JP4257770B2 - Arc interruption circuit, power supply for sputtering and sputtering equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an arc interruption circuit, a sputtering power source, and a sputtering apparatus, and more particularly to an arc interruption circuit that stops a forward current and applies a voltage in the reverse direction to interrupt arc discharge, and for sputtering using the same The present invention relates to a power source and a sputtering apparatus.
[0002]
[Prior art]
In various plasma application devices, high voltage devices, power switching devices, etc., when arc discharge occurs, the operation of the devices is adversely affected. For this reason, a circuit that reliably and quickly interrupts arc discharge is often required. Hereinafter, as a specific example, a sputtering apparatus used for forming a thin film will be described as an example.
[0003]
FIG. 12 is a schematic diagram illustrating a configuration of a main part of a DC (direct current) sputtering apparatus. This sputtering apparatus has a vacuum chamber 101 and a DC power source 110 for sputtering. The anode of the power supply 110 is connected to the chamber 101 via the connection cable 120A and is set to the ground potential. On the other hand, the cathode of the power source 110 is connected to the sputtering target 104 provided inside the chamber 101 via the connection cable 120B. A substrate 100 on which a thin film is deposited is placed inside the chamber 101.
[0004]
In film formation, first, the inside of the chamber 101 is evacuated by the evacuation pump 106 and a discharge gas such as argon (Ar) is introduced from the gas supply source 107 to maintain the inside of the chamber at a predetermined discharge pressure. Then, an electric field is applied between the target 104 and the chamber 101 by the power source 110 to generate a glow discharge 108. Then, positive ions in the plasma generated in the discharge space collide with the surface of the target 104 and eject atoms of the target 104. By utilizing such a sputtering phenomenon, a thin film made of the material of the target 104 can be formed on the substrate 100.
[0005]
However, arc discharge 150 may occur during such sputtering operation. Such arc discharge 150 occurs relatively near the target 104, but may occur near the substrate 100. When such an arc discharge 150 occurs, a large current flows locally, causing damage to the target 104 and the substrate 100.
[0006]
For example, when the arc discharge 150 is generated on the target 104 side, a large current is concentrated in a minute region of the target 104, and a large amount of deposition material is instantaneously discharged from that portion. This phenomenon is referred to as “splash” and the like, and particles of the deposition material are scattered on the surface of the substrate 100, which causes damage.
[0007]
On the other hand, when the arc discharge 150 occurs on the substrate 100 side, the substrate 100 is often damaged and becomes defective.
[0008]
[Problems to be solved by the invention]
The present invention has been made on the basis of recognition of such problems, and an object of the present invention is to provide an arc interruption circuit capable of interrupting arc discharge quickly and reliably, and a sputtering power source and a sputtering apparatus using the arc interruption circuit. is there.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the first arc interrupting circuit of the present invention detects the occurrence of arc discharge in the supplied object to which a positive voltage is applied, and supplies the positive voltage to the supplied object. An arc breaking circuit to stop,
The voltage in the positive direction in the supplied object is divided by a voltage detection resistor and a constant current circuit,
The occurrence of the arc discharge is detected by a decrease in the absolute value of the voltage of the constant current circuit.
[0010]
According to the said structure, generation | occurrence | production of arc discharge can be detected very rapidly and arc interruption | blocking operation | movement can be started.
[0011]
In the second arc interrupt circuit, the current in the constant current circuit may correspond to a current flowing through the voltage detection resistor when the arc discharge occurs in the supply target.
[0012]
Further, a current amplifier for amplifying a current flowing through the voltage detection resistor may be further provided, and the current amplifier and the constant current circuit may be connected.
[0013]
In addition, when the absolute value of the positive voltage to the supply body exceeds a predetermined value, the supply of the positive voltage can be stopped.
[0014]
In addition, when the current flowing through the supply target is observed and the current is less than a predetermined value, the supply of the positive voltage is not stopped even if the absolute value of the voltage of the constant current circuit is reduced. It can be.
[0015]
On the other hand, when the second arc interrupting circuit of the present invention detects the occurrence of arc discharge in the supplied object to which a positive voltage is applied, Output reverse voltage An arc breaking circuit for performing an arc breaking operation,
When the value of the current flowing through the supplied object is larger than a predetermined current threshold value and the voltage at the supplied object is smaller than a predetermined voltage threshold value, the arc interruption operation is performed.
For a predetermined first time after the start of the arc interrupting operation, the arc interrupting operation is continued regardless of the value of the current flowing through the supplied object and the voltage at the supplied object.
The predetermined second time after the first time has elapsed is Even when the voltage at the supply target is the voltage threshold The same current as before the arc interrupting operation is started without starting the arc interrupting operation is output to the supplied object.
[0016]
According to the above configuration, the occurrence of arc discharge can be reliably detected under any circumstances without depending on the state in the chamber.
[0017]
In the second arc interruption circuit, if the arc interruption operation is continued for a predetermined time after the arc interruption operation is started, regardless of the value of the current flowing through the supplied object and the voltage of the supplied object. As long as there is a current and an arc damage is expected even after the inverter of the power supply is stopped, the arc can be interrupted without restriction of the duration.
[0018]
Further, if the voltage threshold is made variable according to the current flowing through the supply target, the arc can be detected and interrupted with the voltage corrected by the discharge current even if the arc discharge voltage increases due to the sputtering characteristics.
In addition, when an interlock signal that prohibits the operation of the power supply that applies the positive voltage is applied, the arc interrupting operation is performed. start If not, it is possible to ensure safety during emergency stop or maintenance.
[0025]
On the other hand, the power source for sputtering of the present invention is a power source for sputtering that forms a thin film by sputtering a target, and applies a positive voltage for applying the positive voltage in any one of the above arc interrupting circuits. Means.
[0028]
On the other hand, the sputtering apparatus of the present invention includes a vacuum chamber capable of maintaining an atmosphere reduced in pressure from atmospheric pressure, and any one of the above-described sputtering power sources,
Sputtering is performed by the positive voltage applied from the positive voltage application means, and the arc discharge generated in the vacuum chamber is cut off by the arc cut-off circuit.
[0029]
According to the above configuration, it is possible to quickly and surely interrupt arc discharge, and to perform sputter deposition with high throughput and good yield.
[0030]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0031]
(First embodiment)
First, as a first embodiment of the present invention, when an arc discharge occurs, the power supply to the chamber is stopped, and a reverse voltage is applied at a high speed within a range in which no discharge occurs in the chamber. The arc interruption circuit to be erased will be described.
[0032]
Here, before describing the arc breaker circuit according to the present embodiment, a description will be given of an arc breaker circuit of a comparative example that the inventors have made as a prototype in the process leading to the present invention.
[0033]
FIG. 2 is a schematic diagram showing a sputtering apparatus provided with an arc interruption circuit of a comparative example.
[0034]
That is, the sputtering apparatus includes a sputtering vacuum chamber 101, a target 104, and a power source connected to them. This power supply includes a DC power supply unit DCPF, a smoothing inductor L0, a reverse bias application circuit RBS, a switching unit Q, and an arc detection circuit (arc sensor) AS.
[0035]
The DC power source DCPF has a role of causing sputtering by applying positive power to the chamber 101 and negative power to the target 104.
[0036]
On the other hand, the reverse bias application circuit RBS has a role of applying a reverse polarity voltage to the chamber 101 and the target 104 when the arc discharge occurs, and interrupting the arc current at high speed. That is, the reverse bias application circuit RBS includes a reverse bias power supply unit DCPR having a polarity opposite to that of the DC power supply unit DCPF, and a capacitor C1 connected in parallel thereto.
[0037]
On the other hand, the arc detection circuit AS has a role of monitoring the occurrence of arc discharge in the chamber from the discharge voltage or current in the chamber and controlling the operation of the switching unit Q.
[0038]
The switching unit Q performs switching of the output of the reverse bias application circuit RBS based on the control signal from the arc detection circuit AS.
[0039]
The operation of the power source of the comparative example shown in FIG. 2 will be described as follows.
[0040]
That is, during normal sputter deposition, the switch unit Q is in an OFF state, and the output current from the DC power supply unit DCPF is sent to the chamber 101 and the target 104 via the output diode D0 and the power transmission cables 120A and 120B. Supplied. At this time, the output from the reverse bias power source DCPR is charged by applying a reverse voltage to the capacitor C1.
[0041]
When the arc detection circuit AS detects a decrease in output voltage (or an increase in current) during sputtering film formation, it recognizes that arc discharge has occurred and starts an arc interrupting operation.
[0042]
Hereinafter, the arc breaking operation will be described.
[0043]
When the arc detection circuit AS detects arc discharge, first, the output of the DC power supply unit DCPF is stopped. Then, the switching unit Q is turned on. Then, the output current from the DC power supply unit DCPF is held by the inductor L0, but since the switching unit Q forms a current bypass, it is not output outside the power source, that is, to the chamber 101 and the target 104.
[0044]
At the same time, the reverse voltage charged in the capacitor C1 is output from the switching unit Q to the chamber via the cables 120A and 120B.
[0045]
When no current flows through the power transmission cable, the output diode D0 is reverse-biased. A reverse current from the reverse bias power source DCPR flows through the output limiting resistor Rpass, and the arc discharge is interrupted by biasing the chamber to a reverse voltage.
[0046]
When the arc interruption is finished, the switching unit Q is turned off, and the output of the DC power supply unit DCPF is resumed.
[0047]
The current of the inductor L0 is supplied to the chamber through the DC power supply unit DCPF. At this time, the sputtering current bypasses the output limiting resistor Rpass and flows through the output diode D0.
[0048]
However, in the case of this comparative example, the capacitor C1 is discharged every time the arc breaking operation is performed, but it is necessary to set the capacitance high so that the reverse voltage can be maintained even in the continuous breaking operation.
[0049]
Further, in the case of the circuit of FIG. 2, since a large current of the inductor L0 passes through the capacitor C1, if the integration of the arc interruption time becomes long, the reverse voltage disappears due to the discharge even if the capacitance of the capacitor C1 is increased. End up. When the reverse voltage disappears, the arc breaking performance decreases.
[0050]
When the arc cut-off operation ends, the sputtering power supply to the chamber is resumed. However, since the current of the inductor L0 rises due to the voltage of the capacitor C1 during the arc cut-off, the chamber current becomes larger than before the cut-off. Here, since the chamber voltage is substantially constant, if the current is larger than before the shut-off operation, the power is excessively supplied, and the arc discharge is likely to reoccur.
[0051]
In order to improve these points, the present inventor has invented the arc breaking circuit of the present embodiment.
[0052]
FIG. 1 is a schematic diagram showing a main part of a sputtering apparatus provided with an arc interruption circuit according to this embodiment.
[0053]
That is, this sputtering apparatus also includes a sputtering vacuum chamber 101, a target 104, and a power source connected to them. This power supply includes a DC power supply unit DCPF, a smoothing inductor L0, a reverse bias application circuit RBS, a switching unit Q, and an arc detection circuit (arc sensor) AS.
[0054]
In the case of the present invention, the reverse bias application circuit RBS has a reverse bias power supply unit DCPR and a capacitor C1 connected thereto in parallel via an inductor L3. A series circuit of a diode D3 and a Zener diode ZD is connected in parallel to the capacitor C1.
[0055]
The operation of the specific example illustrated in FIG. 1 will be described as follows.
[0056]
That is, during normal sputter deposition, the switch unit Q is in an OFF state, and the output current from the DC power supply unit DCPF is sent to the chamber 101 and the target 104 via the output diode D0 and the power transmission cables 120A and 120B. Supplied. At this time, the output from the reverse bias power supply unit DCPR is charged by applying a reverse voltage to the capacitor C1 via the inductor L3.
[0057]
When the arc detection circuit AS detects a decrease in output voltage (or an increase in current) during sputtering film formation, it recognizes that arc discharge has occurred and starts an arc interrupting operation.
[0058]
Hereinafter, the arc breaking operation will be described.
[0059]
When the arc detection circuit AS detects arc discharge, first, the output of the DC power supply unit DCPF is stopped. Then, the switching unit Q is turned on. Then, the output current from the DC power supply unit DCPF is held by the inductor L0, but since the switching unit Q forms a current bypass, it is not output outside the power source, that is, to the chamber 101 and the target 104.
[0060]
At the same time, the reverse voltage charged in the capacitor C1 is output from the switching unit Q to the chamber via the cables 120A and 120B.
[0061]
When no current flows through the power transmission cable, the output diode D0 is reverse-biased. Then, a reverse current from the reverse bias power supply unit DCPR flows through the output limiting resistor Rpass to bias the chamber to a reverse voltage. At this time, if the output impedance of the reverse bias power source DCPR is small, a large amount of current flows in the direction opposite to that during sputtering, which may cause new arc discharge. For this reason, the reverse current is limited by the output limiting resistor Rpass.
[0062]
Capacitor C1 completes discharging by passing the current through inductor L0 after the application of the reverse bias is completed. This eliminates the voltage source that increases the current in the closed loop of the inductor current.
[0063]
During the remaining cutoff period, the current of the inductor L0 charges L3 via the reverse bias power supply unit DCPR.
[0064]
Following the arc interrupting operation described above, an operation for returning to the sputter film forming operation will be described below.
[0065]
When the arc interruption is finished, the switching unit Q is turned off, and the output of the DC power supply unit DCPF is resumed.
[0066]
The current of the inductor L0 is supplied to the chamber through the DC power supply unit DCPF. At this time, the sputtering current bypasses the output limiting resistor Rpass and flows through the output diode D0. At the same time, the current in the inductor L3 charges the capacitor C1, and when the current disappears, the reverse bias power supply unit DCPR becomes reverse bias and stops without resonating.
[0067]
If the charging voltage of the capacitor C1 is insufficient, the capacitor C1 is charged by the reverse bias power supply unit DCPR. On the other hand, when the charging voltage of the capacitor C1 is too high, it is bypassed by the Zener diode ZD to prevent overcharging.
[0068]
As described above, according to the arc breaker circuit of the present embodiment, by providing the inductor L3, there is an effect that the capacitor C1 can be charged quickly and accurately to a predetermined reverse voltage. As a result, even when arc discharge is repeated, it can be erased reliably, and furthermore, excessive power supply after resuming sputtering can be prevented.
[0069]
That is, according to the present invention, as described above with reference to FIG. 1, the capacitance of the capacitor C1 can be set small, and rapid charge / discharge can be repeated each time the arc is interrupted. As a result, in the reverse bias power supply unit DCPR, the capacitor voltage of the reverse voltage source can be eliminated if the chamber voltage is reverse biased at the start of the arc cutoff operation.
[0070]
Further, part of the current energy of the inductor L0 can be distributed to the other inductor L3 during the arc breaking operation.
[0071]
At the end of the arc interrupting operation, the capacitor C1 serving as a reverse voltage source can be charged by the current energy distributed to the inductor L3. When the charging voltage is too high, the charging current of the capacitor C1 can be bypassed by the Zener diode ZD.
[0072]
That is, according to the present embodiment, the voltage of the capacitor C1 serving as the reverse voltage source disappears after the chamber is reverse-biased during the arc breaking operation. Therefore, the current increase in the inductor L0 due to the reverse voltage source is reduced, and the reoccurrence of arc discharge due to excessive supply of power after resuming sputtering can be prevented.
[0073]
Further, according to the present embodiment, when the arc interruption operation is completed, the capacitor C1 is rapidly charged by the inductor L3 regardless of the inverter operation. Therefore, even when the capacitance of the capacitor C1 is set small and arc interruption is repeated by continuous arc discharge, the voltage drop of the capacitor C1 serving as a reverse voltage source is reduced.
[0074]
FIG. 3 is a schematic diagram showing a specific example of a power source for sputtering equipped with an arc breaker circuit according to an embodiment of the present invention.
[0075]
That is, this figure shows a system in which a sputtering DC power supply 110 with a built-in arc interruption function, power transmission cables 120A and 120B, and a chamber 101 are combined. However, the constant power operation of the power source 110 and the control unit of the inverter circuit are omitted as appropriate.
[0076]
In this specific example, the DC power supply unit DCPF includes a rectifier diode group DB0 that receives a three-phase AC input of R, S, and T, a switching transistor IGBT, a transformer T1, and rectifier diode groups DB1 and DB2. However, the DC power supply unit DCPF in the present invention can similarly adopt various configurations in addition to the configuration illustrated in FIG.
[0077]
The output from the DC power supply unit DCPF is supplied to the chamber via the arc cutoff circuit and the power transmission cables 120A and 120B.
[0078]
The arc cut-off circuit monitors the output voltage (or output current) from the power supply and detects arc discharge by voltage drop (or current increase), and N4 winding is added to the transformer T1 of the inverter. Capacitor C1 as a reverse voltage source rectified and smoothed by diode group DB3 and inductor L3, and a transistor (Q1, Q2) that cuts off the current output by providing a detour in the output current and outputs the reverse voltage source (capacitor C1) And diodes (D1, D2) that output a forward current during sputtering film formation, and an output limiting resistor (Rpass) that controls the reverse current to be supplied to the chamber when the arc is interrupted.
[0079]
The operation of the sputtering power source 110 of this specific example will be described as follows.
[0080]
First, the operation during sputtering film formation will be described. At the time of sputtering film formation, the output from the inverter (DB0, IGBT, T1) is rectified and smoothed by the diode group (DB1, DB2) and the smoothing inductor (L1, L2), and the power transmission cable 120A and the diode (D1, D2) are connected. Output via 120B. At this time, the polarity of the chamber 101 is positive and the polarity of the target 104 is negative.
[0081]
Further, during this sputtering operation, the reverse voltage obtained by rectifying and smoothing the output of the N4 winding of the inverter by the diode group (DB3) is charged in the capacitor (C1).
[0082]
On the other hand, when an arc discharge occurs and the arc detection circuit AS detects a decrease in output voltage (or an increase in output current), it recognizes the arc discharge and starts an arc breaking operation.
[0083]
Hereinafter, the arc interruption operation of the power source for sputtering of this specific example will be described.
[0084]
First, when the arc detection circuit AS detects arc discharge, the operation of the switching transistor (IGBT) of the inverter is stopped, and the transistors (Q1, Q2) are turned on. At this time, the output current from the positive DC power supply unit is held for a predetermined time by the inductors (L1, L2), but is not output to the chamber because the transistors (Q1, Q2) form a bypass.
[0085]
At the same time, the reverse voltage charged in the capacitor (C1) is transferred from the transistors (Q1, Q2) through the parallel circuit of the diodes (D1, D2) and the output limiting resistor (Rpass) to the cable (120A , 120B).
[0086]
However, since the cables (120A, 120B) and the chamber have parasitic inductance, it takes time for the forward current to disappear even if the reverse voltage is output. Since the positive current during this period flows through the diodes (D1, D2), the capacitor (Cpass) is not charged. When the forward current of the cable due to parasitic inductance or the like disappears, the backward current becomes dominant, and the diodes (D1, D2) are reverse-biased. Then, a reverse current is supplied to the chamber via the output limiting resistor (Rpass).
[0087]
When the application of the reverse bias to the chamber ends, the capacitor C1 completes the discharge by passing the current through the inductors L1 and L2. As a result, there is no voltage source in the closed loop of the inductor current that increases the sputtering current after resuming sputtering.
[0088]
In the remaining cutoff period, the current of the inductors L1 and L2 distributes current energy to the inductor L3 through the diode group DB3.
[0089]
Thereafter, the film forming operation is resumed. That is, when the arc interruption is completed, the transistors Q1 and Q2 are turned off, and the inverter of the DC power supply unit DCPF resumes its operation. The currents of the inductors L1 and L2 are supplied to the chamber through the DC power supply unit DCPF.
[0090]
At the same time, the current in the inductor L3 charges the capacitor C1, and when the current disappears, the diode group DB3 is reverse-biased and stops without resonance. When the charging voltage of the capacitor C1 is insufficient, the capacitor C1 is charged through the diode group DB3 from the N4 connection of the transformer T1 of the DC power supply unit DCPF. On the other hand, when the charging voltage of the capacitor C1 is too high, overcharge can be prevented by bypassing the Zener diode ZD as described above.
[0091]
As described above, according to the present embodiment, the voltage of the capacitor C1 serving as a reverse voltage source disappears after the chamber is reverse-biased during the arc breaking operation. Therefore, the current increase in the inductor L0 due to the reverse voltage source is reduced, and the reoccurrence of arc discharge due to excessive supply of power after resuming sputtering can be prevented.
[0092]
Further, according to the present embodiment, when the arc interruption operation is completed, the capacitor C1 is rapidly charged by the inductor L3 regardless of the inverter operation. Therefore, even when the capacitance of the capacitor C1 is set small and arc interruption is repeated by continuous arc discharge, the voltage drop of the capacitor C1 serving as a reverse voltage source is reduced.
[0093]
(Second Embodiment)
Next, as a second embodiment of the present invention, an arc interrupt circuit capable of detecting the occurrence of arc discharge at an extremely high speed and starting an arc interrupt operation will be described.
[0094]
Also here, first, before describing the arc breaker circuit of the present embodiment, a description will be given of an arc breaker circuit of a comparative example that was experimentally manufactured by the inventor in the process leading to the present invention.
[0095]
FIG. 5 is a schematic diagram showing a sputtering apparatus provided with an arc interruption circuit of a comparative example.
[0096]
That is, the sputtering apparatus includes a sputtering vacuum chamber 101, a target 104, and a power source connected to them. This power supply includes a DC power supply unit DCPF, a smoothing inductor L0, a reverse bias application circuit (not shown), a switching unit IGBT, and an arc detection circuit (arc sensor) AS.
[0097]
Now, in film formation by normal sputtering, the voltage at the target 104 is minus 400 volts or less (for example, minus 600 volts). However, when arc discharge occurs, the absolute value of the target voltage decreases to minus 150 volts or more (for example, minus 100 volts).
[0098]
In the case of the power source of the comparative example shown in FIG. 5, the discharge voltage during sputtering film formation is divided at a constant ratio by the detection resistor RD and input to the voltage comparator (comparator) CP as the detection voltage (2).
[0099]
On the other hand, as a reference voltage (3), a constant voltage obtained by compressing minus 150 volts, for example, at the same ratio as the detection resistor RD is input to the comparator CP, and compared with the detection voltage (2) from the chamber. When the detection voltage (2) is smaller than the reference voltage (3), it is recognized as arc discharge, and the driver DR of the switching unit IGBT is turned on. The IGBT driver DR amplifies the signal from the comparator CP and drives (ON) the IGBT.
[0100]
When the IGBT is turned on, the DC power supply unit DCPF is short-circuited via the inductor L0, so that the output current to the chamber is cut off.
[0101]
When the predetermined shut-off time ends, the switching unit IGBT is turned off (OFF), and the current supply to the chamber is resumed.
[0102]
Here, the state in which the absolute value of the target voltage is decreased due to the occurrence of arc discharge until the absolute value of the sputtering voltage is increased before the inverter (not shown) constituting the DC power supply unit DCPF is started. There is a need. Therefore, the state of the inverter is distinguished by the operation signal of the inverter of the DC power supply unit DCPF, and when the inverter is stopped, the operation is not shifted to the output cutoff operation.
[0103]
In general, in order to reduce damage caused by arc discharge, it is important to satisfy the following three points.
(1) When arc discharge occurs, the power supply to the chamber is promptly stopped.
(2) Wait for the hot spot that is the source of thermionic emission to cool.
(3) Make the cooling time as short as possible.
[0104]
If the arc discharge continues, the power supply from the power source to the chamber continues, so that the arc discharge is enhanced and the damage is expanded.
[0105]
However, in the case of the power source of the comparative example as illustrated in FIG. 5, there is room for further improvement in the time from when the detection voltage (2) input to the comparator CP changes until the input of the IGBT driver DR changes. was there.
[0106]
On the other hand, if the resistance value of the detection resistor RD is reduced in order to improve the signal delay due to the input capacitance of the comparator CP, there arises a problem that the power loss in the detection resistor increases.
[0107]
Further, in the case of the comparative example of FIG. 5, if the control of the DC power supply unit DCPF is irregular and there is a period during which the inverter does not operate even during sputtering, there is also a phenomenon that the interruption operation is not performed even if arc discharge occurs during this period. It was.
[0108]
Further, when a delay occurs in the detection of the arc, the glow discharge in the chamber may be attenuated when the sputtering operation is output to the chamber after the arc interruption operation is finished. Then, the output voltage becomes excessive due to the counter electromotive force of the inductor L0, the stress on the components constituting the power supply increases, and it may be damaged in some cases.
[0109]
In view of these points, the present inventor has invented the arc breaking circuit of the present embodiment.
[0110]
FIG. 4 is a schematic diagram showing a sputtering apparatus provided with the arc interruption circuit of the present embodiment.
[0111]
That is, the power supply of this example includes a DC power supply unit DCPF that supplies sputtering power to the chamber, a smoothing inductor L0, a reverse bias power supply unit DCPR, a switching unit IGBT, and an arc detection circuit AS.
[0112]
The arc detection circuit AS includes a voltage detection resistor RD, a current amplifier CA, a current monitoring unit CM, a constant current circuit CC, an overvoltage control unit OL, an IGBT drive circuit DR, and a timer TM.
[0113]
The characteristics of the power supply of this embodiment are listed as follows.
[0114]
That is, first, the comparator CP for voltage comparison as illustrated in FIG. 5 is reduced, and the IGBT drive circuit DR is directly turned on / off (ON / OFF) by the voltage detection resistor RD.
[0115]
Further, the current of the voltage detection resistor RD is amplified by the current amplifier CA.
[0116]
When the output voltage to the chamber is excessive, the switching unit IGBT is turned on (ON) for a certain period of time as in the case of arc interruption.
[0117]
Further, whether or not the arc can be interrupted is determined by the current of the inductor L0.
[0118]
These features will be described below with a more specific configuration.
[0119]
First, the voltage detection resistor RD and the constant current circuit CC are connected in series between the output lines of the arc breaker, and the connection midpoint between the voltage detection resistor RD and the constant current circuit CC is connected to the input of the IGBT drive circuit DR. The input voltage of the IGBT drive circuit DR is the output voltage of the constant current circuit CC. The IGBT drive circuit DR turns on the switching unit IGBT when the input voltage decreases (when it approaches 0 volts). Then, the IGBT turned on is turned off after a predetermined time.
[0120]
On the other hand, the current value of the constant current circuit CC can be a current flowing through the voltage detection resistor RD at the maximum output voltage (for example, minus 150 volts) during arc discharge. Furthermore, when the chamber voltage greatly fluctuates due to the chamber current, the current value of the constant current circuit CC is compensated by the chamber current.
[0121]
In order to increase the response speed, the current of the voltage detection resistor RD is amplified by the current amplifier CA and connected to the constant current circuit CC.
[0122]
Further, when the chamber voltage exceeds a predetermined value, the current to the constant current circuit CC is bypassed to reduce the voltage drop. As a result, the IGBT can be turned on for a predetermined time. It is also possible to protect the input to the IGBT drive circuit DR from exceeding the allowable value even if the chamber voltage is excessive.
[0123]
On the other hand, when the current of the inductor L0 is, for example, 1% or less of the rating, it is determined as “undischarged” and the arc breaking operation is prohibited.
[0124]
Hereinafter, the operation of the power source illustrated in FIG. 4 will be described.
[0125]
First, the operation at the time of starting the power supply will be described.
[0126]
After the inverter (not shown) of the DC power supply unit DCPF is started up, the output voltage from the power supply rises, but during this period, discharge has not yet started and arc discharge does not occur. In this state, the output current from the power supply does not flow, so the comparator CP of the current monitoring circuit CM is turned on. Then, the output of the constant current circuit CC is forced to a high level (high level), and the arc interruption does not operate.
[0127]
Next, the operation at the time of sputtering film formation will be described.
[0128]
When the output voltage rises and glow discharge starts, a current flows from the power source to the chamber via the power transmission cable. Then, the comparator CP of the current monitoring circuit CM is turned off, so that the constant current circuit CC is enabled and the arc discharge is monitored.
[0129]
At this time, under many sputtering conditions, the output voltage from the power source is minus 200 V to minus 800 V, and a voltage is applied between the output lines of the power source.
[0130]
Although a larger current tends to flow through the voltage detection resistor RD than at the time of arc discharge, the constant current circuit CC limits, so that the junction potential is kept high. Therefore, the input voltage of the IGBT drive circuit DR becomes high, and the switching unit IGBT is kept off (OFF).
[0131]
Next, the arc interruption operation will be described.
[0132]
When arc discharge occurs, the absolute value of the voltage applied to the chamber decreases from 0V to minus 100V. When this voltage drop is transmitted to the arc breaking circuit, the current of the voltage detection resistor RD is lowered. On the other hand, since the output current of the constant current circuit CC is constant, the output voltage, that is, the input voltage of the IGBT drive circuit DR drops. Even if the current of the voltage detection resistor RD is amplified by the current amplifier circuit CA and connected to the constant current circuit CC, the same operation is performed because the amplification factor is constant.
[0133]
When the input voltage of the IGBT drive circuit DR decreases, the switching unit IGBT is turned on (ON), the output from the DC power supply unit DCPF is cut off, and the reverse voltage from the reverse bias power supply unit DCPR is supplied to the chamber.
[0134]
The timer circuit TM outputs a pause signal to the constant current circuit CC when a predetermined time has elapsed after the signal for turning on the switching unit IGBT is input from the drive circuit DR. Since the output of the constant current circuit CC to which the pause signal is input becomes high, the IGBT drive circuit DR is turned off.
[0135]
The output time of the pause signal is constant in the timer circuit TM, and during that period, the interruption operation is paused regardless of the presence or absence of arc discharge. When the pause is completed, the voltage drop monitoring is resumed, and when the arc discharge is recognized, the output of the DC power supply unit DCPF is shut off again. On the other hand, if the output voltage is restored, the arc is not interrupted.
[0136]
If there is neither arc discharge nor glow discharge when the arc interruption is stopped, the output voltage from the power supply rises rapidly. Therefore, in this case, measures to prevent overvoltage are necessary. Therefore, the overvoltage control circuit OL is turned on (ON) to short-circuit the output of the constant current circuit CC. Then, the IGBT is turned on (ON) in the same manner as the arc interruption even during the rest period. As a result, the current flowing through the inductor L0 of the power supply output can be closed circuit, so that the overvoltage is eliminated and the stress and breakage of the parts can be eliminated.
[0137]
As described above, according to the present embodiment, since arc detection is possible without using a comparator that causes “delay” in signal processing, it is possible to respond to arc discharge at high speed. For example, according to the results of the inventor's trial examination, in the case of the power source using the comparator shown in FIG. 5, the time required from the start of the arc discharge to the start of the interruption operation is about 0.5 micron. In contrast to the second, in the power source shown in FIG. 4, the arc breaking operation could be started in 0.2 microseconds. As a result, it has become possible to minimize damage to the target or the substrate due to arc discharge.
[0138]
On the other hand, according to this embodiment, since a resistor having a large resistance value can be used as the voltage detection resistor RD, power loss can be reduced.
[0139]
Further, even when the discharge is not started when the arc interruption is finished, the overvoltage is not generated, and the stress and damage to the parts can be prevented.
[0140]
Moreover, even if the operation of the power source is unstable, the arc can be reliably interrupted.
[0141]
FIG. 6 is a schematic diagram showing a modification of the sputtering power source of this embodiment. In this figure, the same elements as those described above with reference to FIGS. 4 and 5 are denoted by the same reference numerals, and detailed description thereof is omitted.
[0142]
In the case of this specific example, after the output of the detection resistor RD is amplified by the current amplifier circuit CA, it is connected to the constant current circuit CC and input (2) to the comparator CP from the midpoint of connection. The comparator CP makes a comparison with the signal input (3) from the constant current circuit CC, and the IGBT drive circuit DR turns on the IGBT based on the result.
[0143]
According to the present invention, even when the comparator CP is used, arc discharge can be detected at a higher speed than the circuit illustrated in FIG. Specifically, the arc breaking operation could be started 0.3 microseconds after the occurrence of arc discharge.
[0144]
FIG. 7 is a schematic diagram showing another modification of the sputtering power source of the present embodiment. Also in this figure, the same elements as those described above with reference to FIGS.
[0145]
In the circuit of this modified example, the output from the voltage detection resistor RD is connected to the constant current circuit CC without amplifying the current, and is input to the OR gate (1) of the IGBT drive circuit DR from the connection middle point. Yes. Even in this case, high-speed feedback is possible without using a comparator as illustrated in FIG.
[0146]
(Third embodiment)
Next, as a third embodiment of the present invention, an arc interrupt circuit that can reliably detect the occurrence of arc discharge under any circumstances without depending on the state in the chamber will be described.
[0147]
FIG. 8 is a schematic diagram showing a main part of the sputtering power supply according to the present embodiment. That is, this power supply includes a DC power supply unit DCPF, a smoothing inductor L1, a reverse bias application circuit RBS, a switching unit Q, and an arc detection control circuit ASC.
[0148]
Specific structures and operations of the DC power supply unit DCPF, the reverse bias application circuit RBS, or the switching unit Q can be the same as those described above with reference to the first embodiment, for example.
[0149]
In the present embodiment, when an arc discharge occurs in the chamber, the arc detection control circuit ASC makes an extremely accurate and accurate determination. Then, the gate signal Sg is supplied to the switching unit Q. When receiving the gate signal Sg, the switching unit Q is turned on (ON), applies a reverse bias to the chamber, and the arc is extinguished.
[0150]
In the following, before explaining the arc detection control circuit ASC, first, the technical background of the arc discharge qualification and the timing of the interruption operation in such a sputtering apparatus will be briefly explained.
[0151]
FIG. 9 is a graph illustrating changes in voltage and current when the power supply is started and when arc discharge occurs in the sputtering apparatus.
[0152]
When the power supply of the sputtering apparatus is activated and voltage application is started to the chamber, no current flows until glow discharge starts. Then, when starting sputtering, the control device activates the power supply by releasing the interlock, giving an operation command and a power value to the power supply. The power source starts the inverter, increases the output voltage to a predetermined voltage, and temporarily stops the inverter when overvoltage occurs.
[0153]
When the voltage rises to a predetermined level, glow discharge begins in the chamber and the plasma ignites. As the plasma grows, a discharge current according to the voltage and other various parameters flows. The power supply is operated until the operation command disappears while performing the sputtering while adjusting the output so as to become the set power.
[0154]
A sputtering apparatus or a power source during sputtering monitors a decrease in impedance of the chamber (between the chamber and the target) due to the arc as a decrease in power supply output voltage in order to prevent damage from arc discharge. When a voltage drop is detected, the current output of the power supply is stopped for the first predetermined time.
[0155]
As illustrated in FIG. 9, the voltage threshold value for detecting the arc discharge is a fixed value of, for example, about minus 150 to minus 200 V as the target voltage. That is, when the voltage exceeds this threshold value (the absolute value becomes smaller), the sputtering output is stopped, and an arc interruption sequence such as applying a reverse bias as necessary is executed. Thereafter, in order to continue the sputtering operation, the output from the power source is resumed.
[0156]
When the output from the power supply is resumed, the measurement for the second predetermined time is started, and if the voltage is restored at this time, the sputtering process is continued. However, when the output voltage is below the threshold even after the second predetermined time has elapsed. If the arc discharge cannot be extinguished, the current output is stopped again.
[0157]
When the control device determines that the amount of power input to the chamber has reached the specified value, the operation command to the power supply is stopped.
[0158]
With this stop command, the power supply stops the inverter. The current decreases to zero, and the sputtering ends.
[0159]
By repeating this series of operations, sputtering is performed while suppressing arc discharge.
[0160]
However, if the output voltage exceeds the threshold (for example, minus 150 volts) after the power supply starts the inverter, or if the voltage is reduced due to a factor other than arcing, it is mistaken that arcing has occurred. There is. The following countermeasures can be considered for this.
[0161]
The first is that after the power is turned on, the arc breaking operation is prohibited until the voltage threshold is exceeded. However, according to this method, it is impossible to distinguish between the operation of stopping the power supply according to the command, the time when the plasma does not grow until the continuous discharge with one ignition and the restart, and the voltage increase during arc discharge and ignition waiting.
[0162]
The second is that the decrease in output voltage is ignored during a certain period of time after the power supply inverter is stopped or started. That is, during this time, the arc breaking operation is prohibited. However, according to this method, it is difficult to define the voltage rise time, and even if the glow discharge is changed to the arc discharge while the cutoff operation is prohibited, the cutoff is not cut off. Further, when the inverter is stopped due to hunting due to ignition waiting or power control failure, the arc is not interrupted.
[0163]
On the other hand, since the threshold voltage for determining arc discharge varies depending on conditions, problems may arise if it is managed with a fixed value. For example, when sputtering a silicon material, the chamber voltage at the time of arc discharge is as high as about minus 250 volts (the absolute value is small). In this case, if the threshold value for determining the arc discharge is minus 150 volts, the damage of the arc discharge until the interruption operation is determined after the arc discharge is determined is increased.
[0164]
Based on the technical background described above, the present inventors have invented the sputtering power source of this embodiment as shown in FIG. That is, the arc detection control circuit ASC shown in FIG. 8 solves the problem related to the arc discharge certification as described above.
[0165]
FIG. 10 is a block diagram illustrating the configuration of the arc detection control circuit ASC. That is, the arc detection control circuit ASC includes a current detection unit CSU, a voltage detection unit VSU, an arc determination unit ADU, a timer TMR, a logic operation unit LCU, and a power control unit PCU.
[0166]
The function of each block will be described in detail later, but the items considered in determining the operation of the circuit ASC are as follows.
[0167]
That is, first, before the glow discharge of sputtering starts, the electrostatic capacity of the chamber is small, so that the inrush current when the power supply is activated and the output voltage rises is extremely small.
[0168]
In addition, arc discharge damage is caused by high-density current flowing at a small arc generation point. Therefore, even if the power inverter is stopped, damage may be caused by arc discharge while the current continues. is there. That is, even when the inverter of the power supply is stopped, an arc interruption operation may be necessary.
[0169]
On the other hand, if the chamber current is extremely small regardless of the operation of the inverter, the arc damage is small and can be ignored. That is, when the chamber current is extremely small, it is not necessary to start the arc breaking operation.
[0170]
In summary, it is only necessary to cut off the arc only when the supply current to the chamber, that is, the output current of the power source is large and the damage of arc discharge is great.
[0171]
However, if the power supply needs to be stopped during the power supply interlock, that is, for some reason, all operations must be stopped.
[0172]
This is the condition for arc interruption.
[0173]
On the other hand, when the arc voltage increases as the current increases, it is desirable to increase the arc determination voltage, that is, the voltage threshold value for determining arc discharge, in proportion to the current.
[0174]
Hereinafter, the arc detection control circuit ASC shown in FIG. 10 will be described.
[0175]
First, the current detection unit CSU measures the output current from the sputtering power supply, and sends the measured value CD to the arc determination unit ADU, the logic operation unit LCU, and the power control unit PCU.
[0176]
Moreover, the voltage detection part VSU measures the output voltage from the power supply for sputtering, and sends the measured value VD to the arc determination part ADU and the power control part PCU.
[0177]
The logical operation unit LCU compares the measured value CD of the output current with a predetermined current threshold (for example, 1% of the rated current). Then, the logical product of the excess signal and the interlock release signal ROCK of the power source is calculated, and arc interruption is permitted only when both are established.
On the other hand, the arc is determined in the arc determination unit ADU. That is, the arc determination unit ADU compares the measured voltage value VD with a predetermined voltage threshold value and the power supply output voltage. Here, the voltage threshold is variable according to the current. For example, the voltage at the time of minus 150 volt output is used as a reference, and the current measurement value CD is added to the voltage at a magnification according to parameters such as the target material. In this way, the voltage threshold for determining arc discharge can be set to an optimum value according to the current or other parameters.
[0178]
When the arc determination unit ADU determines arc discharge from the output voltage measurement value VD in the phase in which the logic operation unit LCU determines that the arc interruption is permitted based on the measurement value CD of the output current and the interlock signal ROCK. The timer TMR measures the first time based on the output signal AD, and sends the permission signal AS to the logic operation unit LCU. As a result, the switch unit Q is turned on within a predetermined time, and the output current from the DC power supply unit DCPF is cut off.
[0179]
Then, when the first predetermined time is finished, the current interruption is finished, and the output from the DC power supply unit DCPF is resumed.
[0180]
At the same time, timer TMR measures a second time and shuts off for a predetermined time even if the chamber voltage is at a voltage threshold (typically less than minus 150 volts, eg minus 80 volts). Output the same current as before.
[0181]
When the second predetermined time ends in the timer TMR, the operation returns to the operation before the interruption.
[0182]
However, in any state described above, when the power supply is interlocked or when the output current / voltage exceeds the limit value, the output from the power supply is stopped and the operation of the inverter is stopped.
[0183]
FIG. 11 is a schematic diagram showing a specific example of the sputtering power source of the present embodiment. In this figure, the same elements as those described above with reference to FIGS. 8 to 10 are denoted by the same reference numerals, and detailed description thereof is omitted.
[0184]
The main part will be briefly described. First, in the DC power source DCPF, a current obtained by rectifying the output of the inverter constituted by the DC voltage source DC, the transistor bridges Q1 to Q4 and the transformer T1 by the rectifier DB1 is generated. The current thus rectified is smoothed by the reactor (smoothing inductor) L1 and supplied to the chamber.
[0185]
The output voltage to the chamber is detected by Vsen 1 and 2 and converted into an output voltage signal VD by the differential amplifier VOLTamp (voltage detection unit VSU).
[0186]
Further, the output current to the chamber is detected by Csen and converted into an output current signal CD by the differential amplifier CURamp (current detection unit CSU).
[0187]
The output voltage signal VD and the output current signal CD are multiplied by a multiplier, and a command current signal OC is calculated from the difference between the output power signal and the command power signal Pcom (power control unit PCU).
[0188]
The command voltage signal OV is calculated from the difference between the command current signal OC and the output current signal VD, and PWM modulation is performed to generate the duty signal PWM (power control unit PCU).
[0189]
Then, the transistors Q1 to Q4 are driven by the logical product of the interlock signal ROCK, the operation signal RUN, and the duty signal.
[0190]
On the other hand, arc interruption is performed as follows.
[0191]
First, the output current signal CD and a reference voltage (for example, a reference voltage 1% FS corresponding to 1% of the rating) are compared by the comparator ARCacs to generate a discharge signal.
[0192]
The output current signal CD is added to the variable resistor VR, a compensation voltage proportional to the output current is calculated, and added to the reference voltage 150V corresponding to minus 150V, which is a normal arc judgment level, to set the threshold value of the comparator (AEC sens) To do.
[0193]
The comparator (AEC sens) determines arc discharge when the output voltage signal VD falls below a predetermined threshold value, and outputs an arc signal AD.
[0194]
If it is determined that an arc is occurring during the output of the discharge signal, the transistor Q5 is closed to output a reverse voltage to interrupt the arc discharge, and the timer 1 is started. During the operation of the timer 1, the transistor Q5 is closed and the holding of the command current signal is started.
[0195]
When timer 1 expires, timer 2 is started, and transistor Q5 is not closed while timer 2 is operating. When the timer 2 ends and there is no arc interruption again, the holding of the command current signal is ended.
[0196]
According to the circuit of this embodiment as described above, the following effects can be obtained.
[0197]
First, the arc interruption can be started immediately after the start of glow discharge regardless of the hunting operation of the inverter, the fluctuation of the power supply output voltage, or the rise delay.
[0198]
Moreover, even after the inverter of the power supply is stopped, as long as there is a current and an arc damage is expected, the arc can be interrupted without restriction of the duration.
[0199]
Furthermore, even if the arc discharge voltage increases due to the sputtering characteristics, the arc can be detected and interrupted with the voltage corrected by the discharge current.
[0200]
In other words, regardless of the state of the chamber, accurate determination of arc discharge and rapid arc interruption are possible, minimizing damage caused by arc discharge and minimizing interruption of sputtering work due to arc interruption. it can.
[0201]
The embodiments of the present invention have been described above with reference to specific examples. However, the present invention is not limited to these specific examples.
[0202]
For example, the configuration, structure, number, arrangement, shape, material, etc. of each part in the arc interruption circuit, sputtering power source, sputtering apparatus of the present invention are not limited to the above specific examples, and those appropriately selected and adopted by those skilled in the art As long as the gist of the present invention is included, it is included in the scope of the present invention.
[0203]
More specifically, for example, those skilled in the art appropriately design the specific configuration of the arc detection circuit provided in the arc breaker circuit and the number and arrangement relationship of each circuit element including diodes, resistors, and transistors. Modifications are within the scope of the present invention.
[0204]
In addition, all arc interruption circuits, power supplies for sputtering, and sputtering apparatuses that include elements of the present invention and can be appropriately modified by those skilled in the art are included in the scope of the present invention.
[0205]
【The invention's effect】
As described above, according to the present invention, it is possible to provide an arc interruption circuit capable of quickly and surely interrupting arc discharge, and a sputtering power source and a sputtering apparatus using the arc interruption circuit. is there.
[Brief description of the drawings]
FIG. 1 is a schematic view showing a main part of a sputtering apparatus provided with an arc breaker circuit according to a first embodiment of the present invention.
FIG. 2 is a schematic diagram showing a sputtering apparatus provided with an arc interrupt circuit of a comparative example.
FIG. 3 is a schematic diagram showing a specific example of a power source for sputtering equipped with an arc breaker circuit according to the first embodiment of the present invention.
FIG. 4 is a schematic view showing a sputtering apparatus provided with an arc breaker circuit according to a second embodiment of the present invention.
FIG. 5 is a schematic diagram showing a sputtering apparatus provided with an arc interrupt circuit of a comparative example.
FIG. 6 is a schematic diagram showing a modification of the power supply for sputtering according to the second embodiment of the present invention.
FIG. 7 is a schematic diagram showing another modification of the sputtering power supply according to the second embodiment of the present invention.
FIG. 8 is a schematic diagram showing a main part of a sputtering power supply according to a third embodiment of the present invention.
FIG. 9 is a graph illustrating changes in voltage and current when the power supply is started and when arc discharge occurs in the sputtering apparatus.
FIG. 10 is a block diagram illustrating the configuration of an arc detection control circuit ASC.
FIG. 11 is a schematic diagram showing a specific example of a sputtering power supply according to the third embodiment of the present invention.
FIG. 12 is a schematic diagram showing a main configuration of a DC (direct current) sputtering apparatus.
[Explanation of symbols]
100 substrates
101 Vacuum chamber
104 target
106 Vacuum pump
107 Gas supply source
108 Glow discharge
110, 110A-110Z Power supply for sputtering
120A, 120B cable
150 arc discharge
ADU arc detector
ASC arc detection control circuit
CA current amplifier circuit
CC constant current circuit
CM current monitoring circuit
CP comparator
CSU current detector
DB0-3 Rectifier diode group
DCPF DC power supply
DCPR reverse bias power supply
DR driver (drive circuit)
IGBT switching part
L0 to L3 inductor
LCU logic unit
PCU power controller
Q switching section
Q1-Q5 transistors
Rpass output limiting resistor
RBS reverse bias application circuit
RD voltage detection resistor
ROCK Interlock release signal
RUN operation signal
Sg gate signal
T1 transformer
TM timer
TMR timer
VSU voltage detector
ZD Zener diode

Claims (10)

An arc interruption circuit that stops supply of the voltage in the positive direction to the supply object when detecting the occurrence of arc discharge in the supply object to which a voltage in the positive direction is applied,
The voltage in the positive direction in the supplied object is divided by a voltage detection resistor and a constant current circuit,
An arc interrupting circuit for detecting occurrence of the arc discharge by a decrease in an absolute value of a voltage of the constant current circuit.   2. The arc breaking circuit according to claim 1, wherein the current in the constant current circuit corresponds to a current flowing through the voltage detection resistor when the arc discharge occurs in the supplied object. A current amplifier for amplifying a current flowing through the voltage detection resistor;
The arc interrupt circuit according to claim 1, wherein the current amplifier and the constant current circuit are connected to each other.   The supply of the voltage in the positive direction is stopped when the absolute value of the voltage in the positive direction with respect to the supply object exceeds a predetermined value. Arc interruption circuit.   The current flowing through the supply target is observed, and when the current is less than a predetermined value, the supply of the positive voltage is not stopped even if the absolute value of the voltage of the constant current circuit is reduced. The arc breaker circuit according to any one of claims 1 to 4. When detecting the occurrence of arc discharge in the supplied object to which a positive voltage is applied, an arc interrupting circuit that performs an arc interrupting operation for outputting a reverse voltage to the supplied object,
When the value of the current flowing through the supplied object is larger than a predetermined current threshold value and the voltage at the supplied object is smaller than a predetermined voltage threshold value, the arc interruption operation is performed.
For a predetermined first time after the start of the arc interrupting operation, the arc interrupting operation is continued regardless of the value of the current flowing through the supplied object and the voltage at the supplied object.
The predetermined second time after the elapse of the first time is the same as that before the arc interrupting operation is started without starting the arc interrupting operation even when the voltage at the supply target is the voltage threshold. An arc breaking circuit that outputs an electric current to the supplied body.   The arc interrupt circuit according to claim 6, wherein the voltage threshold is variable according to a current flowing through the supply target. 8. The arc interrupting circuit according to claim 6, wherein the arc interrupting operation is not started when an interlock signal for prohibiting the operation of the power supply for applying the positive voltage is applied. A power supply for sputtering that forms a thin film by sputtering a target,
An arc breaker circuit according to any one of claims 1 to 8 ,
A positive voltage applying means for applying the positive voltage;
A sputtering power source characterized by comprising: A vacuum chamber capable of maintaining an atmosphere depressurized from atmospheric pressure;
A power supply for sputtering according to claim 9 ;
With
Sputtering is performed by the positive voltage applied from the positive voltage applying means,
A sputtering apparatus characterized in that the arc discharge generated in a vacuum chamber is interrupted by the arc interrupt circuit.

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