JPH10212574A - Coating forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the short circuit of an electrode and an earth shield while effective utilization in a vacuum is attained and to enable stable continuous coating formation for a long time by providing the side face of the outer circumference on the side of the surface of a target with a flange and arranging an earth shield on the back face side in the flange part oppositely at intervals with the target. SOLUTION: A target 8 provided with a cathode electrode 5 on the lower part is sputtered by discharge from the electrode 5 in a vacuum chamber 1 to form coating of a target material on a substrate S. In this case, the side of the surface 8a of the target in the outer circumferential side face of the target 8 is projectingly provided with a flange part 9, and an earth shield 14 limiting the discharging region of the electrode 5 is arranged on the back face side 8b thereof. While effective utilization in the vacuum chamber is attained in such a manner that the height of the target 8 is held to be low, the peeled coating forming material and dust are hard to be deposited on the earth shield 14, and the interruption of the discharge caused by the short-circuit of the electrode 5 and the earth shield 14 is prevented, by which stable continuous coating formation can be executed for a long time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a film forming apparatus for forming a film on a substrate in a vacuum chamber using discharge from an electrode, and more particularly to a technical field related to a structure of an earth shield for limiting a discharge area of the electrode. .

[0002]

2. Description of the Related Art Conventionally, a sputtering apparatus which is an example of this kind of film forming apparatus is widely and generally known. In this sputtering apparatus, for example, as shown in FIG. 5, a cathode electrode b is pierced through a wall portion a1 at a ground potential of a vacuum chamber a, and both are joined in an airtight state and in an electrically insulating state by an insulating member g. A target c made of a film-forming material is placed inside the vacuum chamber a of the electrode b, and a high-density plasma by magnetron discharge is generated on the surface of the target c by the curved magnetic field generated by the magnet d of the electrode b. The surface c is sputtered to form a film on the surface of the substrate f in the vacuum chamber a.

[0003] In order to limit the discharge area of the cathode electrode b, an earth shield e conducted to the wall a1 of the vacuum chamber a is arranged at a predetermined interval on the outer peripheral side surface of the target c. Have been done.

However, with such a structure of the earth shield e, the front end portion (inner peripheral portion) of the earth shield e is provided.
The sputtered film material is not only easy to be laminated, but also between the ground shield e and the electrode b passing between the tip of the ground shield e and the target c. Dust easily accumulates,
The short-circuit between the earth shield e and the electrode b may occur due to the growth of the film-forming material and dust, and the discharge may be interrupted, making it difficult to form a stable and continuous film on the substrate f for a long time. was there.

On the other hand, as shown in Japanese Patent Application Laid-Open No. Hei 6-93441, the size of the target is made larger than the backing plate (electrode) so that the outer peripheral edge of the target protrudes from the backing plate. There is proposed a device in which an earth shield is arranged below a target. In this one, the earth shield is located behind the outer peripheral side of the target,
The above problem can be solved.

[0006]

However, on the other hand, in the above-mentioned proposal, since the earth shield is arranged below the outer peripheral portion of the target, the height of the earth shield in the vacuum chamber is reduced by the height of the earth shield. There was a problem that the position of the target was raised and the target had to protrude into the vacuum chamber, so that the vacuum chamber with a limited volume could not be used effectively, for example, it was difficult to move the substrate into and out of the vacuum chamber. .

Since the range of use of the target (sputtering range) is limited to the magnetic field area of the magnet, if the size of the target is made larger than the backing plate as in the above proposed example, the outer peripheral edge of the target becomes the magnetic field area. Will come off. For this reason, the outer peripheral portion of the target becomes a waste portion that is not used for sputtering, so that the use efficiency of the target is lowered, and discharge power is taken to the outer peripheral portion where the area of the target is widened, resulting in a large loss.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a sputtering apparatus or other film forming apparatus having an earth shield for limiting a discharge area of an electrode as described above. By improving the structure of the shield, the height of the earth shield protruding into the vacuum chamber is reduced and effective use in the vacuum chamber is prevented. Another object of the present invention is to make it possible to perform stable continuous film formation for a long time.

[0009]

In order to achieve the above object, according to the first aspect of the present invention, a flange portion is provided on the outer surface of the target by cutting out the back surface of the target. An earth shield is arranged on the back side of the flange.

That is, according to the present invention, an electrode having a target made of a film-forming material fixed on the back surface is installed in a vacuum chamber, and the surface of the target is sputtered by discharge from the electrode, and placed in the vacuum chamber. A film forming apparatus for forming a film on a formed substrate is premised.

[0011] A flange portion is provided on the outer peripheral side surface of the target on the target surface side (sputtering surface side) so as to protrude outside the target from other portions. In addition, an earth shield for limiting a discharge area of the electrode is disposed on the back side of the flange portion of the target at a predetermined distance from the target.

With the above configuration, the flange portion is provided on the outer peripheral side surface of the target, and the ground shield is disposed on the back side of the flange portion. Therefore, the ground shield is hidden behind the flange portion of the target when viewed from the vacuum chamber. The deposition material and dust in the vacuum chamber accumulate on the flange of the target, but hardly accumulate on the ground shield on the back side of the flange, so that the discharge is interrupted due to a short circuit between the electrode and the ground shield. And a continuous film formation can be stably performed over a long period of time.

At this time, since the ground shield is arranged in the space on the back side of the flange portion, the respective height positions of the target and the ground shield are substantially the same, and the projecting height of the target into the vacuum chamber is kept low. The inside of the vacuum chamber can be effectively used.

Further, an earth shield is disposed on the back side of the flange portion on the outer peripheral side surface of the target, and since the outer peripheral edge of the target does not greatly extend from the magnetic field area of the magnet as in the related art, the utilization efficiency of the target is improved. In addition, it is possible to reduce a loss due to an increase in the discharge power of the outer peripheral portion of the target.

In the invention of claim 2, it is noted that a portion to be sputtered is limited to a certain portion of the surface of the target, and the target is attached to a target main body having a sputtered surface and a target main body. The outer peripheral edge is detachably assembled so as to cover a position that does not correspond to the magnet in the electrode, and the outer peripheral edge is divided into a cover part that forms the flange part.

In this case, the portion of the target to be sputtered is only the target main body, and the sputtering is not performed on the cover attached to the outer peripheral portion of the surface of the target main body. Therefore, at the time of replacement due to exhaustion of the target, only the target body is replaced, and the cover portion that is not sputtered can be reused for the next sputtering film formation. Therefore,
The utilization efficiency can be improved as compared with the case where the entire target is replaced, while using the structure of the flange portion of the target successfully.

On the other hand, according to the third aspect of the present invention, an electrode is installed in a vacuum chamber, and a film forming material gas is introduced into the vacuum chamber.
It is premised on a film forming apparatus that forms a film on a substrate placed in a vacuum chamber by chemical vapor deposition of a film forming material gas by discharge from an electrode surface.

Further, a flange portion is provided on the outer peripheral side surface of the electrode on the electrode surface side (discharge surface side) so as to protrude outside the electrode from other portions, and an earth shield for limiting a discharge area of the electrode is provided on the electrode. Are arranged opposite to the electrodes at a predetermined interval on the back side of the flange portion.

According to this configuration, since the flange portion is provided on the outer peripheral side surface of the electrode, and the ground shield is disposed on the back surface side of the flange portion, the ground shield is provided on the flange portion of the electrode when viewed from the vacuum chamber. This makes it difficult for film deposition and dust to accumulate in the vacuum chamber on this earth shield, and enables continuous film formation on the substrate by chemical vapor deposition without interrupting the discharge due to a short circuit between the electrode and the earth shield. It can be performed stably for a long time.

Further, since the earth shield is arranged in the space on the back surface side of the flange portion of the electrode, the position of the electrode can be set at substantially the same height as the earth shield, and the inside of the vacuum chamber is effectively used. be able to.

According to a fourth aspect of the present invention, in the film forming apparatus of the third aspect, the electrode is detachably assembled to the electrode main body so as to cover the entire surface of the electrode main body, and the outer peripheral edge is formed of the flange portion. And a cover part.
Thus, when removing the film or dust deposited on the surface of the electrode and cleaning the electrode, the cover is made easy to clean and the electrode is easily cleaned.

In the fifth aspect of the present invention, the electrode body is made of an aluminum-based material, while the cover is made of stainless steel. In this way, while reducing the weight of the electrode,
The cleaning can be facilitated.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION

(Embodiment 1) FIG. 1 shows a sputtering film forming apparatus according to Embodiment 1 of the present invention, wherein 1 is a vacuum chamber, and a wall portion 2 thereof is set to the ground potential. The inside of the vacuum chamber 1 is connected to a vacuum suction pump (not shown), and the inside of the vacuum chamber 1 is maintained in a vacuum state by suction and exhaust of the vacuum suction pump. In the vacuum chamber 1, a substrate S as a work to be formed into a film is formed.
Is placed at the same ground potential as the wall 2 of the vacuum chamber 1, and the substrate S is supplied into the vacuum chamber 1 through an entrance (not shown) opened to the wall 2 of the vacuum chamber 1 or 1
Taken out of

The bottom wall 2a of the wall 2 of the vacuum chamber 1
In the (lower wall portion), for example, a rectangular (or circular or other) electrode mounting hole 3 is formed so as to penetrate therethrough, and the electrode mounting hole 3 is closed by the cathode electrode 5.
The cathode electrode 5 has a substantially U-shaped cross section opened upward, and an electrode flange portion 5a extending outward in the horizontal direction is integrally formed on the outer periphery of the lower end thereof. And the electrode 5
The electrode flange portion 5a is inserted into the electrode mounting hole 3 with the electrode flange portion 5a positioned outside the bottom wall portion 2a of the vacuum chamber 1 and the opening facing upward (inside the vacuum chamber 1).
A frame-shaped insulating member 18 is interposed between the upper surface and the outer surface (lower surface) of the bottom wall portion 2a to be hermetically sealed.

The opening of the electrode 5 is covered by a backing plate 6 attached to and fixed to the electrode 5. On the upper surface of the backing plate 6, a target 8 made of a film forming material has its surface 8 a (upper surface) in the vacuum chamber 1. Face 8b
Are integrally attached by screws or the like. Further, a magnet 16 made of a permanent magnet is housed inside the electrode 5, and a high-density plasma is generated on the surface of the target 8 by magnetron discharge by a curved magnetic field generated by the magnet 16, and ions of the plasma generate ions on the surface of the target 8. Is sputtered, and the film-forming material obtained by the sputtering is deposited on the surface of the substrate S.

Further, as a feature of the present invention, as shown in detail in FIG. 2, the outer peripheral side surface of the target 8 extends from the end on the target back surface 8b side to the vicinity of the end on the target front surface 8a side. A notch step 10 which is cut out in a step shape is formed, and a portion other than the notch step 10 on the outer peripheral side surface of the target 8 is a flange 9. That is, on the target surface 8a side (upper surface side) on the outer peripheral side surface of the target 8, the flange portion 9 is provided over the entire outer periphery of the target 8 so as to protrude outside the target 8 from other portions.

On the other hand, on the inner surface (upper surface) of the bottom wall 2a of the vacuum chamber 1, an earth shield 14 for limiting the discharge area of the cathode electrode 5 is provided around the electrode mounting hole 3 on the bottom wall 2a. And is fixed at the ground potential by the conduction of. The earth shield 14 has a substantially frame plate shape, and the lower surface of the outer peripheral edge is fixed to the inner surface of the bottom wall 2a. The inner peripheral edge portion 14a of the ground shield 14 stands up and down. The upright inner peripheral edge portion 14a is formed on the rear surface side of the flange 9 on the outer peripheral side surface of the target 8 (inside the notch step portion 10). Flange part 9
The lower surface or the outer peripheral surface of the notch step portion 10 is disposed facing the outer peripheral surface at a predetermined interval.

Therefore, in this embodiment, the substrate S is housed and arranged in the vacuum chamber 1 and brought to the ground potential by conduction with the wall portion 2, and the vacuum chamber 1 is evacuated by suction and exhaust of a vacuum suction pump. By supplying a sputtering gas to the inside and applying a negative voltage to the cathode electrode 5, a high-density plasma is generated on the surface 8 a of the target 8 by magnetron discharge due to a curved magnetic field generated by the magnet 16 in the electrode 5. The target surface 8a is sputtered by the ions, and the film-forming material evaporated by the sputtering adheres to the surface of the substrate S, thereby forming the film on the substrate S.

At this time, a flange portion 9 is provided on the outer peripheral side surface of the target 8 on the side of the target surface 8a, and the inner peripheral edge portion 14a of the earth shield 14 is disposed on the back surface side of the flange portion 9, so that the ground is provided. The inner peripheral edge 14 a of the shield 14 is located behind the flange 9 of the target 8 when viewed from the center of the vacuum chamber 1. For this reason, the film forming material and dust in the vacuum chamber 1 accumulate on the flange 9 of the target 8, but hardly accumulate on the inner peripheral edge 14 a of the earth shield 14 located on the back side of the flange 9. Become. As a result, the interruption of the discharge due to the short circuit between the electrode 5 and the earth shield 14 is suppressed, and the continuous film formation on the substrate S can be stably performed for a long time.

Since the ground shield 14 is arranged in the space on the back side of the flange portion 9, the height of the target 8 and the ground shield 14 are substantially the same, and the target 8 projects in the vacuum chamber 1. The height can be kept low, and the inside space of the vacuum chamber 1 can be effectively used and the substrate S can be easily moved in and out of the vacuum chamber 1.

Further, since the earth shield 14 is arranged on the outer peripheral side surface of the target 8 on the back side of the flange portion 9, the outer peripheral edge of the target 8 is magnet 16
The magnetic field does not greatly expand from the magnetic field area of the target 8, the utilization efficiency of the target 8 can be improved, and the increase in the discharge power at the outer peripheral portion of the target 8 can be suppressed to reduce loss.

(Embodiment 2) FIG. 3 shows Embodiment 2 of the present invention.
(Note that in the following embodiments, the same portions as those in FIGS. 1 and 2 are denoted by the same reference numerals and detailed description thereof is omitted), and the target 8 is divided into a main body and a flange portion 9. Things.

That is, in this embodiment, the target 8 is divided into a target body 11 and a frame-shaped cover portion 12, and the surface of the target body 11 is sputtered. The cover 12 is made of the same material as the target main body 11, and is provided on the target main body 11 at the outer peripheral edge of the surface thereof and the magnet 1
6, the outer peripheral edge of the upper surface of the target main body 11 is cut out, for example, in a step-like manner, and the target body 11 is assembled in a state where it is simply fitted to the step. A flange portion 9 is formed by an outer peripheral portion of the flange 12. Note that the upper surface of the cover 12 and the upper surface of the target main body 11 are desirably flush with each other, but need not be flush.

Therefore, in the case of this embodiment, the portion of the target 8 to be sputtered is only the surface of the target main body 11, and the cover portion 12 attached to the outer peripheral edge of the surface of the target main body 11 is not sputtered. Therefore, at the time of replacement due to consumption of the target 8, only the target body 11 needs to be replaced, and the cover portion 12 that is not sputtered can be reused as it is. Therefore, the use efficiency of the target 8 can be increased as compared with the case where the entire target 8 is replaced while using the structure of the flange portion 9.

(Embodiment 3) FIG. 4 shows Embodiment 3.
This is applied to a plasma CVD film forming apparatus. That is, in this embodiment, the electrode mounting hole 3 is formed in the bottom wall 2 a of the vacuum chamber 1, and the electrode mounting hole 3 is closed by the discharge electrode 20. The discharge electrode 20 has, for example, a rectangular cross section, and its surface 20 a (upper surface) faces the vacuum chamber 1. An outer flange portion 21 extending horizontally outward is integrally formed on the outer periphery of the lower end of the electrode 20. The electrode 20 has an electrode mounting hole with the outer flange portion 21 positioned outside the bottom wall 2 a of the vacuum chamber 1. 3 is inserted.
Then, in a state where the film forming material gas (reactive gas) is introduced into the vacuum chamber 1, chemical vapor deposition is performed by plasma-exciting the film forming material gas by discharge from the surface 20a of the electrode 20.
A film is formed on the surface of the substrate S in the vacuum chamber 1.

On the electrode surface 20a side (upper side) of the outer peripheral side surface of the discharge electrode 20, an inner flange portion 22 is formed over the entire outer periphery of the electrode 20 so as to protrude outside the electrode 20 from other portions. Specifically, the electrode 20 is made of, for example, an electrode body 23 made of an aluminum-based material and a plate-like stainless steel detachably assembled to the electrode body 23 with screws (not shown) so as to cover the upper surface thereof. And the upper surface of the cover portion 24 is the electrode surface 20a. Now, the cover portion 24 is larger than the upper surface of the electrode body 23,
The inner flange portion 22 is mounted so as to protrude from the upper surface of the electrode main body 23 in a horizontal direction by a predetermined dimension, and the protruding portion of the outer peripheral edge of the cover portion 24 is formed.

Further, an earth shield 14 ′ for limiting the discharge area of the discharge electrode 20 is connected to the bottom wall 2 a of the vacuum chamber 1 around the electrode mounting hole 3 on the inner surface (upper surface) of the bottom wall 2 a of the vacuum chamber 1. It is attached and fixed in the state where it was done. This earth shield 14 'has a frame shape with a substantially L-shaped cross section.
The lower surface of the outer peripheral edge portion is fixed to the inner surface of the bottom wall portion 2a of the vacuum chamber 1, while the inner peripheral edge portion 14a 'stands up and down, and the inner flange portion 22 of the electrode 20 (the cover portion 2)
On the back side of the four outer peripheral portions (protruding portions from the electrode body 23), the lower surface of the inner flange portion 22 of the electrode 20 or the upper part of the outer peripheral side surface of the electrode body 23 is opposed to the electrode 20 at a predetermined interval.

Therefore, in the case of this embodiment, the substrate S is accommodated and arranged in the vacuum chamber 1, the vacuum chamber 1 is evacuated, a reaction gas composed of a film forming material is supplied therein, and a voltage is applied to the discharge electrode 20. Is applied, the reaction gas is turned into a plasma state by the discharge from the electrode 20 and is attached to the surface of the substrate S by chemical vapor deposition, whereby the film is formed on the substrate S.

At this time, the inner flange portion 22 is provided on the outer peripheral side surface of the electrode 20, and the inner peripheral edge portion 14a 'of the earth shield 14' is disposed on the back surface side of the inner flange portion 22. ′ Inner peripheral edge 1
4a 'is the inner flange 2 when viewed from the center of the vacuum chamber 1.
2 and the film and dust in the vacuum chamber 1 hardly deposit on the inner peripheral edge portion 14a '. Therefore, continuous film formation by plasma CVD can be stably performed for a long time without interruption of discharge due to short circuit between the electrode 20 and the earth shield 14 '.

Further, since the earth shield 14 'is arranged in the space on the back side of the inner flange portion 22 of the electrode 20, the upper end of the electrode 20 can be located at substantially the same height as the earth shield 14'. The inside of the vacuum chamber 1 can be used effectively.

Further, the electrode 20 comprises an electrode body 23,
The cover is detachably assembled on the upper surface thereof and is divided into a cover portion 24 having an outer peripheral edge portion formed as an inner flange portion 22. Since the cover portion 24 is made of stainless steel, film deposition or dust deposited on the surface 20a of the electrode 20 is performed. When cleaning by removing the like, the electrode surface 20a can be cleaned simply by cleaning the upper surface of the stainless steel cover portion 24, and the electrode 20 can be easily cleaned.

The electrode body 23 is made of an aluminum-based material, and the cover 2 is made of stainless steel.
4, the electrode 20 can be made lighter than when the entire electrode is made of stainless steel, which is easy to clean.

In the third embodiment, the electrode 20 is divided into the electrode main body 23 and the cover portion 24, and the protruding portion of the cover portion 24 is used as the inner flange portion 22. The inner flange portion 22 may be formed integrally by cutting out the lower portion of the outer peripheral side surface of the inner flange portion.

In each of the above embodiments, the electrodes 5, 20
Is arranged on the bottom wall 2 a of the wall 2 of the vacuum chamber 1, but it can be of course arranged on other parts.

[0045]

As described above, according to the first aspect of the present invention, an electrode provided with a target made of a film-forming material is installed in a vacuum chamber, and the surface of the target is sputtered by discharge from the electrode. When forming a film on a substrate in a vacuum chamber, a flange is protruded from the outer surface of the target on the surface of the target, and an earth shield for limiting the discharge area of the electrode is formed on the back of the flange. By arranging them at intervals,
While keeping the target height low and making effective use of the vacuum chamber, it is difficult to deposit film-forming materials and dust in the vacuum chamber on the earth shield, preventing interruption of discharge due to short circuit between the electrode and the earth shield, Stable continuous film formation can be performed for a long time. Also, since there is no need to extend the outer edge of the target from the magnetic field area of the magnet,
The utilization efficiency of the target can be increased, and the loss due to an increase in the discharge power at the outer peripheral portion of the target can be reduced.

According to the second aspect of the present invention, the target is
The target main body to be sputtered and the target main body are detachably assembled so as to cover the outer peripheral edge of the target surface and the position where the magnet of the electrode is removed, and the outer peripheral edge is divided into a cover part forming a flange part. With this configuration, when replacing the target, the cover can be reused without discarding the cover, and the utilization efficiency of the target can be increased while using the structure of the flange portion successfully.

According to the third aspect of the present invention, the electrode is installed in the vacuum chamber, and the film forming material gas is introduced into the vacuum chamber.
When a film is formed on a substrate in a vacuum chamber by chemical vapor deposition of a film material gas by discharge from an electrode surface, a flange portion is protruded from an electrode surface on an outer peripheral side surface of the electrode, and a back surface of the flange portion is provided. By placing an earth shield on the side with an interval between the electrode and the electrode, continuous deposition can be performed between the electrode and the earth shield while effectively utilizing the inside of the vacuum chamber in the deposition apparatus by chemical vapor deposition. It can be performed stably for a long time without interruption of discharge due to short circuit.

According to the fourth aspect of the present invention, the electrode is divided into the electrode body and the electrode body so as to be detachably assembled so as to cover the entire surface thereof, and the outer peripheral edge portion is divided into the cover portion forming the flange portion. With this configuration, it is possible to easily clean the electrode when removing film-forming materials, dust, and the like deposited on the surface of the electrode. According to the invention of claim 5, the electrode body is made of an aluminum-based material. In addition, since the cover portion is made of stainless steel, the electrode can be reduced in weight and can be easily cleaned.

[Brief description of the drawings]

FIG. 1 is a sectional view schematically showing a sputtering film forming apparatus according to a first embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view illustrating a main part of the film forming apparatus according to the first embodiment.

FIG. 3 is a diagram corresponding to FIG. 1, showing a second embodiment.

FIG. 4 is a view corresponding to FIG. 1 showing a third embodiment.

FIG. 5 is a diagram corresponding to FIG. 1 showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vacuum chamber 2 Wall part 2a Bottom wall part 5 Cathode electrode 8 Target 8a Surface 8b Back surface 9 Flange part 11 Target main body 12 Cover part 14, 14 'Earth shield 14a, 14a' Inner peripheral part 16 Magnet 20 Discharge electrode 20a Surface 22 Inside Flange (flange) 23 Electrode body 24 Cover S board

Claims (5)

[Claims] An electrode in which a target made of a film-forming material is fixed on the back surface is placed in a vacuum chamber, and the surface of the target is sputtered by discharge from the electrode to form a substrate disposed in the vacuum chamber. In the film forming apparatus configured to perform film formation, on the target surface side on the outer peripheral side surface of the target, a flange portion that protrudes outside the target from other portions is provided, and an earth shield that restricts a discharge area of the electrode is provided with the ground shield. A film forming apparatus characterized by being disposed on the back side of a flange portion of a target so as to face the target at a predetermined interval. 2. The film forming apparatus according to claim 1, wherein the target is detached so as to cover the target body on which the surface is to be sputtered, and the outer periphery of the target body and a position which does not correspond to the magnet in the electrode. A film forming apparatus which is assembled so as to be capable of being divided into an outer peripheral edge portion and a cover portion constituting a flange portion. 3. An electrode is placed in a vacuum chamber, and a film forming material gas is introduced into the vacuum chamber, and a chemical vapor deposition of the film forming material gas by discharge from the electrode surface is performed on a substrate disposed in the vacuum chamber. In a film forming apparatus configured to perform film formation, on the electrode surface side on the outer peripheral side surface of the electrode, a flange portion that protrudes outside the electrode from other portions is provided, and an earth shield that limits a discharge area of the electrode is provided. A film forming apparatus characterized in that the electrode is disposed on the back side of the flange portion of the electrode so as to face the electrode at a predetermined interval. 4. The film forming apparatus according to claim 3, wherein the electrode is detachably assembled to the electrode main body so as to cover the entire surface of the electrode main body, and the outer peripheral edge portion forms a flange portion. A film forming apparatus characterized by being divided into: 5. The film forming apparatus according to claim 4, wherein the electrode body is made of an aluminum-based material and the cover is made of stainless steel.