JPH1046324A - Arc ion plating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To rapidly extinguish arc discharge with certainty even if arc discharge occurs between a material to be coated and a vacuum chamber and also to reduce the number of parts by obviating the necessity, e.g. of a device for tripping the high voltage generation part of bias power source. SOLUTION: In the arc ion plating apparatus, a material 8 to be coated in a vacuum chamber 1 is held at negative potential with respect to the vacuum chamber 1 by means of a bias power source 11 and a film of target material is formed on the surface of the material 8 to be coated. At this time, a capacitor 15 is connected in parallel between the output terminals of the bias power source 11, and a coil 16 is connected in series to the capacitor 15, on the opposite side of the bias power source 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an arc ion plating apparatus.

[0002]

2. Description of the Related Art Arc ion plating devices include:
As shown in FIG. 5, the target 32 is mounted on the cathode 31 and
In the vacuum chamber 33, the + side of the output terminal of the bias power supply 34 is connected to the vacuum chamber 33 and the − side is connected to the object 35 to be coated in the vacuum chamber 33. 33, the object 35 to be coated is kept at a negative potential,
In some cases, an arc discharge is generated between an anode 36 and a target 32 in a vacuum chamber 33 to form a film of a target material on the surface of an object 35 to be coated.

However, in this type of arc ion plating apparatus, when the potential of a bias power supply 34 increases in the vacuum chamber 33,
5 and the vacuum chamber 33, an arc discharge occurs,
When this arc discharge occurs, an arc trace remains on the object 35 to be coated (so-called trace of running arc) in proportion to the arc discharge time, and a quality problem (for example, the plating film is easily peeled). Happened.

Therefore, in the conventional arc ion plating apparatus, a switching element 39, a step-up transformer 40, a rectifying / smoothing circuit 41 and a control section 42 are provided in a bias power supply 34 as shown in FIG. The output terminal is connected to the object to be coated 35 and the vacuum chamber 33 via the current detection unit 43, and the object to be coated 35
When an arc discharge occurs between the vacuum chamber 33 and the vacuum chamber 33, the arc current is detected by the current detection unit 43 by utilizing the rapid increase in the current value, and the switching element 39 passes through the control unit 42 by the switching element 39 at the preceding stage of the boosting unit. Cut the power supply,
The method of turning off the arc discharge was adopted. Or, as shown in FIG. A voltage detecting unit 44 is provided in place of the current detecting unit 43. When an arc discharge occurs between the object 35 to be coated and the vacuum chamber 33, the voltage detecting unit 44 utilizes the fact that the voltage value suddenly decreases. And the switching element 39 through the control unit 42 cuts off the power supply at the previous stage of the booster to cut off the arc discharge.

In another conventional arc ion plating apparatus, as shown in FIG.
A step-up transformer 46, a rectifying / smoothing circuit 47, a switching element 48, and a control unit 49 are provided, and the object 35 and the vacuum chamber 33 are connected to the output terminal of the bias power supply 34 via the current detection unit 50 or the voltage detection unit 51. Connected. When an arc discharge occurs between the object to be coated 35 and the vacuum chamber 33, the current or the voltage is detected, and the control unit 49 turns off the switching element 48 at the subsequent stage of the boosting unit, thereby cutting off the power supply. The method of extinguishing arc discharge was adopted.

[0006] As protection in the case of a load short circuit,
As in the case of the above-described conventional example, the voltage sensor of the DC voltage generating unit detects that the absolute value of the output voltage decreases with respect to time, and stops high-voltage generation of the DC high-voltage generating unit. As in the case of the related art, the current sensor of the DC voltage generating unit detects that the absolute value of the output current increases with respect to time and stops the high voltage generation of the DC high voltage generating unit. And JP-A-4-133617.

[0007]

However, in the conventional case,
There were the following problems. That is, in the conventional case of FIG.
The current and the voltage are detected, and the switching element 41 in the preceding stage of the booster is turned off, the power supply is cut off, and the arc discharge is extinguished through the control unit 42. Therefore, the current and voltage detection time + the control unit 42 Feedback time +
Reaction time of the switching element 41 + rectification of the subsequent stage of the booster
The discharge time of the capacitor used for smoothing is added as the delay time from the occurrence of arc discharge, and the detection time is 1 μs, the feedback is 1 μs, the switching element reaction time is 20 to
40 μsec (when using a high-speed switching element of 50 KHz), the discharge time of the rectifying capacitor takes several μsec,
It took about 25 to 45 μsec or more at the earliest.

In the prior art shown in FIG. 6, since the switching element 47 for cutting off the power supply is provided in the latter stage of the booster as compared with the prior art in FIG. 5, the discharge time of the capacitor used for rectification and smoothing in the latter stage of the booster is increased. You don't need to think about the current,
The voltage detection time + the feedback time of the control unit 49 + the reaction time of the switching element 47 is added as a delay time from the occurrence of arc discharge, and the detection time is 1 microsecond, the feedback is 1 microsecond, and the switching element reaction time is 20 to 40 microseconds (50 kHz). High-speed switching element), the discharge time of the rectifying capacitor takes several microseconds,
It took more than 45 μs.

That is, when an arc discharge is generated between the object 35 and the vacuum chamber 33, an arc mark remains on the object 35 (so-called trace of the running arc) in proportion to the arc discharge time, and the quality is reduced. The conventional method (for example, the plating film is easily peeled off) occurs, but the conventional method is to detect the arc discharge by current or voltage and cut off the power supply. Since it takes a long time to extinguish the arc after the occurrence of an arc such as a reaction speed, an arc mark may be left on the object 35 to be coated, which causes a quality problem, and a voltage sensor, a current sensor, In addition, there is a need for a device that trips each of the operation units and the DC high-voltage generation unit, and there is a problem that the number of device parts increases.

SUMMARY OF THE INVENTION In view of the above problems, the present invention can quickly and surely extinguish an arc discharge between an object to be coated and a vacuum chamber even when the arc discharge occurs, and furthermore, a high voltage of a bias power supply. The number of parts can be reduced by eliminating the need for a device for tripping the generator.

[0011]

A first technical means of the present invention for solving this technical problem is that a target 5 is provided on a cathode 3.
And the + side of the output terminal of the bias power supply 11 is connected to the vacuum chamber 1 in the vacuum chamber 1.
By connecting the negative side to the coating object 8 in the vacuum chamber 1, the coating object 8 in the vacuum chamber 1 is maintained at a negative potential with respect to the vacuum chamber 1. In the arc ion plating apparatus in which an arc discharge is generated between the electrodes 5 and a target material film is formed on the surface of the object 8 to be coated, a capacitor 15 is connected in parallel between output terminals of the bias power supply 11. And the coil 16 is connected to the opposite side of the capacitor 15 from the bias power supply 11.
Are connected in series.

A second technical means of the present invention is that a target 5 is mounted on the cathode 3, a positive terminal of the output terminal of the bias power supply 11 is connected to the vacuum chamber 1 and a negative terminal is connected in the vacuum chamber 1. By connecting to the coating object 8 in the vacuum chamber 1, the coating object 8 in the vacuum chamber 1 is maintained at a negative potential with respect to the vacuum chamber 1, and between the anode 2 and the target 5 in the vacuum chamber 1. In the arc ion plating apparatus which generates an arc discharge to form a film of a target material on the surface of the object to be coated 8, the bias power source 1
One point is that a capacitor 15 is connected in parallel between the output terminals of the first and second terminals, and a coil 16 is connected in series between the capacitor 15 and the object 8 to be coated.

A third technical means of the present invention is to mount a target 5 on the cathode 3 and connect the + terminal of the output terminal of the bias power source 11 to the vacuum chamber 1 and the-terminal of the bias power supply 11 in the vacuum chamber 1. By connecting to the coating object 8 in the vacuum chamber 1, the coating object 8 in the vacuum chamber 1 is maintained at a negative potential with respect to the vacuum chamber 1, and between the anode 2 and the target 5 in the vacuum chamber 1. In the arc ion plating apparatus which generates an arc discharge to form a film of a target material on the surface of the object to be coated 8, the bias power source 1
1 in that a capacitor 15 is connected in parallel between the output terminals and a coil 16 is connected in series between the capacitor 15 and the vacuum chamber 1.

Therefore, when an arc discharge occurs between the coating object 8 and the vacuum chamber 1 due to the bias potential in the vacuum chamber 1, the output of the bias power supply 4 and the coil 16 and the capacitor 15 inserted between the vacuum chamber 1 are used. Resonance occurs, and the arc discharge is extinguished in the vacuum chamber 1 by replacing the potential with − / + on the opposite pole side from the ground side.

Thus, even if an arc discharge occurs between the object to be coated 8 and the vacuum chamber 1, the arc can be extinguished at an arbitrary time due to the resonance frequency of the coil 16 and the capacitor 15, and the arc discharge can be prevented. The time until arc extinguishing can be shortened arbitrarily. Since the arc discharge generated between the object to be coated 8 and the vacuum chamber 1 can be extinguished in a short time, the arc mark of the object to be coated 8 is small, and the quality problem (the plating film is easily peeled off) is reduced.

A voltage for detecting arc discharge;
The current detector, the feedback circuit, and the switching element become unnecessary, and the reliability can be improved because the number of components is small.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 1 denotes a metallic vacuum chamber having a pair of anodes 2 and cathodes 3 provided on a wall surface. The anode 2 is connected to the + side of the arc power supply 4, the cathode 3 is connected to the − side of the arc power supply 4, and a target 5 is attached to the cathode 3.

Reference numeral 7 denotes a turntable, which is rotatably provided on the bottom side in the vacuum chamber 1, and on which the object to be coated 8 is placed. Reference numeral 11 denotes a bias power supply, which includes a step-up transformer 12 and a rectifying / smoothing circuit 13. The output terminal of the bias power supply 11 has a positive terminal connected to the vacuum chamber 1 and a negative terminal connected to the turntable 7. Thus, the object 8 to be coated in the vacuum chamber 1 is maintained at a negative potential with respect to the vacuum chamber 1, and an arc discharge is generated between the anode 2 and the target 5 in the vacuum chamber 1, so that the object 8 to be coated is A film of the target material is formed on the surface.

A capacitor 15 is connected in parallel between the output terminals of the bias power supply 11, and a coil 16 is connected in series between the capacitor 15 and the object 8 to be coated. According to the above-described embodiment, when an arc discharge occurs between the object 8 to be coated and the vacuum chamber 1 in the vacuum chamber 1 due to the potential applied from the bias power supply 11, the chamber 1 and the object at the time of the arc discharge occur. The equivalent circuit of the coating 8, the capacitor 15 and the coil 16 is as shown in FIG.
6 and the capacitor 15, the resonance frequency f ₀ = 1 / 2π√
(LC) resonance occurs, and the potential is switched between the coating object 8 and the vacuum chamber 1 by the above-described resonance (the potential of the coating object 8 and the vacuum chamber 1 −
/ + Is replaced). During the arc discharge, the electric potential (+,
When-is exchanged, there is a point where the arc discharge current becomes 0 (point P in FIG. 3), and the arc discharge is cut off (arc discharge extinguishing).

In FIG. 3, a so-called arc discharge time t from point Q at which arc discharge occurs to point P at which arc extinction occurs.
_arc is t _arc = １ ／ f ₀ + f (i ₀ ), f ₀ = １ ／ πsp
rt (LC), and t _arc can be arbitrarily determined by L, C and i ₀ . Thus, when an arc discharge occurs between the coating object 8 and the vacuum chamber 1, the coil 1
6 and the resonance frequency of the capacitor 15, the arc can be extinguished at an arbitrary time, and the arc discharge time t _arc from arc generation to arc extinguishing can be arbitrarily shortened.

Therefore, the arc discharge generated between the object to be coated 8 and the vacuum chamber 1 can be extinguished in a short time, so that the trace of the arc of the object to be coated 8 is small and a quality problem (the plating film is easily peeled off). Is alleviated. Actually, although it depends on the degree of vacuum in the vacuum chamber 1 and the number of particles, a time (t _{off in} FIG. 4) during which the electrode is at the opposite potential to that during the arc discharge requires several μsec. This t
_{When off} is small, arc discharge occurs again at point R. The reason that arc discharge occurs again is that ionization occurs due to discharge between the electrodes in the direction that was applied when the arc discharge occurred, and even if the discharge was stopped momentarily, the ionization state where discharge easily occurs was maintained. Occur.

To prevent this re-discharge, the vacuum chamber 1
Although it depends on the degree of vacuum, the number and type of particles, and the shape of the electrode, it is necessary to stop the discharge for several μsec. In the arc ion plating apparatus of the present embodiment, the time t _off is set to 5 to 20 μsec. FIG. 4 shows another embodiment, in which the output terminal of the bias power supply 11
Capacitor 15 is connected in parallel and capacitor 1
A coil 16 is connected in series between an object 5 and an object 8 to be coated. The other points are the same as those of the above-described embodiment. As in the case of the above-described embodiment, the arc discharge generated between the object 8 and the vacuum chamber 1 can be extinguished in a short time. And the quality problem (the plating film is easily peeled off) can be mitigated.

[0023]

According to the present invention, when an arc discharge occurs between the workpiece 8 and the vacuum chamber 1 due to the bias potential of the bias power supply 11 in the vacuum chamber 1, the output of the bias power supply 11 and the vacuum chamber 1
Resonance occurs between the coil 16 and the capacitor 15 interposed therebetween, and the polarity is switched between the coating object 8 and the vacuum chamber 1, so that the arc discharge cannot be sustained, and the arc discharge can be quickly and reliably extinguished. it can.

This eliminates the need for a voltage sensor and a current sensor for load short-circuit and arc discharge protection, and eliminates the need for a device for detecting a load short-circuit (or arc discharge) current and for tripping each arithmetic unit and DC high voltage generating unit. Thus, the number of device parts is reduced, the time involved in the calculation is eliminated, and there is no delay from the load short-circuit (or arc discharge) to the trip of the DC high-voltage generator. Further, an arithmetic element and a switching element become unnecessary, and the possibility of malfunction due to noise is eliminated.

Further, even if an arc discharge occurs between the coating object 8 and the vacuum chamber 1, the resonance frequency can be arbitrarily changed by changing the inductance value of the coil 16 and the capacity of the capacitor 15, so that an arbitrary time can be obtained. Can extinguish the arc, and the time from arc generation to arc extinguishing can be shortened arbitrarily. Since the arc discharge generated between the workpiece 8 and the vacuum chamber 1 can be set arbitrarily, in arc ion plating which requires extinction in a short time, the arc mark on the workpiece 8 is small, and quality problems ( (The plating film is easily peeled off).

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is an equivalent circuit diagram for explaining the operation.

FIG. 3 is a current waveform diagram for explaining the operation.

FIG. 4 is a configuration diagram showing another embodiment.

FIG. 5 is a configuration diagram showing a conventional example.

FIG. 6 is a configuration diagram showing another conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Chamber 2 Anode 3 Cathode 5 Target 8 Coating object 11 Bias power supply 15 Capacitor 16 Coil

Claims (3)

[Claims] 1. A target (5) is mounted on a cathode (3), and a bias power supply (11) is set in a vacuum chamber (1).
Is connected to the vacuum chamber (1) and the-side of the output terminal is connected to the coating object (8) in the vacuum chamber (1), so that the vacuum chamber (1) is connected.
The object to be coated (8) in the vacuum chamber (1) is maintained at a negative potential with respect to
An arc ion plating apparatus wherein an arc discharge is generated between an anode (2) and a target (5) to form a film of a target material on the surface of an object to be coated (8). A capacitor (15) is connected in parallel between the output terminals of the
An arc ion plating apparatus characterized in that a coil (16) is connected in series on the side opposite to the bias power supply (11). 2. A target (5) is mounted on a cathode (3), and a bias power supply (11) is set in a vacuum chamber (1).
Is connected to the vacuum chamber (1) and the-side of the output terminal is connected to the coating object (8) in the vacuum chamber (1), so that the vacuum chamber (1) is connected.
The object to be coated (8) in the vacuum chamber (1) is maintained at a negative potential with respect to
An arc ion plating apparatus wherein an arc discharge is generated between an anode (2) and a target (5) to form a film of a target material on the surface of an object to be coated (8). A capacitor (15) is connected in parallel between the output terminals of the
An arc ion plating apparatus comprising: a coil (16) connected in series between a coil and an object to be coated (8). 3. A target (5) is mounted on a cathode (3), and a bias power supply (11) is set in a vacuum chamber (1).
Is connected to the vacuum chamber (1) and the-side of the output terminal is connected to the coating object (8) in the vacuum chamber (1), so that the vacuum chamber (1) is connected.
The object to be coated (8) in the vacuum chamber (1) is maintained at a negative potential with respect to
An arc ion plating apparatus wherein an arc discharge is generated between an anode (2) and a target (5) to form a film of a target material on the surface of an object to be coated (8). A capacitor (15) is connected in parallel between the output terminals of the
An arc ion plating apparatus comprising: a coil (16) connected in series between a vacuum chamber (1) and a vacuum chamber (1).