KR20120077509A - Adjustable capacitor, plasma impedance matching system and the methode - Google Patents

Abstract

The present invention relates to an apparatus and a method for matching an impedance of plasma in a processing apparatus using a plasma of a variable capacitor and a semiconductor manufacturing facility, wherein a variable capacitor including a plurality of capacitors grouped into n groups has a capacitance control for each group By setting the range and controlling the capacitance by electrically switching the selected capacitor according to the capacitance control value according to the controller's digital control signal, the capacitance is adjusted to match the impedance between the high frequency power supply and the process chamber.

Description

Variable Capacitor, Plasma Impedance Matching Device and its Method {ADJUSTABLE CAPACITOR, PLASMA IMPEDANCE MATCHING SYSTEM AND THE METHODE}

The present invention relates to a variable capacitor, a plasma impedance matching apparatus and a method thereof, and more particularly, to a variable capacitor for adjusting capacitance, an apparatus and method for matching impedance of plasma in a process apparatus using plasma in a semiconductor manufacturing facility. It is about.

Plasma impedance matching device using high frequency power is an important matcher for generating and maintaining plasma as an impedance matcher for maximally delivering high frequency power to the plasma process chamber.

When the high frequency power supply delivers power to the process chamber that generates the plasma, the impedance of the power supply and the plasma must be the same in order for the maximum power to be delivered without the reflected wave, and adjusting the impedance to have such electrical characteristics is called impedance matching. do.

In the plasma, the impedance, which is an electrical characteristic, changes according to the generated conditions such as pressure, high frequency power, and gas used.If the plasma impedance is not matched with the impedance of the power of the high frequency power source, the constant power cannot be delivered, so the plasma density during the process This results in the problem that the variation in process results is high. Therefore, impedance matching must be considered in order to constantly transmit high frequency power into the process chamber, and an impedance matching device is provided between the high frequency power source and the plasma generator in the process chamber.

In general, the impedance matching device is composed of a variable capacitor and an inductor, and the impedance matching is implemented to adjust the variable capacitor so that the impedance of the high frequency power source and the impedance of the process chamber are the same.

A variable capacitor of a typical impedance matching device changes capacitance by changing a capacitor spacing by using a driving means coupled to a stepping motor and a gear stage, thereby changing impedance of a high frequency power source.

However, since the capacitor is adjusted by the mechanical drive means, the preparation time for adjustment is longer by the operating time of the drive means, and precise control is difficult. In particular, when the high frequency power supply supplies power in the pulse mode, fast impedance matching is difficult because the plasma state changes rapidly at a high speed pulse.

It is an object of the present invention to provide a variable capacitor that more accurately and quickly adjusts the capacitance adjustment value required for impedance matching.

It is an object of the present invention to provide a plasma impedance matching device and a method for more accurate and faster matching in plasma impedance matching.

The problem to be solved by the present invention is not limited thereto, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

In the variable capacitor according to the exemplary embodiment of the present invention, a plurality of capacitors grouped into n groups (n is a natural number of 2 or more) and a switch connected to each of the capacitors are interrupted according to a control signal. Including, but adjustable capacitance range according to each group is characterized in that different from each other.

In addition, each of the groups is characterized in that it comprises a plurality of capacitors.

In addition, the groups are characterized in that connected in parallel to each other.

In addition, the plurality of capacitors in each group may be connected in parallel with each other.

In addition, the capacitors belonging to the same group are characterized by having the same capacitance.

In addition, the plurality of capacitors in each capacitor group is characterized by having the same capacitance.

In addition, the plurality of capacitors in each capacitor group is characterized by having nine capacitors.

In addition, the ratio between the capacitance of the capacitor group 1:10:10 ^2: 10 ³ ..... 10 characterized by consisting of a ^{n- 1.}

In addition, the switch is characterized in that consisting of a pin diode.

In accordance with an aspect of the present invention, there is provided a plasma impedance matching device, including a variable capacitor connected to a transmission path of high frequency power to match a plasma impedance, and a controller for transmitting a control signal to the variable capacitor. The variable capacitor includes a plurality of capacitors grouped into n groups (n is a natural number of 2 or more) and a switch connected to each of the capacitors to be controlled according to a control signal, and the capacitance ranges adjustable according to each group are different from each other. It is characterized by different things.

In addition, each of the groups is characterized in that it comprises a plurality of capacitors.

In addition, the groups are characterized in that connected in parallel to each other.

In addition, the plurality of capacitors in each group is characterized in that connected in parallel to each other.

In addition, the capacitors in the same group is characterized by having the same capacitance.

In addition, the plurality of capacitors in each group is characterized by having nine capacitors.

In addition, the ratio between the capacitance of the capacitor group 1:10:10 ^2: 10 ³ ..... 10 characterized by consisting of a ^{n- 1.}

In addition, the high frequency power supply is characterized in that for supplying power in the pulse mode.

In order to achieve the above object, a substrate processing apparatus according to an embodiment of the present invention includes a high frequency power source for outputting high frequency power to the electrode through a high frequency transmission line and an electrode for generating a plasma from a gas supplied into the process chamber and the process chamber; A variable capacitor connected to the high frequency transmission line to match an impedance of high frequency power and a controller for transmitting a control signal to the variable capacitor, wherein the variable capacitor is divided into n groups (n is a natural number of 2 or more) Capacitor and a switch connected to each of the capacitors are intermittent according to the control signal, characterized in that the adjustable capacitance range according to each group is different from each other.

In addition, each of the groups is characterized in that it comprises a plurality of capacitors.

In addition, the groups are characterized in that connected in parallel to each other.

In addition, the plurality of capacitors in each group is characterized in that connected in parallel to each other.

In addition, the capacitors in the same group is characterized by having the same capacitance.

In addition, the plurality of capacitors in each capacitor group is characterized by having nine capacitors.

In addition, the ratio between the capacitance of the capacitor group 1:10:10 ^2: 10 ³ ..... 10 characterized by consisting of a ^{n- 1.}

In order to achieve the above object, in the plasma impedance matching method of the semiconductor manufacturing equipment according to an embodiment of the present invention, generating a plasma in the process chamber by a high frequency power supply, measuring the impedance of the plasma and the plasma Determining a capacitance adjustment value corresponding to the impedance measurement value, and determining whether to operate the variable capacitor according to the capacitance adjustment value, and matching impedance, wherein the capacitance adjustment value is 10 ^n-1 (n is a natural number). ) when it has a digit capacitance of digit capacitance of one of said capacitance adjustment value of the first variable capacitor group is to control, in a 10-digit capacitance of the second variable capacitor group digit capacitance, 10 ² are so controlled To adjust the third variable capacitor group, .... 10 The digit capacitance of ^n-1 is determined by the operation of each variable capacitor group to be controlled by the nth variable capacitor group, and the capacitor to switch according to the capacitance adjustment value in the variable capacitor group in which the operation is determined is digital control signal. It characterized in that it comprises the step of selecting by.

In addition, the plurality of capacitors in the same variable capacitor group has the same capacitance.

In addition, the plurality of capacitors in each variable capacitor group is characterized by having nine capacitors.

According to the present invention, the capacitance can be adjusted more accurately and quickly.

According to the present invention, the reflected power can be minimized by effectively performing plasma impedance matching.

According to the present invention, it is possible to minimize the process failure of the substrate by minimizing the reflected power.

1 is a block diagram showing a substrate processing apparatus combined with a plasma impedance matching apparatus according to an embodiment of the present invention.
2 is a block diagram showing a substrate processing apparatus combined with a plasma impedance matching apparatus according to another embodiment of the present invention.
3 is a block diagram showing a substrate processing apparatus combined with a plasma impedance matching apparatus according to another embodiment of the present invention.
Figure 4 is a block diagram showing a plasma impedance matching device according to an embodiment of the present invention.
5 is a block diagram showing a plasma impedance matching device according to another embodiment of the present invention.
6 is a schematic diagram illustrating a variable capacitor according to an embodiment of the present invention.
7 is a schematic diagram illustrating a variable capacitor according to another embodiment of the present invention.

The embodiments of the present invention can be modified into various forms and the scope of the present invention should not be interpreted as being limited by the embodiments described below. This embodiment is provided to more completely explain the present invention to those skilled in the art. Therefore, the shape of the components in the drawings, etc. are exaggerated in order to emphasize a more clear description.

1 to 3 are diagrams illustrating various substrate processing apparatuses in which a plasma impedance matching apparatus is coupled according to an embodiment of the present invention.

1 to 3, the substrate processing apparatus 1000 to which the plasma impedance matching apparatus 1200 of the present invention is coupled includes a process chamber 1160, an electrode 1170, a high frequency power supply 1110, and a plasma impedance matching apparatus. (1200).

The substrate processing apparatus 1000 is an apparatus for treating a substrate using the same by changing a gas into a plasma state in the process chamber 1160.

The process chamber 1160 performs a substrate processing process using plasma, and the electrode 1170 supplies electrical energy such that a gas flowing into the process chamber 1160 is ionized to change into a plasma state. The electrode 1170 is a capacitively coupled plasma source (CCP) consisting of two electrode plates parallel to the process chamber 1160 or an inductively coupled plasma source (ICP) consisting of an induction coil outside the process chamber. Plasma).

1 and 2, a capacitively coupled plasma source delivers electrical energy to electrons of a gas introduced into the process chamber 1160 using a capacitive electric field. The capacitively coupled plasma source has a form in which a high frequency power source is connected to two electrode plates, or a high frequency power source is connected only to an upper electrode plate of two electrode plates.

Referring to FIG. 3, an inductively coupled plasma source delivers electrical energy to electrons of a gas flowing into the process chamber 1160 using an induction electric field. The inductively coupled plasma source is separately coupled to the plasma generating apparatus above the process chamber 1160 to change the gas introduced into the plasma state and provide the plasma to the process chamber 1160 in a down stream manner.

The high frequency power supply 1110 supplies high frequency power to the electrodes in the process chamber 1160 through the high frequency transmission line 1120 to change electrons of the gas supplied into the process chamber 1160 into a plasma state. The high frequency power supply 1110 may supply power in a pulse mode.

The plasma impedance matching device 1200 includes a variable capacitor 1300 and a controller 1250.

Figure 4 is a block diagram showing a plasma impedance matching device according to an embodiment of the present invention.

5 is a block diagram showing a plasma impedance matching device according to another embodiment of the present invention.

4 and 5, the plasma impedance matching device 1200 is disposed between a high frequency power supply 1110 for supplying high frequency power and a process chamber 1160 for plasma processing the substrate.

The variable capacitor 1300 matches the impedance between the high frequency power supply 1110 and the process chamber 1160.

The variable capacitor 1300 is connected to the high frequency transmission line 1120, and the capacitance is changed according to the control signal transmitted from the controller 1250.

The variable capacitor 1300 includes a plurality of capacitors grouped into n groups (n is a natural number). That is, the variable capacitor 1300 is composed of n variable capacitor groups. Each variable capacitor group 1310, 1320, ... 13 [n-1] 0, 13 [n] 0 is connected in parallel with each other. There may be one or more variable capacitors 1300 and 1400 composed of n groups.

The variable capacitor groups 1310, 1320, ... 13 [n-1] 0, 13 [n] 0 provide from the first variable capacitor group 1310 to the n th variable capacitor group 13 [n] 0. .

Each variable capacitor group 1310, 1320, ... 13 [n-1] 0, 13 [n] 0 has a different adjustable capacitance range.

When the capacitance to be adjusted in the plasma impedance matching device 1200 has a capacitance of 10 ^n-1 digits, the capacitance of 1 digit of the capacitance adjustment value is adjusted by the first variable capacitor group 1310, and The capacitance of the digit is adjusted by the second variable capacitor group 1320, the capacitance of the digit of 10 ² is adjusted by the third variable capacitor group 1330, and the capacitance of the digit of 10 ^n-2 is n- Each capacitor group 1310, 1320, so that the variable capacitor group 13 [n-1] 0 is adjusted, and the digit capacitance of 10 ^n-1 is adjusted by the nth variable capacitor group 13 [n] 0. .13 [n-1] 0,13 [n] 0) defines the capacitance range to be adjusted. For example, when the capacitance adjustment value is 123, the first variable capacitor group adjusts the value 3 using the capacitor, the second variable capacitor group adjusts the value 20 using the capacitor, and the third variable capacitor group uses the capacitor. To adjust 100.

6 is a schematic diagram illustrating a variable capacitor according to an embodiment of the present invention.

7 is a schematic diagram illustrating a variable capacitor according to another embodiment of the present invention.

6 and 7, each variable capacitor group 1310, 1320, ... 13 [n-1] 0, 13 [n] 0 is a capacitor (1312, 1322, ... 13 [n-1) ] 2,13 [n] 2) and switches 1314,1324, ... 13 [n-1] 4,13 [n] 4).

Capacitors 1312, 1322, ... 13 [n-1] 2, 13 [n] 2 are switches 1314, 1324, ... 13 [n-1] for supplying high frequency power in high frequency transmission line 1120. ] 4,13 [n] 4). Capacitors 1312,1322, ... 13 [n-1] 2,13 [n] 2 may be configured in plural and capacitors 1312,1322, ... 13 [n-1] 2,13 [n 2) Switches 1314, 1324, ... 13 [n-1] 4, 13 [n] 4 are connected to each other. Each variable capacitor group 1310, 1320, ... 13 [n-1] 0, 13 [n] 0 has a plurality of capacitors (1312, 1322, ... 13 [n-1] 2, 13 [n] 2) Adjust the capacitance by interrupting the switches (1314, 1324, ... 13 [n-1] 4, 13 [n] 4) connected to each other.

Capacitors 1312, 1322, ... 13 [n-1] 2, 13 [n] 2 in each variable capacitor group 1310, 1320, ... 13 [n-1] 0, 13 [n] 0 Can be connected in parallel with each other. At this time, the capacitance in each variable capacitor group 1310, 1320, ... 13 [n-1] 0, 13 [n] 0 is a plurality of capacitors 1312, 1322, ... 13 [n- connected in parallel. 1] 2,13 [n] 2 of switches 1314,1324, ... 13 [n-1] 4,13 [n] 4) On capacitors 1312,1322, ... 13 [ n-1] 2,13 [n] 2) can be obtained by simply adding the capacitance.

Capacitors 1312, 1322, ... 13 [n-1] 2, 13 [n] 2 in the same group may have the same capacitance. In addition, there may be nine capacitors in each variable capacitor group.

The first variable capacitor group may be provided with nine capacitors having a capacitance of 1, the second variable capacitor group may be provided with nine capacitors having a capacitance of 10, and the third variable capacitor group may have a capacitor having a capacitance of 10 ² . N may be provided, and the n-th variable capacitor group may be provided with nine capacitors having a capacitance of 10 ^n-2 , and the n-th variable capacitor group may be provided with nine capacitors having a capacitance of 10 ^n-1 . Can be.

Accordingly, the first variable capacitor group may adjust capacitances from 1 to 9 as a combination of capacitors having a capacitance of 1 and the switch is on, and the second variable capacitor group is a capacitor having a capacitance of 10. switch is turned on (on) with which to adjust the capacitance of from 10 to 90 by a combination of capacitors, a third variable capacitor group from the combination of the capacitor switch is turned on (on) of the capacitor capacitance 10 ² 10 ² 9 can control the capacitance of up to 10 × ^2, the n-th variable capacitance capacitor group 10 ^n-1 of the capacitor switch is turned on (on) combined with 10 ^{n- 1} from 9 × 10 ^n-1 of the capacitors of the You can adjust the capacitance up to. For example, when the capacitance adjustment value is 123, the first variable capacitor group controls three values by switching on three capacitors having a capacitance of 1, and the second variable capacitor group controls two capacitors having a capacitance of 10. The switch is turned on to adjust 20, and the third variable capacitor group adjusts 100 by switching on one capacitor having a capacitance of 100.

Thus, the plurality of capacitors 1312, 1322, ... 13 [n-1] 2, 13 in each variable capacitor group 1310, 1320, ... 13 [n-1] 0, 13 [n] 0). By combining the capacitances of [n] 2), the capacitance value of the variable capacitor 1300 may be precisely controlled.

The switches 1314, 1324, ... 13 [n-1] 4, 13 [n] 4 are electrically interrupted according to the control signal, and the switches 1314, 1324, ... 13 [n-1] 4, 13 When [n] 4 is on, the capacitors 1312,1322, ... 13 [n-1] 2,13 [n] 2 are powered from the high frequency transmission line 1120. The switches 1314, 1324,... 13 [n-1] 4, 13 [n] 4 can have various forms that are electrically operated, and pin diodes can be used.

The controller 1250 receives the measured value of the impedance in the process chamber 1160 or the measured value of the reflected power on the high frequency transmission line 1120 that enters the high frequency power supply 1110 to receive impedance matching to the variable capacitor 1300. Send the capacitance adjustment value.

The controller 1250 transmits an on / off control signal of the switches 1314, 1324,... 13 [n-1] 4, 13 [n] 4 of the variable capacitor 1300 in response to the capacitance adjustment value. The controller 1250 may switch among the capacitors 1312, 1322, 132, ... 13 [n-1] 2, 13 [n] 2 of the variable capacitor 1300 according to the capacitance adjustment value. Sends a control signal for selecting 13 [n-1] 2, 13 [n] 2). Specifically, the plurality of capacitors 1312, 1322, ... 13 [n] in each variable capacitor group 1310, 1320, ... 13 [n-1] 0, 13 [n] 0 to be selected according to the capacitance adjustment value. Capacitors 1312,1322, ... 13 [n-1] 2,13 [n] 2 selected by selecting a capacitor to be connected to the high frequency transmission line 1120 from -1] 2,13 [n] 2; The control signals are sent to the switches so that the switches 1314, 1324, ... 13 [n-1] 4, 13 [n] 4 are turned on.

The controller 1250 converts an analog signal having a value measured from an electrical characteristic of the high frequency transmission line 1120 into a digital signal, thereby switching the switches 1314, 1324, ... 13 [n-1] 4, 13 [n] 4). Switches 1314, 1324, ... 13 [n-1] 4, 13 [n] 4 operate on digital signals and capacitors 1312, 1322, ... 13 [n-1] 2, 13 [n ] 2) and the high frequency transmission line 1120.

The controller 1250 receives the measured values from the impedance meter 1140 and / or the reflected power meter 1150 to determine a capacitance adjustment value for impedance adjustment between the high frequency power supply 1110 and the process chamber 1160.

The impedance measurer 1140 measures the plasma impedance in the process chamber 1160 and applies an impedance measurement value to the controller 1250.

The reflected power meter 1150 measures the reflected power coming into the high frequency power supply 1110 and applies the reflected power measured value to the controller 1250.

The operation of one embodiment of the plasma impedance matching device of the present invention will be described in detail.

The high frequency power supply 1110 supplies high frequency power to the electrode 1170 through the high frequency transmission line 1120. At this time, the gas flowing into the process chamber 1160 is converted into a plasma state by receiving electrical energy. The process chamber 1160 into which plasma is introduced performs a substrate processing process using plasma. The impedance measurer 1140 measures the plasma impedance in the process chamber 1160 and applies it to the controller 1250, which determines the capacitance adjustment value according to the received plasma impedance measurement. The operation of the variable capacitor 1300 is determined according to the capacitance adjustment value. When the operation of the variable capacitor 1300 is determined, capacitances that can be combined within each variable capacitor group 1310, 1320, ... 13 [n-1] 0, 13 [n] 0 corresponding to the capacitance adjustment value are determined. Select the capacitors 1312, 1322, ... 13 [n-1] 2, 13 [n] 2 to be switched. The controller 1250 sends the digital control signal to the switches 1314, 1324, ... 13 [n-1] 4, 13 [n] 4 of the selected capacitor to activate the switch. The switched capacitors 1312, 1322, ... 13 [n-1] 2, 13 [n] 2 meet the capacitance adjustments required for plasma impedance matching according to their respective capacitance combinations.

Specifically, within each variable capacitor group 1310, 1320, ... 13 [n-1] 0, 13 [n] 0, capacitors 1312, 1322, ... 13 [n-1] 2, 13 [n 2), when the capacitance adjustment value has a capacitance of 10 ^n-1 (n is a natural number), the capacitance of 1 digit of the capacitance adjustment value is controlled by the first variable capacitor group 1310. , the 10-digit capacitance of the second variable capacitor group 1320, the capacitance of the digit, and 10 ² to be adjusted is a third variable capacitor 1330, to a group control, the capacitance of the digit ... 10 ^n-1 Determines whether or not each variable capacitor group operates so that the nth variable capacitor group 13 [n] 0 is adjusted. After this, the capacitors 1312, 1322, ... 13 [n-1 to switch within the variable capacitor groups 1310, 1320, ... 13 [n-1] 0, 13 [n] 0, which are determined to be operated. ] 2,13 [n] 2).

 As such, when the plasma impedance in the process chamber 1160 and the impedance of the high frequency power supply 1110 do not match, the plasma impedance is matched using the variable capacitor 1300 of the plasma impedance matching device 1200.

In one embodiment of the present invention, a plurality of capacitors of the variable capacitor 1300 are connected to each other in parallel. As a result, it is easy to calculate the capacitance of the variable capacitor 1300. However, the present invention is not limited thereto, and the plurality of capacitors of the variable capacitor 1300 may be connected in series with each other.

In one embodiment of the present invention, the high frequency power supply 1110 supplies power in a pulse mode. However, the present invention is not limited thereto, and the high frequency power supply 1110 may supply power at a continuous frequency.

In one embodiment of the present invention, the controller 1250 sends a digital control signal to a switch. However, the present invention is not limited thereto, and the controller 1250 may transmit an analog control signal to a switch.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

1000 substrate processing unit
1110 high frequency power supply 1120 high frequency transmission line
1140 Impedance Meter 1150 Reflective Power Meter
1160 process chamber 1170 electrode
1180 inductors
1200 plasma impedance matching device
1250 controller
1300 Adjustable Capacitors
1310,1320, .. 13 [n-1] 0,13 [n] 0 variable capacitor group
1312,1322, .. 13 [n-1] 2,13 [n] 2 capacitors
1310,1320, .. 13 [n-1] 0,13 [n] 0 switch

Claims (27)

a plurality of capacitors grouped into n groups (n is a natural number); And
A switch connected to each of the capacitors and interrupted according to a control signal,
Adjustable capacitor characterized in that the capacitance range is different from each other according to each group. The method of claim 1,
Wherein each of the groups comprises a plurality of capacitors. The method of claim 2,
And the groups are connected in parallel with each other. The method of claim 3, wherein
And a plurality of capacitors in each group are connected in parallel with each other. The method of claim 4, wherein
And the capacitors belonging to the same group have the same capacitance. The method of claim 5, wherein
And the plurality of capacitors in each group have the same capacitance. The method according to claim 6,
And 9 capacitors in each group. The method of claim 7, wherein
Capacitance ratio between the capacitor of the group is 1:10:10 ² : 10 ³ .....: 10 ^{n- 1} variable capacitor characterized in that consisting of. The method according to claim 1 or 7,
The switch is a variable capacitor, characterized in that consisting of a pin diode. A variable capacitor connected to the transmission path of high frequency power to match the plasma impedance;
And a controller for transmitting a control signal to the variable capacitor.
The variable capacitor
a plurality of capacitors grouped into n groups (n is a natural number); And
A switch connected to each of the capacitors and interrupted according to a control signal,
Plasma impedance matching device, characterized in that the capacitance range is different from each other according to each group. 11. The method of claim 10,
And each of the groups comprises a plurality of capacitors. The method of claim 11,
And said groups are connected in parallel to each other. The method of claim 12,
And a plurality of capacitors connected in parallel to each other in the group. The method of claim 13,
And the capacitors in the same group have the same capacitance. 15. The method of claim 14,
And 9 capacitors in each group. The method of claim 15,
Capacitance ratio between the capacitors of the groups is 1:10:10 ² : 10 ³ .....: 10 ^{n- 1} , characterized in that the plasma impedance matching device. The method according to any one of claims 10 to 16,
And the high frequency power supply supplies power in a pulse mode. Process chambers;
An electrode for generating a plasma from a gas supplied into said process chamber;
A high frequency power supply for outputting high frequency power to the electrode through a high frequency transmission line;
A variable capacitor connected to the high frequency transmission line to match impedance of high frequency power;
A controller for transmitting a control signal to the variable capacitor,
The variable capacitor
a plurality of capacitors grouped into n groups (n is a natural number); And
A switch connected to each of the capacitors and interrupted according to a control signal,
A substrate processing apparatus, characterized in that the capacitance range that is adjustable for each group is different from each other. The method of claim 18,
Wherein each of the groups comprises a plurality of capacitors. The method of claim 19,
And the groups are connected in parallel to each other. 21. The method of claim 20,
And a plurality of capacitors in each group are connected in parallel to each other. 22. The method of claim 21,
And the capacitors in the same group have the same capacitance. The method of claim 22,
And nine capacitors in each group. The method of claim 23,
The capacitance ratio between the capacitors of the groups is 1:10:10 ² : 10 ³ .....: 10 ^{n- 1} , characterized in that the substrate processing apparatus. In the plasma impedance matching method of a semiconductor manufacturing facility,
Generating a plasma in the process chamber by a high frequency power supply;
Measuring an impedance of the plasma;
Determining a capacitance adjustment value corresponding to the plasma impedance measurement value; And
Determining an operation of a variable capacitor according to the capacitance adjustment value to match impedance;
When the capacitance adjustment value has a capacitance of 10 ^n-1 (n is a natural number), the capacitance of one digit of the capacitance adjustment value is adjusted so that the first variable capacitor group adjusts the capacitance of ten digits to zero. second variable capacitor of the variable group to control capacitor groups, of 10 ^2-digit variable capacitor capacitance third group is to adjust, ... capacitance of the digit of the 10 ^n-1 is to regulate the n-th variable capacitor group Determining whether it works; And
And selecting, by a digital control signal, a capacitor to switch in accordance with the capacitance adjustment value in the variable capacitor group in which operation is determined. The method of claim 25,
And a plurality of capacitors in the same variable capacitor group have the same capacitance. The method of claim 26,
And 9 capacitors in each variable capacitor group.

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