JP2002241927A - Film deposition apparatus using cathode arc discharge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film deposition apparatus in which the target surface is uniformly consumed by detecting the position of an arc which fluctuates temporally and controlling the position of the arc. SOLUTION: Arc sensing coils 60a to 60d and position control coils 70a to 70d are arranged with rotation symmetry about the z-axis which passes the center O of a target 11. When an arc A is generated between an anode chamber 12 and a target 11, a detection circuit 61 detects the position of the arc A on the basis of the output signal of the arc sensing coils 60a to 60d. A controller 5 adjusts the exciting current supplied to the position control coils 70a to 70d on the basis of the positional information which the detection circuit 61 has detected, and moves the arc A to the position of an arc A2. By controlling the exciting current of the position control coils 70a to 70d and making the distribution of the generated arc A2 on the surface of the target 11 homogeneous, consumption of the surface of the target 11 in film deposition can be made uniform.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a film forming apparatus for forming a thin film on a substrate by using a cathodic arc discharge, and more particularly to a carbon film formed on a magnetic disk or a magnetic head of a magnetic recording apparatus. The present invention relates to a film forming apparatus used.

[0002]

2. Description of the Related Art Conventionally, as a film forming apparatus for forming a thin film by generating plasma, a parallel plate type or an ECR type is known. In a parallel plate type or ECR type film forming apparatus, plasma is generated using glow discharge. In recent years, for a film forming apparatus using such a glow discharge,
Attention has been paid to a film forming apparatus using cathodic arc discharge, and in particular, it is used for forming a carbon film such as a DLC (diamond-like carbon) film.

In a film forming apparatus using cathode arc discharge, an arc discharge is generated in a target provided on a cathode, and the target is sputtered by the impact of the arc discharge. As a result, a plasma is generated, and the plasma includes target ions emitted from the target. Since the generated arc gradually disappears while moving on the target, the plasma is continuously generated by generating the arc discharge again using the trigger.

[0004]

However, the conventional film forming apparatus has a disadvantage that the position of the generated arc is not stable. For this reason, there has been a problem that the surface of the target is not uniformly consumed and is locally shaved.

An object of the present invention is to provide a film forming apparatus in which a target surface is uniformly consumed by detecting a position of an arc which fluctuates with time and controlling the position of the arc.

[0006]

An embodiment of the present invention will be described with reference to FIGS. (1) According to FIG. 1, the invention according to claim 1 generates an arc discharge between a target 11 and an anode 12 constituting a cathode to generate a plasma beam including ions of the target 11. The plasma beam is applied to the substrate 4
The above-described object is achieved by providing an arc position detecting device 6 that is applied to a film forming apparatus that irradiates a film on the target 1 and detects a magnetic field generated by arc discharge to detect the position of an arc on the target 11. . (2) The invention according to claim 2 is the film forming apparatus according to claim 1, wherein the magnetic field intensity distribution on the target 11 is changed based on the detection information of the arc position detecting device 6, and the position of the arc on the target 11 is changed. Is provided with an arc position control device 7 for controlling the pressure. (3) In connection with FIGS.
According to the invention of the second aspect, in the film forming apparatus according to the second aspect, the arc position control device 7 changes a magnetic field generation unit 80 that forms a magnetic field on the target 11 and a relative position between the target 11 and the magnetic field generation unit 80. The position change device 81 is provided. (4) Explaining with reference to FIGS. 1 to 3, the invention according to claim 4 is the film deposition apparatus according to claim 2, wherein the arc position control device 7 includes at least three magnetic coils 70 a to 70.
0d, a power supply 71 for supplying an exciting current to each of the magnetic coils 70a to 70d,
The above-mentioned object is achieved by providing an excitation current control unit 5 that controls the excitation current supplied to each of the target regions 0a to 70d so that the magnetic field in a predetermined area on the target 11 is larger than the magnetic fields in other areas. I do. (6) A description will be given with reference to FIGS.
According to the invention, in the film forming apparatus according to any one of claims 1 to 4, a bent duct having an inlet 206 through which plasma generated by arc discharge is incident and an outlet 207 through which plasma is emitted to the substrate 41. 20 and a magnetic force generated by a magnetic coil 21 wound around the duct 20, the plasma beam is introduced along the duct 20 into the entrance 206.
Transfer devices 17 and 2 for transferring from the outlet to the outlet 207
1 and 22.

[0007] In the section of the means for solving the above problems, the drawings of the embodiments of the present invention are used to make the present invention easy to understand, but the present invention is not limited to the embodiments of the present invention. Not something.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. -First Embodiment- FIG. 1 is a view showing one embodiment of a film forming apparatus according to the present invention, and is a view showing a schematic configuration of a film forming apparatus for forming a film using a cathodic arc discharge. . As shown in FIG. 1, the film forming apparatus includes a plasma generating section 1, a filter section 2, a beam scanning apparatus 3, a film forming chamber 4, and a control apparatus 5 for controlling the entire apparatus. In addition, the plasma generator 1 includes:
An arc position detector 6 for detecting the position of the generated arc and an arc position controller 7 for controlling the arc position are provided.

The plasma generating section 1 includes a cathode section 10 on which a target 11 is mounted, an anode chamber 12 in which the cathode section 10 is fixed, and a trigger 14 for generating a trigger for arc discharge. The cathode unit 10 is connected to the negative terminal of an arc power source (constant current source) 13, while
The anode chamber 4 connected to the positive terminal 4 and the positive terminal of the arc power supply 13 are each grounded and at a ground potential. The trigger 14 is rotationally driven by a driving unit 15 such as a step motor using the shaft 140 as a rotation axis. The angle of the trigger 14 is detected by an angle sensor (not shown).

The cathode section 10 and the anode chamber 12 are electrically insulated by an insulating member 10a. A magnetic coil 16 for forming an axial magnetic field in the anode chamber 12 is provided on the outer periphery of the anode chamber 12.
7 supplies an exciting current. Although not shown, the cathode unit 10 is provided with a cooling means such as a water cooling jacket.

The filter section 2 has a bent toroidal duct 20 and a magnetic coil 21 provided therearound. An excitation current is also supplied from the power supply 17 to the magnetic coil 21. The filter section 2 and the anode chamber 12 are fixed to each other via an insulating material 23, and both are electrically insulated. A bias voltage can be applied to the toroidal duct 20 by a bias power supply 22.

A substrate stage 42 is provided in the film forming chamber 4, and a substrate 41 to be formed is mounted on the substrate stage 42. A beam scanning device 3 is provided around the beam introduction duct portion 43 of the film forming chamber 4, and deflects and scans the plasma beam emitted from the filter portion 2 in a direction orthogonal to the beam. The beam scanning device 3 includes, for example, a pair of C-shaped magnetic cores (not shown). The magnetic poles of one magnetic core are disposed vertically above and below the duct portion 43, and the magnetic poles of the other magnetic core are disposed in a direction perpendicular to the plane of the drawing across the duct portion 43.
In this case, the plasma beam is deflected and scanned in the vertical direction in the drawing and the direction perpendicular to the plane of the drawing. Beam scanning device 3
A solenoid coil (not shown) is wound around the magnetic core, and an exciting current is supplied from a power supply 31 to the solenoid coil.

FIG. 2 is a diagram showing the details of the arc position detector 6 and the arc position controller 7 provided in the plasma generator 1. In FIG. 2, four detection coils 60a
1 to 60d (see FIG. 3) and a detection circuit 61 for detecting an induced current induced in each of the detection coils 60a to 60d.
Of the arc position detecting section 6 of FIG. 1. The four position control coils 70a to 70d shown in FIG. 2 and the power supply 71 for supplying an exciting current to each of the position control coils 70a to 70d constitute the arc position control unit 7 in FIG. Each of the coils 60a to 60d and 70a to 70d is constituted by a solenoid-shaped coil wound around an axis parallel to the z-axis. The power supply 71 supplies exciting currents Ia to Id to the respective position control coils 70a to 70d individually.
To Id can be independently controlled. The control device 5 controls the position control coils 70a to 70a based on the positions of the arcs A detected by the detection coils 60a to 60d.
The excitation current of 70d is controlled respectively.

FIG. 3 is a diagram showing the arrangement of the detection coils 60a to 60d and the position control coils 70a to 70d.
(A) is a view of the detection coils 60a to 60d viewed from the target 11, and (b) is a position control coils 70a to 70d.
FIG. 5 is a diagram of Od as viewed from a target 11 side. FIG. 3 (a)
As shown in the figure, the detection coils 60a and 60c are connected to the target 11 on the axis J1 forming an angle of 45 (deg) with the x-axis.
Are arranged at equal distances from the center O of The detection coils 60a and 60c are connected to an axis J2 orthogonal to the axis J1.
It is arranged at an equal distance from the upper center O. That is, the detection coils 60a to 60d are arranged rotationally symmetric with respect to the z-axis passing through the center O of the target 11. On the other hand, the position control coils 70a to 70d are respectively arranged below the corresponding detection coils 60a to 60d in the drawing, and x
The arrangement in the y-plane is as shown in FIG.
The arrangement is the same as a to 60d.

FIG. 4 is a view showing an example of the shape of the toroidal duct 20, wherein FIG.
(B) is a front view. The toroidal duct 20 has three straight pipe parts 201, 203, 205 and two bent parts 202, 204 connecting them. Flanges 206 and 207 are provided in the openings of the straight pipe portions 201 and 205. The axial direction of the straight pipe part 201 and the axial direction of the straight pipe 207 form an angle of 90 degrees with each other.
Are arranged along the z-axis, and the straight pipe 205 is arranged along the x-axis.

Next, the operation of generating a plasma beam will be described. When the arc discharge is generated, the trigger 14 retracted to the position shown by the broken line in FIG. The potential difference between the cathode section 10 and the anode chamber 12 is expressed by the following equation
When the trigger tip 14a provided at the tip of the trigger 14 comes into contact with the surface of the target 11, an arc discharge is induced, and a reference A indicates between the anode chamber 12 and the target 11. Such an arc is formed.

When the arc discharge occurs, plasma is generated, and this plasma contains positive ions generated from the target 11. For example, when a carbon film is formed, graphite is used as the target 11, and plasma containing carbon ions is generated by arc discharge. At this time, the graphite target 11 emits clusters composed of a large number of carbon atoms called macro particles in addition to carbon ions.

The controller 5 constantly monitors the state of the arc power supply 13 and, when detecting the occurrence of arc discharge, drives the drive unit 1.
5 to trigger 14 from the surface of target 11
Pull up. At this time, trigger 1 when an arc discharge occurs
4 is detected by the above-described angle sensor, and the detected angular position is stored in a storage unit (not shown) provided in the control device 5. After the occurrence of the arc discharge, the discharge state weakens as time elapses.
4 by the drive unit 15 to the stored position,
Control is performed so that stable arc discharge is maintained.

As described above, an axial magnetic field is formed in the anode chamber 12 by the magnetic coil 16. Therefore, a plasma beam generated by the arc discharge, that is, a plasma beam containing carbon ions and electrons emitted from the target 11 is focused by the axial magnetic field and guided to the toroidal duct 20 of the filter unit 2.

The toroidal duct 20 has a bias power supply 2
2, a radial electric field is formed in the toroidal duct 20. Further, an axial magnetic field along the axis of the toroidal duct 20 is also formed by the magnetic coil 21 provided around the toroidal duct 20. Therefore, the plasma beam containing positive carbon ions is guided to the film forming chamber 4 in the toroidal duct 20 by these electric and magnetic fields.

By the way, since the toroidal duct 20 is bent as shown in FIG. 4, the neutral macroparticles generated in the plasma generating section 1 impinge on the duct inner wall from the flange 206 in the z-axis direction. . At this time, macro particles having small kinetic energy adhere to the inner wall of the duct, and macro particles having large kinetic energy are reflected on the wall. In the case of the toroidal duct 20 that is bent as shown in FIG. 4, the reflected macroparticle again collides with the inner wall of the toroidal duct 20, and is not emitted from the flange 207 by one reflection.

When colliding with the wall surface, a part of the kinetic energy of the macro particles is taken away, so that the macro particles reflected in the first collision almost adhere to the inner wall of the duct in the second collision. As a result, macroparticles that become a source of contamination during film formation can be almost completely removed by the filter unit 2.

The plasma beam guided to the film forming chamber 4 is applied to the substrate 41 mounted on the substrate stage 42. At this time, by deflecting and scanning the plasma beam in the direction orthogonal to the direction using the beam scanning device 3,
A large area of the substrate 41 can be uniformly irradiated with the plasma beam.

Next, referring to FIGS. 2 and 3, detection coils 60a-60d and position control coils 70a-70 will be described.
The arc position control using d will be described. Here, as shown by a solid line A in FIG.
An example in which an arc generated at a position deviated from the center is moved to the center O as indicated by a two-dot chain line A2 will be described.

First, when the arc A occurs, its position is detected by the detection coils 60a to 60d. When the arc A occurs, a magnetic field is generated around the arc A, and the magnetic flux passing through each of the detection coils 60a to 60d changes. As a result, induced electromotive force is induced in each of the detection coils 60a to 60d, and an induced current flows through each of the detection coils 60a to 60d which is a closed circuit. In the detection circuit 61, each detection coil 60a
誘導 60d of induced current is detected, and the detection result is sent to the control device 5.

For example, as shown in FIG. 2 and FIG.
When an arc A is generated between the portion of the target 11 near the detection coil 60b and the anode chamber 12, the induction current ICb of the detection coil 60b near the arc Aa is the induced current flowing through the detection coil 60d on the opposite side. It is larger than ICd. Further, the induced currents ICa and ICc flowing through the detection coils 60a and 60c are larger than ICd and smaller than ICb. That is, ICb> ICa ≒ ICc> ICd
If the induced current is detected by the detection coils 60a to 60d, it can be estimated that the arc A as shown in FIG. Even if the arc A is continuously generated, the position of the arc A changes every moment, so that the induced currents ICa to ICa are applied to the detection coils 60a to 60d.
d will be induced.

As described above, each of the detection coils 60a to 60d
By detecting the induced current induced in the target 11 by the detection circuit 61, it is possible to estimate at which position of the target 11 the arc A has occurred. Therefore, the arc generation distribution on the target 11 can be obtained using the detection result. Note that a magnetic field generated by the coil 16 is also formed in the anode chamber 12, but this magnetic field is always a constant magnetic field.
No induced electromotive force is induced in 60d.

Next, arc position movement using the position control coils 70a to 70d will be described. When the excitation current is supplied to each of the position control coils 70a to 70d by the power supply 71, the position control coils 70a to 70d
A magnetic field according to 70d is formed. As described above, the exciting currents Ia to Id of the position control coils 70a to 70d can be controlled independently. Regions can be formed.

Since the arc A tends to move in the direction of the strong magnetic field, the position of the arc A on the target 11 can be changed by controlling the exciting currents Ia to Id. That is, when the arc A is detected by the detection circuit 61, the exciting current Id is supplied to the position control coil 70d. As a result, the magnetic field in the portion where the position control coil 70d is arranged in FIG. 3B is increased, and the arc A starts moving toward the center O of the target 11 (see FIG. 2). Then, the detection coils 60a to 60
If the arc position detected by d becomes the center O of the target 11 as indicated by A2, the position control coil 70d
Is set to zero.

As described above, in the film forming apparatus of the present embodiment, the position of the arc A on the target 11 can be freely controlled by the arc position detector 6 and the arc position controller 7 shown in FIG. . Therefore, by controlling the distribution density of the arc A on the target 11 to be uniform, the consumption of the target 11 can be made uniform.

Second Embodiment FIGS. 5 and 6 are views for explaining a second embodiment of the film forming apparatus according to the present invention. In the film forming apparatus of the present embodiment, only the structure of the arc position control unit 7 (see FIG. 1) is different from the film forming apparatus of the above-described first embodiment, and other configurations are the same as those of the first embodiment. The same is true.

FIG. 5 is a diagram showing details of the arc position detecting unit 6 and the arc position control unit 7 provided in the plasma film forming apparatus 1 of the film forming apparatus, and is a diagram showing the same parts as in FIG. . As shown in FIG. 5, in the present embodiment, only one position control coil 80 is provided, and this position control coil 80 can be moved two-dimensionally in the xy plane by the driving device 81. The position control coil 80 has a power supply 8
2 supplies an exciting current.

FIGS. 6A and 6B are diagrams for explaining arc position control by the position control coil 80. FIG. 6A shows a first control example, and FIG. 6B shows a second control example. 6A and 6B are views of the detection coils 60a to 60d and the position control coil 80 as viewed from the target 11 side.
The detection coils 60a to 60d are indicated by broken lines. here,
As in the first embodiment, an example will be described in which the arc A generated at a position shifted from the center O of the target 11 is moved to the center O like the arc A2.

In the first control example shown in FIG. 6A, the driving device 81 moves the position control coil 80 to the position of the arc A. Next, the position control coil 8 is
After supplying the exciting current to 0, the position control coil 80 is moved to the center O of the target 11. As a result, the region of the strong magnetic field moves to the center O, so that the arc A also moves to the center O
And the arc becomes like the two-dot chain line A2.

On the other hand, in the second control example shown in FIG. 6B, first, the position control coil 80 is moved to the center O of the target 11 where the arc A is to be moved. Thereafter, an exciting current is supplied to the position control coil 80 to form a magnetic field. As a result, the magnetic field near the center O becomes stronger and the arc A moves to the position of the arc A2.

By moving the position control coil 80 to which the exciting current is supplied over the entire area of the target 11, the distribution of the arc A generated on the surface of the target 10 can be made uniform. Further, in the film forming apparatus according to the second embodiment, the number of position control coils can be reduced as compared with the film forming apparatus according to the first embodiment. A permanent magnet may be provided instead of the position control coil 80, and the permanent magnet may be moved two-dimensionally by the driving device 81.

Third Embodiment FIG. 7 is a view for explaining a third embodiment of the film forming apparatus according to the present invention, and shows parts different from the film forming apparatus of the first embodiment. Things. FIG. 7A is a view showing a part of the film forming apparatus, and shows a part similar to FIG. FIG. 7B is a sectional view taken along line BB of FIG. In FIG. 7, reference numerals 90a to 90d denote magnetic sensors constituted by Hall elements and the like, and the magnetic field when the arc A is generated is detected by the magnetic sensors 90a to 90d.

Detection signals Sa of the magnetic sensors 90a to 90d
To Sd are input to the detection circuit 94, and the detection circuit 94 calculates the position of the arc A by comparing the magnitudes of the detection signals Sa to Sd. For example, when the arc A as shown in FIG. 7 occurs, the magnitudes of the detection signals Sa to Sd are as follows: Sb> Sa ≒ Sc> Sd.

An excitation current is supplied from a power supply 93 to a position control coil 91 provided so as to surround the periphery of the anode chamber 12 to form an axial magnetic field in the z direction in the vicinity of the target 11 in the anode chamber 12. Position control coil 9
1 can be moved two-dimensionally in the xy plane by the driving device 92. The strength of the magnetic field formed by the position control coil 91 is the strongest at the center of the position control coil 91, and by moving the position control coil 91 in the xy plane, it is possible to two-dimensionally move the region with a strong magnetic field. it can. When the center of the position control coil 91 coincides with the center O of the target 11, the magnetic field near the center O becomes the strongest.

For example, when the arc A generated at a position shifted from the center O of the target 11 is moved in the center direction, the center of the position control coil 91 is moved to the center O of the target 11 as shown in FIG. The excitation current is supplied in agreement. As a result, the magnetic field near the center O becomes stronger and the arc A
Moves in the center O direction. Further, by driving the position control coil 91 by the driving device 92 and moving the center thereof two-dimensionally in the xy plane, the distribution of the arc A on the surface of the target 10 can be made uniform. The second
Similarly to the embodiment, a permanent magnet may be provided instead of the position control coil 91, and the permanent magnet may be moved two-dimensionally by the driving device 92.

In the above-described embodiment, the position control coils 70a to 70d, 80, 91 of the arc position control unit 7,
Although the detection coils 60 a to 60 d and the magnetic sensors 90 a to 90 d of the arc position detection unit 6 are provided outside the anode chamber 12, they may be provided inside the anode chamber 12. For example, as shown in FIG. 8, detection coils 60a to 60d and position control coils 70a to 70d are provided below the target 11 in the anode chamber 12. As a result, the detection coils 60a to 60d and the position control coil 7
Since 0a to 70d can be provided close to the target 11, the accuracy of arc position detection and the accuracy of arc position control can be improved.

Since the inside of the anode chamber 12 is in a vacuum state and the outside of the chamber is at atmospheric pressure, the cathode section 10 is provided with a feedthrough 95 for wiring between vacuum and atmospheric pressure. The detection coils 60a to 60d and the position control coils 70a to 70d are connected to a detection circuit 61 and a power supply 71 via a feedthrough 95, respectively.

In principle, the number of the detection coils 60a to 60d and the number of the magnetic sensors 90a to 90d may be two or more, but by increasing these numbers, the arc position can be detected more accurately. Can be.

Further, in the second and third embodiments, the position control coils 80 and 91 are two-dimensionally driven with respect to the target 11.
The target 11 may be moved two-dimensionally with 0 and 91 fixed. In addition, by performing detection and control by an electric circuit, the detection coils 60a to 60d
And the position control coils 70a to 70d.

In the correspondence between the embodiment described above and the elements of the claims, the arc position detecting section 6 is an arc position detecting apparatus, the arc position controlling section 7 is an arc position controlling apparatus, and the position control coils 80 and Reference numeral 91 denotes a magnetic field generation unit, drive devices 81 and 92 each include a position changing device, control device 5 includes an excitation current control unit, toroidal duct 20 includes duct 20, flange 206 includes an inlet, flange 207 includes an outlet, and power supply 17. , Magnetic coil 21 and bias power supply 2
Reference numeral 2 denotes a plasma transfer device.

[0046]

As described above, (1) According to the first aspect of the present invention, the arc position on the target can be accurately recognized by detecting the arc position by the arc position detecting device. (2) According to the second to fourth aspects of the present invention, since the arc position on the target can be controlled by the arc position control device, the distribution of arc generation on the target is made uniform, thereby reducing the consumption of the target surface. It can be uniform. (3) In particular, in the invention of claim 5, since the macroparticles and the like generated at the time of arc discharge are removed by the duct, a high-purity thin film with little contaminants can be formed.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a first embodiment of a film forming apparatus according to the present invention, and is a diagram illustrating a schematic configuration of a film forming apparatus that performs film formation using cathode arc discharge.

FIG. 2 is a diagram showing details of an arc position detector 6 and an arc position controller 7 provided in the plasma film forming apparatus 1.

3A and 3B are diagrams showing the arrangement of detection coils 60a to 60d and position control coils 70a to 70d, where FIG. 3A is a plan view of the detection coils 60a to 60d as viewed from a target 11, and FIG. It is a top view of coils 70a-70d.

4A and 4B are diagrams showing an example of the shape of the toroidal duct 20, wherein FIG. 4A is a plan view as viewed from above the duct, and FIG. 4B is a front view.

FIG. 5 is a cross-sectional view illustrating details of an arc position detection unit 6 and an arc position control unit 7 in the film forming apparatus according to the second embodiment.

6A and 6B are diagrams for explaining arc position control by a position control coil 80, wherein FIG. 6A shows a first control example, and FIG.
Shows a second control example.

FIG. 7 is a view showing a third embodiment of the film forming apparatus according to the present invention, wherein (a) is a cross-sectional view showing a part of the film forming apparatus;
(B) is BB sectional drawing of (a).

FIG. 8 is a cross-sectional view showing a case where detection coils 60a to 60d and position control coils 70a to 70d are arranged in an anode chamber 12.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Plasma generation part 2 Filter part 3 Beam scanning part 4 Film-forming chamber 5 Control device 6 Arc position detection part 7 Arc position control part 10 Anode part 11 Target 12 Anode chamber 13 Arc power supply 14 Trigger 20 Toroidal duct 41 Substrate 60a-60d Detection Coil 70a to 70d, 80, 91 Position control coil 81, 92 Driving device 90a to 90d Magnetic sensor

Claims (5)

[Claims] 1. A film forming apparatus that generates an arc discharge between a target constituting a cathode and an anode to generate a plasma beam containing ions of the target, and irradiates the plasma beam onto a substrate to form a film. 3. The film forming apparatus according to claim 1, further comprising an arc position detecting device that detects a magnetic field generated by the arc discharge and detects a position of the arc on the target. 2. The arc according to claim 1, wherein a magnetic field intensity distribution on the target is changed based on detection information of the arc position detection device to control a position of the arc on the target. A film forming apparatus provided with a position control device. 3. The film forming apparatus according to claim 2, wherein the arc position control device changes a relative position between the target and the magnetic field generating unit that forms a magnetic field on the target. A film forming apparatus comprising: a position changing device. 4. The film forming apparatus according to claim 2, wherein the arc position control device comprises: at least three magnetic coils; a power supply for supplying an exciting current to each of the magnetic coils; A film forming apparatus comprising: an exciting current control unit that controls each of the supplied exciting currents so that a magnetic field in a predetermined area on the target is larger than a magnetic field in another area. 5. The film forming apparatus according to claim 1, wherein a bent duct having an inlet through which plasma generated by arc discharge enters and an outlet through which plasma is emitted to the substrate is provided. And a plasma transfer device for transferring the plasma beam from the inlet to the outlet along the duct by a magnetic force generated by a magnetic coil wound around the duct.