (eg a bolt 3) is provided in each eccentrically formed inner section 2a. Figure 3 and Figure 4 As shown, the bolt 3 can enter the opening, so that due to the inner contour 2a formed by the eccentricity, the eccentric shaft 2 is Figure 3 Rotation in the direction of the arrow in the figure causes bolt 3 to rotate Figure 3 Therefore, according to Figure 1 , Figure 2 and Figure 5 In the embodiment of , a corresponding rotation of the eccentric shaft 2 causes the preassembled unit of dark space shield 4 , target 8 a and target backing plate 8 b to be pulled radially towards the center / middle axis of the eccentric shaft, ie in the direction of the two bearing blocks 14 .

[0030] As from Figure 6 clear, Figure 6This movement, showing further components of the coating apparatus of the invention, causes the preassembled unit of the dark space shield 4, the target 8a and the target backing plate 8b to be pressed in the direction of the magnet system 7 of the coating apparatus. In order to facilitate the correct positioning of the preassembled unit relative to the magnet system 7, positioning pins 13 are provided which can enter corresponding positioning sleeves 16 in the preassembled unit.

[0031] The attachment of the pre-assembled unit to the coating device is preferably accomplished by manually rotating the eccentric shaft 2 (eg, using an actuating element 2b (see Figure 3 and Figure 4 )) to carry out.

[0032] Figure 5 The cross section of again shows the positioning of the pre-assembled unit relative to the magnet system 7. Furthermore, cooling channels 5 for cooling the backing plate 8a as well as an insulator 9 which electrically insulates the target 8a and the target backing plate 8b from the dark space shield 4 are shown.

[0033] Figure 5 Also shown is a portion of the vacuum chamber 1 of the coating device. As can be clearly seen, the chamber wall 6 of the vacuum chamber 1 extends between the magnet system 7 on one side and the preassembled unit consisting of the dark space shield 4, the target 8a and the target backing plate 8b on the other side. In other words, Figure 5 The dotted line in forms an imaginary dividing line with atmospheric pressure on one side and vacuum on the other side. Therefore, the coupling mechanism of the present invention (i.e., in particular the eccentric shaft 2) is located in the vacuum of the processing area, so that no additional opening is required. In other words, the entire target attachment (including the eccentric shaft and the actuating element) is located in the vacuum. In this way, vacuum leaks can be avoided. According to an alternative embodiment, it is possible that only the actuating element 2b of the eccentric shaft 2 extends into the area of ​​atmospheric pressure. The clamping is performed outside the target area without extending into the processing chamber. Therefore, the clamping mechanism does not need to be sealed to the atmosphere, and the influence on the magnetic field is reduced to a minimum.

[0034] Figure 2 A cross-sectional view through a section of a coating device is shown, which includes an inlet 10 for a cooling medium and for an electric current. In particular, mounting screws 11 and insulators 12 for a power source can be seen. Thus, a medium connection block 10 for the medium is located separately outside the treatment area and the target 8a is separated. Connections for a power source and a water supply, as well as vacuum and atmospheric sealing between the cathode and the chamber are ensured by screws 11.

Claims

1. A coating device for coating a substrate by sputtering, the coating device comprising: at least a magnet system, a dark space shield, a target and a target backing plate, wherein the dark space shield, the target and the target backing plate form a preassembled unit, which can be introduced into the coating device as a unit and can be replaced as a unit, wherein the target and the dark space shield are electrically insulated from each other, wherein the coating device further comprises a coupling mechanism, which allows the preassembled unit to be attached to the coating device, and wherein the coupling mechanism is fixed to the dark space shield or interacts with the dark space shield.

2. The coating apparatus of claim 1, wherein the coupling mechanism comprises an eccentric shaft.

3. A coating device as described in claim 2, wherein the eccentric shaft comprises a tube or a round rod having one or more eccentrically formed inner sections, wherein at least one opening for receiving a coupling element is arranged at each eccentrically formed inner section in the eccentrically formed inner sections.

4. A coating device as described in claim 2 or 3, wherein the dark space shield or the section of the coating device to which the preassembled unit can be attached comprises one or more coupling elements, and the one or more coupling elements are adapted to engage with the eccentric shaft, in particular with the opening of the eccentric shaft.

5. Coating apparatus according to any one of claims 2 to 5, wherein rotation of the eccentric shaft causes the unit consisting of dark space shield, target and target backing plate to be moved towards the magnet system and held in a defined position.

6. Coating apparatus according to any one of claims 2 to 5, wherein the pre-assembled unit of dark space shield, target and target backing plate has a longitudinal extension, and the eccentric shaft extends along the longitudinal extension.

7. The coating device according to any one of claims 2 to 6, wherein the eccentric shaft allows a maximum stroke of at most 10 mm, preferably at most 5 mm, and particularly preferably at most 2 mm.

8. The coating apparatus according to any one of claims 2 to 7, wherein the eccentric shaft can be directly rotated manually.

9. The coating apparatus of any one of the preceding claims, wherein the coating apparatus comprises a vacuum region which is evacuated for the coating process, and wherein the coupling mechanism is located entirely within the vacuum region.

10. The coating apparatus of claim 6, wherein the vacuum region must be opened to allow manual operation of the coupling mechanism.

11. The coating apparatus of any one of the preceding claims, wherein the dark space shield and the coupling mechanism are electrically insulated from the target.

12. A coating apparatus as claimed in any one of the preceding claims, wherein the magnet system is displaceable in three spatial directions relative to the preassembled unit of dark space shield, target and target backing plate and optionally tiltable relative to the preassembled unit of dark space shield, target and target backing plate.

13. A coating device as claimed in any of the preceding claims, wherein the coating device further comprises a connecting section, via which current and / or coolant can be supplied to the preassembled unit of the dark space shield, the target and the target backing plate, wherein preferably at least one additional threaded connection is arranged in the area of ​​the connecting section.

14. A process for replacing a target in a coating apparatus as claimed in any one of the preceding claims, the process comprising: - disconnecting said preassembled unit of dark space shield, target and target backing plate from the rest of the coating apparatus by operating said coupling mechanism; - removing said preassembled unit of dark space shield, target and target backing plate from said coating apparatus; - introducing a new preassembled unit of dark space shield, target and target backing plate into the coating apparatus; as well as - Attaching the pre-assembled unit of dark space shield, target and target backing plate to the rest of the coating apparatus by operating the coupling mechanism.

15. The method of claim 14, wherein the coupling mechanism comprises an eccentric shaft, and wherein the detachment and attachment of the preassembled unit of dark space shield, target and target backing plate is preferably performed manually by rotating an operating section of the eccentric shaft, preferably by a maximum rotation of 330°, more preferably by a maximum rotation of 180°.

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