KR102143563B1 - RF Filter for Plasma Process - Google Patents

Abstract

The RF filter according to the present invention includes an HF band filter comprising a parallel LC resonance circuit and a series LC resonance circuit connected in parallel to each of the parallel LC resonance circuits through two connection lines connected to a plasma chamber side or a heater side, Equipped with an MF band or LF band filter including a parallel LC resonance circuit and an input parallel capacitor connected in parallel to each of the parallel LC resonance circuits by two connection lines connected to the AC power control supply side, and a single frequency power In the process of using power of multiple frequencies, the parallel LC resonance circuit formed in the RF filter and the series LC resonance circuit connected in parallel to the parallel LC resonance circuit are used to cut off individual frequency power as well as control the impedance for individual frequencies, and a variable capacitor element There is an effect of minimizing the deviation between equipments or the impedance deviation of the RF filter itself due to compensation through.

Description

RF Filter for Plasma Process {RF Filter for Plasma Process}

The present invention relates to an RF filter for an RF plasma process in a semiconductor process, wherein the RF filter is a heater provided in the wafer support assembly of the plasma chamber and a wafer support assembly of the plasma chamber in a plasma chamber that performs a process by generating plasma. The present invention relates to an AC power control supply unit for applying AC power to a heater provided in the heater and an RF filter for a plasma process formed by being connected by two connection lines between the heater and the AC power control supply unit.

With the growth of the IoT and big data markets, the demand for semiconductors and high-spec, highly integrated semiconductor products are continuously increasing rapidly.

In general, semiconductors are completed by performing several steps. In particular, by applying RF power into the plasma chamber to generate plasma, the semiconductor deposition process is performed in a plasma state, and a specific gas to form a desired pattern is plasma It is injected into the chamber to perform an etching process. At this time, process performance can be improved by controlling the temperature between the reaction gas and the wafer. In addition, in order to control the process temperature in the wafer support assembly fixing the wafer in the plasma chamber, the optimum process temperature can be maintained by the heating wire of the heater that generates heat.

On the other hand, recently, as semiconductor process technology becomes more and more finer, the demand for a technology capable of minimizing process deviations such as deviations between process parts and wafer characteristics is increasing rapidly.

That is, as a method of minimizing the above process deviation, continuous research is being conducted in order to minimize the performance deviation between parts to secure reproducibility for each component module of a semiconductor facility or to perform TTTM (Tool to Tool Matching).

According to the prior art Patent Document 1, various technologies for improving process performance according to the optimal plasma chamber impedance condition are proposed, but a heater used for controlling the process temperature in a wafer support assembly that fixes a wafer in a plasma chamber. It has not been able to propose a method for improving the reproducibility of the process by reducing the process deviation by compensating for the impedance deviation of the plasma chamber and the impedance deviation of the RF filter generated by the wafer support assembly.

Meanwhile, in the semiconductor process, the process deviation generated by the heater and the wafer support assembly that generates heat in order to control the process temperature in the wafer support assembly fixing the wafer in the plasma chamber can be divided into two cases as follows.

First, due to the deviation of the wafer support assembly used to improve the process performance through temperature control and the connection part between the heater and the RF filter that generates heat, the impedance of the plasma chamber may be affected, resulting in a process deviation.

That is, in order to control the process temperature in the wafer support assembly that fixes the wafer in the plasma chamber, the temperature of a plurality of heaters generating heat can be measured and controlled at the same temperature. Impedance variation according to frequency may occur in the plasma chamber due to various factors such as a structure and mounting method of the wafer support assembly, as well as impedance variation.

Secondly, as a deviation that may be generated by the component modules of the facility, it may be generated by RF noise due to leakage of RF energy transmitted through RF electrodes formed in the upper and lower portions of the plasma chamber to generate plasma. The characteristic deviation of the RF filter that may be caused or the characteristics of the RF filter may change during the process.

In other words, when impedance deviation occurs in the RF filter itself formed by being connected between the heater inside the wafer support assembly and the AC power control supply unit for applying AC power to the heater to block the leakage of RF energy as described above, RF The impedance variation of the filter itself may slightly affect the impedance of the process plasma chamber, and such a minute change in the impedance of the plasma chamber has emerged as a problem that cannot be overlooked in an increasingly subtle process.

On the other hand, prior art Patent Documents 2 to 4 are inventions including a heater for temperature control and an RF filter for process improvement according to the prior art, which are transmitted through upper and lower RF electrodes provided to generate plasma in a plasma chamber. A technique for preventing RF energy from leaking through a heater inside a wafer support assembly fixing a wafer has been proposed.

However, in the prior art Patent Documents 2 to 4 according to the prior art, in order to prevent leakage of RF energy transmitted through the upper and lower RF electrodes provided for generating plasma in the plasma chamber, a temperature control heater for process improvement Using an RF filter connected between the heater inside the wafer support assembly and the AC power control supply unit for applying AC power to the heater, the RF filter is used to determine the impedance deviation of the process plasma chamber due to parasitic components that may exist in the wafer support assembly. Methods that can be used to minimize or compensate for the deviation of the RF filter itself, and measures to improve process deviation by minimizing factors that may change the performance of the RF filter due to heat generation of the RF filter due to RF energy. Could not be presented.

Therefore, measures to block RF noise generated due to leakage of RF energy through a heater that generates heat in order to control the process temperature in the wafer support assembly for fixing the wafer, which are the problems according to the prior art as described above, are continuously However, as the recent ultrafine nanoprocessing and ultra-precise semiconductor process technologies such as 3D memory are developed, the technology and process that can minimize the process plasma chamber impedance deviation due to RF filter deviation as well as the function of blocking existing RF noise are developed. The development of technology that can secure reproducibility is more and more urgently required.

In particular, RF filters connected between the heater and the AC power control supply unit for applying AC power to the heater include Iron Power Core, Ferrite Core, Nano & Amorphous Core (( Nano&Amorphorous core) or toroidal core (Toroidal Core), etc. can be formed of a magnetic material, and in the case of forming an RF filter by such a magnetic material, the properties of the magnetic material gradually change over time or the heater The impedance of the RF filter itself may inevitably change because the properties of the magnetic material itself are changed due to unwanted heat generation due to leakage of the AC power applied to the AC power or the RF power used to generate the plasma. Due to the change in the impedance of the RF filter according to the temperature, it may affect the impedance of the process plasma chamber, resulting in process variation.

Therefore, since the RF power level applied to the process plasma chamber or the impedance deviation of the RF filter itself and the impedance of the process plasma chamber may be affected over time, there is an urgent need to develop a technology that can minimize such process deviation. In addition, in the case of performing the RF plasma process by a plurality of multiple RF frequency power instead of a single RF frequency power in order to perform the recent ultra-fine semiconductor process, RF noise generated due to leakage of RF energy is blocked and multiple frequencies. The demand for a technology that can effectively block RF noise even in a process using electric power and minimize the effect on the impedance of the plasma chamber by suppressing heat generation of magnetic material elements is increasing rapidly.

Patent Document 1: Korean Patent Registration No. 10-1054558 (2011.08.04) Patent Document 2: Korean Patent Registration No. 10-1522894 (2015.05.26) Patent Document 3: Korean Patent Publication No. 10-2015-0054767 (2015.05.20) Patent Document 4: Korean Patent Publication No. 10-2007-0118959 (2007.12.18)

In order to solve the problems related to the prior art as described above, the RF filter for the plasma process according to the present invention generates heat in order to control the process temperature in the wafer support assembly in a plasma chamber using plasma generated by applying RF power. Minimizes the plasma chamber impedance deviation that can be caused by the heater generated by the connection between the wafer support assembly and the wafer support assembly, and the plasma chamber impedance deviation due to the impedance change of the RF filter itself or the time due to RF energy during the process. The purpose of this is to minimize the change in the reproducibility of the process due to the change in RF filter characteristics.

More specifically, the RF filter for a plasma process according to the present invention includes a heater, a wafer support assembly, and a wafer support assembly that generate heat to control a process temperature in a wafer support assembly that fixes a wafer in a plasma chamber of a semiconductor process. As a method to improve the process impedance deviation and the process deviation due to the deviation or change of RF filter characteristics, which may occur due to the connection part with, can be classified into the following three cases.

First, the RF filter for a plasma process according to the present invention aims to improve the impedance deviation of the plasma chamber due to the wafer support assembly used to improve process performance through temperature control and the heater generating heat.

That is, the RF filter for the plasma process according to the present invention includes a variable element to block RF noise between a heater generating heat and an AC power control supply unit to control a process temperature in a wafer support assembly in a plasma chamber. The purpose of this is to minimize the impedance variation between process equipment parts by providing an RF filter and adjusting the impedance of the plasma chamber by a variable element of the RF filter.

Second, the RF filter for the plasma process according to the present invention includes a heater and AC power in order to improve the impedance deviation of the plasma chamber by the wafer support assembly used to improve process performance through temperature control and the heater generating heat. An RF filter including a variable element for blocking RF noise is formed between the control supply units, and the purpose of this is to minimize the deviation of the RF filter element with respect to the RF filter impedance by the variable element of the RF filter.

That is, in the RF filter for the plasma process according to the present invention, the impedance deviation of the RF filter itself is an RF filter by compensating for parasitic components that may be generated by the device deviation and the connection line inside the RF filter, etc. It aims to minimize the deviation of the device and maintain the impedance of the RF filter at a constant performance.

Thirdly, the RF filter for the plasma process according to the present invention, in the RF plasma process using a plurality of multi-frequency power, generates heat in the RF filter element, and changes the performance of the RF filter. It aims to minimize process deviation.

That is, the RF filter for the plasma process according to the present invention is applied to the plasma chamber even in the case of an RF filter formed of a magnetic material inevitably in a process using a single frequency power and a plasma chamber using a plurality of multi-frequency power. In the process of using multi-frequency power, the series LC resonance characteristics of the RF filter are applied to minimize the occurrence of impedance deviation of the plasma chamber over time depending on the RF power level and RF power isolation. It aims to minimize process deviation by efficient isolation.

An RF filter for a plasma process according to an embodiment of the present invention includes a heater provided in the wafer support assembly of the plasma chamber and a wafer of the plasma chamber in a plasma chamber that generates plasma with single or multiple frequency power to perform a process. In the RF filter for a plasma process formed by being connected by two connection lines between an AC power control supply unit for applying AC power to a heater provided in a support assembly, and the heater and the AC power control supply unit, the RF The filter includes an HF band filter including a parallel LC resonance circuit and a series LC resonance circuit connected in parallel to each of the parallel LC resonance circuits by two connecting lines connected to the plasma chamber side or the heater side, and the AC power control supply side. And an MF band or LF band filter including a parallel LC resonance circuit and an input parallel capacitor connected in parallel to each of the two connecting lines to be connected.

The parallel LC resonance circuit of the HF band filter comprises a series inductor connected in series to a connection line connected to the heater and a variable capacitor element connected in parallel to the series inductor to form a parallel LC resonance circuit.

The parallel LC resonance circuit of the HF band filter includes a series inductor connected in series to a connection line connected to the heater, one terminal is connected in parallel to the connection line, and the other terminal is connected to the RF ground. To form a parallel LC resonance circuit.

The RF filter for the plasma process according to the present invention includes an output parasitic capacitor formed in parallel with a series inductor provided in a parallel LC resonance circuit of an HF band filter and connected to an RF ground, and a parasitic capacitor formed in parallel with the series inductor. The component is compensated for the impedance of the RF filter to a desired value by adjusting the variable capacitor element of the parallel LC resonance circuit of the HF band filter, thereby canceling and adjusting the RF impedance to maintain a constant RF impedance of the plasma chamber.

In the series LC resonance circuit of the HF band filter, one terminal is connected in parallel to the parallel LC resonance circuit of the HF band filter, and the other terminal is formed by being connected to the RF ground, and a series capacitor connected in parallel to the connection line and A series inductor connected in series with the series capacitor is connected to form a series LC resonance circuit.

The series LC resonance circuit of the HF band filter is formed with a low impedance value selectively only the desired frequency to block the flow of RF energy of the frequency of the HF band from flowing into the MF band or LF band filter side and the AC power control supply side. do.

The parallel LC resonance circuit of the MF band or LF band filter comprises an input inductor formed by winding a conductor wire around a magnetic material core and a variable capacitor element connected in parallel to the input inductor to form a parallel LC resonance circuit. do.

The RF filter for the plasma process according to the present invention includes an input inductor parasitic capacitor formed in parallel with an input inductor provided in a parallel LC resonance circuit of an MF band or LF band filter, and a variable capacitor element connected in parallel to the input inductor. The parasitic resistance component formed by being connected in parallel to the MF band or the LF band filter's RF of the plasma chamber by compensating and adjusting the impedance of the RF filter to a desired value by adjusting the variable capacitor element of the parallel LC resonance circuit Keep the impedance constant.

The RF filter for the plasma process according to the present invention includes adjustment of a variable capacitor value connected in parallel with the input inductor of the parallel LC resonance circuit of the MF band or LF band filter, and the input parallel connected in parallel with the parallel LC resonance circuit. Blocks RF power and RF noise from flowing into the AC power control supply by controlling to be a larger impedance value of a medium frequency (MF) frequency band or a low frequency (LF) frequency band lower than a high frequency band (HF) by a capacitor do.

An RF filter for a plasma process according to another embodiment of the present invention includes a heater provided in a wafer support assembly of the plasma chamber and a heater provided in a wafer support assembly of the plasma chamber in a plasma chamber performing a process by generating plasma with single or multiple frequency power. In the RF filter for a plasma process formed by being connected by two connection lines between an AC power control supply unit for applying AC power to a heater provided in the wafer support assembly, and the heater and the AC power control supply unit, the The RF filter includes an HF band filter including a parallel LC resonance circuit and a series LC resonance circuit connected in parallel to each of the parallel LC resonance circuits by two connection lines connected to the plasma chamber side or the heater side, and an AC power control supply unit. Characterized by having an MF band or LF band filter including a parallel LC resonance circuit in each of two connection lines connected to the side and a series LC resonance circuit connected in parallel with each of the parallel LC resonance circuits do.

The parallel LC resonance circuit of the HF band filter comprises a series inductor connected in series to a connection line connected to the heater and a variable capacitor element connected in parallel to the series inductor to form a parallel LC resonance circuit.

The parallel LC resonance circuit of the HF band filter includes a series inductor connected in series to a connection line connected to the heater, one terminal is connected in parallel to the connection line, and the other terminal is connected to the RF ground. To form a parallel LC resonance circuit.

The RF filter for the plasma process according to the present invention includes an output parasitic capacitor formed in parallel with a series inductor provided in a parallel LC resonance circuit of an HF band filter and connected to an RF ground, and a parasitic capacitor formed in parallel with the series inductor. The component is compensated for the impedance of the RF filter to a desired value by adjusting the variable capacitor element of the parallel LC resonance circuit of the HF band filter, thereby canceling and adjusting the RF impedance to maintain a constant RF impedance of the plasma chamber.

In the series LC resonance circuit of the HF band filter, one terminal is connected in parallel to the parallel LC resonance circuit of the HF band filter, and the other terminal is formed by being connected to the RF ground, and a series capacitor connected in parallel to the connection line and A series inductor connected in series with the series capacitor is connected to form a series LC resonance circuit.

The series LC resonance circuit of the HF band filter is formed with a low impedance value selectively only the desired frequency to block the flow of RF energy of the frequency of the HF band from flowing into the MF band or LF band filter side and the AC power control supply side. do.

The parallel LC resonance circuit of the MF band or LF band filter comprises an input inductor formed by winding a conductor wire around a magnetic material core and a variable capacitor element connected in parallel thereto to form a parallel LC resonance circuit.

The RF filter for the plasma process according to the present invention includes an input inductor parasitic capacitor formed in parallel with an input inductor provided in a parallel LC resonance circuit of an MF band or LF band filter, and a variable capacitor element connected in parallel to the input inductor. The parasitic resistance component formed by being connected in parallel to the MF band or the LF band filter's RF of the plasma chamber by compensating and adjusting the impedance of the RF filter to a desired value by adjusting the variable capacitor element of the parallel LC resonance circuit Keep the impedance constant.

In the series LC resonance circuit of the MF band or LF band filter, one terminal is connected in parallel to the parallel LC resonance circuit of the MF band or LF band filter, and the other terminal is formed by being connected to the RF ground, and the connection line A series capacitor connected in parallel and a series inductor connected in series with the series capacitor are connected to form a series LC resonance circuit.

The RF filter for the plasma process according to the present invention includes adjustment of a variable capacitor value connected in parallel with the input inductor of the parallel LC resonance circuit of the MF band or LF band filter, and a series LC connected in parallel with the parallel LC resonance circuit. The resonant circuit prevents RF power and RF noise from flowing into the AC power control supply unit by controlling to be a larger impedance value of the MF (Medium Frequency) frequency band or LF (low frequency) frequency band lower than the high frequency band (HF). Block.

An RF filter for a plasma process according to another embodiment of the present invention includes a heater provided in a wafer support assembly of the plasma chamber and a plasma chamber in a plasma chamber for performing a process by generating plasma with single or multiple frequency power. An AC power control supply unit for applying AC power to a heater provided in a wafer support assembly of, and an RF filter for a plasma process formed by being connected by two connection lines between the heater and the AC power control supply unit, The RF filter includes a parallel LC resonance circuit and a series LC resonance circuit connected in parallel to each of the parallel LC resonance circuits by two connection lines connected to the plasma chamber side or the heater side to block the frequency band of the VHF band. The LF band includes a VHF band filter and a series LC resonance circuit connected in parallel with a parallel LC resonance circuit and a series LC resonance circuit connected in parallel with each of the two connection lines connected to the AC power control supply side. An LF band filter that cuts off a frequency band, and a series connected in parallel to each of the parallel LC resonance circuit and the parallel LC resonance circuit by connecting lines connected to the plasma chamber side or the heater side between the VHF band filter and the LF band filter. It characterized in that it comprises an MF band filter that cuts off a frequency band of the MF band including an LC resonance circuit.

The parallel LC resonance circuit of the VHF band filter or the MF band filter consists of a series inductor connected in series to a connection line connected to the heater and a variable capacitor element connected in parallel to the series inductor to form a parallel LC resonance circuit. RF filter for a plasma process, characterized in that.

The parallel LC resonance circuit of the VHF band filter or MF band filter is formed such that a series inductor is connected in series to a connection line connected to the heater, one terminal is connected in parallel to the connection line, and the other terminal is connected to the RF ground. It consists of a variable capacitor element to form a parallel LC resonance circuit.

The RF filter for the plasma process according to the present invention includes an output parasitic capacitor formed in parallel with a series inductor provided in a parallel LC resonance circuit of the VHF band filter or the MF band filter and connected to the RF ground, and parallel to the series inductor. By adjusting the variable capacitor element of the parallel LC resonance circuit of the VHF band filter or the MF band filter, the impedance of the RF filter is compensated for, canceled and adjusted to a desired value, thereby adjusting the RF impedance of the plasma chamber to be constant. Keep it

In the series LC resonance circuit of the VHF band filter or MF band filter, one terminal is connected in parallel to the parallel LC resonance circuit of the VHF band filter or MF band filter, and the other terminal is formed by being connected to the RF ground, and the connection line A series capacitor connected in parallel to and a series inductor connected in series to the series capacitor are connected to form a series LC resonance circuit.

The series LC resonance circuit of the VHF band filter is formed with a low impedance value selectively only the desired frequency to block the flow of RF energy of the frequency of the VHF band from flowing into the MF band or LF band filter side and the AC power control supply side. And, the series LC resonance circuit of the MF band filter is formed with a low impedance value selectively only the desired frequency to block the flow of RF energy of the frequency of the MF band from flowing into the LF band filter side and the AC power control supply side. .

The parallel LC resonance circuit of the LF band filter comprises an input inductor formed by winding a conductor wire around a magnetic material core, and a variable capacitor element connected in parallel to the input inductor to form a parallel LC resonance circuit.

The RF filter for the plasma process according to the present invention includes an input inductor parasitic capacitor formed in parallel with an input inductor provided in a parallel LC resonance circuit of an LF band filter, and a variable capacitor element connected in parallel to the input inductor. The connected parasitic resistance component is compensated for the impedance of the RF filter to a desired value by adjusting the variable capacitor element of the parallel LC resonance circuit of the MF band or LF band filter, canceling and adjusting the RF impedance of the plasma chamber to be constant. Keep it

The RF filter for the plasma process according to the present invention is provided by adjusting the value of a variable capacitor connected in parallel with the input inductor of the parallel LC resonance circuit of the LF band filter and an input parallel capacitor connected in parallel with the parallel LC resonance circuit. The impedance of the low frequency (LF) frequency band, which is lower than the high frequency band (HF) and the medium frequency (MF) frequency band, is controlled to be a larger impedance value to block RF power and RF noise from flowing into the AC power control supply unit. .

Therefore, the RF filter for the plasma process according to the present invention is the impedance of the plasma chamber generated by the heater and the wafer support assembly to generate heat in order to control the process temperature in the wafer support assembly for fixing and placing the wafer in the plasma chamber. There is an effect of minimizing the deviation of the multi-frequency power process and improving the stability of the semiconductor process by efficiently isolating individual frequency power inside the RF filter in the multi-frequency power process.

Also. The RF filter for the plasma process according to the present invention is generated by a heater and an upper electrode that generate heat in order to control the process temperature in the same manner in a component facility that controls the temperature by generating heat to the wafer support assembly and the upper electrode. In the process of minimizing process impedance deviation and using multi-frequency power, impedance control for each frequency and energy cut-off are easy, thereby improving the process deviation by the RF filter, thereby improving the stability of the semiconductor process.

The RF filter for the plasma process according to the present invention is generated by the impedance control for the individual frequency of the single or multi-frequency power process in the RF filter and the nonlinear characteristics of the plasma according to the single or multi-frequency power through a process deviation improvement method. There is an effect that it is possible to compensate for the fundamental resonance frequency for the higher harmonic frequency or the individual impedance for the higher harmonic and minimize the deviation.

The RF filter for the plasma process according to the present invention not only can effectively compensate for parasitic components existing between the plasma and the RF filter in the RF filter for diagnosing plasma, but also can minimize the deviation of the RF filter itself, and can In addition to the process equipment that uses power, there is an effect that it is possible to individually control the desired impedance and minimize deviations even for components for high-order harmonics generated in plasma.

The RF filter for the plasma process according to the present invention is capable of cutting off individual frequency power as well as controlling impedance for individual frequencies by a series LC resonance circuit formed in the RF filter in a process using power of a single frequency and power of multiple frequencies. It is possible, and there is an effect of minimizing the deviation between equipments or the impedance deviation of the RF filter itself due to compensation through the variable element.

1 is a view showing a connection between a wafer support assembly in a plasma chamber and an RF filter according to the prior art.
2 is a view for explaining a parasitic capacitor and a parasitic inductor component generated at a connection portion between a wafer support assembly and an RF filter in a plasma chamber according to the prior art.
3 is a diagram for explaining a change in impedance of a plasma chamber according to the impedance of an RF filter according to the prior art.
4 is a diagram showing a circuit configuration of an RF filter according to the prior art.
5 is a diagram showing a circuit configuration of an RF filter for a plasma process according to an embodiment of the present invention.
6 is a diagram showing a circuit configuration of an RF filter for a plasma process according to another embodiment of the present invention.
7 is a view for explaining parasitic components of elements in the RF filter in the RF filter according to an embodiment of the present invention.
8 is a flow chart of RF energy for dual frequency (HF and LF) power in the RF filter according to the prior art of FIG. 4.
9 is a flow chart of RF energy when HF is isolated from dual frequency power in the RF filter according to an embodiment of the present invention of FIG. 5.
10 is a diagram showing a circuit configuration of an RF filter in a process using multi-frequency power according to the present invention.
11 is a diagram for explaining a higher-order harmonic generated in an RF plasma.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art may easily implement the present invention. Since the description of the present invention is merely an embodiment for structural or functional description, the scope of the present invention should not be construed as being limited by the embodiments described in the text.

That is, since the present invention is not limited to the embodiments described herein since various modifications are possible and can be implemented in various different forms, the scope of rights according to the present invention includes equivalents capable of realizing the technical idea. It must be understood.

Meanwhile, the meanings of terms described in the present invention should be understood as follows.

Terms such as "first" and "second" are used to distinguish one component from other components, and the scope of rights is not limited by these terms. For example, a first component may be referred to as a second component, and similarly, a second component may be referred to as a first component.

When a component is referred to as being "connected" to another component, it should be understood that although it may be directly connected to the other component, another component may exist in the middle. On the other hand, when it is mentioned that a certain component is "directly connected" to another component, it should be understood that there is no other component in the middle. On the other hand, other expressions describing the relationship between components, that is, "between" and "just between" or "neighboring to" and "directly neighboring to" should be interpreted as well.

Singular expressions are to be understood as including plural expressions unless the context clearly indicates otherwise, and terms such as “comprise” or “have” refer to implemented features, numbers, steps, actions, components, parts, or It is to be understood that it is intended to designate that a combination exists and does not preclude the presence or addition of one or more other features or numbers, steps, actions, components, parts, or combinations thereof.

In each step, the identification code (e.g., a, b, c, etc.) is used for convenience of explanation, and the identification code does not describe the order of each step, and each step has a specific sequence clearly in context. Unless otherwise stated, it may occur differently from the stated order. That is, each of the steps may occur in the same order as specified, may be performed substantially simultaneously, or may be performed in the reverse order.

All terms used herein have the same meaning as commonly understood by one of ordinary skill in the field to which the present invention belongs, unless defined otherwise. Terms defined in commonly used dictionaries should be interpreted as having meanings in the context of related technologies, and cannot be interpreted as having an ideal or excessive formal meaning unless explicitly defined in the present invention.

It should be noted that the drawings are schematic and are not drawn to scale. Relative dimensions and ratios of parts in the drawings are exaggerated or reduced in size for clarity and convenience in the drawings, and any dimensions are merely exemplary and not limiting. In addition, the same reference numerals are used to indicate similar features to the same structure, element, or part appearing in two or more drawings.

Examples according to the present invention specifically represent an ideal embodiment of the present invention. As a result, various variations of the illustration are expected. Accordingly, the embodiment is not limited to a specific shape in the illustrated area, and includes, for example, a modification of the shape by manufacturing.

Hereinafter, an RF filter for improving the stability of a semiconductor process according to an embodiment of the present invention will be described with reference to the accompanying drawings.

1 is a view showing a connection between a wafer support assembly in a plasma chamber and an RF filter according to the prior art, and FIG. 2 is a parasitic capacitor and a parasitic inductor generated at a connection portion between the wafer support assembly and an RF filter in the plasma chamber according to the prior art. It is a figure for demonstrating an ingredient.

As shown, an AC power control supply unit for applying AC power to a plasma chamber 100 for performing deposition and etching processes of a semiconductor wafer, and a heater provided in the wafer support assembly 130 in the plasma chamber 100 (200) and the RF filter 300 formed between the wafer support assembly 130 and the AC power control supply unit 200 of the plasma chamber 100 and the lower electrode provided in the wafer support assembly 130 to ground. It includes an RF ground 400.

In the plasma chamber 100, a process plasma 120 formed by RF power applied to the plasma chamber 100 and a semiconductor process are formed by an upper electrode 110 upwardly, and a lower part of the upper electrode 110. A wafer support assembly 130 connected to the RF ground 400 and comprising a lower electrode 131, a heater 132, and a wafer support (not shown), wherein the upper surface of the lower electrode 131 has a semiconductor The wafer 140 on which the process is performed is fixedly seated, and a heater 132 for heating the wafer 140 is mounted and formed on the lower surface of the lower electrode 131. That is, the heater 132 of the plasma chamber 100 receives AC power from the AC power control supply unit 200 connected to the RF filter 300, and the wafer 140 is mounted on the upper surface of the lower electrode 132. It generates heat to control the process temperature of Further, a bellows 150 is further included under the plasma chamber 100.

The wafer 140 is deposited and etched by the plasma 120 and the process gas supplied through the upper electrode 110 and applied. In particular, when the temperature of the semiconductor process is controlled to control process performance As shown in FIG. 1, the wafer support assembly 130 on which the wafer 140 is fixedly seated may be formed of a lower electrode 131, a heater 132, and a wafer support (not shown).

Also. When performing temperature control during semiconductor process control, the plasma chamber 100 itself is undesirably depending on the structure of the heater 132 for generating heat with a heating wire or the like on the lower side of the wafer 140 and the material of the heater 132 Since the RF impedance of the plasma chamber 100 changes, it may affect the voltage/current of the RF power applied to the plasma chamber 100, so if the impedance of the plasma chamber itself is changed as mentioned in the prior art patent document 1 Alternatively, a process deviation occurs, and since such a process deviation adversely affects the semiconductor process, the precision of the semiconductor wafer is deteriorated.

In addition, as shown in FIG. 2 for explaining parasitic capacitors and parasitic inductor components that may be generated at the connection portion between the heater 132 of the wafer support assembly 130 and the RF filter 300 in the plasma chamber 100, Since there is a parasitic capacitor 301 and a parasitic inductor 302 between unwanted equipment parts between the connection part between the RF filter 300 and the heater 132 provided in the wafer support assembly 130 and the bellows 150, the above The parasitic capacitor 301 between the equipment parts, the parasitic inductor 302, and the mounting stability between the equipment parts may affect the RF impedance of the plasma chamber 100, resulting in a process deviation.

In addition, as shown in FIGS. 1 and 2, an impedance deviation of the RF filter 300 itself is basically generated, which directly affects the RF impedance of the plasma chamber 100, and thus process deviation may also occur.

Therefore, in order to minimize the deviation between equipment parts or between processes, the RF impedance deviation of the plasma chamber 100 that may occur in the lower electrode 131 and the heater 132 and the heater 132 of the wafer support assembly 130 There is an urgent need for a way to maintain a constant impedance by minimizing or compensating for an impedance deviation of the RF filter 300 generated at a connection between the and the RF filter 300.

As for the method for improving the process characteristics according to the impedance of the plasma chamber 100 as described above, various methods are presented in Patent Document 1 of the prior art, but the semiconductor process is improved by minimizing the RF impedance deviation of the RF filter 300 itself. There is no proposed plan for this.

3 is a diagram for explaining a change in impedance of a plasma chamber according to the impedance of an RF filter according to the prior art.

As shown, a diagram for explaining how the impedance change of the RF filter 300 affects the impedance of the plasma chamber 100, which is the input impedance of the upper electrode 110 in the plasma chamber 100. The correlation is shown with the impedance of the filter 300 as the X-axis and the impedance of the plasma chamber 100 as the Y-axis.

The plasma chamber, which is the input impedance of the upper electrode 110, may have various correlations according to the type or characteristic of the plasma chamber 100, and when the impedance of the RF filter 300 is between 100Ω and 1kΩ. It can be seen that the size of the impedance of (100) varies from 6.58Ω to 11.61Ω depending on the impedance of the RF filter 300.

That is, according to the prior art, as a solution to simply block RF noise leaking from the heater 132 that generates heat in order to control the process temperature in the wafer support assembly 130 on which the wafer 1400 is fixed and placed. The method of forming the impedance of the plasma chamber 100 with a relatively high impedance compared to the impedance of the RF filter 300 has been mainly used, but as the semiconductor process becomes finer and more complex, the process deviation can be minimized. , There is an urgent need for a method capable of compensating for a more precise impedance deviation for the RF filter 300.

4 is a diagram showing a circuit configuration of an RF filter according to the prior art.

As shown, noise leaked through the heater 132 that generates heat in the wafer support assembly 130 on which the wafer 140 of FIG. 2 is fixed and mounted to control the process temperature, and the plasma chamber 100 It is a circuit for simply blocking RF noise leaking through the AC power control supply unit 200 for supplying AC power to the heater 132.

That is, according to the prior art, as shown in Fig. 4, the impedance of the RF filter 300 in the RF frequency band is formed to have a relatively high impedance value compared to the own impedance of the plasma chamber 100, so that the RF energy is simply It can prevent leakage.

As a method for forming a high impedance inductance for the RF filter 300, the RF filter 300 may be formed of cores 701 and 702 such as ferrite or iron. .

That is, in order to form a high impedance for the RF filter 300, the output inductors L _OUT1 and L formed toward the plasma chamber 100 or the heater 132 formed by winding a wire around the cores 701 and 702 _OUT2 (707, 708), L _IN1 , L _IN2 (709-1, 709-2), which are input inductors formed toward the AC power control supply unit 200, and the plasma chamber formed to block RF noise ( 100) or output parallel capacitors C _OUT1, C _OUT2 (703, 704) formed toward the heater 132 and C _IN1, C _IN2 (705, 706) input parallel capacitors formed toward the AC power control supply unit 200 ) Are respectively connected to the ground.

In particular, the cores 701 and 702 according to the prior art, iron powder (Power) core (Core), fair light (ferrite) core (Core), Nano & Amorphorous (Nano & Amorphorous) core (core ) Is a case formed by applying a device mainly made of magnetic material to the RF filter 300, and since the deviation of the magnetic material device itself occurs about ±25%, this adversely affects the RF filter 300. (300) There is a problem that may cause a larger impedance deviation of itself.

In addition, AC power supplied to the heater 132 that generates heat and RF applied to the plasma chamber to control the process temperature to the wafer support assembly 130 that fixes and places the wafer 140 in the plasma chamber 100 Due to the leakage of the power level, desired heat is generated, and as time passes, the characteristics of the elements of the magnetic material cores 701 and 702 forming the RF filter 300 change, so that the impedance of the RF filter 300 A problem that is inevitably changed is caused.

5 is a diagram showing a circuit configuration of an RF filter for a plasma process according to an embodiment of the present invention.

As shown, the RF filter for the plasma process according to an embodiment of the present invention. As a circuit for solving the problems that may occur in FIG. 4 according to the prior art, the RF filter for the plasma process according to the present invention compensates for variations in equipment parts or prevents parasitic components generated inside the plasma chamber 100. Since a variable element capable of compensation is applied, the impedance of the plasma chamber 100 can be constantly adjusted to minimize process deviation. Moreover, in the process of using multi-frequency power in recent years, by connecting a series LC resonance circuit for each frequency band to the RF ground 400 inside the RF filter 300, impedance control of the RF filter 300 and leakage RF energy are controlled for each frequency band. You can block it effectively.

In more detail, as shown in the circuit configuration of the RF filter for the plasma process of FIG. 5 according to an embodiment of the present invention for solving the problems of the prior art, it will be described with reference to FIG. The RF filter 300 according to the present invention includes a heater 132 provided in the wafer support assembly 130 of the plasma chamber 100 and a heater provided in the wafer support assembly 130 in the plasma chamber 100 ( The RF energy leaked from the plasma chamber 100 is formed by being connected by two connection lines between the AC power control supply unit 200 and the AC power control supply unit 200 for applying AC power to 132. It serves to fundamentally block the flow of the AC power control supply unit 200.

The RF filter 300 is a parallel LC resonance circuit (710, 720) and a series LC resonance circuit (730, 740) in parallel by two connection lines connected to the plasma chamber 100 side or the heater 132 side, respectively. Connected to the HF band filter 310 may be formed.

A parallel LC resonant circuit of the HF band pass filter 310, 710 and 720, the series inductor is C ₁ (712) is a variable capacitance element that is formed by connecting in parallel to L ₁ (711) and L ₂ (721), respectively _, C ₂ (722) to form a parallel LC resonance circuit.

In addition, one terminal of the series LC resonance circuits 730 and 740 of the HF band filter 310 is connected in parallel to the rear ends of the parallel LC resonance circuits 710 and 720, and the other terminal is connected to the RF ground 400. Connected and formed. That is, the series LC resonance circuits 730 and 740 are connected to series capacitors C _{P1 and} C _P2 (731, 741) and series inductors connected in series, L _{P1 and} L _P2 (732, 742), It is formed by a resonance circuit.

Therefore, the HF band filter 310 of the RF filter 300 connected by two connection lines connected to the plasma chamber 100 side or the heater 132 side is in parallel with the parallel LC resonance circuits 710 and 720 Impedance control and RF in a relatively high frequency band (HF) that can flow into the AC power control supply unit 200 from the plasma chamber 100 or the heater 132 by the connected series LC resonance circuits 730 and 740 It has the effect of blocking power and RF noise.

In addition, the RF filter 300 includes a parallel LC resonance circuit 750 and 760 each of two connection lines connected to the AC power control supply unit 200 and a parallel capacitor C ₁₁₁ which is an input parallel capacitor by two connection lines, respectively _, C ₂₂₂ (780, 790) may be connected in parallel to form an MF band or LF band filter 320.

The parallel LC resonance circuits 750 and 760 of the MF band or LF band filter 320 are input inductors L _{11 and} L ₂₂ (751, 761) formed by winding wires around the core 770 and the core 770. ), and variable capacitor elements C _11, C ₂₂ (752, 762) to form a parallel LC resonance circuit,

Therefore, in parallel with the MF band of the RF filter 300 or the parallel LC resonance circuits 750 and 760 of the LF band filter 320 connected by two connection lines connected to the AC power control supply unit 200 side. By the connected input parallel capacitors C _111, C ₂₂₂ (780, 790), lower than the high frequency band (HF) that can flow into the AC power control supply unit 200 from the plasma chamber 100 or the heater 132 Impedance control of MF (Medium Frequency) frequency band or LF (low frequency) frequency band, and RF power and RF noise can be blocked.

According to another embodiment of the present invention, in the circuit configuration of the RF filter of FIG. 5, L _{11 and} L _, which are input inductors of the MF band or LF band filter 320, are formed toward the AC power control supply unit 200. ₂₂ (751, 761) can be replaced with an air core inductor formed of an enamel wire or a conductive wire without using the core 770.

In addition, according to another embodiment of the present invention, in the circuit configuration of the RF filter of FIG. 5, the parallel LC resonance circuit of the MF band or LF band filter 320 formed toward the AC power control supply unit 200 ( The series LC of the HF band filter 310 formed toward the plasma chamber 100 or the heater 132, instead of the input parallel capacitors C _111, C ₂₂₂ (780, 790) connected in parallel with the 750, 760 By replacing the series inductors L _P1, L _P2 (732, 742), which are resonant circuits (730, 740), and C _P1, C _P2 (731, 741), which are series capacitors of the series LC resonant circuit, It is formed by impedance and has the effect of effectively blocking RF energy.

In addition, according to an embodiment of the present invention, in the circuit configuration of the RF filter of FIG. 4 according to the prior art, a device made of a nonmagnetic material formed by being replaced with a copper tube or an enamel wire instead of a core element made of a magnetic material That is, it can be formed by replacing the parallel LC resonance circuits 710 and 720 of the HF band filter 310 formed by being connected to the plasma chamber 100 side or the heater 132 side of FIG. 5 according to the present invention. .

That is, the output inductor L ₁ 711 which is the parallel LC resonance circuits 710 and 720 of the HF band filter 310 of FIG. 5, which is a non-magnetic material element, instead of the core element composed of the conventional magnetic material shown in FIG. formed by substitution in L ₂ (721), and formed to replace it with the output inductor L ₁ (711) and a variable capacitance element that is formed by connecting in parallel to the _{L 2 (721) C 1,} C 2 (712, 722) By doing so, it is possible to realize the desired impedance by forming a parallel LC resonance circuit in the desired frequency band, and by compensating the deviation of the component element itself or the parasitic component inside the product with the variable capacitors C _1, C ₂ (712, 722), the plasma chamber (100) The impedance of itself is maintained at a constant reference impedance value.

To explain this in more detail, the structure of the heater 132 provided in the wafer support assembly 130 that generates heat with a heating wire or the like on the lower side of the wafer 140 that may be generated in the semiconductor plasma process chamber, and the heater ( Output inductor L, which is the parallel LC resonance circuits 710 and 720 of the HF band filter 310 shown in FIG. _The plasma chamber 100, which is the input impedance of the upper electrode 110, is compensated by the variable capacitor elements C _{1 and} C ₂ (712, 722) formed by being connected in parallel to the ₁ (711) and L ₂ (721). It has the effect of minimizing process deviation between equipment parts by keeping its own impedance constant at the reference impedance value.

Meanwhile, the connection between the RF filter 300 and the heater 132 provided in the wafer support assembly 130 and the bellows 150 shown in FIG. 2 according to the prior art described above are generated and present in the bellows 150. Since the parasitic capacitor 301 and the parasitic inductor 302 are formed between facilities, the RF filter 300 itself, which can be generated depending on the mounting stability of the parasitic capacitor 301 and the parasitic inductor 302 between facilities, The impedance deviation is also the output inductors L ₁ 711 and L, which are parallel LC resonance circuits 710 and 720 of the HF band filter 310 formed in the RF filter 300 for the plasma process of FIG. 5 according to the present invention. ₂ By compensating by the variable capacitor elements C _{1 and} C ₂ (712, 722) formed by being connected in parallel to the 712, the impedance of the plasma chamber 100 itself, which is the input impedance of the upper electrode 110, is referenced. It has the effect of minimizing the process deviation between equipment parts by keeping it constant at the impedance value.

In addition, in the case of forming an RF filter by a core, which is a conventional magnetic material, heat or the characteristics of the magnetic material itself are changed by applying a high RF voltage/current, so the RF filter itself Although there is a problem that deviation may occur due to a change in the impedance value of, according to an embodiment of the present invention, as shown in FIG. 5, which is formed by replacing a core element made of a magnetic material with a copper tube or an enamel wire that is a non-magnetic material element. It is formed by replacing the output inductors L ₁ 711 and L ₂ 721, which are parallel LC resonance circuits 710 and 720 of the HF band filter 310 formed in the RF filter 300 for the plasma process, and the output Heat generated by applying high RF voltage/current by replacing the variable capacitor elements C _{1 and} C ₂ (712, 722), which are formed by connecting inductors L ₁ (711) and L ₂ (721) in parallel. However, there is an improved effect of preventing a change in an RF power level or an impedance value of an RF filter itself over time due to a change in characteristics of the magnetic material itself.

Moreover, in the case where most recent semiconductor plasma processes use multi-frequency power, in the case of the RF filter shown in FIG. 4 according to the prior art, the magnetic material core of the plasma chamber 100 side or the heater 132 side when forming a Core_ _OUT (701) due to not be fully block the RF power from Core_ _OUT (701) and the output capacitor _{C OUT1, C OUT2 (703,} 704), RF power is delivered to the Core_ _iN (702) There is a problem in that the RF power level or the impedance of the RF filter itself changes over time due to heat generation due to unwanted RF power loss or changes in magnetic material properties. Conversely, output to block RF power more efficiently Even if the values of the capacitors C _OUT1 and C _OUT2 (703, 704) are increased, the output impedance for AC1_OUT of FIG. 4 is undesirably lowered from multiple frequencies to other frequencies as shown in (Equation 1) below. .

That is, the AC1_OUT output impedance Z_AC1_OUT, which is the input input impedance of the plasma chamber 100 side or the heater 132 side, can be expressed as the following [Equation 1].

이고,

이며, here,

ego,

Is,

이고,

이며, 부하 AC전력제어공급부(200)의 임피던스는 50Ω 조건이다.

ego,

And the impedance of the load AC power control supply unit 200 is 50Ω.

에 의해 대부분 결정될 수 있으나, 플라즈마챔버(100)의 자체 임피던스에 비하여 RF필터(300)의 자체 임피던스값을 상대적으로 높은 임피던스 값으로 나타날 경우에 RF에너지가 AC전력제어공급부(200) 측으로 유입되는 것을 방지할 있는데, 고주파수로부터 저주파수의 대역까지

을 증가할 경우에, RF필터(300)의 출력임피던스가 높은 임피던스 값으로 나타날 수 있지만 높은

의 값으로 증가시키기는 현실적으로 불가능할 뿐만 아니라, 또 다른 인덕턴스 성분인

을 증가시킬 경우에도 출력 캐패시턴스인

과 병렬로 형성되어 있기 때문에 RF필터(300)의 임피던스를 원하는 큰 값의 임피던스 값으로 구현하기가 역시 불가능한 것이다.The impedance of the RF filter 300 in [(Equation 1] above is

It can be determined mostly by, but when the self-impedance value of the RF filter 300 appears as a relatively high impedance value compared to the self-impedance of the plasma chamber 100, RF energy is prevented from flowing into the AC power control supply unit 200. From high frequency to low frequency

When is increased, the output impedance of the RF filter 300 may appear as a high impedance value.

It is not only practically impossible to increase it to the value of, but also another inductance component,

Even when increasing the output capacitance

Since it is formed in parallel with, it is also impossible to implement the impedance of the RF filter 300 with a desired large impedance value.

Therefore, according to the present invention, instead of the output capacitors C _OUT1 and C _OUT2 (703, 704) on the plasma chamber 100 side or the heater 132 side in the RF filter of FIG. 4 according to the prior art, as shown in FIG. Likewise, the series inductors L _{P1 and} L of the series LC resonance circuits 730 and 740 formed by being connected to the RF ground 400 of the HF band filter 310 formed toward the plasma chamber 100 or the heater 132 By replacing with _P2 (732, 742) and series capacitors C _P1, C _P2 (731, 741) of series LC resonance circuit, it is possible to effectively block RF energy by selectively forming low impedance only in the desired frequency band. There is.

That is, as shown in [Equation 2] below, only the desired frequency band is formed with a low impedance to effectively block the corresponding frequency energy, and at a relatively low frequency, L _P1 (732), C _P1 (731), and L _P2 (742) By forming the series LC resonance impedance of and C _P2 (741) to a high value, the influence on the impedance of a relatively low frequency can be minimized.

In addition, a relatively low frequency is L _11, L ₂₂ (751, 761) _, which are input inductors of the parallel LC resonance circuits 750 and 760 of the MF band or LF band filter 320 formed toward the AC power control supply unit 200. Wow, by designing a parallel LC resonance circuit in which C _{11 and} C ₂₂ (752, 762), which are variable capacitor elements, are formed in parallel, it is possible to control a desired high impedance and a desired impedance by designing a parallel resonance at a relatively low frequency.

That is, the AC1_OUT output impedance Z_AC1_OUT, which is the input input impedance of the plasma chamber 100 side or the heater 132 side, can be expressed as the following [Equation 2].

이고,

이며,

이고,here,

ego,

Is,

ego,

이며,

이고,

이며,

Is,

ego,

Is,

이고,

이며, 부하 AC전력제어공급부(200)의 임피던스는 50Ω 조건이다.

ego,

And the impedance of the load AC power control supply unit 200 is 50Ω.

에서

의 값으로 공진주파수가 되도록 L_P1(732)과 C_P1(731)을 선정하여 원하는 주파수 대역의 임피던스값을 zero 값 근처로 낮출 수 있으며, 또한, 상대적으로 높은 주파수 전력의 임피던스는 출력 인덕터 L₁(711)과 가변캐패시터 소자인 C₁(712)을

과 같이 HF대역 필터(310)의 LC병렬공진회로(710, 720)의 공진주파수인

의 값 근처로 L₁(711)과 C₁(712) 값을 설정하여 원하는 임피던스로 조정할 수 있다. As shown in [Equation 2], in the RF filter 200 of FIG. 5 according to the present invention, a relatively high frequency power is used as a series resonance combination.

in

By selecting L _P1 (732) and C _P1 (731) to be the resonant frequency with the value of, the impedance value of the desired frequency band can be lowered to near the zero value.In addition, the impedance of the relatively high frequency power is the output inductor L ₁ (711) and the variable capacitor element C ₁ (712)

As shown in the figure, the resonance frequency of the LC parallel resonance circuits 710 and 720 of the HF band filter 310

You can adjust the desired impedance by setting the values of L ₁ (711) and C ₁ (712) near the values of.

으로 공진됨으로써 낮은 임피던스로 형성되며, 상대적으로 저주파수대인 경우에

가 되며, C_P1(731)의 임피던스로 형성되어 종래기술인 도 4의 출력 캐패시터인 C_OUT1(703)보다 상대적으로 작은 캐패시터값으로 형성되기 때문에 즉, C_P1(731)은 고주파수대에서는 낮은 임피던스 값으로 형성되고, 저주파수대에서는 높은 임피던스 값으로 형성하기 때문에 결과적으로 저주파수대에 대한 영향성을 최소화할 수 있다.And, in the case of the circuit configuration of the RF filter of FIG. 4 according to the prior art, even if the input inductor L _IN1 709 is increased in a relatively low frequency band, the desired large impedance value is obtained by the output capacitor C _OUT1 703. Although it was impossible to form, the RF filter for the plasma process of FIG. 5 according to the present invention, in the case of a relatively high frequency band, of the HF band filter 310 formed toward the plasma chamber 100 or the heater 132 The series inductors L _P1, L _P2 (732, 742) of the series LC resonance circuit (730, 740) formed by being connected to the RF ground 400 and the series capacitors of the series LC resonance circuit C _P1, C _P2 (731, 741), which is a combination of series resonance circuit

It is formed with low impedance by resonating with, and in the case of a relatively low frequency band

C _P1 731 is formed with an impedance of C _P1 731 and is formed with a relatively smaller capacitor value than C _OUT1 703, which is an output capacitor of FIG. 4, which is a conventional art. That is, C _P1 731 is a low impedance value in the high frequency band. As a result, since it is formed with a high impedance value in the low frequency band, the influence on the low frequency band can be minimized.

와 같이 병렬형태로 L₁₁(721)과 C₁₁(723)이 상대적으로 저주파수대에서 병렬 공진주파수가 형성되도록 L₁₁(721)과 C₁₁(723)을 선택하여 원하는 큰 임피던스 값으로도 조정할 수 있다.Accordingly, L _{11 and} L ₂₂ (751, 761) _, which are input inductors of the parallel LC resonance circuits 750 and 760 of the MF band or LF band filter 320 formed toward the AC power control supply unit 200, and a variable capacitor The impedance of the low frequency band is relatively low by the parallel LC resonance circuit in which the elements C _{11 and} C ₂₂ (752, 762) are formed in parallel.

As shown in Fig. 1, L ₁₁ (721) and C ₁₁ (723) can be adjusted to a desired large impedance value by selecting L ₁₁ (721) and C ₁₁ (723) so that a parallel resonance frequency is formed in a relatively low frequency band. have.

Accordingly, the RF filter for the plasma process of FIG. 5 according to the present invention can be generated when not only can control with a desired impedance for various frequencies in a recent multi-frequency process, but also can not effectively block power in other frequency bands. There is an effect of minimizing the change in the impedance of the RF filter 300 itself with the passage of time and the RF power level even with respect to heat generated or a change in characteristics of a magnetic material.

6 is a circuit diagram of an RF filter according to another embodiment of the present invention.

As shown, all the circuit configurations of the RF filter 200 of FIG. 5, which is an embodiment of the present invention, are the same, but are formed of two connecting lines connected to the plasma chamber 100 side or the heater 132 side. Only the parallel LC resonance circuits 710 and 720 of the HF band filter 310 are formed differently.

That is, the parallel LC resonance circuits 710 and 720 of the HF band filter 310 are series inductors L ₁ 711 and L ₂ 721 connected in series with two connection lines connected to the heater 132. ), one terminal is connected in parallel to the two connection lines connected to the heater 132 from the front end of the series inductors L ₁ (711) and L ₂ (721), and the other terminal is connected to the RF ground (400). By forming a parallel LC resonance circuit composed of C ₁ 712 _and C ₂ 722 _, which are variable capacitor elements that are formed to be, the operating principle and effect of FIG. 6 are the same as in FIG. 5, and the impedance, power, and RF noise for each frequency band. 5, 6, and 10 according to the present invention, the circuit configuration of the RF filter of FIG. 5, 6, and 10, as well as the wafer support assembly 130 of FIG. The same can be applied to equipment that is used to control temperature.

7 is a view for explaining parasitic components of elements in the RF filter in the circuit configuration of the RF filter according to an embodiment of the present invention.

7 is an exemplary circuit diagram for explaining various parasitic components that may be generated in the RF filter 300 itself of FIG. 5 described above. As shown, the basic configuration of the RF filter 300 is the same. , Parasitic components are generated from two connection lines connected to the plasma chamber 100 side or the heater 132 side, and each of the two connection lines connected to the plasma chamber 100 side or the heater 132 side is an HF band filter ( One terminal is connected in parallel to each of the series inductors L ₁ (711) and L ₂ (721) of the parallel LC resonance circuits (710, 720) of 310) and the other terminal is connected to the RF ground, C _par1 , an output parasitic capacitor. (714) and C _par2 (724) are formed, and C _{par_L1} (713) and C _{par_L2} (723), which are parasitic capacitors of the series inductors present in the series inductors L ₁ (711) and L ₂ (721), are It can be formed by being connected in parallel.

Therefore, the parasitic capacitors C _{par_L1} (713), C _{par_L2} (723), C _par1 (714) and C _par2 (724) generated in the parallel LC resonance circuits 710 and 720 of the HF band filter 310 are variable capacitors. The impedance of the RF filter 300 on the plasma chamber 100 or the heater 132 is compensated to a desired value by means of the elements C _{1 and} C ₂ (712, 722) to compensate and adjust the plasma chamber 100 itself. There is an effect that the impedance of the RF filter 300 can be constantly adjusted based on the AC1_OUT and AC2_OUT terminals of the RF filter 300 that mainly affect the impedance.

Therefore, the HF (high frequency) impedance of the RF filter 300 is C _par1 714 and C _par2 724, which are parasitic capacitors of the RF filter 300 by the variable elements C _{1 and} C ₂ (712, 722). _W , and by compensating the parasitic capacitors C _{par_L1} (713) and C _{par_L2} (723) of the output inductors L ₁ (711) and L ₂ (712), the desired impedance value in the HF (high frequency) band of the RF filter 300 There is an effect that can be adjusted with.

In addition, as shown, the basic configuration of the RF filter 300 is all the same, and parasitic components are generated from the two connection lines connected to the AC power control supply unit 200 side, to the AC power control supply unit 200 side. C, an input inductor parasitic capacitor that may exist in the input inductors L _{11 and} L ₂₂ (751, 761) of the parallel LC resonance circuits 750 and 760 of the MF band or LF band filter 320 through each of the two connected lines. _{par_L11} , C _{par_L22} (753, 763) and the parasitic resistance of the input inductor of the core 770 of the AC power control supply 200 side, parallel to the input inductors L _{11 and} L ₂₂ (751, 761), respectively Parasitic resistors R _{par_L11} and R _{par_L22} (754, 764) connected in parallel to each of the variable capacitor elements C _{11 and} C ₂₂ (752, 762) connected to each other may be formed.

Therefore, the impedance of the MF (medium frequency) or LF (low frequency) filter side of the RF filter 200 is input inductors L _11, L ₂₂ (721, 722) by the variable elements C _11, C ₂₂ (752, 762). ), the input inductor parasitic capacitors C _{par_L11} , C _{par_L22} (728, 729) and Core (770) are compensated for deviations from the device itself to achieve a desired impedance value in the MF (medium frequency) or LF (low frequency) band. There is an effect that can be adjusted.

8 is a flowchart of RF energy for dual frequency (HF and LF) power in the circuit configuration of the RF filter according to the prior art of FIG. 4.

8 is an RF filter according to the prior art, in the case of using a high frequency (HF) and a low frequency (LF) band frequency in a process of using power of multiple frequencies, for each individual frequency energy of HF or LF As a diagram for explaining the power flow, as shown, the RF energy of the HF band leaked through the plasma chamber 100 or the heater 132 is mostly output inductors L _OUT1 and L _OUT2 (707, 708) and Although most of the RF energy is output in the directions A and B by the output parallel capacitors C _OUT1, C _OUT2 (703, 704), it is cut off. RF energy in some HF bands is discharged in the directions C and D through input inductors L _IN1 and L _IN2 (709-1, 709-2) and input parallel capacitors C _{IN1 and} C _IN2 (705, 706). As such, some may leak.

Therefore, the RF energy partially leaked in the directions C and D through the input parallel capacitors C _{IN1 and} C _IN2 (705, 706) as described above is a parasitic resistance of the input inductor of the core 770 shown in FIG. That is, the parasitic resistance R _{par_L11} , which is connected in parallel to the variable capacitor elements C _{11 and} C ₂₂ (752, 762), which are respectively connected in parallel to the input inductors, L _{11 and} L ₂₂ (751, 761), Unwanted heat generation may occur due to R _{par_L22} (754, 764), etc., and the characteristics of the core (770) device itself are changed due to heat generated from the parasitic resistance R _{par_L11} and R _{par_L22} (754, 764) components. The HF band impedance of the RF filter 300 may be changed to cause a process deviation.

9 is a flow chart of RF energy for dual frequency power in the RF filter according to an embodiment of the present invention shown in FIG. 5.

According to the present invention, in order to fundamentally block the leakage of RF energy that may occur in FIG. 8 according to the prior art as described above, in the RF filter 300 of a semiconductor process using dual frequency power as shown in FIG. 9 of the present invention. , Efficient by the series LC resonance circuits 730 and 740 connected in parallel with the parallel LC resonance circuits 710 and 720 of the HF band filter 310 connected to the plasma chamber 100 side or the heater 132 side. As a result, RF energy in the HF band is output in the directions E and F, so that not only can all be blocked so that it does not flow into the MF band or LF filter filter 320, but also the impedance to other frequencies in the multi-frequency process is reduced or the influence is minimized. Thus, there is an effect of blocking RF energy for individual frequencies and effectively controlling the impedance value.

10 is a circuit configuration of an RF filter in a process using multi-frequency power according to the present invention.

As illustrated, FIG. 10 is an RF filter 300 applied to a process of using power of a multi-frequency of two or more frequencies, and filters according to a plurality of frequencies may be formed respectively. In other words, it is possible to individually control impedance and cut off RF energy in various frequency bands such as VHF or HF band filter (3100), MF band filter (3200) and LF band filter (3300), and the impedance of equipment parts or RF filter itself. The deviation can also be minimized.

Here, the parallel LC resonance circuits 7910 and 7920 of the LF band filter 3300 connected by two connection lines connected to the AC power control supply unit 200 and the input parallel capacitors C _LF111, C connected in parallel _{thereto. By LF222} (7930, 7940), in the parallel LC resonance circuits (7910, 7920) of the LF band filter (3300), the LF inductors L _LF11 and L _LF22 (7911, 7921) replace the core (7900) with enamel wire or It can also be formed of an air core inductor made of copper tube or the like.

As shown, it is connected in parallel with the parallel LC resonance circuits 7100 and 7200 of the VHF or HF band filter 3100 formed from the RF filter 300 toward the plasma chamber 100 and connected to the RF ground 400. The VHF band or HF band impedance and the RF energy of the HF band are blocked by the formed series LC resonance circuits (7300, 7400), and are output in the directions of G and H, MF band filter (3200) or LF band filter (3200). ) However, it can block the inflow.

In addition, the MF band filter 3200 is connected in parallel with the parallel LC resonance circuits 7500 and 7600 of the MF band filter 3200 and is connected to the RF ground 400 to form a series LC resonance circuit 7700 and 7800. The impedance of the MF band and RF energy of the MF band are cut off and output in the directions of the indication codes I and J to block the inflow of the LF band filter 3200.

In addition, the input parallel capacitors C _LF111, C _LF222 (7930, 7940), which are input parallel capacitors formed by being connected in parallel with the parallel LC resonance circuits 7910 and 7920 of the LF band filter 3300 and connected to the RF ground 400, The impedance of the band and the RF energy of the LF band are cut off and are output in the directions M and N of the display symbols to block the inflow to the AC power control supply unit 200. The remaining AC power control supply unit 200 may block noise of AC power or noise flowing into or leaking from the RF filter.

11 is a diagram for explaining a higher-order harmonic generated in an RF plasma.

As shown, generated from the plasma chamber 100 and the RF generator 500 in which a single frequency is generated and the RF generator 500 between the plasma chamber 100 and the RF generator 500 It consists of an RF matcher (RF Matcher) 600 for transmitting the maximum power to the plasma chamber 100 of the single frequency waveform 10.

When an RF waveform is detected between the RF matcher 600 and the plasma chamber 100, an RF waveform 20 including a higher-order harmonic generated by plasma distortion exists. In this way, not only the basic resonance frequency of the process, but also higher harmonic frequency waveforms such as second, third, fourth, etc. generated due to non-linear plasma characteristics are generated.

Therefore, in order to minimize the effect on the process when the RF waveform 20 including the higher-order harmonic generated by plasma distortion as described above exists,

First, for the frequency of the RF power generated in the plasma process and the higher harmonic frequency, the RF energy is reduced by adjusting the output impedance of the RF filter 300 to a larger impedance value than the impedance of the plasma chamber 100 itself. Avoid leakage.

Second, the output impedance value of the RF filter 300 should be maintained at a larger impedance value for the frequency of the RF power generated in the plasma process and the higher harmonic frequency, while minimizing the output impedance deviation of the RF filter 300 itself.

Third, the RF filter 300 due to AC power applied from the AC power control supply unit 200 and RF power used to generate plasma to control the temperature of the heater 132 provided in the wafer assembly 130 The temperature of the ferrite element of the magnetic material forming the is not increased or the output impedance of the RF filter 300 must not change.

Therefore, in a preferred case, the size of the RF filter 300 is made large so that a ferrite element is not used, and the output impedance of the RF filter 300 is high over the entire band of VHF or HF, MF, and LF. Although it can be formed as a pure air inductor to have a value, it is practically impossible to implement it as a high-impedance air inductor in the LF and MF frequency bands due to the limitations of the facility space.

Therefore, in order to implement high impedance in the LF frequency band and the MF frequency band in a given facility space, it is inevitable to form a ferrite element.

In addition, in the case of forming the RF filter 300 as a ferrite device, the inductor to be designed is designed because the frequency band capable of performing the normal inductor function changes due to the intrinsic permeability characteristics of the ferrite device. The intrinsic permeability of the ferrite element should be selected according to the value of and the frequency band to be used, and should be used only in the frequency band in which the ferrite element can operate normally as an inductor.

Therefore, according to the present invention, first, for the frequency and the higher harmonic frequency of each RF power used in the plasma process, the output impedance of the RF filter 300 is relatively larger than the impedance of the plasma chamber 100 itself. The RF power frequency to be blocked by the RF filter 300 is formed to have a high impedance at each frequency by applying a parallel L resonance structure to prevent leakage of RF energy by adjusting the impedance value.

Here, not simply grounding the parallel capacitor as in the prior art, but according to the present invention, by grounding through a series LC resonance circuit in a filter circuit of each frequency band to be selected, energy in the corresponding frequency band is blocked, while Impedances of other frequency bands are formed to have high impedance at the output terminal of the RF filter 300.

Second, for the frequency and higher harmonic frequency of each RF power used in the plasma process, in order to minimize the output impedance deviation of the RF filter 300 itself while forming to have a large value of the output impedance of the RF filter 300 The output impedance of the RF filter 300 is minimized by using a variable capacitor element.

Here, the variable capacitor of the RF filter 300 may minimize the deviation of its own output impedance of the RF filter 300, and the parasitic capacitor 301 and the parasitic capacitor present at the connection portion between the heater 132 and the RF filter 300 Impedance variation of the plasma chamber 100 can be minimized by the inductor 302.

Third, the RF filter 300 due to the AC power applied from the AC power control supply unit 200 and RF power used to generate plasma to control the temperature of the heater 132 provided in the wafer support assembly 130 In order not to increase the temperature of the ferrite element forming the) or to prevent the output impedance of the RF filter 300 from changing, it is formed as an air inductor, and inevitably a ferrite element must be used. Also, for each frequency, the output impedance of the RF filter 300 is high by the parallel LC resonance circuit, and the energy of the unwanted frequency band is formed as a ferrite element by connecting the series LC resonance circuit to the ground. The phenomenon of heat generation was blocked by preventing it from flowing into one filter end.

5, 6, and 10 according to an embodiment of the present invention provided in the HF band filters 310 and 3100 and the MF band filters 3200 formed toward the plasma chamber 100 side or the heater 132 side. Parallel LC resonance circuits (710, 720, 7100, 7200, 7500, 7600) and series LC resonance circuits (730, 740, 7300, 7400, 7700, 7800) formed by being connected in parallel thereto, and the AC power control supply unit 200 The parallel LC resonance circuits 750 and 760 provided in the LF band filters 320 and 3300 formed by two connection lines connected to the) side and the input parallel capacitors C _{111 and} C ₂₂₂ (780) respectively through two connection lines. For each individual high-order harmonic frequency of each of the RF waveforms (20) containing high-order harmonics generated by plasma distortion by 790), effective impedance control, RF energy cutoff, and equipment parts and RF filter impedance deviation can be minimized. have.

10: single frequency waveform 20: RF waveform including higher-order harmonics
100: plasma chamber
110: upper electrode 120: plasma
130: wafer support assembly
131: lower electrode 132: heater
140: wafer 150: bellows
200: AC power control supply unit 300: RF filter
310: HF band filter 320: MF band or LF band filter
400: RF ground 500: RF generator
600: RF matcher
701: Core_ _OUT 702: Core_ _IN
703: output parallel capacitor C _OUT1 704: output parallel capacitor C _OUT2
705: input parallel capacitor C _IN1 706: input parallel capacitor C _IN2
707: output inductor L _OUT1 708: output inductor L _OUT2
709-1: input inductor L _IN1 709-2: input inductor L _IN2
710, 720: parallel LC resonance circuit 730, 740: series LC resonance circuit
711: series inductor L ₁ 721: series inductor L ₂
712: variable capacitor C ₁ 722: variable capacitor C ₂
713: Parasitic capacitor C of the output inductor _{par_L1}
723: Output inductor parasitic capacitor C _{par_L2}
714: output parasitic capacitor C _par1 724: output parasitic capacitor C _par2
731: series capacitor C _P1 741: series capacitor C _P2
732: series inductor L _P1 742: series inductor L _P2
750, 760: parallel LC resonance circuit 770: core
751: input inductor L ₁₁ 761: input inductor L ₂₂
752: variable capacitor C ₁₁ 762: variable capacitor C ₂₂
753: Input inductor parasitic capacitor C _{par_L11}
763: Input inductor parasitic capacitor C _{par_L22}
754: Parasitic resistance R _{par_L11} 764: Parasitic resistance R _{par_L22}
780: parallel capacitor C _111, 790: parallel capacitor C ₂₂₂
3100: VHF or HF band filter
3200: MF band filter 3300: LF band filter
7100, 7200, 7500, 7600: parallel LC resonance circuit
7300, 7400, 7700, 7800: Series LC resonance circuit
7900: Core
7910, 7920: parallel LC resonance circuit
7911: LF inductor L _LF11 7921: LF inductor L _LF22
7930: Input parallel capacitor C _LF111
7940: Input parallel capacitor C _LF222

Claims (28)

AC power control for applying AC power to the heater provided in the wafer support assembly of the plasma chamber and the heater provided in the wafer support assembly of the plasma chamber in a plasma chamber that generates plasma with single or multiple frequency power to perform a process In the RF filter for a plasma process formed by being connected by a supply unit and two connection lines between the heater and the AC power control supply unit,
The RF filter,
An HF band filter including a parallel LC resonance circuit and a series LC resonance circuit connected in parallel to each of the two connection lines connected to the plasma chamber side or the heater side, and two connected to the AC power control supply unit. It comprises a parallel LC resonance circuit through each of the four connection lines and an MF band or LF band filter including an input parallel capacitor connected in parallel to each of the parallel LC resonance circuits,
The parallel LC resonance circuit of the HF band filter; A series inductor connected in series to a connection line connected to the heater and a variable capacitor element formed by being connected in parallel to the series inductor, or a series inductor connected in series to a connection line connected to the heater, and one side The terminal is connected in parallel to the connection line, and the other terminal consists of a variable capacitor element formed to be connected to the RF ground,
The series LC resonance circuit of the HF band filter; One terminal is connected in parallel to the parallel LC resonance circuit of the HF band filter, and the other terminal is formed by being connected to the RF ground, and a series capacitor connected in parallel to the connection line and a series inductor connected in series to the series capacitor Is connected,
The parallel LC resonance circuit of the MF band or LF band filter; An RF filter for a plasma process, comprising: an input inductor formed by winding a conductor wire around a magnetic material core; and a variable capacitor element connected in parallel to the input inductor.
delete delete The method according to claim 1,
An output parasitic capacitor formed in parallel with a series inductor provided in the parallel LC resonance circuit of the HF band filter and connected to the RF ground, and a parasitic capacitor component formed in parallel with the series inductor, are used in a parallel LC resonance circuit of the HF band filter. RF filter for a plasma process, characterized in that the RF impedance of the plasma chamber is maintained constant by compensating, canceling, and adjusting the impedance of the RF filter to a desired value by adjusting the variable capacitor element of.
delete The method according to claim 1,
The series LC resonance circuit of the HF band filter is formed with a low impedance value selectively at a desired frequency to block the flow of RF energy of the HF band frequency from flowing into the MF band or LF band filter side and the AC power control supply side. RF filter for plasma processing characterized by.
delete The method according to claim 1,
An input inductor parasitic capacitor formed in parallel with an input inductor provided in a parallel LC resonance circuit of an MF band or LF band filter, and a parasitic resistance component formed by being connected in parallel to a variable capacitor element connected in parallel to the input inductor, Plasma characterized in that the RF impedance of the plasma chamber is maintained constant by compensating and canceling the impedance of the RF filter to a desired value by adjusting the variable capacitor element of the parallel LC resonance circuit of the MF band or LF band filter. RF filter for the process.
The method of claim 8,
MF lower than the high frequency band (HF) by adjusting the value of the variable capacitor connected in parallel with the input inductor of the parallel LC resonance circuit of the MF band or LF band filter and the input parallel capacitor connected in parallel with the parallel LC resonance circuit. Medium Frequency) RF filter for a plasma process, characterized in that the control so as to be a larger impedance value of the frequency band or LF (low frequency) frequency band to block RF power and RF noise from flowing into the AC power control supply.
AC power control for applying AC power to the heater provided in the wafer support assembly of the plasma chamber and the heater provided in the wafer support assembly of the plasma chamber in a plasma chamber that generates plasma with single or multiple frequency power to perform a process In the RF filter for a plasma process formed by being connected by a supply unit and two connection lines between the heater and the AC power control supply unit,
The RF filter,
An HF band filter including a parallel LC resonance circuit and a series LC resonance circuit connected in parallel to each of the two connection lines connected to the plasma chamber side or the heater side, and two connected to the AC power control supply unit. Comprising an MF band or LF band filter including a parallel LC resonance circuit and a series LC resonance circuit connected in parallel to each of the parallel LC resonance circuits through each of the four connecting lines,
The parallel LC resonance circuit of the HF band filter; A series inductor connected in series to a connection line connected to the heater and a variable capacitor element formed by being connected in parallel to the series inductor, or a series inductor connected in series to a connection line connected to the heater, and one side The terminal is connected in parallel to the connection line, and the other terminal consists of a variable capacitor element formed to be connected to the RF ground,
The series LC resonance circuit of the HF band filter; One terminal is connected in parallel to the parallel LC resonance circuit of the HF band filter, and the other terminal is formed by being connected to the RF ground, and a series capacitor connected in parallel to a connection line and a series inductor connected in series to the series capacitor are provided. Is connected,
The parallel LC resonance circuit of the MF band or LF band filter; It consists of an input inductor formed by winding a conductor wire around a magnetic material core, and a variable capacitor element connected in parallel to the input inductor,
The series LC resonance circuit of the MF band or LF band filter; One terminal is connected in parallel to the parallel LC resonance circuit of the MF band or LF band filter, and the other terminal is formed by being connected to the RF ground, and connected in series to the series capacitor and the series capacitor connected in parallel to the connection line. RF filter for a plasma process, characterized in that formed by connecting a series inductor.
delete delete The method according to claim 10,
An output parasitic capacitor formed in parallel with a series inductor provided in the parallel LC resonance circuit of the HF band filter and connected to the RF ground, and a parasitic capacitor component formed in parallel with the series inductor, are used in a parallel LC resonance circuit of the HF band filter. RF filter for a plasma process, characterized in that the RF impedance of the plasma chamber is maintained constant by compensating, canceling, and adjusting the impedance of the RF filter to a desired value by adjusting the variable capacitor element of.
delete The method of claim 13,
The series LC resonance circuit of the HF band filter is formed with a low impedance value selectively at a desired frequency to block the flow of RF energy of the HF band frequency from flowing into the MF band or LF band filter side and the AC power control supply side. RF filter for plasma processing characterized by.
delete The method of claim 10,
An input inductor parasitic capacitor formed in parallel with an input inductor provided in a parallel LC resonance circuit of an MF band or LF band filter, and a parasitic resistance component formed by being connected in parallel to a variable capacitor element connected in parallel to the input inductor, Plasma characterized in that the RF impedance of the plasma chamber is maintained constant by compensating and canceling the impedance of the RF filter to a desired value by adjusting the variable capacitor element of the parallel LC resonance circuit of the MF band or LF band filter. RF filter for the process.
delete The method according to claim 10,
MF lower than the high frequency band (HF) by adjusting the value of the variable capacitor connected in parallel with the input inductor of the parallel LC resonance circuit of the MF band or LF band filter and a series LC resonance circuit connected in parallel with the parallel LC resonance circuit. RF filter for plasma process, characterized in that it blocks RF power and RF noise from flowing into the AC power control supply unit by controlling to be a larger impedance value in a (Medium Frequency) frequency band or a low frequency (LF) frequency band. .
AC power control for applying AC power to the heater provided in the wafer support assembly of the plasma chamber and the heater provided in the wafer support assembly of the plasma chamber in a plasma chamber that generates plasma with single or multiple frequency power to perform a process In the RF filter for a plasma process formed by being connected by a supply unit and two connection lines between the heater and the AC power control supply unit,
The RF filter,
A VHF band filter that blocks a frequency band of the VHF band, including a parallel LC resonance circuit and a series LC resonance circuit connected in parallel to each of the parallel LC resonance circuits by two connecting lines connected to the plasma chamber side or the heater side, respectively, Including a parallel LC resonance circuit and a series LC resonance circuit connected in parallel with each of the two connecting lines connected to the AC power control supply side in parallel, respectively, to block the frequency band of the LF band. LF band filter, and a series LC resonance circuit connected in parallel to each of the parallel LC resonance circuit and the parallel LC resonance circuit by connecting lines connected to the plasma chamber side or the heater side between the VHF band filter and the LF band filter, respectively. It is made by including an MF band filter that blocks the frequency band of the MF band,
A parallel LC resonance circuit of the VHF band filter or MF band filter; Consisting of a series inductor connected in series to a connection line connected to the heater and a variable capacitor element formed by being connected in parallel to the series inductor, or a series inductor connected in series to a connection line connected to the heater, and one terminal It is connected in parallel to the connection line, and the other terminal consists of a variable capacitor element formed to be connected to the RF ground,
The series LC resonance circuit of the VHF band filter or MF band filter; One terminal is connected in parallel to the parallel LC resonance circuit of the VHF band filter or MF band filter, and the other terminal is formed by being connected to the RF ground, and connected in series to the series capacitor connected in parallel to the connection line and the series capacitor. Is made by connecting a series inductor that is
The parallel LC resonance circuit of the LF band filter; An RF filter for a plasma process, comprising: an input inductor formed by winding a conductor wire around a magnetic material core; and a variable capacitor element connected in parallel to the input inductor.
delete delete The method of claim 20,
An output parasitic capacitor formed in parallel with a series inductor provided in a parallel LC resonance circuit of the VHF band filter or the MF band filter and connected to an RF ground, and a parasitic capacitor component formed in parallel with the series inductor, the VHF band filter Alternatively, by adjusting the variable capacitor element of the parallel LC resonance circuit of the MF band filter, the impedance of the RF filter is compensated to a desired value, canceled, and adjusted to keep the RF impedance of the plasma chamber constant. RF filter.
delete The method of claim 20,
The series LC resonance circuit of the VHF band filter is formed with a low impedance value selectively only the desired frequency to block the flow of RF energy of the frequency of the VHF band from flowing into the MF band or LF band filter side and the AC power control supply side. And, the series LC resonance circuit of the MF band filter is formed with a low impedance value selectively only a desired frequency to block the flow of RF energy of the frequency of the MF band from flowing into the LF band filter side and the AC power control supply side. RF filter for a plasma process, characterized in that.
delete The method of claim 20,
An input inductor parasitic capacitor formed in parallel with an input inductor provided in a parallel LC resonance circuit of the LF band filter, and a parasitic resistance component formed by being connected in parallel to a variable capacitor element connected in parallel to the input inductor, the MF band. Alternatively, by adjusting the variable capacitor element of the parallel LC resonance circuit of the LF band filter, the impedance of the RF filter is compensated to a desired value, canceled, and adjusted to keep the RF impedance of the plasma chamber constant. RF filter.
The method of claim 20,
High frequency band (HF) and medium frequency (MF) frequencies by adjusting the value of a variable capacitor connected in parallel with the input inductor of the parallel LC resonance circuit of the LF band filter and an input parallel capacitor connected in parallel with the parallel LC resonance circuit. RF filter for a plasma process, characterized in that by controlling the impedance of the lower LF (low frequency) frequency band than the band to be a larger impedance value to block RF power and RF noise from flowing into the AC power control supply.

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