Film-forming device

Abstract

In order to prevent, during film-forming on one surface of a substrate, a film-forming material from sticking to another surface of the substrate, this sputtering film-forming device (1) comprises: a film-forming chamber (11) in which to perform a film-forming process; a substrate holder (22) for mounting a substrate (S) having one surface and another surface; and a rotary drum (12) that is disposed inside the film-forming chamber (11) and retains the substrate holder (22). The substrate holder (22) is disposed, with respect to the rotary drum (12), so as to be reversible or rotatable to a first position at which to perform film-forming on the one surface of the substrate (S) and a second position at which to perform film-forming on the other surface of the substrate (S). The sputtering film-forming device also comprises a masking member (24) for shielding the other surface of the substrate (S) if film-forming is performed on the one surface of the substrate (S) when the substrate holder (22) is at the first position.

Description

Film forming equipment

[0001] The present invention relates to a film forming apparatus, and more particularly to an apparatus for forming films on both sides of a substrate.

[0002] A vacuum deposition apparatus capable of forming a film on both sides of a substrate is known (see, for example, Patent Document 1). In this vacuum deposition apparatus, a substrate is attached to a substrate holder so that both sides of the substrate are exposed, and the substrate holder is rotatably attached to a substrate jig. After a deposited film is formed on one side of the substrate, the substrate holder is rotated relative to the substrate jig to flip the substrate. Then, a deposited film is formed on the other side of the flipped substrate, thereby forming films on both sides of the substrate.

[0003] Japanese Patent Application Publication No. 5-271935

[0004] In the conventional vacuum deposition apparatus, the substrate holder for holding the substrate is mounted in a reversible manner, so a gap is required between the substrate holder and the adjacent substrate holder to prevent interference with each other. However, during film formation, the deposition material flows through this gap to the back surface of the substrate holder, forming a film on part of the back surface of the substrate. Due to the influence of this flowing film, the film performance on the back surface does not exhibit the designed film performance.

[0005] An object of the present invention is to provide a film forming apparatus that can prevent film forming material from adhering to one surface of a substrate while a film is being formed on the other surface of the substrate.

[0006] The present invention solves the above problem by providing a film formation apparatus comprising a film formation chamber for performing film formation processing, a substrate holder for mounting a substrate having one side and another side, and a rotating body provided within the film formation chamber and holding the substrate holder, wherein the substrate holder is provided so as to be reversible or rotatable relative to the rotating body between a first position for forming a film on one side of the substrate and a second position for forming a film on the other side of the substrate, and further comprising a masking member for shielding the other side of the substrate when the substrate holder is at the first position to form a film on one side of the substrate.

[0007] According to the present invention, while a film is being formed on one surface of the substrate, the other surface of the substrate is shielded with a masking member, thereby preventing the film-forming material from adhering to the other surface of the substrate while a film is being formed on one surface of the substrate.

[0008] 1. A cross-sectional view showing an embodiment of a film forming apparatus according to the present invention. A vertical-sectional view taken along line II-II in FIG. 1. An enlarged view of part III in FIG. 2, which is a front view showing a first embodiment of a masking member according to the present invention. A view taken along line IV-IV in FIG. 3. An enlarged view of part V in FIG. 4. A view taken along line VI-VI in FIG. 5. A view taken along line IV-IV in FIG. 3, showing an operation (part 1) of a first embodiment of a masking member according to the present invention. A view taken along line IV-IV in FIG. 3, showing an operation (part 2) of a first embodiment of a masking member according to the present invention. A view taken along line IV-IV in FIG. 3, showing an operation (part 3) of a first embodiment of a masking member according to the present invention. A perspective view showing a second embodiment of a masking member according to the present invention. An enlarged perspective view of part XI in FIG. 10. An enlarged perspective view of part XII in FIG. 10. A plan view showing an operation (part 1) of a second embodiment of a masking member according to the present invention. A plan view showing an operation (part 2) of a second embodiment of a masking member according to the present invention. FIG. 10 is a plan view showing the operation (part 3) of the second embodiment of the masking member according to the present invention.

[0009] An embodiment of the present invention will now be described with reference to the drawings. Fig. 1 is a cross-sectional view showing one embodiment of a film formation apparatus according to the present invention, and Fig. 2 is a longitudinal cross-sectional view taken along line II-II in Fig. 1. The film formation apparatus of this embodiment is a sputtering film formation apparatus 1, and includes a film formation chamber 11 that can be depressurized and that can introduce a discharge gas and that forms a film on a substrate S, a rotating drum 12 that is rotatably provided within the film formation chamber 11, and a first sputtering electrode 13 and a second sputtering electrode 14 that face the outer surface of the rotating drum 12.

[0010] The film formation chamber 11 is made of a hollow housing that forms a substantially sealed space, and is rectangular in plan and side views, for example, as shown in Figures 1 and 2. A suction port of a first exhaust device 15 such as a turbomolecular pump is connected to a wall surface of the film formation chamber 11, and gas is exhausted from the internal space of the film formation chamber 11, thereby maintaining the film formation chamber 11 at a predetermined reduced pressure atmosphere.

[0011] The film formation chamber 11 is also provided with a gas introduction device 16 that introduces a discharge gas (a gas that emits electrons that collide with the target during sputtering) and, if necessary, a reactive gas into the internal space of the film formation chamber 11. The gas introduction device 16 of this embodiment stores the discharge gas and also stores the reactive gas when performing a reactive sputtering process or the like. The discharge gas is not particularly limited, but an inert gas such as argon gas is used, for example. The reactive gas is selected depending on the type of film to be formed; for example, oxygen gas is used for an oxide film, and nitrogen gas is used for a nitride film.

[0012] 1 and 2, the film formation chamber 11 is provided with a first sputtering electrode 13 and a second sputtering electrode 14 on a portion of the wall surface facing the outer wall of the rotating drum 12. In this embodiment, the first sputtering electrode 13 and the second sputtering electrode 14 are each connected to a power supply 17, and a target serving as a film formation material is attached to the tip of the sputtering electrode. The first sputtering electrode 13 and the second sputtering electrode 14 are each oriented so that the surface of the target faces the substrate S supported by the rotating drum 12, and a voltage from the power supply 17 is applied to the target during film formation.

[0013] In the sputtering film formation apparatus 1 of this embodiment, a load lock chamber 19 is provided on one of the sidewalls of the film formation chamber 11 via a gate valve 18, as shown in Figure 1, and the rotating drum 12 supporting the substrate S is loaded and unloaded via the load lock chamber 19. A door 20 for loading and unloading the rotating drum 12 is provided on one of the walls of the load lock chamber 19. In addition, a suction port of a second exhaust device 21 such as a turbomolecular pump is connected to the wall of the load lock chamber 19, and by exhausting gas from the internal space of the load lock chamber 19 with the door 20 closed, the inside of the load lock chamber 19 is maintained at a reduced pressure.

[0014] The rotating drum 12 in this embodiment is a carousel-type drum, and substrates S are attached to the sidewall surface of the drum via substrate holders 22. The rotating drum 12 is rotated in a predetermined direction at a predetermined speed around a rotation shaft 121 rotatably provided in the film formation chamber 11 by a drive device 122, for example, an electric motor.

[0015] Fig. 3 is an enlarged front view of part III in Fig. 2, showing a plurality of substrate holders 22 attached along the cylindrical outer wall surface of the rotating drum 12, and Fig. 4 is a view taken along line IV-IV in Fig. 3. The substrate holder 22 of this embodiment is interposed between an upper skeletal member 123 and a lower skeletal member 124 of the rotating drum 12, and a shaft 221 of the substrate holder 22 is rotatably supported by both the upper skeletal member 123 and the lower skeletal member 124.

[0016] The substrate S as a film-forming object is detachably attached to the substrate holder 22 via a dedicated jig or the like. In particular, the substrate S in this embodiment has product specifications in which films are formed on both the front and back surfaces, and therefore the substrate holder 22 is reversible or rotatable relative to the rotating drum 12 between a first position where a film is formed on one surface (e.g., the front surface) of the substrate S and a second position where a film is formed on the other surface (e.g., the back surface) of the substrate S. Note that in the present invention, when the substrate holder 22 is moved between the first position and the second position, the substrate holder 22 may be reversed each time or may be rotated 180° at a time.

[0017] Specifically, as described above, each of the plurality of substrate holders 22 is rotatably supported by the upper skeletal member 123 and the lower skeletal member 124 of the rotating drum 12. In addition, as shown in Figures 3 and 4, a cam member 222 is fixed to the upper end of the shaft 221 of each substrate holder 22, while a pin member 23 is provided on the film formation chamber 11 side so as to be able to protrude and retract. The pin member 23 is actuated by an actuator or the like to a retracted position where the pin member 23 retracts and does not interfere with the cam member 222, and a protruding position where the pin member 23 protrudes and interferes with the cam member 222.

[0018] Then, while a film is being formed on one side (e.g., the front surface) of the substrate S, with the pin members 23 in the recessed position, each substrate holder 22 stops at a first position in which one side (e.g., the front surface) of the supported substrate S faces the outside of the rotating drum 12, thereby causing one side (e.g., the front surface) of the substrate S to face the first sputtering electrode 13 and the second sputtering electrode 14, and a sputtered film is formed on that one side (e.g., the front surface).

[0019] Once a predetermined sputtered film has been formed on one surface (e.g., the front surface) of the substrate S, the pin members 23, which had been recessed, are actuated to the protruding position, and the rotating drum 12 is rotated. This rotation of the rotating drum 12 causes the pin members 23 to abut against the cam members 222 of each substrate holder 22, rotating the substrate holder 22 by 180°. As a result, the substrate holder 22 is inverted, and the other surface (e.g., the back surface) of the supported substrate S stops at a second position facing the outside of the rotating drum 12, so that the other surface (e.g., the back surface) of the substrate S faces the first sputtering electrode 13 and the second sputtering electrode 14. If the film formation process is resumed from this state, a sputtered film will also be formed on the other surface (e.g., the back surface) of the substrate S.

[0020] Incidentally, when each of the multiple substrate holders 22 is rotatably attached to the rotating drum 12, it is necessary to provide a small gap between adjacent substrate holders 22 so that they do not interfere with each other during rotation. However, there is a problem that during film formation, the film material can get around to the back side of the substrate holder 22 through this gap and adhere to the back surface of the substrate S. When films are formed on both sides of the substrate S for the purpose of film formation such as decoration, even if a small amount of film material adheres to the back surface of the substrate S, this does not pose much of a problem for the decorated product. However, for products such as optical lenses, which require strict spectral characteristics of the film, even if even a small amount of film material adheres to the back surface of the substrate S, there is a problem that the desired optical characteristics cannot be obtained.

[0021] For this reason, the sputtering film formation apparatus 1 of this embodiment is further provided with a masking member 24 that shields the other surface of the substrate S when a film is formed on one surface of the substrate S. In this case, the masking member 24 shields the other surface of the substrate S on which a film has not yet been formed when a film is formed on one surface of the substrate S, and also shields the one surface of the substrate S on which a film has already been formed when a film is formed on the other surface of the substrate S. The masking member 24 according to the present invention will be described below with reference to two embodiments.

[0022] 3 to 9 show a first embodiment of the masking member 24 according to the present invention. The masking member 24 of the first embodiment has a curtain-shaped member 241 made of metal, synthetic resin, or ceramic, which has rigidity or flexibility, and the upper end of the curtain-shaped member 241 is supported by the upper skeletal member 123 of the rotating drum 12 via an intermediate member 242, and the lower end of the curtain-shaped member 241 is a free end.

[0023] Figure 5 is an enlarged view of the V portion of Figure 4, and Figure 6 is a view taken along line VI-VI of Figure 5. As shown in Figure 5, the intermediary member 242 is made of a rigid plate material such as metal or synthetic resin, and is a member having an L-shaped cross section as shown in Figure 5. A first hinge 243, such as a flat hinge, is fixed between the upper end of the intermediary member 242 and the upper frame member 123 of the rotating drum 12, thereby allowing the intermediary member 242 to rotate about the rotation axis of the first hinge 243 relative to the rotating drum 12. A second hinge 244, also such as a flat hinge, is fixed between the lower end of the intermediary member 242 and the upper end of the curtain-shaped member 241, thereby allowing the curtain-shaped member 241 to rotate about the rotation axis of the second hinge 244 relative to the intermediary member 242. As shown in FIG. 6, one first hinge 243 is provided in the center of the intermediate member 242 in the width direction, and two second hinges 244 are provided at both ends of the intermediate member 242 in the width direction.

[0024] 7 to 9 are views taken along the line IV-IV in Fig. 3, showing the operation of the masking member 24 according to the first embodiment, with Fig. 7 showing a state in which the rotating drum 12 is stopped and the substrate holder 22 is in the first or second position, Fig. 8 showing a state in which the substrate holder 22 is in the first or second position and the rotating drum 12 is rotating, and Fig. 9 showing a state in which the rotating drum 12 is stopped and the substrate holder 22 is inverting or rotating.

[0025] As shown in Fig. 7 , when the rotating drum 12 is stopped and the substrate holder 22 is in the first or second position, the curtain-shaped member 241 of the masking member 24 hangs down at a position slightly away from the back surface of the substrate holder 22. The upper end of the curtain-shaped member 241 is attached to the upper frame member 123 of the rotating drum 12 via an intermediate member 242, one first hinge 243, and two second hinges 244, and the lower end is a free end. Therefore, when the rotating drum 12 rotates from the state shown in Fig. 7 to start film formation, a centrifugal force acts on the curtain-shaped member 241 of the masking member 24. This centrifugal force acts to move the curtain-shaped member 241 outward from the rotating drum 12, and therefore the curtain-shaped member 241 is pressed against the back surface of the substrate holder 22, as shown in Fig. 8 .

[0026] Here, the curtain-shaped member 241 of the masking member 24 of this embodiment is attached to the rotating drum 12 via an intermediary member 242, a first hinge 243, and a second hinge 244, so that the entire curtain-shaped member 241, from its top to bottom, is in close contact with the back surface of the substrate holder 22. Note that, depending on the fixing position of the first hinge 243 relative to the upper skeletal member 123 of the rotating drum 12, the intermediary member 242 does not need to have an L-shaped cross section and may be formed of a flat plate. Furthermore, in the masking member 24 according to the present invention, it is sufficient that the curtain-shaped member 241 can shield the back surface of the substrate S, so any of the intermediary member 242, the first hinge 243, or the second hinge 244 may be omitted.

[0027] When the substrate holder 22 is inverted or rotated 180° to form a film on the other surface (e.g., the back surface) of the substrate S after film formation on one surface (e.g., the front surface) is completed, even if the substrate holder 22 is rotated 90° from the first or second position, which is the film formation position, as shown in Fig. 9, the curtain-like member 241 of the masking member 24 can be retracted inside the rotating drum 12 by the intermediary member 242, the first hinge 243, and the second hinge 244. This makes it possible to prevent the masking member 24 from interfering with the inversion or 180° rotation of the substrate holder 22.

[0028] Second Embodiment A second embodiment of a masking member according to the present invention is shown in Figures 10 to 15. The masking member 24 of the second embodiment has a rigid or flexible flat plate-like member 245 made of metal, synthetic resin, or ceramic, and pressing members 246 are attached to the upper and lower ends of this flat plate-like member 245.

[0029] Fig. 10 is a perspective view showing a second embodiment of a masking member 24 according to the present invention, which is a view of a portion of the rotating drum 12 as seen from the inside, Fig. 11 is an enlarged perspective view of part XI in Fig. 10, and Fig. 12 is an enlarged perspective view of part XII in Fig. 10. As shown in detail in Fig. 11, the upper pressing member 246 shown in Fig. 10 includes a link member 2461 having one end rotatably provided on a support shaft 125 fixed to the rotating drum 12 and the other end rotatably provided on the flat plate-like member 245 of the masking member 24, and two spring members 2462 and 2463 that urge the link member 2461 in the rotational direction toward the substrate holder 22. Similarly, the lower pressing member 246 shown in Figure 10, as shown in detail in Figure 12, comprises a link member 2461 having one end rotatably attached to a support shaft 125 fixed to the rotating drum 12 and the other end rotatably attached to the flat member 245 of the masking member 24, and two spring members 2462, 2463 that urge the link member 2461 in a rotational direction toward the substrate holder 22.

[0030] Of the two spring members, the spring member 2463 provided between the link member 2461 and the support shaft 125 spring-biases the link member 2461 in a direction towards the substrate holder 22 around the support shaft 125, and also has the function of retracting the flat member 245 towards the inside of the rotating drum 12 when the substrate holder 22 is inverted or rotated 180 degrees as described below. In contrast, the spring member 2462 provided between the link member 2461 and the flat member 245 spring-biases the flat member 245 in a direction towards the substrate holder 22 around the connecting shaft thereof, and has the function of bringing the flat member 245 into close contact with the back surface of the substrate holder 22.

[0031] 13 to 15 are plan views showing the operation of the masking member 24 according to the second embodiment, with Fig. 13 showing a state in which the rotating drum 12 is stopped or rotating and the substrate holder 22 is in the first position or the second position, Fig. 14 showing a state in which the rotating drum 12 is stopped and the substrate holder 22 has started to turn over or rotate 180° from the first position or the second position, and Fig. 15 showing a state in which the rotating drum 12 is stopped and the substrate holder 22 has turned over or rotated 90°.

[0032] 13 , in the masking member 24 of the second embodiment, when the substrate holder 22 is in the first position or the second position, regardless of whether the rotating drum 12 is stopped or rotating, the flat plate-shaped member 245 of the masking member 24 is in a position pressed against the back surface of the substrate holder 22. In this state, one spring member 2463 spring-biases the flat plate-shaped member 245 in the direction toward the substrate holder 22 via the link member 2461, and at the same time, the other spring member 2462 spring-biases the flat plate-shaped member 245 in the direction toward the substrate holder 22, thereby bringing the flat plate-shaped member 245 into close contact with the back surface of the substrate holder 22 without any gaps.

[0033] When the substrate holder 22 is inverted or rotated 180° to form a film on the other surface (e.g., the back surface) of the substrate S after film formation on one surface (e.g., the front surface) is completed, as shown in Fig. 14 , when the substrate holder 22 starts to rotate from the first or second position, which is the film formation position, the flat plate-like member 245 starts to retract toward the inside of the rotating drum 12, mainly against the biasing force of the spring member 2463. Then, as shown in Fig. 15 , even when the substrate holder 22 rotates 90°, the flat plate-like member 245 of the masking member 24 can retract toward the inside of the rotating drum 12 while resisting the biasing force of the spring member 2463. This makes it possible to prevent the masking member 24 from interfering with the inversion or 180° rotation of the substrate holder 22.

[0034] As described above, according to the sputtering film-forming apparatus 1 of this embodiment, while a film is being formed on one surface of the substrate S, the other surface of the substrate S is shielded by the masking member 24, thereby preventing the film-forming material from adhering to the other surface of the substrate S while a film is being formed on one surface of the substrate S.

[0035] The film formation apparatus of the present invention is not limited to sputtering film formation apparatuses, but can also be applied to vapor deposition apparatuses. Furthermore, although the rotating body of the present invention is embodied as the rotating drum 12 in the above-described embodiment, the rotating body of the present invention is not limited to rotating drums, but can also be applied to umbrella-shaped rotating bodies provided at the top of film formation chambers of vapor deposition apparatuses, etc.

[0036] Furthermore, in the first embodiment described above, the curtain-like member 241 of the masking member 24 is configured to be pressed against the rear surface of the substrate holder 22 by the centrifugal force generated by the rotation of the rotating drum 12, but the curtain-like member 241 may also be configured to be pressed against the rear surface of the substrate holder 22 by the elastic force of a spring member or the like.

[0037] DESCRIPTION OF SYMBOLS 1...Sputtering film formation apparatus 11...Film formation chamber 12...Rotating drum 121...Rotating shaft 122...Driver 123...Upper frame member 124...Lower frame member 125...Support shaft 13...First sputtering electrode 14...Second sputtering electrode 15...First exhaust device 16...Gas introduction device 17...Power supply 18...Gate valve 19...Load lock chamber 20...Door 21...Second exhaust device 22...Substrate holder 221...Shaft 222...Cam member 23...Pin member 24...Masking member 241...Curtain-shaped member 242...Intermediary member 243...First hinge 244...Second hinge 245...Plate-shaped member 246...Pressing member 2461...Link member 2462...Spring member 2463...Spring member S...Substrate

Claims

1. A film formation apparatus comprising: a film formation chamber for performing a film formation process; a substrate holder for mounting a substrate having one side and another side; and a rotor provided within the film formation chamber and holding the substrate holder, wherein the substrate holder is provided so as to be invertible or rotatable relative to the rotor between a first position for forming a film on one side of the substrate and a second position for forming a film on the other side of the substrate, the film formation apparatus further comprising a masking member for shielding the other side of the substrate when the substrate holder is at the first position to form a film on one side of the substrate.

2. The film forming apparatus of claim 1, wherein when a film is formed on one surface of the substrate and then the substrate holder is inverted or rotated from the first position to the second position to form a film on the other surface of the substrate, the masking member shields the one surface of the substrate.

3. A film forming apparatus as described in claim 1 or 2, wherein the masking member is a curtain-shaped member whose upper end is supported by the rotating body and whose lower end is a free end, and is pressed toward the other surface of the substrate by centrifugal force acting on the masking member due to rotation of the rotating body.

4. A film formation apparatus as described in claim 3, further comprising: an intermediate member provided between an upper end of the masking member and the rotating body; a first hinge fixed to each of the rotating body and the upper end of the intermediate member; and a second hinge fixed to each of the lower end of the intermediate member and the upper end of the masking member, wherein when the substrate holder is inverted or rotated between the first position and the second position relative to the rotating body, the masking member is retracted inside the rotating body by the intermediate member, the first hinge, and the second hinge.

5. A film forming apparatus as described in claim 1 or 2, wherein the masking member is made of a flat plate-like member, and further comprising a pressing member which presses the masking member toward the other side of the substrate when the substrate holder is in the first position, and presses the masking member toward one side of the substrate when the substrate holder is in the second position.

6. The film formation apparatus of claim 5, wherein the pressing member comprises a link member having one end rotatably attached to the rotating body and the other end rotatably attached to the masking member, and a spring member which urges the link member in a rotational direction toward the substrate holder, wherein when the substrate holder is inverted or rotated between the first position and the second position relative to the rotating body, the masking member retreats toward the inside of the rotating body against the urging force of the spring member of the pressing member, and when the inversion or rotation of the substrate holder is completed, the masking member is pressed toward the substrate holder by the pressing member.

7. The film forming apparatus according to claim 5, wherein the pressing members are provided at the upper and lower ends of the masking member.

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