JPH07331433A - Sputtering device - Google Patents

Abstract

(57) [Abstract] [Purpose] In a magnetron sputtering apparatus for large substrates, by placing a ground potential electrode in conjunction with movable magnetron plasma, plasma stabilization is achieved, and the quality and thickness of the sputtered film can be controlled. Aim for uniformity. [Structure] A target material is deposited by sputtering on a substrate 7 facing a target 2 provided in a vacuum container 1. At this time, the movable ground potential electrode 5 between the target 2 and the substrate 7 is moved in association with the moving magnetron magnet 6 to stabilize the plasma. A fixed ground potential electrode 4 is also arranged around the target 2. Instead of the movable ground potential electrode 5, a second fixed ground potential electrode can be provided between the target 2 and the substrate 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sputtering apparatus for film formation, and more particularly to a magnetron type sputtering apparatus for confining a plasma serving as an ion generation source on a target electrode by a magnetron magnetic field when performing sputtering.

[0002]

2. Description of the Related Art Sputtering devices have been in increasing demand in various fields as one of means for thinning various materials. Particularly in recent years, this sputtering technique has become particularly important in place of the conventional plating method in order to reproducibly form a thinner film.

Among them, the magnetron type sputtering apparatus discharges using a target electrode and a substrate electrode in an atmosphere of an inert gas such as argon in a vacuum of about 10 to ¹ to 10 to ⁴ Torr, and discharges them onto the target electrode. A plasma (magnetron plasma) closed by a magnetron magnetic field is generated, and a target electrode (hereinafter, referred to as a target) is sputtered by the ions generated at this time, and sputtered particles ejected from the target are used as substrate electrodes (hereinafter,
It is deposited on a substrate) to form a thin film, and various types are conceivable and put into practical use depending on the application.

This magnetron type sputtering device is
It is estimated that the plasma is confined in a narrow region by the magnetron magnetic field, the number of ions is increased by increasing the density of the plasma, and the number of ions jumping into the target is increased, whereby efficient sputtering can be performed.

In a mass-production sputtering apparatus, it is important to obtain a uniform film thickness and film quality in a wide area with the increase in the size of substrates or the simultaneous processing of a plurality of substrates. .

As one method for clearing this problem, there is a transfer film forming method in which sputtering is performed while the substrate is being transferred. If the film thickness distribution in the direction perpendicular to the carrying direction can be secured by this method, the film thickness distribution in the carrying direction is uniform, which is very advantageous for obtaining a uniform film thickness and film quality in the wide area. In addition, the length of the target in the carrying direction is short, and it is possible to avoid increasing the size of the target.

However, the above-described substrate transfer method has a drawback that the vacuum container becomes large in the transfer direction.

In recent years, due to the miniaturization of the vacuum container and the review of the single-wafer type device, it is required to use a large target instead of the substrate transfer system and obtain uniform film quality and film thickness in a wide area of a fixed substrate. Is coming. To efficiently consume a large target and obtain a uniform film quality and thickness,
As disclosed in JP-A-1-309965, a technique has been proposed in which a magnetron magnet (in other words, magnetron plasma) is positively moved to widen an erosion region.

Incidentally, in other conventional techniques of the sputtering apparatus (including those other than the magnetron system), for example, as disclosed in Japanese Patent Laid-Open No. 61-64877, the substrate is surrounded by a substrate and a target. A potential electrode and a negative potential electrode are arranged, the positive potential electrode captures secondary electrons flying from the target, and the negative potential electrode captures positive ions flowing into the substrate to enable low temperature film formation. ,
As disclosed in JP-A-63-176470,
A movable grid electrode is provided between the substrate and the target, the grid electrode is not inserted at the time of deposition, and the grid electrode is inserted at the time of etching so that the deposition rate and the etching rate can be set independently. As disclosed in Japanese Patent Laid-Open No. 3-75364, the non-erosion area of the cathode (target) is covered with a ground shield so that arc discharge is not induced in the erosion area of the cathode. As disclosed in Japanese Patent Laid-Open No. 4-17671,
In a magnetron-type sputtering system, the substrate is moved in the lateral direction of the magnetron magnet, and the relative positions of the target and magnetron magnet are moved alternately in the same direction as the substrate moving direction, improving the effective use and utilization efficiency of the target. Various techniques have been proposed, such as moving the shutter according to the movement of the magnetron magnet between the substrate and the target as shown in the publication.

[0010]

Of the above-mentioned conventional techniques,
JP-A-1-309965, JP-A-4-17671
The method of moving the magnetron magnet as described in the publication has the advantage that even if the target is larger than that of the magnetron magnet, the erosion area of the target can be widened and the density of plasma ions can be increased to effectively use the target.

By the way, in the magnetron plasma,
In addition to the ions, there are secondary electrons generated when the target is irradiated with the ions.
The plasma becomes unstable due to partial heating of the deposited film due to an increase in secondary electron jumping to the substrate side or sudden arcing into a nearby ground potential part, causing plasma instability and sputtered film quality. The film thickness becomes uneven.

To solve such a problem, if a fixed ground potential electrode is provided around the target under the condition that the magnetron magnet is fixed so that the magnetron plasma is efficiently covered on the target surface, surplus electrons are generated around the target. It is trapped in the ground potential portion of the device at a substantially constant rate, and the arc discharge can be prevented to stabilize the plasma.

However, in the case of the above-mentioned method of moving the magnetron magnet, when the magnetron plasma moves to the vicinity of the center of the target, this plasma region largely separates from the fixed ground potential electrode around the target, so that the electron trapping function deteriorates. Then, the secondary electrons are prevented from jumping into the substrate side and the secondary electrons diffuse the magnetron plasma to reduce the plasma confinement effect by the magnetron magnetic field,
It was not enough to stabilize the plasma. In order to deal with the above problems, we tried to control this by using input power, magnetic field strength, gas pressure, etc. as parameters.
I couldn't control it completely.

The present invention has been made in view of the above points, and an object thereof is to always secure a stable plasma and make uniform even when a movable magnetron magnetic field system is adopted for a sputtering apparatus corresponding to a fixed large substrate. The purpose is to obtain a sputtered film with the desired film quality and film thickness.

[0015]

The present invention basically proposes the following means for solving the problems in order to achieve the above object.

According to a first aspect of the present invention, a target (electrode) and a substrate (electrode) are arranged to face each other in a vacuum container, a discharge is generated between these electrodes, and a plasma (magnetron plasma) closed on the target by a magnetron magnetic field. ) Is generated, and the target is sputtered by the ions in the magnetron plasma to deposit sputtered particles on the substrate to form a film, the magnetron magnet for forming the magnetron magnetic field is
It is set so as to be movable along the back surface of the target facing the atmosphere side, and a fixed ground potential electrode for capturing electrons is arranged around the target, and according to the movement of the magnetron magnet between the target and the substrate. It is characterized in that a movable ground potential electrode for trapping electrons that moves outside the magnetron plasma region is arranged along the target surface.

The second invention has a movable magnetron magnet as in the first invention and a fixed ground potential electrode (first fixed ground potential electrode) arranged around the target, and in addition to the movable ground potential. Instead of the electrode, a second fixed ground potential electrode for trapping electrons located outside the magnetron plasma region on the target surface is arranged between the target and the substrate.

[0018]

According to the first invention, the magnetron plasma region on the surface of the target moves with the movement of the magnetron magnet, but this magnetron plasma region is relatively close to the fixed ground potential electrode arranged around the target. When in the position, the secondary electrons existing in the plasma escape to the ground mainly through the fixed ground potential electrode (or the fixed ground potential electrode and the movable ground potential electrode).

Even when the magnetron plasma region moves to the center of the target surface and moves away from the fixed ground potential electrode, the movable ground potential electrode is positioned above the magnetron plasma region with an optimum distance. By doing so, secondary electrons existing in the magnetron plasma region escape to the ground via the movable ground potential electrode by the movable ground potential electrode.

Therefore, the secondary electrons in the plasma do not always lose their destinations, the secondary electrons are prevented from jumping into the substrate side, and the plasma is stabilized.

If the movable ground potential electrode is moved in parallel with the target above the plasma region in synchronization with the magnetron magnet, the movable ground potential electrode can maintain a constant or almost constant distance from the magnetron plasma region (closed by the magnetron magnetic field). Strictly speaking, the plasma region may be subtly changed due to subtle fluctuations in the magnetron magnetic field.In this case, therefore, even if the movable ground potential electrode is moved in parallel with the target, the movable ground potential electrode with respect to the magnetron plasma region is moved. The distance is almost constant).

If the distance between the magnetron plasma region and the movable ground potential electrode is too short, arc discharge occurs between the movable ground potential electrode and the magnetron plasma, the plasma becomes unstable, and the film uniformity is impaired. It is necessary to always maintain an optimum distance between the movable ground potential electrodes.

Next, according to the second invention, the first magnetron plasma region in which the moving magnetron plasma region is arranged around the target is used.
When relatively close to the fixed ground potential electrode of, the secondary electrons existing in the plasma escape to the ground through the first fixed ground potential electrode.

Even when the magnetron plasma region moves toward the center of the target surface and moves away from the first fixed ground potential electrode, the second fixed ground potential electrode is optimally located above the plasma region. By keeping the distance, the secondary fixed ground potential electrode allows secondary electrons existing in the magnetron plasma region to escape to the ground via the second fixed ground potential electrode.

In this case, the relative positional relationship between the magnetron plasma region and the second fixed ground potential electrode changes, and depending on the degree of plasma, the magnetron plasma region and the second fixed ground potential electrode may have a certain distance (allowable). If the distance is less than or equal to the distance, secondary electrons may flow at a stretch between them and arc discharge may occur. Therefore, if there is such a concern depending on the device, the second fixed ground potential electrode is opened / closed as necessary. A switch is provided. If such a switch is provided, the magnetron plasma region and the second
When the distance between the fixed ground potential electrode and the fixed ground potential electrode is less than the allowable distance, the switch is opened to disconnect the second fixed ground potential electrode from the ground and bring the potential floating state. When the ground is temporarily released in this way, the secondary electrons are captured and retained in the second fixed ground potential electrode. Then, again, when the magnetron plasma region becomes more than the allowable distance from the second fixed ground potential electrode due to the movement of the magnetron magnetic field, the switch is closed to ground the second fixed ground potential electrode.
In this way, the accumulated secondary electrons escape to the ground, and the newly captured secondary electrons also escape to the ground.

Also in the present invention, as in the first invention, even when the magnetron magnet moves, secondary electrons in the plasma do not always lose their destinations and secondary electrons are prevented from jumping to the substrate side. And stabilize the plasma.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail based on the embodiments shown in the drawings.

1A and 1B are explanatory views according to a first embodiment of the present invention, in which FIG. 1A is an overall structural view and FIG. 1B is a partial perspective view of a magnetron magnet.

As shown in FIG. 1, a target 2 is fixed via an insulating member (insulating seal) 3 to the bottom opening of a vacuum container 1 forming a sputtering film forming chamber, and the inside of the vacuum container 1 is the target 2. And, it is hermetically closed by the insulating member 3.

On the atmosphere side (target back surface side) of the target 2, a magnetron magnetic field G is formed on the surface of the target 2.
A magnetron magnet 6 for forming a magnet is arranged.

In the magnetron magnet 6, as shown in FIG. 3B, an N pole (or S pole) is arranged at the center of a rectangular frame-shaped S pole (or N pole). For example, rail mechanisms 61, 6 are provided.
2 is set to be movable by a drive mechanism (not shown) along the surface of the target 2 facing the atmosphere side (target rear surface), and the speed is controlled by the control unit 20.

The surface of the target 2 faces the inside of the vacuum container 1, and in the vacuum container 1, the target 2 and the substrate (object to be film-formed)
7 are arranged to face each other, and these target 2 and substrate 7
Forms an electrode for plasma formation, and the high frequency power supply 10 or the negative DC power supply is applied to the target 2 among them.
The substrate 7 is held by a substrate tray (not shown).

A frame-shaped fixed ground potential electrode 4 for capturing electrons is arranged around the target 2 so as to keep an optimum distance near the target 2.

Reference numeral 5 denotes a movable ground potential electrode provided between the target 2 and the substrate 7, which is set to be movable along the surface of the target 2 in parallel with the target. The movable ground potential electrode 5 is, for example, an annular conductive frame 5A having a shape and size substantially equal to the shape and size of the magnetron magnet 6 and a mesh-shaped conductive member 5B arranged therein. It may be configured by a rod-shaped or rod-shaped conductive member. The movable electrode 5 includes the control unit 20 and the drive mechanism 11 so that the frame body 5A overlaps the position of the movable magnetron magnet 6 during movement.
It is designed to move in synchronization with the magnetron magnet 6 via the movable magnetron plasma P, which will be described later.
It is designed to keep a constant or almost constant distance from the area. In addition, the opening of the frame body 5A faces the region of the magnetron plasma P to ensure the passage of sputtered particles.

In the drive mechanism 11 for the movable ground potential electrode 5, the rod 12 for supporting the movable ground potential electrode 5 is led out of the container 1 through the insertion hole 1A provided in the side wall of the vacuum container 1, and the screw is provided at the leading end thereof. A rod 16 is provided, and an output gear 14 of the motor 15 is meshed with the screw rod 16. The rotation of the motor 15 is converted into a linear movement via the gear 14 and the screw rod 16, and the linear movement causes the movable ground potential electrode 5 to move on the surface of the target 2.

Further, the drive mechanism 11 has a bellows 13 for ensuring the sealing of the rod insertion hole 1A of the vacuum container 1 and the movement of the rod 12, and one end of the bellows 13 has a seal 18 on the side wall of the vacuum container 1. 2 and the other end
As shown in (4), it is fixed to a flange 12A provided on the rod 12 via a seal 17.

The control unit 20 controls the movable ground potential electrode 5 and the magnetron magnet 6, and one of the main controls is to indirectly detect the sputtering film formation state from the luminous intensity of the magnetron plasma P and the like. The signal of the detector 21 is input to control the movement of the magnetron magnet 6 and the movable ground potential electrode 5 and the speed control as necessary.

Next, the operation of this embodiment will be described.

The inside of the vacuum container 1 is set to a vacuum degree of about 10 to ¹ to 10 to ⁴ Torr, and an inert gas such as argon is introduced. In this state, when the target 2 and the substrate 7 are discharged, a plasma (magnetron plasma) P closed by the magnetron magnetic field G is generated on the target 2 and the target 2 is irradiated with the ions in the plasma P.
The target 2 is sputtered by the ions, and sputtered particles that fly out from the target 2 are deposited on the substrate 7 to form a sputtered film on the substrate 7.

In this magnetron sputtering method, the plasma P is confined in a narrow region by the magnetron magnetic field G,
By increasing the density of the plasma, the number of ions is increased, and the number of ions jumping into the target 2 is increased, so that the sputtering is efficiently performed.

Further, the magnetron magnet 6 is moved in parallel along the target 2 so that the large-area substrate 7 and the target 2 can be accommodated by the small magnetron magnet 6, and the region of the magnetron plasma P is moved along the surface of the target 2. Then, the entire substrate 7 is sputtered. At this time, the movable ground potential electrode 5 is also moved by the drive mechanism 11 in synchronization with the speed of the magnetron magnet 6 so as to always maintain a constant or almost constant distance with respect to the magnetron plasma P region.

The moving speed of the magnetron magnet 6 is determined by the control unit 20 on the basis of the output signal of the plasma detector 21 in accordance with the sputtering film formation conditions. At this time, the control unit 2
A speed command signal is output from 0 to the movable ground potential electrode drive motor 15 to control the movement of the movable ground potential electrode 5.

As described above, the magnetron plasma P region on the surface of the target 2 moves along with the movement of the magnetron magnet 6, but this plasma P region is relatively large with respect to the fixed ground potential electrode 2 arranged around the target 2. In the case of the close position, the secondary electrons existing in the magnetron plasma P escape to the ground mainly via the fixed ground potential electrode 4 (or the fixed ground potential electrode 4 and the movable ground potential electrode 5).

Even if the magnetron plasma P region moves to the center on the surface of the target 2 and moves away from the fixed ground potential electrode 5, the movable ground potential electrode 5 has an optimum distance above the magnetron plasma P region. By keeping the movable ground potential electrode 5, secondary electrons existing in the plasma P region due to the movable ground potential electrode 5, that is, secondary electrons generated from the target 2 by plasma ion irradiation escape to the ground via the movable ground potential electrode 5.

Therefore, the secondary electrons in the plasma do not always lose their destinations, the secondary electrons are prevented from jumping into the substrate 7 side, and the plasma P is stabilized, so that the substrate 7 is made uniform. It is possible to obtain a sputter film having a film quality and a film thickness.

If the distance between the magnetron plasma P region and the movable ground potential electrode 5 is too short, arc discharge occurs between the movable ground potential electrode 5 and the magnetron plasma P, the plasma becomes unstable, and the film uniformity becomes unsatisfactory. Therefore, it is necessary to always maintain an optimum distance between the magnetron plasma P and the movable ground potential electrode 5.

In the present embodiment, the movable ground potential electrode 5
Is synchronized with the moving speed of the magnetron magnet 6, but the movable ground potential electrode 5 and the magnetron plasma P are moved according to the relative positions of the target 2 and the movable ground potential electrode 5.
If it is more convenient to variably control the relative distance for plasma stabilization and sputtering film formation, the movable ground potential electrode 5 is independently driven so that the distance changes in relation to the magnetron plasma region. The position may be controlled.

If the open / close switch 22 is provided on the ground conductive line of the movable ground potential electrode 22, it is possible to deal with this by opening (turning off) the switch 22 when only the fixed ground potential electrode 4 is desired to be used.

According to the present embodiment, the plasma can be stabilized and sputtering can be performed even in the system in which the magnetron magnet 6 is moved, so that the following effects can be obtained.

(1) The film quality distribution of sputter deposition on a large substrate is dramatically improved, which leads to stable improvement of productivity.

(2) The use efficiency of the target can be improved.

(3) The vacuum container of the sputtering apparatus can be miniaturized by enabling the sputtering film formation on a large substrate without using the substrate transfer system.

FIG. 3 is a configuration diagram of a main part according to the second embodiment of the present invention, in which the same reference numerals as those in the first embodiment indicate the same or common elements (note that the reference numerals in the drawings after FIG. 4 are also the same. The same).

The difference between this embodiment and the first embodiment is the shape of the movable ground potential electrode 5.

That is, the movable ground potential electrode 5 of this embodiment
The side wall of the conductive frame body 5A has a cylindrical shape. By doing so, it is possible to prevent the sputtered particles passing through the opening 5B of the movable ground potential electrode 5 from scattering to other than the substrate 7.

FIG. 4 is a block diagram according to the third embodiment of the present invention.

This embodiment also has the fixed ground potential electrode 4 around the target and the movable magnetron magnet 6 as in the first and second embodiments. The difference from these embodiments is the movable ground potential. Instead of the electrode 5, a second fixed ground potential electrode 25 for electron trapping, which is located outside the magnetron plasma P region, is disposed between the target 2 and the substrate 7, for example, above the center of the target surface.

The second fixed ground potential electrode 25 has a rod shape and is disposed at least above the center of the target 2 so as to lie in a direction perpendicular to the moving direction of the magnetron magnet 6. The ground potential electrode 25 may have various shapes, and a plurality of the ground potential electrodes 25 may be arranged in parallel with the surface of the target 2 or may be arranged in a grid pattern.

Further, the open / close switch 26 is connected to the ground conductive wire.
Is provided to switch between grounding and non-grounding of the second fixed ground potential electrode 25.

According to this embodiment, when the moving magnetron plasma P region is located relatively close to the first fixed ground potential electrode 4 arranged around the target, it exists in this plasma 2. The secondary electrons escape to the ground via the first fixed ground potential electrode 4.

Even when the magnetron plasma P region moves toward the center on the target surface and moves away from the first fixed ground potential electrode 4, the second
Since the fixed ground potential electrode 25 of No. 2 is positioned above the magnetron plasma P region with an optimum distance, the secondary electrons existing in the magnetron plasma P region are second fixed by the second fixed ground potential electrode 25. Ground potential electrode 25
Escape to the ground through.

In this case, the magnetron plasma P
The relative positional relationship between the region and the second fixed ground potential electrode changes, and depending on the state of the magnetron plasma, when the magnetron plasma region and the second fixed ground potential electrode 25 are below a certain distance, secondary electrons are generated between them. If there is such a concern depending on the device, the second fixed ground potential electrode 2 may be discharged at a dash and arc discharge may occur.
The opening / closing switch 26 of No. 5 is opened / closed as necessary.

That is, in this embodiment, when the distance between the magnetron plasma P region and the second fixed ground potential electrode 25 becomes equal to or less than the allowable distance, the switch 26 is opened to change the second distance.
The second fixed ground potential electrode 25 is temporarily cut off from the fixed ground potential electrode 25 of
Is released from ground. As a result, secondary electrons are trapped and retained in the second fixed ground potential electrode 25 and its conductive wire. Then, when the magnetron plasma P region passes under the second fixed ground potential electrode 25 and the magnetron plasma P region becomes a distance more than the allowable distance with respect to the second fixed ground potential electrode 25 again, The retained secondary electrons escape to the ground, and the newly captured secondary electrons also escape to the ground.

Also in the present embodiment, even if the magnetron plasma P region moves on the target, secondary electrons in the plasma do not always lose their destinations and secondary electrons are prevented from jumping to the substrate side. At the same time, the plasma can be stabilized, the same effect as that of the first embodiment can be achieved, and the movable ground potential electrode drive mechanism and its control system as in the first embodiment are not required, so that the entire sputtering apparatus can be simplified. It can be planned.

FIG. 5 shows a fourth embodiment of the present invention.

In this embodiment, the movable ground potential electrode 5 is in direct contact with the fixed ground potential electrode 4. In addition to the same effects as the first embodiment, this embodiment also provides the same effects as when only the fixed ground potential electrode 4 is used when the movable ground potential electrode 5 is not operating.

[0067]

As described above, according to the present invention, even when a movable magnetron magnetic field system is adopted in a sputtering apparatus corresponding to a fixed large substrate, a stable plasma is always secured to obtain a uniform film quality and film quality. A thick sputter film can be obtained.

[Brief description of drawings]

FIG. 1A is an overall configuration diagram according to a first embodiment of the present invention, and FIG. 1B is an example diagram of a magnetron magnet used therein.

FIG. 2 is a partial cross-sectional view showing a part of a drive mechanism for a movable ground potential electrode used in the above embodiment.

FIG. 3 is a cross-sectional view of essential parts showing a second embodiment of the present invention.

FIG. 4 is a cross-sectional view of an essential part showing a third embodiment of the present invention.

FIG. 5 is a cross-sectional view of a main part showing a fourth embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Vacuum container, 2 ... Target, 4 ... Fixed earth potential electrode, 5 ... Movable earth potential electrode, 6 ... Magnetron magnet, 7
... substrate, 10 ... power supply, 11 ... movable ground potential electrode drive mechanism, 20 ... control unit, G ... magnetron magnetic field, P ... plasma, 22 ... ground open / close switch, 25 ... second fixed ground potential electrode, 26 ... ground Open / close switch.

Claims (10)

[Claims] 1. A target electrode and a substrate electrode are arranged to face each other in a vacuum container, and discharge is generated between these electrodes to generate plasma (hereinafter referred to as magnetron plasma) closed on the target electrode by a magnetron magnetic field. Then, in the sputtering apparatus for sputtering the target electrode by the ions in the magnetron plasma to deposit the sputtered particles on the substrate electrode to form a film, the magnetron magnet for forming the magnetron magnetic field is the atmosphere side by a driving mechanism. It is set so as to be movable along the back surface of the target electrode facing the target electrode, and a fixed ground potential electrode for electron capture is arranged around the target electrode, and the magnetron magnet is moved between the target electrode and the substrate electrode. Depending on the target electrode surface the magnetron plasm Sputtering apparatus characterized by comprising placing a movable ground electrode for electron capture moving the extracellular region. 2. The movable ground potential electrode is set so as to move while synchronizing with the moving speed of the magnetron magnet, thereby keeping a constant or substantially constant distance from the magnetron region. The sputtering apparatus according to claim 1, wherein: 3. The sputtering apparatus according to claim 1, wherein the movable ground potential electrode has an annular frame shape having an opening facing the magnetron plasma region. 4. The sputtering apparatus according to claim 1, wherein the movable ground potential electrode has any one of a mesh shape, a lattice shape, and a rod shape so as to allow the sputtered particles to pass therethrough. 5. The movable ground potential electrode has an opening facing the magnetron plasma region, and the periphery of this opening is shaped so as to close the space between the target electrode and the substrate electrode. Item 2. The sputtering apparatus according to item 2. 6. The movable ground potential electrode has an open / close switch, and is set to be grounded when the switch is closed and ungrounded when the switch is opened. The sputtering apparatus according to any one of 5 above. 7. A target electrode and a substrate electrode are arranged to face each other in a vacuum container, and a discharge is generated between these electrodes to generate plasma (hereinafter referred to as magnetron plasma) closed on the target electrode by a magnetron magnetic field. Then, in the sputtering apparatus for sputtering the target electrode by the ions in the magnetron plasma to deposit the sputtered particles on the substrate electrode to form a film, the magnetron magnet for forming the magnetron magnetic field is the atmosphere side by a driving mechanism. The first fixed ground potential electrode for capturing electrons is arranged around the target electrode, and the target electrode surface is located between the target electrode and the substrate electrode. A second electron trap located outside the upper magnetron plasma region Sputtering apparatus characterized by comprising placing a fixed ground potential electrode of. 8. The second fixed ground potential electrode has a rod shape and is disposed at least above the center of the target electrode so as to lie in a direction perpendicular to the moving direction of the magnetron magnet. The sputtering apparatus according to claim 7, which is characterized in that. 9. The sputtering apparatus according to claim 7, wherein the second fixed ground potential electrode is arranged in a grid pattern in parallel with the surface of the target electrode. 10. The second fixed ground potential electrode has a switch, and is set to be grounded when the switch is closed and not grounded when the switch is opened, and the switch is a magnetron plasma region. 10. The sputtering apparatus according to any one of claims 7 to 9, wherein is set so that the switch is opened when the distance from the second fixed ground potential electrode is less than an allowable distance with respect to the second fixed ground potential electrode.