JPH09268369A - Sputtering film forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformize the distribution of the pressure of a film by allowing an anode electrode to reciprocate parallel to a stopped substrate face. SOLUTION: A substrate 1 is set to the space between a feeding chamber 21 and a coiling chamber 22. Then, a pressing frame 4 is pressed till the substrate 1 is inserted into the space between the circumferential parts of the opening 20 of a body vessel 2 by a driving actuator, and a film forming chamber holding an anode electrode 9, a target 7 and a magnet 8 at the inside is airtightly formed by a seal 11. The film forming chamber is evacuated and discharge 15 generated between the target 7 and the anode electrode 9 by the application of a power source to generate plasma. By the impacting effect of this plasma on the target 7, a metallic film is formed on the face of the substrate 1. At this time, by the movement of a moving stand up and down by a driving motor, the magnet 8 and the anode electrode 9 are allowed to take scanning movement over the whole face of the target 7. As a result, the grains uniformly sputtered on the face of the substrate 1 are film-formed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention repeats an operation of stopping a conveyed flexible substrate in a film forming chamber and forming a film on the surface of the substrate by a sputtering method for manufacturing a thin film photoelectric conversion element, for example. The present invention relates to a sputtering film forming apparatus that can be used.

[0002]

2. Description of the Related Art A method of manufacturing a thin film element such as a thin film photoelectric conversion element using a long flexible substrate is excellent in productivity. As a method for forming a film on a long substrate, a roll-to-roll method for forming a film on a substrate moving in each film forming chamber and a method for forming a film on a substrate stopped in the film forming chamber and then completing the film formation There is a stepping roll method in which the substrate portion is sent out of the film forming chamber.

An example of a conventional roll-to-roll type sputtering film forming apparatus is shown in FIG. 3 in a vertical sectional view. In this apparatus, the flexible substrate 1 is continuously conveyed from the feed roll 31 of the feed chamber 21 to the take-up roll 32 of the take-up chamber 22 with the substrate surface horizontal, and the can roll 33 of the intermediate film forming chamber 23. The film is formed by sputtering as it passes over. Sputtering is performed by applying a voltage between the opposing anode electrode 41 and the target 43 connected to the power supply 42. The target 43 is a magnet 44 and an insulating plate 45.
Lower plate 24 of the film forming chamber 23
It is supported by. Anode electrode 41 and target 43
Anti-adhesion plates 46 are erected on both sides of the.

[0004]

When sputtering is performed using the film forming apparatus of FIG. 3, sputter discharge is generated between the anode electrode 41 and a part of the target 43 facing the target, and the target 43 is the discharge part. Only wear intensively. As a result, the utilization rate of the target 43 is as low as 30% or less at present. Therefore, the target is frequently replaced, and the cost of the target itself and the maintenance cost increase. Further, the anode electrode 41 is located on the central portion of the target 43 and is sputtered to prevent particles flying to the substrate 1 on the can roll 33. For this reason, the sputtering rate on the substrate 1 is reduced, and the deposits on the anode electrode 41 fall on the target 43, which causes a problem such as abnormal discharge. In addition, the problem that the anode electrode is heated and deformed due to long-time discharge and stable discharge cannot be maintained, and the radiant heating to the substrate is increased due to the temperature rise of the anode electrode, and the temperature is higher than the initial temperature condition of the substrate. Film formation. This results in uneven film formation and uneven product quality.

In addition, the lower plate 24 of the film forming chamber 22
Integral target 43 and insulating plate 4 supported by
5. For maintenance of the magnet 44 and the anode electrode 41 facing the magnet 44, the lower plate 24 must be moved downward, auxiliary power is required for moving the components, and the apparatus becomes large. , The cost is getting higher.

Further, another film forming method, plasma CV
In the method D, it is difficult to form a film on a substrate that is continuously conveyed, and a stepping roll method must be adopted. Therefore, the roll-to-roll type sputtering film forming apparatus and the plasma CVD apparatus as shown in FIG. 3 cannot be arranged in the same line, and separate sputter film forming dedicated apparatus and CVD film forming dedicated apparatus are required. In addition, the apparatus cost becomes high, and the substrate setting time and the film forming preparation such as evacuation are doubled, which increases the running cost. However, when the sputtering method is performed by step film formation, the sputter particles are blocked by the peripheral member of the opening that defines the sputter region, and the film thickness at the peripheral edge of the sputter region becomes thin. As a countermeasure, the target size is increased, but the cost is increased. Due to the large size, the maintainability is remarkably poor, and the film thickness distribution exceeds 10%.

An object of the present invention is to solve the above-mentioned problems and to provide a sputter film forming apparatus of a stepping roll system which can be arranged in the same line as the plasma CVD film forming apparatus and which makes the film thickness distribution uniform. is there. Another object of the present invention is to provide a sputtering film forming apparatus capable of reducing the adhesion of spatter to the anode electrode, obtaining a high sputtering rate, and maintaining stable discharge. Another object is to provide a sputtering film forming apparatus capable of continuously forming a film at a constant temperature.

[0008]

In order to achieve the above-mentioned object, the present invention stops a flexible substrate conveyed from a feed chamber toward a take-up chamber, facing a target and stopping the flexible substrate. In a sputtering film forming apparatus that generates plasma under reduced pressure between the first electrode provided in the space and the second electrode on the target side to form a film on the substrate, the first electrode is parallel to the stopped substrate surface. It shall be fixed to a movable table that can reciprocate.

Since the plasma generating part reciprocates on the substrate film formation surface by the reciprocating motion of the first electrode, the target surface can be uniformly sputtered. As a result, the wear region of the target is expanded, the utilization factor of the target is improved, and a large target can be used. A magnetron sputtering device in which a first electrode of this device is an anode electrode, a target also serves as a second electrode of a cathode electrode, and a magnet is provided on the side of the target opposite to the substrate, and the first electrode of the magnet is also fixed. It is effective to be fixed on the moving table. The magnet provided on the back side of the target serving as the cathode moves together with the first electrode serving as the anode, so that stable magnetron sputtering is continuously performed. It is preferable that the stopped substrate is brought into close contact with the end face around the opening of the wall surrounding the target, the first electrode, and the moving base to form a sputtering film formation space where plasma is generated. As a result, the substrate can be used as a part of the wall body that divides the space of the sputtering film forming apparatus, so that the structure is simplified. A holding frame body that is on the side opposite to the target of the substrate and that can move in the direction toward the target and has an end surface that can be sandwiched between the substrate and the end surface of the wall body that forms the sputtering film formation space is provided. good. By sandwiching the substrate between the end surface of the wall body and the end surface of the pressing frame body that partition the sputtering film formation space, the airtight adhesion of the substrate to the end surface of the wall body is ensured. It is preferable that the pressing frame body is provided with a heating body facing the surface of the substrate opposite to the target side. This heating body brings the temperature of the substrate to a temperature required for film formation. It is preferable that the reciprocating speed of the movable table is controlled to be low near the end where the direction is reversed and high at the center. Since the first electrode or the anode electrode and the magnet move at high speed in the central part of the film formation region and move at low speed in the peripheral part, it is possible to prevent the sputtering film thickness from becoming thin in the peripheral part of the film formation region. It is preferable that the number of reciprocating movements of the movable table can be controlled. Thereby, the film thickness can be controlled. It is preferable that a position detection sensor for controlling the reciprocating motion of the moving table is provided so as to face the moving table. According to the position detected by this sensor, the moving speed of the moving table can be easily controlled and the moving direction can be changed, and the end of the reciprocating motion can be determined. The first electrode is preferably in the shape of a square ring. This reduces the shielding of the sputtered particles by the first electrode and improves the film thickness distribution. The first electrode may be hollow so that the refrigerant can circulate inside. Radiant heating to the substrate is reduced by cooling the first electrode, the temperature of the substrate does not change from the initial temperature condition, and continuous film formation can be performed at a constant temperature. It is preferable that the substrate surface is within the vertical plane during film formation. As a result, the sputter flakes accumulated on the electrodes do not drop on the stopped substrate or target, abnormal discharge can be prevented, and the film quality is improved. In this case, it is preferable that the target, the first electrode, and the moving table are supported by a door that can be opened and closed in the horizontal direction. By opening and closing the door in the horizontal direction, it is possible to easily perform the cleaning operation such as cleaning of each member such as an electrode for sputtering film formation and the replacement of the target, and the auxiliary power for moving the member up and down is not required. Further, the substrate holding frame and the substrate heating body may be supported by a door that can be opened and closed in the horizontal direction. This facilitates maintenance work on the heating element.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION A flexible substrate is conveyed from a feed roll in a feed chamber to a take-up roll in a take-up chamber through a sputtering film forming chamber formed in a vacuum chamber with its substrate surface vertical. The front surface of the sputter deposition chamber is partitioned by a wall formed with a door that can be opened horizontally, and accommodates sputtering members such as an anode electrode, a target held by an insulating plate, and a magnet. Among these members, the anode electrode and the magnet are fixed to a moving table which reciprocates by a drive shaft driven by a motor outside the film forming chamber. The pressing frame that can sandwich the substrate between the end face around the opening of the sputter film forming chamber and the substrate heating heater is fixed to the drive shaft that penetrates the door that opens and closes in the horizontal direction of the vacuum chamber.
The drive shaft is supported by the door via a bellows. The drive shaft is driven toward the substrate surface by an external actuator, and the substrate is pressed by the pressing frame. The movement of the movable table is controlled as described in claims 6 to 8. As the film to be formed, various metal thin films, transparent conductive films such as ITO and ZnO, and the like can be used.

Hereinafter, embodiments of the present invention will be described in more detail with reference to the drawings. 1 and 2 show a sputtering film forming apparatus according to an embodiment of the present invention. FIG. 1 is a plan sectional view,
2 is a cross-sectional view taken along the line AA of FIG. 1, and the same parts as those of FIG. 3 are designated by the same reference numerals. A main body container 2 communicating with both chambers is arranged in the middle of a feeding chamber 21 containing a feeding roll 31 of the flexible substrate 1 and a winding chamber 22 containing a winding roll 32. In the vacuum chamber 3 formed in the main body container 2, there is a substrate heating heater 53 connected to a front-rear drive shaft 52 held by a straight-movement bearing 51 and a holding frame 4 covering the heater 53. As shown in FIG. 2, the front-rear drive shaft 52, which can be driven back and forth by the drive actuator 55 via the connecting bar 54, is supported by the heater maintenance door 61 via the bellows 56. The heater maintenance door 61 can be opened horizontally by a hinge 63.

The peripheral portion of the holding frame 4 faces the peripheral portion of the opening 20 of the main body container 2. A target 7 made of ITO is held outside the opening 20 of the main body container 2 by an insulating plate 72 via a back plate 71 made of copper, and these are covered by a target maintenance door 62 via a bracket 73 as shown in FIG. Supported by. The target maintenance door 62 is divided into two parts, and can be horizontally opened by a hinge 63. The magnet 8 mounted on the moving table 81 is arranged outside the insulating plate 72. The movable table 81 also supports the anode electrode 9 via the fixed block 82. Then, it can be moved up and down by the drive shaft 83 and the guide 84 provided on the side surface. The drive shaft 83 penetrates through the target maintenance door 62 and is rotated by a drive motor 85 attached to the outer surface of the door 62. Target maintenance door 62
Two pairs of a speed control sensor 86 and a direction control sensor 87, which detect the position of the moving base 81, are vertically mounted on the inner surface of, and are connected so as to send an operation signal to a control panel provided outside.

Next, a film forming operation using this apparatus will be described. The substrate 1 is previously set between the feed chamber 21 and the winding chamber 22, and the vacuum chamber 3 is evacuated by a vacuum pump (not shown) to discharge the gas adhering to the substrate 1 and the stored gas for cleaning. At the same time, the heater 53 is heated to accelerate the degassing of the substrate 1 due to the heating effect.
The substrate 1 itself is heated to a temperature required for film formation. Then, as shown in FIG. 2, the pressing frame 4 is moved by the operation of the drive actuator 55 to move the substrate 1 to the opening 2 of the main body container 2.
It is pressed until it is sandwiched between itself and the peripheral portion of 0, and a sputtering film forming chamber 10 which houses the anode electrode 9, the target 7 and the magnet 8 therein is formed by hermetically closing a seal 11. The sputtering film forming chamber 10 was decompressed by a separately provided vacuum pump, and an argon gas as a sputtering gas was introduced and connected to the pack plate 71.
When the DC power source 12 is turned on, a discharge is generated between the target 7 and the anode electrode 9 to form plasma.
Due to the impact effect of the plasma on the target 7, an ITO film is formed on the surface of the substrate 1. At this time, the magnet 8 and the anode electrode 9 are scanned over the entire surface of the target by the vertical movement of the drive base 81 by the drive motor 85. As a result, uniformly sputtered particles are formed on the surface of the substrate 1. Further, the target surface is uniformly eroded because the plasma discharge part moves.

The moving base 81 moves at a constant speed between the speed control sensors 86 arranged vertically, and gradually decelerates after passing the front surface of the speed control sensor 86. Then, when passing the front surface of the direction control sensor 87, the moving direction is reversed, and after gradually accelerating, the speed control sensor 86 is accelerated until it operates, and then the movement at a constant speed is started. In another control method, the moving speed is changed from a high speed to a low constant speed after the speed control sensor 86 has passed through the front surface.
The speed does not change gradually. The movement of the movable table 81 is counted as one operation, and the film thickness is controlled by stopping the application of the DC voltage and the movement of the movable table by a scanning motion of an arbitrary established number of operations.

In this film forming apparatus, it is necessary to periodically perform maintenance such as cleaning of the inside of the sputtering film forming chamber 10, cleaning of the seal portion sandwiching the substrate 1, and replacement of the target 7. The maintenance is performed by opening the heater maintenance door 61 and the target maintenance door 62 in the horizontal direction. FIG. 4 is a detailed view of the anode electrode 9 used in the device of FIG. The anode electrode 9 attached to the movable table 81 via the fixed block 82 has two end portions 93, which are parallel to two beam portions 91 and 92 which are perpendicular to the longitudinal direction of the substrate.
94 and a square ring having a hollow cross section. The coolant 12 such as water enters the one end 93 through the hollow cross section, passes through the beam portions 91 and 92, and exits to the outside through the other end 94. Since the anode electrode 9 moves, the introduction and discharge of the refrigerant are performed by a flexible conduit tube whose one end is fixed to the target maintenance door 62.

5 (a), 5 (b) and 5 (c) show examples of the sectional shape of the hollow anode electrode 9. As shown in FIG. The rectangular section shown in FIG. 5A can be manufactured at the lowest cost. The rectangle has a short side facing the target 7 and a long side perpendicular to the target surface. This is to stabilize the plasma discharge and reduce the adhesion of sputtered particles. FIG. 5B is a triangle whose cross section is directed to the target side, and FIG. 5C is an elliptical anode electrode whose cross section has a long axis perpendicular to the target surface. The Arnod electrode 9 of FIG. 5 (b) has no surface parallel to the target 7, and the adhesion of sputtered particles is minimal. The amount of sputtered particles deposited on the anode electrode 9 in FIG. 5C is larger than that in FIG. 5B, but the plasma discharge is more stable.

When the plasma VCD device is installed on the same line as this sputtering film forming device, the vacuum chamber is extended to the winding chamber side to form a common vacuum chamber, and the CVD chamber is formed between the vacuum chamber and the winding chamber. Forming the film chamber reduces the device cost and running cost.

[0018]

According to the present invention, when a film is formed on a stopped flexible substrate surface by sputtering, an electrode or its electrode and a magnet are reciprocated in parallel with the substrate surface to generate an electric discharge. It was possible to achieve uniform film formation by cooling the anode electrode with water to prevent the substrate temperature from rising due to radiant heating, and to keep the substrate surface vertical to prevent abnormal discharge due to falling sputter flakes and improve film quality. The utilization efficiency of the target can be improved by making the anode electrode into a square ring shape.

[Brief description of drawings]

FIG. 1 is a plan sectional view of a sputtering film forming apparatus according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG. 1;

FIG. 3 is a vertical sectional view of a conventional roll-to-roll type sputtering film formation.

FIG. 4 is a perspective view showing an anode electrode portion of a sputtering film forming apparatus according to an embodiment of the present invention.

FIG. 5: 3 of the sputtering film forming apparatus of the embodiment of the present invention
Sectional drawing which shows the types of anode electrodes in (a), (b), (c).

[Explanation of symbols]

 1 Flexible Substrate 2 Main Container 3 Vacuum Chamber 4 Holding Frame 52 Front-Back Driving Axis 53 Substrate Heating Heater 55 Drive Actuator 56 Bellows 61 Heater Maintenance Door 62 Target Maintenance Door 63 Hinge 7 Target 72 Insulation Plate 8 Magnet 81 Moving Base 82 Fixed Block 83 Drive shaft 84 Guide 85 Drive motor 86 Speed control sensor 87 Direction control sensor 9 Anode electrode 10 Sputter deposition chamber 11 Seal 12 Refrigerant 21 Feed chamber 22 Winding chamber 31 Feed roll 32 Winding roll

Claims (13)

[Claims] 1. A first electrode provided in a space facing a target and a second electrode on the target side, wherein a flexible substrate conveyed from a feed chamber to a winding chamber is stopped with respect to the target. In a sputtering film forming apparatus for forming plasma on a substrate by generating plasma under a reduced pressure during the sputtering, the first electrode is fixed on a movable table capable of reciprocating movement parallel to the stopped substrate surface. Deposition apparatus. 2. A magnetron sputtering apparatus in which a first electrode is an anode electrode, a target also serves as a second electrode which is a cathode electrode, and a magnet is provided on the side of the target opposite to the substrate. The sputtering film forming apparatus according to claim 1, wherein the sputtering film forming apparatus is fixed on a fixed moving table. 3. The stopped substrate is a target, a first electrode,
3. The sputtering film forming apparatus according to claim 1, which is capable of forming an airtight sputtering film forming space in which plasma is generated by closely contacting with an end surface around an opening of a wall body surrounding the movable table. 4. A holding frame body that is on the side opposite to the target of the substrate and is movable in the direction toward the target, and has an end face that can be sandwiched between the substrate and the end face of the wall body that forms the sputtering film formation space. The sputtering film forming apparatus according to claim 1, further comprising: 5. The sputtering film forming apparatus according to claim 4, wherein the pressing frame body is provided with a heating body facing the surface of the substrate opposite to the target side. 6. The sputtering film forming apparatus according to claim 1, wherein the reciprocating speed of the moving table is controlled to be low near the end where the direction is reversed and high near the center. 7. The sputtering film forming apparatus according to claim 1, wherein the number of reciprocating movements of the moving table can be controlled. 8. The sputtering film forming apparatus according to claim 6, further comprising a position detection sensor for controlling the reciprocating movement of the moving table, which is opposed to the moving table. 9. The first electrode has a rectangular ring shape.
The sputtering film forming apparatus according to any one of 1. 10. The sputtering film forming apparatus according to claim 1, wherein the first electrode is hollow and a coolant can circulate inside. 11. The sputtering film forming apparatus according to claim 1, wherein the substrate surface is within a vertical plane during film formation. 12. The target, the first electrode and the moving table are
3. A door supported by a horizontally openable door.
1. The sputtering film forming apparatus according to 1. 13. A substrate pressing frame and a substrate heating body are provided.
5. A door supported by a door that can be opened and closed horizontally.
1. The sputtering film forming apparatus according to 1.