TW201330704A - Substrate processing device and impedance matching method - Google Patents

Abstract

Provided are a substrate processing device and an impedance matching method. The substrate processing device includes: a high frequency power source for generating high frequency power; a process chamber for performing a plasma process by using the high frequency power; a matching circuit for compensating for a changed impedance of the process chamber; and a transformer disposed between the process chamber and the matching circuit in order to reduce the impedance of the process chamber.

Description

Substrate processing apparatus and method of impedance matching

The invention disclosed herein relates to a substrate processing apparatus and a method of impedance matching, and more particularly to a substrate processing apparatus for impedance matching during a plasma process and a method of impedance matching.

Impedance matching is critical because high frequency power must be used during the plasma process of processing the substrate with plasma. The impedance matching controls the impedance equally in the power transmission terminal and the receiving terminal to efficiently transmit power. The plasma process requires impedance matching between the power supply providing the high frequency power and the chamber receiving the high frequency power to generate and maintain the plasma.

Since the impedance of the plasma is determined based on different variables such as the type of source gas, temperature, and pressure, the impedance of the chamber constantly changes during the process. Therefore, impedance matching compensates for the varying impedance of the chamber during the plasma process via a matching circuit having a capacitor and an inductor.

However, since there is a limitation in the response speed when the impedance is compensated by adjusting the capacitance or the inductance capacitance, a time delay occurs during impedance matching. Especially when the impedance of the chamber changes drastically due to the generation of plasma during the initial process, arc and plasma density occur in the chamber due to reflected waves generated by a response that is not fast enough for the impedance of the chamber. deviation.

The present invention provides a substrate processing apparatus that performs fast impedance matching and a method of substrate processing.

The present invention also provides a substrate processing apparatus that performs impedance matching on high frequency power in a wide frequency band and a method of substrate processing.

Embodiments of the present invention provide a substrate processing apparatus including: a high frequency power supply for generating high frequency power; a processing chamber for performing a plasma process by using the high frequency power; a matching circuit And for compensating for a varying impedance of the processing chamber; and a transformer disposed between the processing chamber and the matching circuit to reduce the impedance of the processing chamber.

In some embodiments, the transformer can be a Ruthroff transformer.

In other embodiments, the Ruthroff transformer can be a 1:4 unbalanced-to-unbalanced transformer (1:4).

In other embodiments, the apparatus may further include: an impedance measuring unit for measuring an impedance of the processing chamber; a reflected power measuring unit for measuring a reflected power; and a And a controller for controlling the matching circuit based on the measured values of the impedance measuring unit and the reflected power measuring unit.

In other embodiments, the matching circuit may include a plurality of capacitors disposed in parallel with each other and a plurality of switches respectively connected to the plurality of capacitors; and the controller generates a control signal based on the measured values; and the matching circuit A plurality of switches are opened/closed in response to the control signal.

In other embodiments, the matching circuit can be an inverse-L-type circuit.

In still other embodiments, the processing chamber can include: a housing that provides space to perform a plasma process; and a plasma generator that supplies plasma to the housing by using high frequency power.

In a further embodiment, the plasma generator can be a capacitively coupled plasma (CCP) generator comprising a plurality of electrodes spaced apart from one another in the housing.

In another embodiment, the high frequency power, the matching circuit, and the transformer may be A plurality of high frequency power sources can generate high frequency power of different frequencies; different frequencies can be applied to a plurality of electrodes; and matching circuits and transformers can be connected to each of the electrodes to which high frequency power is applied.

In other embodiments of the present invention, the impedance matching method in the substrate processing apparatus that performs the plasma process by using the high frequency power may include: reducing a variation impedance of a processing chamber by a transformer during the plasma process The transformer is disposed between a matching circuit and a processing chamber; and the reduced impedance is compensated by the matching circuit to perform impedance matching.

In some embodiments, the transformer can be a 1:4 transformer; and the matching circuit can compensate for 1/4 of the impedance change of the processing chamber to perform impedance matching.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings. However, the invention may be embodied in different forms and should not be construed as being limited to the embodiments set forth herein. Rather, the embodiments are provided so that this disclosure will be thorough and complete, and the scope of the invention will be fully conveyed by those skilled in the art.

The substrate processing apparatus 100 according to the present invention will be described below.

The substrate processing apparatus 100 performs a process. The plasma process may include a plasma deposition process, a plasma etching process, a plasma ashing process, and a plasma cleaning process. High frequency power is applied to the source gas to generate plasma, such as during a plasma process. Of course, the substrate processing apparatus 100 can perform various plasma processes other than the above examples.

Further, the substrate herein includes a flat panel display (FPD) and all substrates for fabricating a product having a circuit pattern on the film.

FIG. 1 is a view of a substrate processing apparatus 100.

Referring to FIG. 1, a substrate processing apparatus 100 includes a processing chamber 1000, a high frequency power supply 2000, an impedance matching device 3000, and a transmission line 110. The processing chamber 1000 performs a plasma process by using high frequency power. The high frequency power source 2000 generates high frequency power, and the transmission line 110 connects the high frequency power source 2000 to the processing chamber 1000 and transmits the high frequency power to the processing chamber 1000. The impedance matching device 3000 matches the impedance between the high frequency power source 2000 and the processing chamber 1000.

A substrate processing apparatus 100 according to an embodiment of the present invention will hereinafter be described.

2 is a diagram showing the substrate processing apparatus 100 of FIG. 1 in accordance with an embodiment of the present invention.

Processing chamber 1000 includes a housing 1100 and a plasma generator 1200.

The housing 1100 provides space to perform a plasma process.

The plasma generator 1200 provides plasma to the outer casing 1100. The plasma generator 1200 applies high frequency power to the source gas to generate plasma.

A capacitively coupled plasma generator (CCPG) 1200a can be used as the plasma generator 1200.

The CCPG 1200a can include a plurality of electrodes in the housing 1100.

For example, the CCPG 1200a can include a first electrode 1210 and a second electrode 1220. The first electrode 1210 is disposed on the inner top of the outer casing 1100, and the second electrode 1220 is disposed on the inner bottom of the outer casing 1100. The first electrode 1210 and the second electrode 1220 are vertically disposed parallel to each other. High frequency power is applied to one of the first electrode 1210 and the second electrode 1220 via the transmission line 110, and the other is grounded. Once high frequency power is applied, a capacitive electric field is formed between the first electrode 1210 and the second electrode 1220. The source gas interposed between the first electrode 1210 and the second electrode 1220 is ionized by receiving electric energy from the electric field of the capacitor, and becomes a plasma state. In addition, this source gas can be from outside air A body supply source (not shown) flows into the housing 1100.

The high frequency power source 2000 generates high frequency power. Here, the high frequency power supply 2000 can generate high frequency power in a pulse mode. The high frequency power supply 2000 can generate high frequency power at a specific frequency. For example, the high frequency power supply 2000 can generate power at a frequency of 2 Mhz, 13.56 Mhz, or 100 Mhz. Of course, the high frequency power supply 2000 can generate high frequency power at another frequency than the above frequencies.

Transmission line 110 transmits high frequency power from high frequency power supply 2000 to processing chamber 1000.

Since the high frequency power is transmitted in this way via the transmission line 110, if the impedance at the transmission terminal of the power transmission line 110 does not match the impedance at the reception terminal, a reflected wave occurs, which in turn causes reflected power. In the case of high frequency power, the delayed power occurs in a non-consumptive circuit, such as a capacitor or a capacitor during the transmission process, and thus a reflected wave occurs due to the phase difference. Once such reflected waves occur, the power transmission efficiency decreases. Further, the power from the high frequency power source 2000 to the processing chamber 1000 becomes irregular, so it is difficult to generate plasma or maintain a uniform density. In addition, when reflected waves are accumulated in the processing chamber 1000, arc discharge occurs, which may directly damage the substrate S.

The impedance matching device 3000 can perform impedance matching. Once the impedances are matched, the reflected waves do not occur and the power is transmitted efficiently.

The impedance matching device 3000 may include a matching circuit 3100, a transformer 3200, a controller 3300, an impedance measuring unit 3400, and a reflected power measuring unit 3500.

Matching circuit 3100 matches the impedance at processing chamber 1000 to the impedance at high frequency power supply 2000. Matching circuit 3100 includes circuitry such as a capacitor or inductor. All or some of the circuit devices of the matching circuit 3100 It can be a variable circuit device.

FIG. 3 is a circuit diagram showing the matching circuit 3100 of FIG. 2.

According to an embodiment of the invention, the matching circuit 3100 can include a variable capacitor 3110 and an inductor 3120. Referring to FIG. 3, the variable capacitor 3110 can be connected in parallel to the transmission line 110 and the inductor 3120 can be connected in series to the transmission line 110. The matching circuit 3100 adjusts the capacitance of the variable capacitor 3110 to achieve impedance matching.

The variable capacitor 3110 can include a plurality of capacitors 3111 and a plurality of switches 3112. A plurality of capacitors 3111 can be connected in parallel to each other. A plurality of switches 3112 are respectively coupled to a plurality of capacitors 3111 and are closable or open in response to control by controller 3300 (described later).

The switch 3112 can adjust the short circuit of the capacitor and the high frequency transmission line 110 in response to the control signal from the controller 3300. A plurality of capacitors are coupled to switch 3112, which regulates the short circuit of the capacitors. For example, the controller 3300 transmits a control signal for controlling the short circuit of the switch 3112, and the switch 3112 adjusts the short circuit of each capacitor according to the control signal.

A digital switch can be used as the switch 3112. For example, switch 3112 can include an RF relay, a PIN diode, and a metal oxide semiconductor field effect transistor (MOSFET). The digital switch opens/closes the corresponding capacitor 3110 in response to the on/off signal, so the digital switch can respond to the speed compensated impedance faster than the mechanically driven switch. Therefore, the response speed of the impedance matching is improved, the delay time is reduced, and the reflected wave is removed.

The capacitance of the variable capacitor 3110 can be determined based on the combination of states of the switches 3112. That is, the capacitance of the variable capacitor 3110 can be determined based on the sum of the capacitances of the capacitors 3111 having the closed switches 3112 among the capacitors 3111 connected in parallel.

Here, the plurality of capacitors 3111 may have the same capacitance. In addition, the ratio of the capacitance of the plurality of capacitors 3111 may be 1:2:3:...:n:. In addition, the ratio of the capacitance of the plurality of capacitors 3111 may be 1:21:22:...:2n:.

Since the total capacitance of the variable capacitor 3110 is the sum of the connected capacitors 3111, when the capacitor 3111 has a capacitance according to the above value, the capacitance of the variable capacitor 3110 is easy to control and can be applied to a wide range.

However, although the matching circuit 3100 including a variable capacitor 3110 and the inductor 3120 has been described above, the type, number, and connection relationship of the circuit devices constituting the matching circuit 3100 may be different from the above description.

4 is a circuit diagram showing the matching circuit 3100 of FIG. 2 in accordance with another embodiment. FIG. 5 is a circuit diagram showing the matching circuit 3100 of FIG. 2 in accordance with another embodiment.

Referring to FIG. 4, a matching circuit 3100 can be implemented using an L-type circuit including a variable capacitor 3110a connected in parallel to the transmission line 110, and a capacitor 3110b and an inductor 3120 connected in series to the transmission line 110. In addition, referring to FIG. 5, the matching circuit 3100 can be implemented using a π-type including an inductor 3120 connected in series to the transmission line 110, and a variable capacitor 3110a and a capacitor 3110b connected in parallel to the transmission line 110. Of course, the matching circuit 3100 can be implemented using an inverted L-type circuit, various typical circuits, and, if necessary, appropriately modified circuits.

A transformer 3200 is mounted on the transmission line 110 to transform the impedance at the input side and the output side.

FIG. 6 is a circuit diagram showing the transformer 3200 of FIG. 2, in accordance with an embodiment. FIG. 7 is a plan view showing the transformer 3200 of FIG. 6 in accordance with an embodiment.

Referring to Figure 6, a Ruthroff transformer can be used as the transformer 3200. Ruthroff The transformer performs impedance conversion for wide bandwidth and has excellent transmission efficiency. Figures 6 and 7 show a 1:4 unbalanced to unbalanced Ruthroff transformer. As shown in FIG. 7, the 1:4 Ruthroff transformer can be fabricated by winding a strand on a toroidal core via a bootstrap principle. At this time, if the first coil L1 and the second coil L2 have the same value, the conversion ratio between the impedance at the output side and the impedance at the input side is 1:4.

If the number of strands wound around the core is increased in the Ruthroff transformer, the impedance conversion ratio is changed. In the case of three strands, the 1:2.25 unbalanced to unbalanced transformer operates. In the case of four strands, a conversion ratio of 1:1.78 is provided.

In addition, when the Ruthroff transformers are connected in series, a large conversion ratio can be provided.

Fig. 8 is a view when a plurality of transformers 3200 of Fig. 6 are connected.

Referring to FIG. 8, when two 1:4 unbalanced to unbalanced transformers are connected in series, the initial output side has a 1:4 conversion ratio with respect to the input side, and the conversion ratio of the final output side to the initial output side becomes 1 again: 4. Therefore, the impedance conversion ratio between the final output side and the input side becomes 1:16.

In the substrate processing apparatus 100, the transmission line 110 is connected from the high frequency power supply 2000 to the processing chamber 1000, and the matching circuit 3100 and the transformer 3200 are connectable between the high frequency power supply 2000 and the processing chamber 1000. That is, the transmission line 110 can sequentially connect the high frequency power supply 2000, the matching circuit 3100, the transformer 3200, and the processing chamber 1000.

Therefore, based on the transformer 3200, the high frequency power supply 2000 and the matching circuit 3100 are disposed on the input side of the transformer 3200, and the processing chamber 1000 is disposed on the output side. Therefore, the transformer 3200 can reduce the impedance at the processing chamber 1000.

In general, high frequency power supply 2000 has a fixed impedance of, for example, about 50 ohms, but processing chamber 1000 has an impedance of at least a few ohms up to 300 ohms during the plasma process. When the impedance of the processing chamber 1000 is delivered to the input side via the transformer 3200, in the case of a 1:4 unbalanced to unbalanced transformer, it is reduced by about 70 ohms. Therefore, even when the impedance of the processing chamber 1000 is significantly changed by several hundred ohms in the matching circuit 3100 connected to the input side, the matching can be matched by making the adjustment amount of the impedance equal to the amount by which the impedance is reduced according to the conversion ratio. The impedance between the chamber 1000 and the high frequency power source 2000.

In particular, when power is supplied to the processing chamber 1000 in a pulsed mode and plasma is generated by a high-speed pulse at the beginning of the plasma processing, the impedance changes drastically. Next, the matching circuit 3100 compensates for the varying impedance reduced by the transformer 3200 to match the impedance. Therefore, the impedance matching speed can be improved.

FIG. 9 is a graph showing a change in current caused by the transformer 3200 of FIG. FIG. 10 is a graph showing a voltage change caused by the transformer 3200 of FIG. FIG. 11 is a graph showing changes in impedance caused by the transformer 3200 of FIG.

Referring to Figures 9 and 10, in the case of a 1:4 unbalanced to unbalanced Ruthroff transformer and a high frequency power of 2 Mhz, the current and voltage are on the high frequency power supply 2000 side compared to the processing chamber 1000 side. The value is increased by a factor of two and the impedance is reduced to 1/4.

However, the transformer 3200 is not limited to the above examples, and the Ruthrof transformer may be replaced by a transformer that performs its same or similar function.

The controller 3300 generates a control signal for impedance compensation based on the measured values of the impedance measuring unit 3400 and the reflected power measuring unit 3500, and transmits the control signal to the matching circuit 3100 to control the matching circuit. Here, the impedance measuring unit 3400 measures the impedance of the processing chamber 1000 and transmits the measured value to the controller 3300. In addition, the reflected power measuring unit 3500 measures the reflected power caused by the reflected wave, and transmits the measured value to the controller 3300.

For example, the control signal turns on/off a plurality of switches 3120 in the matching circuit 3100. When the switch 3120 is turned on or off in response to the control signal in the matching circuit 3100, the capacitance of the matching circuit can be adjusted.

The controller 3300 can be implemented by a computer or a computer-like device using hardware, software, or a combination thereof.

In terms of hardware, special application integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), The controller 3300 is implemented by a processor, a microcontroller, a microprocessor, or an electrical device similar to the above-described apparatus that performs control functions.

Additionally, in the case of software, the controller 3300 can be implemented with a software code or software application written in at least one programming language. In addition, the soft system is installed when it is transferred from an external device such as a software server to the above hardware configuration.

The substrate processing apparatus 100 is described based on a processing chamber 1000 including a CCPG 1200a in which a single frequency of high frequency power is applied to the CCPG 1200a, but the substrate processing apparatus 100 may be different from the above description.

12 to 14 are views showing modifications of the substrate processing apparatus 100 of Fig. 1.

Referring to FIG. 12, inductively coupled plasma generator (ICPG) 1200b can be used in processing chamber 1000 in substrate processing apparatus 100 instead of CCPG 1200a. ICPG 1200b flows into the processing chamber 1000 around the source gas Part of it is installed to form an induced electric field. Therefore, the source gas flowing into the processing chamber 1000 is ionized by the induced electric field and becomes a plasma state.

In addition, the processing chamber 1000 in the substrate processing apparatus 100 can perform a plasma process by simultaneously using high frequency power of different frequencies. In the case of the plasma etching process, when the plasma process is performed using a plurality of different high-frequency powers, a more excellent effect can be obtained as compared with the case of using a single-frequency high-frequency power.

Referring to Fig. 13, the two electrodes 1210a and 1210b of the CCPG 1200a in the substrate processing apparatus 100 can be respectively connected to two high frequency power sources 2000a and 2000b, and the high frequency power sources 2000a and 2000b generate high frequency power of different frequencies. Therefore, different high frequency power is applied to the first electrode 1210a and the second electrode 1210b, and thus the plasma process is performed by simultaneously using two high frequency powers of different frequencies.

Referring to Figure 14, three different frequencies can be used in the substrate processing apparatus 100. For example, the first electrode 1210a is disposed on top of the outer casing 1100, and the second electrode 1210b and the third electrode 1210c are disposed below and spaced apart from the first electrode 1210a. At this time, the high-frequency power sources 2000a, 2000b, and 2000c for generating different first high-frequency power, second high-frequency power, and third high-frequency power are connected to the electrodes 1210a, 1210b, and 1210c, respectively. Therefore, the plasma process is performed in the processing chamber 1000 by simultaneously using three high frequency powers. For example, the first high frequency power, the second high frequency power, and the third high frequency power may be 2 Mhz, 13.6 Mhz, and 100 Mhz, respectively. Further, in the same case, the second electrode 1210b and the third electrode 1210c may be integrally provided.

When frequencies having a wide bandwidth are simultaneously used as above, it is difficult to predict the change in impedance and match the impedance due to different bandwidths. However, Ruthroff transformers are designed for wide bandwidth conversion impedance and are therefore used effectively.

FIG. 15 is a view showing impedance matching in the substrate processing apparatus 100 of FIG.

Referring to Figure 15, when using a 1:4 unbalanced to unbalanced Ruthroff transformer, the impedance is matched to the 50 ohm fixed impedance of the high frequency power supply 2000 side for the three bandwidths of Mhz, 13.6 Mhz, and 100 Mhz.

An impedance matching method using the substrate processing apparatus 100 according to the present invention will be described below. However, the impedance matching method can be performed by using the same or similar device as the substrate processing apparatus 100 described above. Additionally, the impedance matching method can be stored in a computer readable recording medium via a code or program for executing the method.

In the case of the impedance matching method, the source gas first flows into the processing chamber 1000 from a gas supply source (not shown). Once the source gas flows, the high frequency power source 2000 generates high frequency power and transmits the generated high frequency power to the plasma generator 1200 via the transmission line 110. The plasma generator 1200 generates a plasma by ionizing the source gas with the high frequency power. Once the plasma is generated, the processing chamber 1000 processes the substrate by using the plasma. Therefore, when plasma is generated and the substrate is processed, various process conditions such as impurities from the substrate, density of the plasma, type of source gas, and internal temperature and internal pressure of the processing chamber 1000 may change the plasma impedance or process. The impedance of the chamber 1000. In particular, the impedance can vary drastically at the beginning of the plasma process that provides high frequency power in pulsed mode.

The impedance measuring unit 3400 measures the impedance of the processing chamber 1000 and applies the measured value to the controller 3300. In addition, impedance matching can be broken when the impedance changes, and due to this, a reflected wave can occur. At this time, the reflected power measuring unit 3500 measures the reflected power of the high frequency power supply 2000 side, and applies the measured value to the controller 3300.

The controller 3300 obtains the measured values from the impedance measuring unit 3400 and the reflected power measuring unit 3500 to generate a control signal, and transmits the generated control signal to the matching circuit 3100.

In matching circuit 3100, a plurality of switches 3112 are opened or closed in response to the control signal. The capacitance of the variable capacitor 3110 is adjusted to the sum of the capacitances of the capacitors 3111 connected to the closed switches 3112 of the plurality of switches 3112. Therefore, impedance matching is performed at the high frequency power source 2000 and the processing chamber 1000. However, the circuit configuration of the matching circuit 3100 is not limited to the variable capacitor 3110. Even in some different configurations, the impedance can be compensated in a similar manner in response to the control signal.

The controller 3300 transmits a digital signal during the impedance matching process, and the digital switch 3112 implemented by the diode or the transistor is turned on/off in response to the control signal, so the digital switch compensates the impedance faster than the mechanical switch. .

Here, the matching circuit 3100 can perform impedance matching on the actual varying impedance in the processing chamber 1000 by compensating for the variation that is reduced via the transformer 3200. Transformer 3200 is disposed between matching circuit 3100 and processing chamber 1000 such that the transformer can reduce the impedance of processing chamber 1000 at matching circuit 3100. When a 1:4 unbalanced to unbalanced Ruthroff transformer is used, the impedance of the process chamber 1000 is reduced to 1/4. Therefore, the matching circuit 3100 compensates for an impedance equal to 1/4 of the impedance variation in the processing chamber 1000 in order to perform impedance matching.

In particular, since the impedance of the processing chamber 1000 changes drastically when power is supplied in the initial pulse mode of the plasma process, the matching circuit 3100 uses a digital switch, so a minimum delay time can occur. However, since the impedance variation of the processing chamber is reduced and the response speed of the matching circuit 3100 is improved, The reflected wave is minimized.

According to the present invention, the matching circuit compensates for the impedance variation that is reduced via the transformer even when the impedance of the processing chamber changes drastically. Therefore, a quick match is possible.

According to the present invention, since the impedance matching is fast, the delay time is reduced and the reflected waves are removed to prevent arcing during the processing chamber. Therefore, the process efficiency is improved.

According to the present invention, since a Ruthroff transformer is used, impedance matching is performed for high frequency power of various frequencies having a wide bandwidth.

The above-disclosed subject matter is to be construed as illustrative and not limiting, and all such modifications, enhancements, and other embodiments are intended to be included within the scope of the invention. The scope of the present invention is to be construed as being limited by the scope of the appended claims and the claims.

L1‧‧‧ first coil

L2‧‧‧second coil

S‧‧‧Substrate

100‧‧‧Substrate processing unit

110‧‧‧ transmission line

110a‧‧‧ transmission line

110b‧‧‧ transmission line

1000‧‧‧Processing chamber

1100‧‧‧ Shell

1200‧‧‧ Plasma generator

1200a‧‧‧Capacitively Coupled Plasma Generator (CCPG)

1200b‧‧‧Inductively Coupled Plasma Generator (ICPG)

1210‧‧‧First electrode

First electrode / first electrode of 1210a‧‧ CCPPG 1200a

Second electrode/second electrode of 1210b‧‧‧CCPG‧‧‧1200a

1210c‧‧‧ third electrode

1220‧‧‧second electrode

1220a‧‧‧second electrode

2000‧‧‧High frequency power supply

2000a‧‧‧High frequency power supply

2000b‧‧‧High frequency power supply

2000c‧‧‧High frequency power supply

3000‧‧‧ impedance matching device

3000a‧‧‧ impedance matching device

3000b‧‧‧ impedance matching device

3000c‧‧‧ impedance matching device

3100‧‧‧Matching circuit

3100a‧‧‧matching circuit

3110‧‧‧Variable capacitor

3110a‧‧‧Variable Capacitor

3110b‧‧‧ capacitor

3111‧‧‧ capacitor

3112‧‧‧Switch

3120‧‧‧Inductors/Switches

3200‧‧‧Transformer

3200a‧‧‧Transformer

3200b‧‧‧Transformer

3300‧‧‧ Controller

3400‧‧‧ Impedance measurement unit

3500‧‧‧reflection power measurement unit

3500a‧‧‧reflection power measurement unit

3500b‧‧‧reflection power measurement unit

The accompanying drawings are included to provide a further understanding of the invention The drawings illustrate exemplary embodiments of the invention and, together, 1 is a view of a substrate processing apparatus; FIG. 2 is a view showing a substrate processing apparatus of FIG. 1 according to an embodiment of the present invention; and FIG. 3 is a view showing an embodiment of the present invention. 2 is a circuit diagram of a matching circuit; FIG. 4 is a diagram showing the matching power of FIG. 2 according to another embodiment of the present invention. FIG. 5 is a circuit diagram showing the matching circuit of FIG. 2 according to another embodiment of the present invention; FIG. 6 is a circuit diagram showing the transformer of FIG. 2 according to an embodiment of the present invention; A plan view of the transformer of FIG. 6 according to an embodiment of the present invention; FIG. 8 is a view when a plurality of transformers of FIG. 6 are connected; FIG. 9 is a view showing a change of current caused by the transformer of FIG. 10 is a view showing a voltage change caused by the transformer of FIG. 6. FIG. 11 is a view showing a change in impedance caused by the transformer of FIG. 6. FIG. 12 to FIG. 14 are views showing a modification of the substrate processing apparatus of FIG. FIG. 15 is a view showing impedance matching in the substrate processing apparatus of FIG. 14.

100‧‧‧Substrate processing unit

110‧‧‧ transmission line

1000‧‧‧Processing chamber

1100‧‧‧ Shell

1200a‧‧‧Capacitively Coupled Plasma Generator (CCPG)

1210‧‧‧First electrode/first electrode of CCPG 1200a

1220‧‧‧Second electrode/second electrode of CCPG 1200a

2000‧‧‧High frequency power supply

3000‧‧‧ impedance matching device

3100‧‧‧Matching circuit

3200‧‧‧Transformer

3300‧‧‧ Controller

3400‧‧‧ Impedance measurement unit

3500‧‧‧reflection power measurement unit

Claims (11)

A substrate processing apparatus comprising: a high frequency power supply for generating high frequency power; a processing chamber for performing a plasma process by using the high frequency power; and a matching circuit for compensating One of the processing chambers varies impedance; and a transformer is disposed between the processing chamber and the matching circuit to reduce the impedance of the processing chamber. The device of claim 1, wherein the transformer is a Ruthroff transformer. The apparatus of claim 2, wherein the Ruthroff transformer is a 1:4 unbalanced to unbalanced transformer. The apparatus of any one of claims 1 to 3, further comprising: an impedance measuring unit for measuring an impedance of the processing chamber: a reflected power measuring unit for the amount Measuring a reflected power; and a controller for controlling the matching circuit based on the measured values of the impedance measuring unit and the reflected power measuring unit. The device of claim 4, wherein the matching circuit comprises a plurality of capacitors disposed in parallel with each other and a plurality of switches respectively connected to the plurality of capacitors; the controller generates a control signal based on the measured values; And the matching circuit opens/closes the plurality of switches in response to the control signal. The device of any one of claims 1 to 3, wherein the The matching circuit is an inverted L-type circuit. The apparatus of any one of claims 1 to 3, wherein the processing chamber comprises: a housing that provides a space for performing the plasma process; and a plasma generator that uses the high The frequency power supplies the plasma to the outer casing. The device of claim 7, wherein the plasma generator is a capacitively coupled plasma (CCP) generator comprising a plurality of electrodes spaced apart from each other in the housing. The device of claim 8, wherein the high frequency power, the matching circuit and the transformer are plural; the high frequency power source generates high frequency power of different frequencies; the different frequencies are applied to the plurality of electrodes; And the matching circuit and the transformer are connected to each of the electrodes to which the high frequency power is applied. An impedance matching method in a substrate processing apparatus for performing a plasma process by using high frequency power, the method comprising: reducing a change impedance of a processing chamber by a transformer during the plasma process, The transformer is disposed between a matching circuit and a processing chamber; and the reduced impedance is compensated by the matching circuit to perform impedance matching. The method of claim 10, wherein the transformer is a 1:4 transformer; and the matching circuit compensates 1/4 of a change in impedance of the processing chamber to perform impedance matching.