JP6155796B2 - Arc plasma deposition system - Google Patents

Description

  The present invention relates to an arc plasma film forming apparatus for forming a film by forming arc plasma.

  An arc plasma film forming apparatus using arc plasma has been proposed for use in forming a diamond like carbon (DLC) film. In the arc plasma film forming apparatus, one of the problems is to realize long-term continuous use. The arc plasma deposition apparatus uses a solid target, and the surface of the target is locally melted by an arc spot during arc discharge. The arc discharge falls into the deep hole (concave) formed thereby, and the discharge becomes unstable. As a result, there has been a problem that the film formation rate is reduced, or arc discharge disappears and film formation is interrupted.

  In particular, in an arc plasma film forming apparatus for forming a DLC film, a concave hole is formed in the arc spot portion due to arc discharge on the surface of the carbon target, and the discharge becomes unstable or the discharge is interrupted. The problem is remarkable.

  For this reason, a method has been proposed in which the target surface is cut in a chamber and the target surface is corrected flatly. The amount of cutting at one time is about 3 mm. In the conventional method, a long target of 100 mm to 200 mm is used, and the target surface is periodically cut in the chamber to ensure a flat surface. Thereby, the same target is used for a certain period. As a result, the operation rate of the apparatus is improved by suppressing the target exchange time, the vacuum vent, and the exhaust time. Further, a method has been proposed in which a plurality of targets are prepared, a film forming process is performed with one target, and the surface of the other target is cut to further improve the operating rate of the apparatus (for example, Patent Document 1).

JP-A-2005-240182

  However, in the method of cutting the target surface in the chamber, there is a problem that a large amount of dust that becomes a particle source accumulates in the chamber and is mixed into the film formation surface.

  In view of the above problems, an object of the present invention is to provide an arc plasma film forming apparatus that realizes a high operating rate and does not accumulate cutting dust on a target in a chamber.

According to one aspect of the present invention, there is provided an arc plasma film forming apparatus for forming an arc plasma containing ions of a material element of a film forming target and forming a thin film containing the material element as a main component on a substrate to be processed. (B) a chamber having a sample chamber in which a substrate is installed and a discharge chamber in which arc plasma is formed; and (b) a film forming position in which a plurality of targets are stored and connected to the discharge chamber through a through hole. And (c) supporting a plurality of targets in the target storage chamber so that one of the plurality of targets is disposed at the film formation position as a film formation target, and changing the relative positional relationship. comprising a target support device for moving a plurality of targets simultaneously without, a target transport mechanism for transporting (d) a film-forming target positioned in the deposition position to the discharge chamber, a plurality Each target is part of the target on the bottom surface of the target holder having a mounting structure in the target holder so as to be exposed to project from the bottom surface, the film formation target of the bottom surface of the target holder equipped with a deposition target An arc plasma film-forming apparatus that provides a hermetic seal between the discharge chamber and the target storage chamber is provided by allowing the remaining region of the exposed portion to adhere to the outside of the discharge chamber around the through hole.

  According to the present invention, it is possible to provide an arc plasma film forming apparatus that realizes a high operating rate and does not accumulate target cutting dust in the chamber.

It is a schematic diagram which shows the structure of the arc plasma film-forming apparatus which concerns on embodiment of this invention. FIG. 2A is a schematic diagram illustrating an example in which a deposition target is disposed at a deposition position in an arc plasma deposition apparatus according to an embodiment of the present invention, and FIG. 2A is a diagram before the deposition target is pushed into a through hole. FIG. 2B shows a state after the film-forming target is pushed into the through hole. It is a schematic diagram which shows the example of a target arrangement | positioning in the arc plasma film-forming apparatus which concerns on embodiment of this invention. FIG. 4A is a schematic diagram illustrating a configuration of a target transport mechanism and a gate valve of an arc plasma film forming apparatus according to an embodiment of the present invention, and FIG. 4A illustrates a state in which a through hole is blocked by the gate valve; (B) shows an example in which the gate valve is supported by the target storage chamber. It is a schematic diagram for demonstrating the function of the target rotation mechanism which the target conveyance mechanism of the arc plasma film-forming apparatus which concerns on embodiment of this invention has. FIG. 6A is a schematic diagram showing another example of the arrangement of targets in the arc plasma film forming apparatus according to the embodiment of the present invention, and FIG. 6A is an example in which targets are arranged in tandem in the vertical direction, and FIG. ) Is an example in which targets are arranged in rows in the horizontal direction.

  Embodiments of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic. Further, the embodiment described below exemplifies an apparatus and a method for embodying the technical idea of the present invention, and the embodiment of the present invention has the following structure and arrangement of components. It is not something specific. The embodiment of the present invention can be variously modified within the scope of the claims.

  An arc plasma film forming apparatus 1 according to an embodiment of the present invention forms an arc plasma containing material element ions of a film forming target by arc discharge, and a thin film containing the material element as a main component on a substrate to be processed. This is an arc plasma film forming apparatus. The “deposition target” is exposed to arc plasma to form a desired thin film on the substrate.

  As shown in FIG. 1, the arc plasma film forming apparatus 1 includes a chamber 10 in which a substrate 100 to be processed is installed, a target storage chamber 20 in which a plurality of targets 40 are stored, and one of the plurality of targets 40. A target support device 30 that supports a plurality of targets 40 in the target storage chamber 20 so as to be disposed at the film position 25, and a target transport mechanism 50 that transports the target 40 disposed at the film formation position 25 to the discharge chamber 12. With.

  The chamber 10 has a sample chamber 11 in which the substrate 100 is disposed and a discharge chamber 12 in which arc plasma is formed. The chamber 10 further includes an induction tube 13 that connects the sample chamber 11 and the discharge chamber 12 and guides arc plasma from the discharge chamber 12 to the sample chamber 11.

  The target 40, which is a material to be deposited on the substrate 100, is supported while being mounted on the target holder 42, and is evaporated by arc discharge. For example, when a DLC film is formed on the substrate 100, carbon is used for the target 40.

  The target 40 has a cylindrical shape, for example. The target 40 is mounted on the target holder 42 so that the surface of the target 40 is exposed on the bottom surface of the target holder 42. The remaining area of the area where the target 40 is exposed on the bottom surface of the target holder 42 is in close contact with the outside of the discharge chamber 12 around the through hole 120, so that the space between the discharge chamber 12 and the target storage chamber 20 is hermetically sealed. Therefore, the outer shape of the target 40 and the shape of the through hole 120 correspond to each other.

  In the target storage chamber 20, a film formation position 25 that is connected to the discharge chamber 12 via the through hole 120 is defined. As shown in FIG. 2A, the target support device 30 selectively places one of a plurality of target holders 42 each having a target 40 mounted thereon at the film formation position 25. Then, as shown in FIG. 2B, the target transport mechanism 50 moves the target holder 42 into the through-hole 120 so that the deposition target 40 </ b> T disposed at the deposition position 25 is exposed in the discharge chamber 12. Push in. The film formation target 40T and the target holder 42 supported by the target support device 30 are transported to the discharge chamber 12 by extending and contracting the transport rod 500.

  Further, by pressing the target holder 42 to which the film-forming target 40T is mounted as described above against the through hole 120, the through hole 120 is closed by the target holder 42, and the target storage chamber 20 is in the chamber 10. Is hermetically sealed. For this reason, regardless of the pressure state in the target storage chamber 20, even if the inside of the target storage chamber 20 becomes atmospheric pressure, the vacuum state in the chamber 10 is maintained.

  FIG. 3 shows an example in which a plurality of targets 40 are arranged in the target storage chamber 20 around the rotation axis C in a circular shape. FIG. 3 is a side view seen from the direction in which the rotation axis C extends, and the film formation target 40T is pushed into the through hole 120 along the rotation axis C. FIG. As shown in FIG. 3, since the target support device 30 supports the target 40 with a revolver structure, any target can be obtained by rotating the plurality of targets 40 around the rotation axis C as indicated by the arrows. 40 can be arranged at the film forming position 25.

  Although FIG. 3 shows an example in which eight targets 40 are stored in the target storage chamber 20, the number of targets stored in the target storage chamber 20 is not limited to eight. Moreover, you may arrange | position the some target 40 not only in a perfect circle shape but elliptical. Alternatively, the plurality of targets 40 may be stored in the target storage chamber 20 in an arrangement form other than the annular shape.

  In the arc plasma film forming apparatus 1, arc plasma including positive ions of raw materials included in the film forming target 40 </ b> T is generated by arc discharge generated using the film forming target 40 </ b> T as a cathode. This plasma is guided from the discharge chamber 12 to the surface of the substrate 100 in the sample chamber 11 via the induction tube 13 to form a thin film on the substrate 100. For example, plasma is transported along the induction tube 13 by a magnetic field formed by a coil (not shown) arranged around the induction tube 13. In arc discharge, fine particles called droplets, which are neutral particles, are generated separately from plasma. By using a curved induction tube 13 as shown in FIG. 1, the plasma is bent along the induction tube 13 by a coil magnetic field. In contrast to being transported, neutral particles that are not charged are filtered by the bent portion of the guide tube 13 and do not reach the substrate 100.

  As will be described later, arc plasma is formed in the film forming process after the chamber 10 is evacuated. On the other hand, the inside of the target storage chamber 20 and the inside of the chamber 10 are hermetically sealed by a target holder 42 of a film formation target 40T that closes the through hole 120. For this reason, even when the inside of the chamber 10 is in a vacuum state or when arc plasma is formed in the chamber 10, the inside of the target storage chamber 20 can be at atmospheric pressure, for example. That is, the inside of the chamber 10 can be separated from the inside of the target storage chamber 20 to be in a vacuum state. Therefore, the target 40 disposed in the target storage chamber 20 can be replaced with a new unused target during the film forming process of the substrate 100.

  Alternatively, during the film forming process of the substrate 100, the target 40 disposed in the target storage chamber 20 can be taken out and the surface of the target 40 can be cut and polished. Specifically, the film forming target 40T is replaced with another target 40 in the target storage chamber 20 by the target support device 30, and the used target 40 is moved from the film forming position 25 at the same time. Since the inside of the target storage chamber 20 can be set to atmospheric pressure while performing the film forming process, the used target 40 in the target storage chamber 20 can be taken out from the target storage chamber 20. For this reason, the surface of the used target 40 can be polished by a polishing apparatus or the like.

  By polishing the surface of the used target 40, the smoothness of the surface of the target 40 is recovered, and the discharge stability can be obtained.

  In addition, by preparing the gate valve 60 that closes the through hole 120 as shown in FIG. 4A in the target storage chamber 20, the vacuum state in the chamber 10 is maintained regardless of the pressure state in the target storage chamber 20. be able to. That is, by closing the through hole 120 with the gate valve 60, the inside of the target storage chamber 20 is set to atmospheric pressure while maintaining the vacuum state in the chamber 10 even when the target 40 is not pushed into the through hole 120. Is possible.

  For example, as shown in FIG. 4B, a gate valve 60 that is supported by a fulcrum F and is movable in the target storage chamber 20 is prepared. The gate valve 60 is disposed at a position away from the through hole 120 during the film forming process. On the other hand, when all of the target 40 is not exposed in the discharge chamber 12, the through hole 120 is closed by the gate bulb 60 moved in the direction of the arrow as shown in FIG. Thereby, the inside of the target storage chamber 20 can be made atmospheric pressure without breaking the vacuum state in the chamber 10. For this reason, it is possible to take out the used target 40 from the target storage chamber 20 or place a new target 40 in the target storage chamber 20 while the inside of the chamber 10 is kept in a vacuum state. Since the vacuum state in the chamber 10 is maintained, the operating rate of the arc plasma film forming apparatus 1 is improved.

  As shown in FIG. 4A, the target transport mechanism 50 includes a target rotation mechanism 51, a target power supply mechanism 52, and a target cooling mechanism 53.

  The target rotation mechanism 51 rotates the film formation target 40T with the surface normal direction of the bottom surface of the target holder 42 as a rotation axis. For example, the film forming target 40T is rotated together with the target holder 42 as shown in FIG. 5 by rotating the transfer rod 500 connected to the target holder 42. By rotating the deposition target 40T during arc discharge, the evaporation amount on the surface of the deposition target 40T can be made uniform. For example, the transport rod 500 is rotated using a motor or the like.

  The target power supply mechanism 52 supplies power to the film formation target 40T in order to form arc plasma. Specifically, power is supplied to the film formation target 40T through the transport rod 500 and the target holder 42 so that the film formation target 40T becomes a cathode. Thereby, desired plasma is formed in the discharge chamber 12.

  The target cooling mechanism 53 cools the film formation target 40T via the transfer rod 500. During the film forming process, the temperature of the film forming target 40T exposed to the arc plasma rises. When the deposition target 40T is in a high temperature state, it is difficult to maintain arc discharge. In addition, the temperature of the hermetic seal portion between the discharge chamber 12 and the target storage chamber 20 rises, resulting in problems such as exceeding the durability of the seal material. For this reason, it is effective to cool the deposition target 40T during the deposition process. For the target cooling mechanism 53, for example, a water cooling method in which cooling water is allowed to flow in the transfer rod 500 can be employed.

  Hereinafter, an example of a method for forming a film on the substrate 100 to be processed by the arc plasma film forming apparatus 1 shown in FIG. 1 will be described. In the following description, the target 40 disposed in the target storage chamber 20 is referred to as a first target, a second target, a third target,.

  First, the substrate 100 to be processed is stored in the sample chamber 11 and the sample chamber 11 is evacuated. A space between the sample chamber 11 and the target storage chamber 20 is hermetically sealed by a gate valve 60. A plurality of targets 40 used in the film forming process are arranged in the target storage chamber 20, and the target storage chamber 20 is evacuated. The target 40 includes a raw material for a film to be formed on the substrate 100.

  Next, the target support device 30 moves the plurality of targets 40 arranged in the target storage chamber 20 so that the first target is arranged at the film formation position 25 as the film formation target 40T. Then, the gate valve 60 is opened, the first target arranged at the film forming position 25 is pushed into the through hole 120, and the target 40 of the first target is exposed in the discharge chamber 12.

  Then, arc plasma is formed on the surface of the first target exposed in the discharge chamber 12. The arc plasma is formed, for example, by generating an arc discharge with a high electric field. That is, by the occurrence of arc discharge, the target 40 is evaporated and ionized, and arc plasma is formed. A film forming process using the first target is performed by introducing and depositing ions of the target 40 in the arc plasma on the surface of the substrate 100.

  After a predetermined discharge time, the arc discharge is stopped, and the arrangement of the target 40 in the target storage chamber 20 is changed by the target support device 30. Specifically, the second target moves to the film formation position 25 instead of the used first target. When this target is replaced, the vacuum state is maintained in the target storage chamber 20 as in the chamber 10. Thereafter, arc discharge is resumed, and film formation using the second target is performed.

  Furthermore, after a predetermined discharge time, the arc discharge is stopped, and the target support device 30 moves the third target to the film forming position 25 instead of the used second target. Then, a film forming process using the third target is performed.

  Thereafter, every time a predetermined discharge time elapses, the film forming process is performed while replacing the film forming target 40T.

  The predetermined discharge time for forming a film using one target 40 is such that, for example, the size of the recess formed on the surface of the target 40 by the arc spot does not significantly deteriorate the generation and maintenance of the arc discharge. Is set. By exchanging the film-forming target 40T at a constant frequency, the surface smoothness of the film-forming target 40T is always ensured, and a stable arc discharge can be obtained.

  As described above, in the arc plasma film forming apparatus 1, film formation is performed while replacing the film formation target 40T using the plurality of targets 40 in the target storage chamber 20 while the chamber 10 is kept in a high vacuum state. Processing is performed. For this reason, a high operation rate can be maintained.

  Furthermore, while performing the film forming process in the chamber 10, the used target 40 in the target storage chamber 20 can be replaced with a new unused target 40, or the surface of the used target 40 can be polished. . Also in this case, a high operating rate can be maintained. Further, since the target 40 is not polished in the chamber 10, there is no accumulation of cutting dust that becomes a particle source in the chamber 10, and mixing of particles on the substrate surface is reduced.

  As described above, according to the arc plasma film forming apparatus 1 according to the embodiment of the present invention, an arc plasma film forming apparatus that achieves a high operating rate and does not accumulate target cutting dust in the chamber 10. Can be provided.

(Other embodiments)
As mentioned above, although this invention was described by embodiment, it should not be understood that the description and drawing which form a part of this indication limit this invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

  In the description of the embodiment already described, an example in which a plurality of targets 40 are annularly arranged in the target storage chamber 20 has been shown. However, besides the annular shape, for example, a plurality of targets 40 may be arranged in a straight line in the target storage chamber 20. Specifically, the targets 40 may be arranged in the vertical direction as shown in FIG. 6A, or the targets 40 may be arranged in the horizontal direction as shown in FIG. 6B. The desired target 40 can be disposed at the film forming position 25 by sliding the plurality of targets 40 on which the target support device 30 is linearly disposed.

  As described above, the present invention naturally includes various embodiments not described herein. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

DESCRIPTION OF SYMBOLS 1 ... Arc plasma film-forming apparatus 10 ... Chamber 11 ... Sample chamber 12 ... Discharge chamber 13 ... Induction tube 20 ... Target storage chamber 25 ... Film-forming position 30 ... Target support device 40 ... Target 40T ... Film-forming target 42 ... Target holder DESCRIPTION OF SYMBOLS 50 ... Target conveyance mechanism 51 ... Target rotation mechanism 52 ... Target electric power feeding mechanism 53 ... Target cooling mechanism 60 ... Gate valve 100 ... Substrate 120 ... Through-hole 500 ... Conveyance rod

Claims (6)

An arc plasma film forming apparatus for forming an arc plasma containing ions of a material element of a film forming target and forming a thin film containing the material element as a main component on a substrate to be processed,
A chamber having a sample chamber in which the substrate is installed and a discharge chamber in which the arc plasma is formed;
A target storage chamber in which a plurality of targets are stored and a film forming position is defined which is connected to the discharge chamber via a through hole;
The plurality of targets are supported in the target storage chamber so that one of the plurality of targets is disposed at the film formation position as the film formation target, and the plurality of targets are supported without changing the relative positional relationship. A target support device to be moved simultaneously;
A target transfer mechanism for transferring the film formation target disposed at the film formation position to the discharge chamber;
Each of the plurality of targets has a structure attached to the target holder such that a part of the target protrudes from the bottom surface of the target holder and is exposed.
The remaining area of the area where the part of the film forming target on the bottom surface of the target holder on which the film forming target is mounted is in close contact with the outside of the discharge chamber around the through hole. An arc plasma film-forming apparatus characterized by hermetically sealing between the discharge chamber and the target storage chamber. The plurality of targets are annularly arranged in the target storage chamber, the target support device rotates the plurality of targets, and the target transport mechanism uses the one of the plurality of targets as the film formation target as the discharge. The arc plasma film forming apparatus according to claim 1, wherein the apparatus is transported to a chamber.   The target storage chamber includes a gate valve that moves independently of the plurality of targets and closes the through holes in parallel with the main surface of the target support device in which the plurality of targets are arranged in the same plane, 3. The arc plasma film formation according to claim 1, wherein a vacuum state in the chamber is maintained regardless of a pressure state in the target storage chamber in a state where the through hole is closed by a gate valve. apparatus.   The target transport mechanism includes a target rotation mechanism that rotates the film-forming target with a surface normal direction of the bottom surface of the target holder as a rotation axis. The arc plasma film-forming apparatus as described.   5. The arc plasma film forming apparatus according to claim 1, wherein the target transport mechanism includes a target power supply mechanism that supplies power to the film formation target in order to form the arc plasma. .   The arc plasma film-forming apparatus according to claim 1, wherein the target transport mechanism includes a target cooling mechanism that cools the film-forming target.

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