JP6572424B2 - Power supply for sputtering equipment - Google Patents

Description

  The present invention relates to a power supply device used for generating plasma in a sputtering apparatus, and more particularly to a power supply apparatus suitable for a DC sputtering apparatus or a DC pulse sputtering apparatus.

  In a sputtering apparatus used for a semiconductor film forming process, a gas such as argon is ionized by power supplied between a target and a substrate (film formation target), and plasma is generated mainly. The target material is knocked out of the target by the action of ions, and particles of the material reach the substrate to form a film on the surface of the substrate. Examples of the sputtering apparatus include a direct current (DC) sputtering apparatus that applies a DC voltage between a target that is a cathode and a substrate that is an anode, and a radio frequency (RF) sputtering apparatus that applies a high frequency voltage between the cathode and the anode. Is widely used. Although there are restrictions such as the inability to use an insulating target, the DC sputtering device has a simpler device structure than a high-frequency sputtering device and can use a relatively low temperature plasma to suppress damage to the substrate surface. There are advantages such as.

  As disclosed in Patent Document 1 and the like, in general, a power source device for a DC sputtering apparatus is provided with an inductor for stabilizing current between a DC power source including a DC / DC converter and the negative voltage output terminal, The line connecting the power source and the positive voltage output terminal is grounded. The inductor generates an electromotive force in a direction to prevent current fluctuation by self-inductive action, and accumulates electric energy as magnetic energy. Thereby, for example, even when the impedance of the discharge load fluctuates, a large fluctuation in current can be suppressed.

  Although the direct current sputtering apparatus has the advantages as described above, as described in Patent Documents 2 and 3, etc., arc discharge is relatively easy to occur, and a film formation defect due to the arc discharge may occur. The DC pulse sputtering apparatus is for solving such a problem. A pulse voltage generated by switching the DC voltage is applied between the cathode and the anode, or the DC voltage is applied during application of the DC voltage. Applies a reverse polarity voltage between the cathode and anode in a pulsed manner. By applying such a pulsed voltage, charging of the target surface can be suppressed, and the occurrence of arc discharge can be suppressed.

  In such a power supply device for a DC pulse sputtering apparatus, an inductor for current stabilization and a semiconductor switching element for voltage switching are connected in series between the DC power supply and the negative voltage output terminal. In that case, if the impedance of the discharge load suddenly increases due to the extinction of the plasma due to the deviation of the discharge condition and the current flowing through the inductor suddenly decreases, a large voltage is induced in the inductor so that the current supply is sustained. The voltage may damage the chamber. Further, since a large voltage is applied to the semiconductor switching element due to the induced voltage, it is necessary to use a high-cost element having a large withstand voltage as the semiconductor switching element.

  On the other hand, in the power supply device described in Patent Document 2, a current regeneration diode is provided in parallel to the series circuit of the inductor and the semiconductor switching element. In this device, since the diode is connected in parallel with the inductor when the semiconductor switching element is in the ON state, if the impedance of the discharge load is extremely increased, it is derived from the energy accumulated in the inductor up to that point. Current flows through the diode so as to short-circuit the inductor. As a result, there is no increase in the voltage across the inductor, and there is no increase in the voltage applied to the semiconductor switching element and no increase in the voltage applied to the discharge load.

  However, even when the impedance of the discharge load rises transiently and the current flowing through the inductor decreases, the induced voltage of the inductor that prevents the current decrease occurs in the direction of diode conduction. No function will work and the current will remain reduced. On the other hand, when the impedance of the discharge load decreases transiently and the current flowing through the discharge load increases, the current increase in the inductor with respect to the increased current flows back to the inductor via the diode. Therefore, even if the impedance of the discharge load is restored, the increase in current is maintained as it is. This means that the energy stored in the inductor is not useful for fluctuations in the discharge load, specifically, the increase or decrease in the impedance of the discharge load. It will not fulfill the function of stabilizing. As a result, there is a serious problem that the stability of the current supplied from the power supply device to the discharge load of the sputtering device is lowered and the plasma generation state is deteriorated.

  On the other hand, in the power supply device described in Patent Document 3, a snubber circuit including a capacitor, a resistor, a diode, and the like is provided in parallel with a semiconductor switching element that turns on and off a current supplied to a discharge load. In this device, even if a surge voltage due to an induced voltage of the inductor is generated due to, for example, a sudden increase in impedance of the discharge load, the surge voltage applied to the semiconductor switching element is reduced by the snubber circuit. Therefore, it is possible to prevent the semiconductor switching element from being destroyed by the surge voltage.

  However, in such a snubber circuit, the energy stored in the capacitor due to the surge voltage is consumed by the resistor (that is, converted into heat), so that the efficiency of the power supply device is lowered. In addition, since it is necessary to add a snubber circuit, the size of the device increases accordingly.

JP 2003-73826 A JP 2001-295042 A JP 2008-75112 A

  The present invention has been made to solve the above-described problems, and an object of the present invention is to additionally prevent an excessive voltage from being applied to the semiconductor switching element by consuming energy such as a snubber circuit. Without using a circuit, it is possible to prevent an excessive voltage from being applied to the semiconductor switching element due to a sudden increase in impedance of the discharge load or switching of the semiconductor switching element, and even if the impedance of the discharge load fluctuates, the discharge load It is an object of the present invention to provide a sputtering power supply device that can stably maintain a current supplied to the substrate.

In order to generate plasma in a chamber of a sputtering apparatus, the present invention has been made to solve the above-described problems. A direct current voltage or a pulsed current is generated between a pair of voltage output terminals from a pair of electrodes disposed in the chamber. In the power supply device that applies the voltage of
a) a power supply unit that outputs a predetermined DC voltage or pulsed voltage for maintaining a steady plasma between a pair of output terminals;
b) A main winding is provided electrically in series in a path between one output end of the power supply unit and one of the pair of voltage output ends, and the main winding is disposed on the power supply unit side of the main winding. One end of the regenerative winding is connected, an inductor in which the polarity of the main winding and the regenerative winding is opposite with respect to the connection point of the main winding and the regenerative winding;
c) forming a series circuit connected in parallel to the power supply unit with connected in series with the regenerative winding regenerative winding of the inductor, the at closed circuit including said with the series circuit power supply section A diode connected in a direction to block current flowing from the power supply unit;
Wherein the diode sometimes no current flows to the regenerative winding I is blocked state that is functional main winding of the inductor as the inductor to regulate the current supplied to said chamber from said voltage output terminal while for, before the voltage induced across the Kikai raw winding rises to the diode becomes conductive, the power supply current derived from the voltage induced in the regenerative winding via the diode It is characterized in that the so that is regenerative separate component.

In the power supply device for a sputtering apparatus according to the present invention, the power supply unit typically includes a rectifier that converts AC power supplied from the outside into DC power, and DC that converts the DC power into DC power having a different voltage. A circuit including a DC converter.
In the power supply device for a sputtering apparatus according to the present invention, when the diode connected in series with the regenerative winding of the inductor is in the blocking state, no current flows through the closed circuit including these circuit elements and the power supply unit. Therefore, for example, the impedance of the discharge load fluctuates to some extent due to the effect of current stabilization by the main winding of the inductor provided in the path between one output end of the power supply unit and the voltage output end of the apparatus. Even when this is done, large fluctuations in the current flowing through the discharge load can be suppressed.

  A current flows through the closed circuit including the discharge load and the main winding of the inductor by the voltage applied between the pair of electrodes in the chamber through the voltage output terminal from the power supply unit. Even in normal operation, the discharge load changes from moment to moment and the load impedance fluctuates. Due to the accompanying current change, a voltage is induced across the regenerative winding of the inductor. As the current flowing through the main winding increases, the voltage induced in the regenerative winding also increases. Since one end of the regenerative winding (the end opposite to the side connected to the diode) is connected to the end of the main winding on the power supply unit side, when the induced voltage of the regenerative winding increases, With reference to the connection point between the regenerative winding and the main winding, the potential at the connection point between the regenerative winding and the diode (the anode) increases. Since the series circuit of the regenerative winding and the diode is connected in parallel to the power supply unit, when the voltage across the regenerative winding is lower than the output voltage of the power supply unit, the diode is reverse-biased and becomes blocked. maintain. This state is maintained in a normal operation in which there is no problem in the sputtering apparatus or the plasma generation state.

For example, when the impedance of the discharge load suddenly increases due to extinction of plasma or the like and almost no current flows through the discharge load, a large voltage is induced in the main winding of the inductor. As a result, when the voltage across the regenerative winding rises and the voltage exceeds the output voltage of the power supply unit, the diode is forward-biased and becomes conductive. Then, a closed circuit including the regenerative winding, the diode, and the power supply unit is substantially formed, and a current flows through the closed circuit. As a result, the current derived from the voltage induced in the regenerative winding is regenerated in the power supply unit, and the voltage across each of the main winding and the regenerative winding of the inductor is clamped to the output voltage of the power supply unit. In this way, even when the impedance of the discharge load increases rapidly, it is possible to avoid applying an excessive voltage between the main winding of the inductor and the discharge load connected thereto, that is, a pair of electrodes in the chamber.
In the power supply device for a sputtering apparatus according to the present invention, one end of the regenerative winding of the inductor may be directly connected to the power supply side end of the main winding of the inductor. Or may be indirectly connected via another circuit element such as a diode or a resistor other than the diode.
The inductor may be one in which each winding having a two-winding structure is used as a main winding and a regenerative winding. In a tap inductor having a single winding structure, the windings on both sides with the tap as a boundary are used as the main winding and What was used as a regenerative winding may be used.

  The power supply device for a sputtering apparatus according to the present invention is also applicable to a power supply device for a DC sputtering apparatus that continuously supplies DC power to plasma formed in a chamber, but it supplies DC power intermittently. In some cases, the present invention is particularly useful for a power supply device for a DC pulse sputtering apparatus that applies a voltage of opposite polarity between a pair of electrodes while the supply of DC power is stopped. That is, in the power supply device for a sputtering apparatus according to the present invention, preferably, a semiconductor switching element is provided in series with the main winding of the inductor, and the semiconductor switching element is turned on / off so that the pair of the output terminals from the voltage output terminal. It is preferable that a pulse voltage be applied between the electrodes.

  As described above, in the power supply device for a sputtering apparatus according to the present invention, the excessive voltage generated when the impedance of the discharge load increases rapidly by the action of the regenerative winding of the inductor and the diode is suppressed. It is possible to prevent the semiconductor switching element from being damaged and to avoid damage to the element.

  According to the power supply device for a sputtering apparatus according to the present invention, a circuit that regenerates the energy of the inductor generated easily and excessively to the power supply unit without adding a protection circuit that wastes power like a snubber circuit. Therefore, it is possible to prevent an excessive voltage from being generated due to a rapid increase in the impedance of the discharge load. In addition, since the main winding of the inductor functions as a current stabilizing inductor which is the original main purpose, the current supplied to the discharge load can be stabilized even when the impedance of the discharge load varies.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic block diagram of the power supply device for DC pulse sputtering apparatuses which is one Example of this invention. The timing diagram and waveform diagram for demonstrating the operation | movement in the power supply device for DC pulse sputtering devices of a present Example.

A power supply device for a DC pulse sputtering apparatus according to an embodiment of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a schematic configuration diagram of a power source device for a DC pulse sputtering apparatus according to the present embodiment, and FIG. 2 is a timing and waveform diagram for explaining the operation of the power source device for the DC pulse sputtering apparatus according to the present embodiment.

  A positive voltage output terminal 9a and a negative voltage output terminal 9b, which are voltage output terminals in the power supply device, are connected to an anode 10a and a cathode 10b installed in the chamber 10 of the sputtering apparatus, respectively. That is, the entire space in the chamber 10 including the anode 10a and the cathode 10b is the discharge load 10c of the power supply device. Usually, the anode 10a is a substrate to be deposited, and the cathode 10b is a target to be sputtered.

  In the present power supply device, the positive output terminal of the DC power source 1 including a rectifier that converts AC power into DC power, a DC-DC converter, and the like is connected to the positive voltage output terminal 9a. Is connected to the negative voltage output terminal 9b through a series circuit of the main winding 2a of the inductor 2 and the first semiconductor switching element 3. The DC power source 1, the space in the chamber 10 (discharge load 10c), the first semiconductor switching element 3, and the main winding 2a of the inductor 2 constitute a first closed circuit. As shown in the figure, since the anode 10a of the chamber 10 is normally grounded, the potential of the positive voltage output terminal 9a is 0V, and the negative voltage output terminal 9b is negative. For example, the output voltage of the DC power supply 1 is 700 V, and the rated output power is 5 kW. The first closed circuit including the DC power supply 1 is a power supply path for supplying power to the plasma in order to maintain the plasma during steady operation after the plasma is generated in the chamber 10.

  A series circuit of the first diode 4 and the second semiconductor switching element 5 is connected in parallel between both ends of the main winding 2 a of the inductor 2. The first diode 4, the second semiconductor switching element 5, and the main winding 2a of the inductor 2 form a second closed circuit.

In addition, a series circuit of the regenerative winding 2b of the inductor 2 and the second diode 6 is connected in parallel between both output terminals of the DC power supply 1 to form a third closed circuit. The polarities of the main winding 2a and the regenerative winding 2b of the inductor 2 are opposite to each other with respect to the connection point between the main winding 2a and the regenerative winding 2b, and as shown by the arrows in FIG. The direction of the voltage generated in the line 2a is the direction from the first semiconductor switching element 3 side toward the connection point, and the direction of the voltage generated in the regenerative winding 2b is the direction from the connection point toward the second diode 6.
Further, here, for convenience of explanation, the turns ratio of the main winding 2a and the regenerative winding 2b of the inductor 2 which is tightly coupled is 1: 1, but the winding ratio is not limited to this and can be appropriately adjusted. Needless to say.

Both the first and second semiconductor switching elements 3 and 5 are on / off controlled by drive signals G1 and G2 generated by the switching element driving unit 8 based on an instruction from the control unit 7. The DC-DC converter included in the DC power supply 1 operates so as to output a predetermined voltage and a predetermined current in accordance with a control signal from the control unit 7.
The control unit 7 includes a CPU and a memory (for example, a flash ROM) in which a control program is stored in order to perform characteristic control operations described later. As the first and second semiconductor switching elements 3 and 5, it is preferable to use SiC (silicon carbide) -MOSFET having a high breakdown voltage, a high switching speed, and a low on-resistance. Further, as the first and second diodes 4 and 6, SiC-SBD (Schottky barrier diode) having high breakdown voltage, high switching speed and low forward voltage may be used.

  For convenience of explanation, in FIG. 1, an ignition circuit that can apply a voltage (current is small) higher than a steady voltage during plasma ignition between the anode 10a and the cathode 10b is omitted. In addition, as will be described later, there is a case where a predetermined voltage having a reverse polarity is applied during a period in which a DC voltage from the DC power source 1 is not applied between the anode 10a and the cathode 10b. This circuit is also omitted in FIG.

  With reference to FIG. 2 in addition to FIG. 1, the operation of the power supply device for the DC pulse sputtering apparatus of the present embodiment at the time of plasma maintenance, that is, in the state where plasma is formed after ignition will be described.

As shown in FIGS. 2A and 2B, the control unit 7 performs the second operation during a period (T ₁ period) in which the drive signal G1 input to the gate of the first semiconductor switching element 3 is at the H level. drive signal G2 inputted to the gate of the semiconductor switching element 5 becomes L level, and conversely, the drive signal G2 is at the H level period (T ₂ period) drive signal G1 becomes L level so that the driving signal By controlling G1 and G2, both semiconductor switching elements 3 and 5 are complementarily turned on and off. During the T ₁ period when the first semiconductor switching element 3 is on, a current flows through the first closed circuit for supplying power from the DC power source 1 to the discharge load 10 c, and this current is the main winding of the inductor 2. Via 2a. During the T ₂ period when the second semiconductor switching element 5 is on, the first semiconductor switching element 3 is turned off and the first closed circuit is cut off. Instead, the inductor 2 passes through the first diode 4. A second closed circuit for short-circuiting the main winding 2a is formed.

In FIG. 2, at time t ₀ , the drive signal G1 rises and the first semiconductor switching element 3 is turned on. Conversely, the drive signal G2 falls and the second semiconductor switching element 5 is turned off. The time t _c second semiconductor switching element 5 rising drive signal G2 is is turned on, the first semiconductor switching element 3 is fallen drive signals G1 conversely switched respectively to the OFF state. A period from time t ₀ to time t _c is a T ₁ period, and a current flows to the discharge load 10 c through the first closed circuit. Further, the period from time t _c to time t ₀ is the T ₂ period, and the current flowing in the first closed circuit in the immediately preceding T ₁ period is switched to the second closed circuit and flows.

In FIG. 2, (c) is a load current I ₀ flowing through the discharge load 10c in a normal state, and (d) is a voltage V ₀ across the discharge load 10c.
When the first semiconductor switching element 3 is on and the second semiconductor switching element 5 is off, a current flows through the first closed circuit to the discharge load 10c as described above. At this time, since the voltage generated at both ends of the main winding 2 a of the inductor is lower than the output voltage of the DC power supply 1, the voltage induced in the regenerative winding 2 b is also lower than the output voltage of the DC power supply 1. Therefore, the connection point between the regenerative winding 2b and the second diode 6, that is, the anode potential of the diode 6 is lower than the cathode potential, and the diode 6 is reverse-biased. Therefore, no current flows in the third closed circuit.

After the second semiconductor switching element 5 is turned on, the impedance of the second closed circuit is very low and can be regarded as being almost short-circuited. During this T ₂ period, the magnetization level of the iron core of the inductor 2 cannot change, and the voltage across the main winding 2a does not change. Therefore, the current value flowing in the first closed circuit at the start of the T ₂ period, that is, at the time t _c is retained. As a result, the value of the current flowing through the main winding 2a of the inductor 2 common to the first closed circuit and the second closed circuit is both the T ₁ period and the T ₂ period, that is, one period of the pulse period. It becomes almost constant throughout the period T. This means that the pulse peak value of the current I ₀ flowing through the discharge load 10c in the T ₁ period becomes substantially constant regardless of the pulse duty ratio D = T ₁ / T. This also means that little energy is required for current switching, ie commutation, between the first closed circuit and the second closed circuit. Therefore, the pulse frequency is determined depending on the switching speed of the semiconductor switching elements 3 and 5, and can usually be increased to several hundred kHz.

In FIG. 2, (e) and (f) are waveform diagrams showing the load current I ₀ and the voltage V ₀ when the plasma becomes unstable due to factors such as fluctuations in discharge conditions and the impedance of the discharge load 10c increases. It is. This shows a case where the impedance of the discharge load 10c increases about 1.5 times compared to the steady state only during the period from time t _{a to} t _{b in} the T ₁ period.

If the impedance of the discharge load 10c increases during the period of time t _{a to} t _b , the current flowing through the first closed circuit tends to decrease, but the load voltage V ₀ and the output voltage of the DC power source 1 increase accordingly. Is induced in a direction corresponding to the polarity of the main winding 2a of the inductor 2, and the current is increased so as to maintain the current flowing in the main winding 2a immediately before. That is, the main winding 2a functions as an inductor for stabilizing the current main purpose, whereby the load current I ₀ is kept almost constant without decreasing.

Similarly, when the impedance of the discharge load 10c is lower than the steady state due to factors such as fluctuations in discharge conditions, or when the impedance is extremely decreased due to the occurrence of arc discharge or a short circuit of the load, the inductor 2 Since the main winding 2a functions as a current stabilizing inductor, the load current I ₀ is maintained almost constant.

  As the increase in the impedance of the discharge load 10c increases, the voltage generated across the main winding 2a of the inductor 2 increases. Since the same magnitude of voltage is induced in the regenerative winding 2b of the inductor 2 in the direction corresponding to the polarity by the magnetic coupling, the potential of the anode of the second diode 6 also increases with the increase in the impedance of the discharge load 10c. To rise. When the increase in impedance of the discharge load 10c is extremely large, the anode potential of the second diode 6 becomes higher than the cathode potential, the second diode 6 becomes forward biased, and the diode 6 is in a conductive state. It becomes.

FIGS. 2G and 2H are waveform diagrams of the current I ₀ and the voltage V ₀ of the discharge load 10c when the impedance of the discharge load 10c is extremely increased.
When the impedance of the discharge load 10c is extremely increased due to factors such as the extinction of plasma during the period of time t _{a to} t _b , the load current I ₀ becomes almost zero. A voltage generated between both ends of the main winding 2a of the inductor 2 above the output voltage of the DC power source 1 is also induced in the regenerative winding 2b, and the second diode 6 becomes conductive in a forward bias state. Then, a third closed circuit is formed, and the current derived from the voltage induced in the regenerative winding 2 b is regenerated to the DC power source 1 via the second diode 6. When the second diode 6 is turned on, the voltage across the regenerative winding 2b of the inductor 2 is clamped to substantially the same level as the output voltage of the DC power supply 1, and the voltage across the main winding 2a is also clamped to almost the same level. The Thereby, it is possible to avoid applying an excessive voltage to the semiconductor switching elements 3 and 5. That is, the inductor 2 and the second diode 6 function as a voltage clamper when the impedance of the discharge load 10c is extremely increased.

That is, in the power supply device for a sputtering apparatus of this embodiment, until the load voltage V ₀ which discharge load 10c is approximately twice the output voltage of the DC power source 1 main winding 2a of the inductor 2 is the original main object It functions as an inductor that stably maintains current, and functions as a component of a voltage clamper when the load voltage V ₀ exceeds about twice the output voltage of the DC power supply 1. For example, when the output voltage of the DC power supply 1 is 700 V, the voltage threshold value of the load voltage V ₀ of the discharge load 10 c at which the current stabilization function and the voltage clamper function are switched is −1400 V.

As described above, in the above embodiment, for convenience of explanation, the turns ratio of the main winding 2a and the regenerative winding 2b of the inductor 2 is 1: 1, but for example, when the turns ratio is 1.2: 1. Is as follows. That is, the voltage value clamped in the regenerative winding 2b of the inductor 2 when the second diode 6 is in a conductive state is [magnetic voltage output] to the main winding 2a [output voltage value of the DC power source 1] × 1. Appears as a voltage of 2. Therefore, the voltage threshold value of the load voltage V ₀ of the discharge load 10c at which the above-described current stabilization function and voltage clamper function are switched is [output voltage value of the DC power supply 1] × (1 + 1.2). Therefore, when the output voltage of the DC power source 1 is 700 V, the clamp voltage value of the main winding 2a of the inductor 2 is 840V, the voltage threshold of the load voltage V ₀ is -1540V. As described above, by appropriately adjusting the turns ratio of the main winding and the regenerative winding of the inductor 2, the output voltage of the DC power source 1, the withstand voltage of the semiconductor switching elements 3 and 5, and the voltage threshold can be appropriately set. Design is possible.

Further, in the above embodiment, when the first semiconductor switching element 3 is in the OFF state, the load voltage V ₀ becomes the ground potential (zero volts), but the positive voltage output terminal 9a and the negative voltage output terminal 9b A reverse bias application circuit is provided between the DC power supply 1 and a reverse bias application circuit capable of applying a voltage having a polarity opposite to that of the DC power supply 1 (here, a positive polarity with respect to the ground potential) to the negative voltage output terminal 9b. A reverse polarity voltage may be applied between the anode 10a and the cathode 10b during at least a part of the T ₂ period. By applying such a reverse polarity voltage for a short time, charging of the target surface and the like can be prevented, and the occurrence of arc discharge due to charging can be suppressed. Even in such a configuration, it is clear that the current stabilizing function and the voltage clamper function can be achieved by the characteristic circuit described in the above embodiment.

In the above embodiment, one end of the main winding 2a of the inductor 2, one end of the regenerative winding 2b, and the negative output end of the DC power source 1 are connected, and the second diode 6 is connected to the other end of the regenerative winding 2b. The connection position is such that the second diode 6 is inserted in the middle of the wiring from the connection point between the main winding 2a and the negative output terminal of the DC power supply 1 to one end of the regenerative winding 2b. May be changed. Alternatively, the position of the second diode 6 is left as shown in FIG. 1, and another diode is placed in the middle of the wiring from the connection point between the main winding 2a and the negative output end of the DC power supply 1 to one end of the regenerative winding 2b. May be connected in an equivalent series. Even in such a modified circuit, the operations and functions of the third closed circuit and the inductor 2 described above are exactly the same as those in the above embodiment.
Furthermore, in the above embodiment, the inductor 2 has a two-winding structure having the main winding 2a and the regenerative winding 2b. However, a tapped inductor having a single winding structure is used as the inductor 2, and the tap is implemented as described above. It may be a connection point between the main winding 2a and the regenerative winding 2b in the example.

  In addition, the above-described embodiments and the above-described various modifications are merely examples of the present invention, and it is a matter of course that modifications, modifications, and additions within the scope of the present invention are included in the scope of the claims of the present application. is there.

DESCRIPTION OF SYMBOLS 1 ... DC power supply 2 ... Inductor 2a ... Main winding 2b ... Regenerative winding 3 ... 1st semiconductor switching element 4 ... 1st diode 5 ... 2nd semiconductor switching element 6 ... 2nd diode 7 ... Control part 8 ... Switching element drive Part 9a: Positive side voltage output terminal 9b ... Negative side voltage output terminal 10 ... Chamber 10a ... Anode 10b ... Cathode 10c ... Discharge load

Claims (2)

In order to generate plasma in the chamber of the sputtering apparatus, a power supply apparatus that applies a DC voltage or a pulsed voltage between a pair of electrodes disposed in the chamber from a pair of voltage output ends,
a) a power supply unit that outputs a predetermined DC voltage or pulsed voltage for maintaining a steady plasma between a pair of output terminals;
b) A main winding is provided electrically in series in a path between one output end of the power supply unit and one of the pair of voltage output ends, and the main winding is disposed on the power supply unit side of the main winding. One end of the regenerative winding is connected, an inductor in which the polarity of the main winding and the regenerative winding is opposite with respect to the connection point of the main winding and the regenerative winding;
c) forming a series circuit connected in parallel to the power supply unit with connected in series with the regenerative winding regenerative winding of the inductor, the at closed circuit including said with the series circuit power supply section A diode connected in a direction to block current flowing from the power supply unit;
Wherein the diode sometimes no current flows to the regenerative winding I is blocked state that is functional main winding of the inductor as the inductor to regulate the current supplied to said chamber from said voltage output terminal while for, before the voltage induced across the Kikai raw winding rises to the diode becomes conductive, the power supply current derived from the voltage induced in the regenerative winding via the diode sputtering system power supply device being characterized in that the so that is regenerative separate component.
The power supply device for a sputtering apparatus according to claim 1,
A semiconductor switching element is provided in series with the main winding of the inductor,
A power supply apparatus for a sputtering apparatus, wherein a pulse voltage is applied between the pair of electrodes from the voltage output terminal by turning on and off the semiconductor switching element.

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