RF plasma generating apparatus

Abstract

An RF plasma generating device according to one embodiment of the present invention includes: an AC filter that blocks harmonic components included in an RF signal applied from an RF power source and external power noise; a TC filter that forms a path configured to have a relatively low impedance compared to the output impedance of the RF power source and induces harmonic components of a specific frequency band among the RF signal to ground through the path; and a matching network that matches the output impedance of the RF power source with the load impedance of the plasma chamber to compensate for the mismatch between the output impedance of the RF power source and the load impedance of the plasma chamber to which the RF signal is applied.

Description

Technology Field

[0001] Embodiments of the present invention relate to an RF plasma generation device. Background Technology

[0002] delete

[0003] This invention is derived from the research of the project "Development of RF Plasma Heater Harmonic Matching System Technology" (Project No. E2510012, Lead Organization FNS, Research Period June 2, 2025 – Nov 28, 2025), conducted as part of the Gyeonggi Economic & Science Promotion Agency's "Support Project for Fostering Materials, Parts, and Equipment Enterprises." As the integration density of semiconductor devices increases and miniaturization progresses, the importance of plasma-based process equipment, such as dry etching or deposition processes using plasma, is gradually increasing. Generally, technologies that generate plasma using RF (Radio Frequency) power and etch wafer surfaces or deposit thin films through plasma are widely utilized. However, RF signals applied through RF power may contain various harmonic components and noise components introduced from external power sources in addition to the fundamental frequency component. These harmonic and noise components distort the waveform of the signal applied to the plasma chamber, impair plasma uniformity, and cause problems that reduce the reliability of process results. In particular, in RF frequency bands such as 13.56 MHz and 27.12 MHz, which are mainly used in semiconductor manufacturing processes, second and third harmonics are prone to occur, making it difficult to ensure stable plasma formation and uniform processing characteristics.

[0004] To solve these problems, conventional techniques have proposed methods to eliminate external power noise by placing an AC filter between the RF power supply and the plasma chamber, or to eliminate specific harmonic frequency components by short-circuiting them to ground using a TC filter. Additionally, techniques using a matching network to compensate for changes in the load impedance of the plasma chamber and to minimize mismatch with the output impedance of the RF power supply (e.g., 50Ω) are also known.

[0005] However, the conventional technology described above has limitations in that, as each filter and matching network exists as a separate configuration, the overall installation space of the device increases, leading to higher costs due to the increased number of components and complexity in maintenance. Furthermore, there are limitations in simultaneously satisfying harmonic suppression and impedance matching characteristics in high frequency and multiple frequency bands.

[0006] The matters described in the background technology above are intended to aid in understanding the background of the invention and may include matters that are not disclosed prior art. Prior art literature

[0007] Korean Patent Publication No. 10-2143563 (August 5, 2020) The problem to be solved

[0008] The problem that the present invention aims to solve is to provide an RF plasma generator that integrates an AC filter, a TC filter, and a matching network into an all-in-one structure within a single housing, and effectively suppresses specific frequencies and harmonic components through an LC resonant network combined with a mesh ground plate, while simultaneously stably matching the impedance between the RF power source and the plasma load. means of solving the problem

[0009] An RF plasma generating device according to one embodiment of the present invention is an RF plasma generating device that generates plasma using an RF (Radio Frequency) power source, and includes: an AC (Alternating Current) filter that blocks harmonic components included in an RF signal applied from the RF power source and external power noise; a TC (Trap Circuit) filter that forms a path configured to have a relatively lower impedance compared to the output impedance of the RF power source and induces harmonic components of a specific frequency band among the RF signal to ground through the path; and a matching network that matches the output impedance of the RF power source with the load impedance of the plasma chamber to compensate for the mismatch between the output impedance of the RF power source and the load impedance of the plasma chamber to which the RF signal is applied.

[0010] The above AC filter may be a low-pass filter (LPF) configured to allow low-frequency components introduced from the RF power source to pass through, while blocking harmonic components and external power noise.

[0011] The above TC filter may include an LC resonant circuit that resonates in the specific frequency band and short-circuits the harmonic components of the corresponding frequency band.

[0012] The above specific frequency band may include at least one of 13.56 MHz and 27.12 MHz.

[0013] The above LC resonant circuit has a structure in which an inductor and a capacitor are connected in series, and may include a first trap circuit that resonates at 13.56 MHz to short-circuit harmonic components of the corresponding frequency band, and a second trap circuit that resonates at 27.12 MHz to short-circuit harmonic components of the corresponding frequency band.

[0014] The above matching network may include a vacuum variable capacitor configured to adjust a resonant frequency corresponding to the operating frequency of the RF power supply according to a change in the load impedance; and an inductor connected in series or parallel with the vacuum variable capacitor.

[0015] The above matching network includes a series resonant circuit and a parallel resonant circuit corresponding to each of the first frequency band and the second frequency band among the above specific frequency bands, and the series resonant circuit may be composed of the vacuum variable capacitor and an inductor connected in series with the vacuum variable capacitor, and the parallel resonant circuit may be composed of the vacuum variable capacitor and an inductor connected in parallel with the vacuum variable capacitor.

[0016] The above matching network can be formed into a mesh ground plate structure combined with an LC resonant network in which the series resonant circuit and the parallel resonant circuit are cross-connected.

[0017] The above matching network may be configured to be electrically connected to the plasma chamber through the mesh ground plate structure to perform impedance matching for the fundamental frequency component of the RF signal, while simultaneously absorbing or suppressing the second or third harmonic components included in the RF signal, thereby transmitting only the frequency components necessary for the formation and maintenance of the plasma to the plasma chamber.

[0018] The above AC filter, the above TC filter, and the above matching network can be integrated within a single housing and configured as a single module. Effects of the invention

[0019] According to embodiments of the present invention, by processing an RF signal applied from an RF power source through an integrated module including an AC filter, a TC filter, and a matching network, a miniaturized device can be implemented and installation space reduced, and manufacturing costs can be reduced and maintenance can also be simplified due to the reduction in the number of parts.

[0020] According to embodiments of the present invention, harmonic interference and external noise generated in a plasma process can be effectively suppressed, impedance matching stability can be secured, and power transfer efficiency and plasma uniformity can be improved.

[0021] According to embodiments of the present invention, the quality of the signal transmitted to the plasma chamber can be improved by passing the fundamental frequency component through an AC filter with a low-pass filter structure while effectively blocking noise and harmonic components introduced from an external power source.

[0022] According to embodiments of the present invention, harmonic components of frequency bands such as 13.56 MHz or 27.12 MHz can be guided to ground and removed through a TC filter including an LC resonant circuit that resonates in a specific frequency band, and thereby only a stable and purified RF signal is applied to the plasma chamber, thereby increasing the stability of the plasma formation process.

[0023] According to embodiments of the present invention, even if the load impedance fluctuates during the plasma process, reflected power can be suppressed and power transfer efficiency improved by compensating for the mismatch between the output impedance of the RF power source and the load impedance of the plasma chamber through a matching network.

[0024] According to embodiments of the present invention, through a structure combining an LC resonant network composed of an inductor and a vacuum variable capacitor and a mesh ground plate, stable impedance matching is provided for the fundamental component, while second and third harmonic components can be absorbed or canceled out. As a result, a uniform and stable plasma is formed inside the plasma chamber, which can significantly improve the precision and reproducibility of process results. Brief explanation of the drawing

[0025] FIG. 1 is a block diagram illustrating an RF plasma generation device according to one embodiment of the present invention. Figure 2 is a block diagram illustrating the detailed configuration of the TC filter of Figure 1. Figures 3 and 4 are block diagrams illustrated to explain the detailed configuration of the matching network of Figure 1. FIG. 5 is a diagram showing the circuit design structure of a mesh ground harmonic impedance tuner according to one embodiment of the present invention. FIG. 6 is a flowchart illustrating the operation method of an RF plasma generation device according to one embodiment of the present invention. Specific details for implementing the invention

[0026] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

[0027] The embodiments are provided to more fully explain the invention to those skilled in the art, and the following embodiments may be modified in various different forms, and the scope of the invention is not limited to the following embodiments. Rather, these embodiments are provided to make the disclosure more faithful and complete and to fully convey the spirit of the invention.

[0028] The terms used herein are for describing specific embodiments and are not intended to limit the invention. Additionally, the singular form in this specification may include the plural form unless the context clearly indicates otherwise. Terms such as “comprising,” “having,” and “having” in this application are intended to specify the presence of features, numbers, steps, actions, components, parts, or combinations thereof of the invention, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0029] The drawings are intended solely to facilitate an understanding of the concept of the present invention and should not be interpreted as limiting the scope of the invention. Additionally, relative thicknesses, lengths, or sizes in the drawings may be exaggerated for convenience and clarity of explanation.

[0030] FIG. 1 is a block diagram illustrating an RF plasma generating device according to an embodiment of the present invention, and FIG. 2 is a block diagram illustrating a detailed configuration of the TC filter of FIG. 1. FIG. 3 and FIG. 4 are block diagrams illustrating a detailed configuration of the matching network of FIG. 1, and FIG. 5 is a diagram showing the circuit design structure of a mesh ground harmonic impedance tuner according to an embodiment of the present invention.

[0031] Referring to FIGS. 1 to 5, an RF plasma generating device (100) according to one embodiment of the present invention may be configured to include an RF power source (110), an AC filter (120), a TC filter (130), a matching network (140), and a plasma chamber (150).

[0032] According to one embodiment of the present invention, the AC filter (120), the TC filter (130), and the matching network (140) may be integrated within a single housing and configured as a single module. In other words, the AC filter (120), the TC filter (130), and the matching network (140) may be configured as an all-in-one module.

[0033] The RF power supply (110) is a power supply device that generates and outputs high-frequency power for generating plasma. The RF power supply (110) generally generates high-frequency alternating voltage in industrial standard frequency bands such as 13.56 MHz and 27.12 MHz, and can be configured to have an output impedance of 50 Ω, which is used in conventional communication equipment and plasma generating devices.

[0034] The RF power supply (110) stably supplies a high-frequency signal to the plasma chamber (150), thereby ionizing the gas inside the plasma chamber (150) to form plasma, and enables the etching or deposition process of a semiconductor substrate to be performed using the formed plasma.

[0035] At this time, the RF signal output from the RF power source (110) may contain harmonic components such as second and third harmonics or noise components introduced from an external power source in addition to the original fundamental frequency component. These components may have a negative effect on the formation stability and uniformity of the plasma, reduce transmission efficiency, and increase reflected power.

[0036] Accordingly, according to one embodiment of the present invention, by processing the RF signal output from the RF power source (110) through an All-in-one module, harmonics and noise are suppressed, and the output impedance of the RF power source (110) and the load impedance of the plasma chamber (140) are efficiently matched to ensure the stability of plasma generation and process uniformity. This will be explained in detail below.

[0037] The AC filter (120) performs the function of blocking harmonic components and external power noise included in the RF signal applied from the RF power source (110). That is, the AC filter (120) performs the function of effectively suppressing noise from external power sources and harmonic components that are integer multiples of the fundamental frequency that may be mixed into the RF signal before the RF signal output from the RF power source (110) is applied to the plasma chamber (150).

[0038] To this end, the AC filter (120) may include a low-pass filter (LPF) configured to allow low-frequency components introduced from the RF power source (110) to pass through, while blocking harmonic components and external power noise. That is, the AC filter (120) may include a low-pass filter composed of an inductor and a capacitor to allow low-frequency components to pass through without loss and to attenuate or block unnecessary high-frequency components and power noise existing above a set cutoff frequency.

[0039] An AC filter (120) is placed between the output terminal of the RF power supply (110) and the TC filter (130) so that the RF signal applied to the plasma chamber (150) contains only the target fundamental frequency (e.g., 13.56 MHz, 27.12 MHz) and other frequency components are removed in the direction of ground, thereby improving plasma generation efficiency and stability.

[0040] For example, when generating plasma using a 13.56 MHz RF power supply (110) in a semiconductor process, the signal output from the actual power supply may contain unwanted frequency components of 27.12 MHz (second harmonic) or higher. In this case, the AC filter (120) is designed as a low-pass filter (LPF) so that the 13.56 MHz fundamental wave passes through with almost no loss, while blocking and directing frequency components of 27.12 MHz and higher to ground. Accordingly, only a stable and distortion-minimized RF signal is transmitted to the plasma chamber (150), so that the plasma can be formed and maintained uniformly.

[0041] The TC filter (130) forms a path configured to have a relatively low impedance compared to the output impedance of the RF power supply (110), and can induce harmonic components of a specific frequency band of the RF signal to ground through the formed path. To this end, the TC filter (130) may include an LC resonant circuit that resonates at a specific frequency band and short-circuits the harmonic components of that frequency band. Here, the specific frequency band may include at least one of 13.56 MHz and 27.12 MHz.

[0042] At this time, the LC resonant circuit may have a structure in which an inductor and a capacitor are connected in series. For example, the LC resonant circuit may include a first trap circuit (210) that resonates at 13.56 MHz and short-circuits the harmonic components of the corresponding frequency band, and a second trap circuit (220) that resonates at 27.12 MHz and short-circuits the harmonic components of the corresponding frequency band.

[0043] More specifically, the TC filter (130) forms a low-impedance path for a specific harmonic component of the RF signal output from the RF power source (110) and guides that component to ground, thereby ensuring that the signal transmitted to the plasma chamber (150) is maintained only as a fundamental frequency component.

[0044] To this end, the TC filter (130) may include an LC resonant circuit composed of an inductor and a capacitor, and the LC resonant circuit resonates in a set specific frequency band to minimize impedance for the frequency component, and consequently, can eliminate the component in the direction of ground.

[0045] Here, specific frequency bands may include 13.56 MHz and 27.12 MHz, which are widely used in semiconductor processes, and trap circuits (210, 220) that resonate independently for each band may be arranged. Specifically, the first trap circuit (210) is designed to resonate at 13.56 MHz to remove harmonic components of 13.56 MHz, and the second trap circuit (220) is designed to resonate at 27.12 MHz to remove harmonic components of 27.12 MHz.

[0046] Additionally, the trap circuits (210, 220) may be arranged in multiple numbers within a single module, and additional LC resonant circuits corresponding to different frequency bands (e.g., 40.68 MHz, 60 MHz, etc.) may be provided as needed. Through this, the RF plasma generating device (100) according to one embodiment of the present invention can selectively remove unnecessary harmonic components that may occur in various frequency bands and can improve the stability and process uniformity of the plasma.

[0047] In particular, in the TC filter (130), the capacitor used in the LC resonant circuit can be configured as a vacuum variable capacitor, thereby allowing the resonance point to be finely adjusted even under conditions of plasma load change or frequency fluctuation. Accordingly, the TC filter (130) can perform dynamic tuning functions beyond simple fixed filtering functions.

[0048] For example, when using a 13.56 MHz RF power supply (110), the signal output from the RF power supply (110) may include a 27.12 MHz (second harmonic) component. In this case, the second trap circuit (220) resonates at 27.12 MHz and shorts the corresponding component to ground, thereby allowing only the 13.56 MHz fundamental wave to be transmitted to the plasma chamber (150) (single frequency suppression).

[0049] As another example, when the plasma chamber (150) is operated in dual frequency mode and needs to use 13.56 MHz and 27.12 MHz simultaneously, the first trap circuit (210) and the second trap circuit (220) can each remove harmonic components in the corresponding frequency band so that only the two necessary fundamental frequency components are transmitted to the plasma chamber (150) (multi-frequency suppression).

[0050] In another example, if the harmonic suppression performance is degraded due to fluctuations in the plasma load caused by changes in process conditions, the first trap circuit (210) and the second trap circuit (220) can compensate by adjusting the vacuum variable capacitor to finely change the resonant frequency of the LC resonant circuit so that the corresponding harmonic component is effectively induced back to ground (dynamic adjustment).

[0051] The matching network (140) can perform the function of matching the output impedance of the RF power supply (110) and the load impedance of the plasma chamber (150) so as to compensate for the mismatch between the output impedance of the RF power supply (110) and the load impedance of the plasma chamber (150) to which the RF signal is applied. To this end, the matching network (140) may be configured to include an LC resonant network (310) and a mesh ground plate.

[0052] That is, the matching network (140) can be formed as a mesh ground plate (320) structure combined with an LC resonant network (310). The LC resonant network (310) can be configured to include a series resonant circuit (410, 430) and a parallel resonant circuit (420, 440) corresponding to a first frequency band and a second frequency band, respectively, among specific frequency bands.

[0053] The series resonant circuit (410, 430) may be composed of a first series resonant circuit (410) corresponding to a first frequency band among specific frequency bands and a second series resonant circuit (430) corresponding to a second frequency band among specific frequency bands. The first series resonant circuit (410) and the second series resonant circuit (430) may each include a vacuum variable capacitor and an inductor. The vacuum variable capacitor may be configured to adjust the resonant frequency corresponding to the operating frequency of the RF power supply (110) according to the change in the load impedance of the plasma chamber (150), and the inductor may be connected in series with the vacuum variable capacitor.

[0054] A parallel resonant circuit (420, 440) may be composed of a first parallel resonant circuit (420) corresponding to a first frequency band among specific frequency bands and a second parallel resonant circuit (440) corresponding to a second frequency band among specific frequency bands. The first parallel resonant circuit (420) and the second parallel resonant circuit (440) may each include a vacuum variable capacitor and an inductor. The vacuum variable capacitor may be configured to adjust the resonant frequency corresponding to the operating frequency of the RF power supply (110) according to the change in the load impedance of the plasma chamber (150), and the inductor may be connected in parallel with the vacuum variable capacitor.

[0055] That is, the LC resonant network (310) may have a structure in which a series resonant circuit (410, 430) and a parallel resonant circuit (420, 440) are cross-connected. In other words, in the LC resonant network (310), a first series resonant circuit (410) corresponding to a first frequency band and a first parallel resonant circuit (420) corresponding to a second frequency band are connected in series, and a second series resonant circuit (430) corresponding to a second frequency band and a second parallel resonant circuit (440) corresponding to a first frequency band are connected in series.

[0056] Here, a cross-connected structure means that circuits corresponding to the same frequency band are not connected to each other, but rather circuits corresponding to different frequency bands are connected to each other. For example, if the first frequency band is 13 MHz and the second frequency band is 27 MHz, a first series resonant circuit (410) corresponding to 13 MHz and a first parallel resonant circuit (420) corresponding to 27 MHz are connected in series, and a second series resonant circuit (430) corresponding to 27 MHz and a second parallel resonant circuit (440) corresponding to 13 MHz are connected in series, and this can also be described as a cross-connected structure.

[0057] The matching network (140) can be electrically connected to the plasma chamber (150) through a mesh ground plate (320) structure and configured to perform impedance matching for the fundamental frequency component of the RF signal, while simultaneously absorbing or suppressing the second or third harmonic components included in the RF signal, thereby transmitting only the frequency components necessary for the formation and maintenance of the plasma to the plasma chamber (150).

[0058] Meanwhile, the matching network (140) is designed not only to compensate for the load impedance of the plasma chamber (150) but also to actively respond to fluctuations in various frequency components that occur during the plasma process. In particular, by combining an LC resonant network (310) composed of an inductor and a vacuum variable capacitor with a mesh ground plate (320), a uniform ground impedance can be secured in the transmission path of high-frequency signals. This allows unstable plasma current generated inside the plasma chamber to be effectively dissipated through the ground plane, thereby contributing to maintaining a uniform density distribution of the plasma.

[0059] In addition, the vacuum variable capacitor included in the LC resonant network (310) can adjust the resonant frequency in real time according to changes in external power conditions or plasma state, thereby continuously maintaining accurate impedance matching for the output frequency of the RF power supply (e.g., 13.56 MHz, 27.12 MHz). This effectively suppresses reflected power, reduces power loss, and consequently improves power transfer efficiency.

[0060] Furthermore, the mesh ground plate (320) includes a grid-shaped conductive pattern to provide multiple ground paths through which high-frequency current can be uniformly distributed and returned, thereby suppressing the asymmetric discharge phenomenon of the plasma caused by the imbalance of high-frequency current. Thus, even though the matching network (140) is implemented as a miniaturized and integrated structure, it can achieve technical effects such as stable plasma generation in various frequency bands, minimization of reflected power, and securing uniform plasma density.

[0061] For example, when the RF power applied to the plasma chamber (150) in the semiconductor etching process operates at 13.56 MHz, the LC resonant network (310) precisely matches the resonant frequency to 13.56 MHz by adjusting the capacitance of the vacuum variable capacitor, and accordingly, the load impedance of the plasma chamber (150) and the output impedance of the RF power (110) can be effectively matched.

[0062] As another example, when the impedance of the plasma load fluctuates due to a change in electron density during the plasma process, the matching network (140) immediately performs a compensation operation by adjusting the variable capacitor of the LC resonant network (310) combined with the mesh ground plate (320), thereby suppressing reflected power and maintaining a stable plasma discharge.

[0063] The plasma chamber (150) can perform the function of forming plasma by ionizing the gas charged inside the chamber using an RF signal applied from the RF power source (110). The plasma chamber (150) can be used in various industrial processes such as semiconductor manufacturing, display panel processing, and surface treatment, and ensuring the uniformity, stability, and processing speed of the plasma is an important factor.

[0064] Although not shown in the drawing, the plasma chamber (150) may be configured to include a chamber body capable of maintaining a vacuum state, a gas injection section, an exhaust section, an electrode structure, etc. Process gases such as argon (Ar), oxygen (O2), and fluorinated gases (CF4, SF6) are injected into the interior of the plasma chamber (150), and an RF signal transmitted from the RF power source (110) is applied through the electrode structure, thereby ionizing the gas molecules and converting them into a plasma state.

[0065] Since the plasma chamber (150) acts as a load directly connected to the output impedance of the RF power supply (110), the load impedance continuously fluctuates depending on process conditions (gas pressure, flow rate, electron density inside the chamber, etc.). Such fluctuations can lead to an increase in reflected power of the RF signal and a decrease in power transfer efficiency. Therefore, in one embodiment of the present invention, only a stabilized RF signal that has passed through an AC filter (120), a TC filter (130), and a matching network (140) is applied to the plasma chamber (150), thereby ensuring stable formation and uniformity of the plasma.

[0066] In particular, the mesh ground plate (320) combined with the matching network (140) is electrically connected to the plasma chamber (150) so that the fundamental frequency is transmitted without loss and harmonic components are absorbed or eliminated, thereby allowing a uniform plasma to be generated and maintained by a stable and pure RF signal inside the plasma chamber (150).

[0067] For example, when argon (Ar) gas is injected into the plasma chamber (150) and a 13.56 MHz RF signal is applied, argon atoms inside the plasma chamber (150) are ionized to form plasma, and this plasma can be used to uniformly etch the surface of a semiconductor substrate (basic operation).

[0068] As another example, if the internal pressure of the chamber changes or the plasma density fluctuates during the process, the load impedance of the plasma chamber (150) may change. In this case, the matching network (140) can adjust the vacuum variable capacitor of the LC resonant network (310) to change the resonant frequency, thereby matching it again with the output impedance of the RF power supply (110), and as a result, a stable RF signal can be applied to the plasma chamber (150) without reflected power (impedance fluctuation compensation).

[0069] As another example, when a 27.12 MHz RF signal is applied to a plasma chamber (150), a 54.24 MHz (second harmonic) component included in the RF signal may be introduced along with it. The TC filter (130) and the matching network (140) can eliminate this harmonic component to ground and transmit only the 27.12 MHz fundamental wave to the plasma chamber (150), thereby preventing distortion of the plasma density distribution (harmonic suppression effect).

[0070] Meanwhile, in FIG. 5, Pr1, Pr2, Pr3, and Pr4 are each RF switches that control the connection state of an LC resonant circuit composed of an inductor and a capacitor to perform the function of switching the impedance characteristics in a specific frequency band. Hereinafter, Pr1, Pr2, Pr3, and Pr4 will be referred to as the first RF switch, the second RF switch, the third RF switch, and the first RF switch, respectively.

[0071] Specifically, the first RF switch (Pr1) serves to selectively connect or disconnect a resonant circuit (210, 430) composed of L7, C7, L3, and C3. When the first RF switch (Pr1) is in a conducting state, the corresponding resonant circuit (210, 430) is inserted into the RF path to provide a short-circuit effect for the 13 MHz band and simultaneously perform an impedance tuning function in the 27 MHz band. Conversely, when the first RF switch (Pr1) is in a disconnected state, the resonant circuit (210, 430) is excluded from the RF path and does not affect operation.

[0072] The second RF switch (Pr2) controls the operation of the LC resonant circuit (410) composed of L4 and C4. When the second RF switch (Pr2) is in a conducting state, L4 and C4 are connected to the circuit to enable impedance tuning in the 13 MHz band, thereby compensating for load impedance fluctuations of the plasma chamber (150).

[0073] The third RF switch (Pr3) and the fourth RF switch (Pr4) are placed in an intermediate path and perform the operation of bypassing or connecting the resonant circuits (210, 430, 410, 220) as needed. For example, when the third RF switch (Pr3) and the fourth RF switch (Pr4) are conducted simultaneously in a specific mode, the selected resonant circuit is directly included in the RF signal path and performs frequency-specific matching or short-circuiting operations. On the other hand, when the third RF switch (Pr3) and the fourth RF switch (Pr4) are turned off, the corresponding resonant circuit is excluded from the RF path and remains in an open state.

[0074] In this way, the LC resonant circuit connected to the RF path of the first RF switch (Pr1) to the fourth RF switch (Pr1~Pr4) changes according to their respective control states (On / Off), and as a result, various operating modes such as 13MHz Open, 13MHz Short, 13MHz Impedance Tuning, 27MHz Open, 27MHz Short, and 27MHz Impedance Tuning can be implemented. Accordingly, the first RF switch (Pr1) to the fourth RF switch (Pr1~Pr4) can function to enable the matching network (140) to operate flexibly in multiple frequency bands.

[0075] FIG. 6 is a flowchart illustrating the operation method of an RF plasma generation device according to one embodiment of the present invention.

[0076] Referring to FIGS. 1 and FIGS. 6, in step (610), the AC filter (120) can block harmonic components and external power noise included in the RF signal applied from the RF power source (110).

[0077] That is, the AC filter (120) can effectively suppress noise from an external power source and harmonic components that are integer multiples of the fundamental frequency that may be mixed into the RF signal before the RF signal output from the RF power source (110) is applied to the plasma chamber (150). To this end, the AC filter (120) may include a low-pass filter (LPF) configured to allow low-frequency components from the RF power source (110) to pass through, while blocking harmonic components and external power noise.

[0078] Next, in step (620), the TC filter (130) can form a path configured to have a relatively low impedance compared to the output impedance of the RF power supply (110).

[0079] Next, in step (630), the TC filter (130) can guide harmonic components of a specific frequency band of the RF signal to ground through the formed path.

[0080] To this end, the TC filter (130) may include an LC resonant circuit that resonates in a specific frequency band and short-circuits the harmonic components of that frequency band. Here, the specific frequency band may include at least one of 13.56 MHz and 27.12 MHz.

[0081] Next, in step (640), the matching network (140) can match the output impedance of the RF power supply (110) with the load impedance of the plasma chamber (150) so as to compensate for the mismatch between the output impedance of the RF power supply (110) and the load impedance of the plasma chamber (150) to which the RF signal is applied.

[0082] To this end, the matching network (140) may be configured to include an LC resonant network (310) and a mesh ground plate. That is, the matching network (140) may be formed with a mesh ground plate (see "320" in FIG. 3) structure combined with an LC resonant network (see "310" in FIG. 3). The LC resonant network may be configured to include a series resonant circuit (see "410", "430" in FIG. 4) and a parallel resonant circuit (see "420", "440" in FIG. 4) corresponding to a first frequency band and a second frequency band, respectively, among specific frequency bands.

[0083] That is, the LC resonant network may have a structure in which a series resonant circuit and a parallel resonant circuit are cross-connected. In other words, in the LC resonant network, a first series resonant circuit corresponding to a first frequency band and a first parallel resonant circuit corresponding to a second frequency band may be connected in series, and a second series resonant circuit corresponding to a second frequency band and a second parallel resonant circuit corresponding to a first frequency band may be connected in series.

[0084] The matching network (140) can be electrically connected to the plasma chamber (150) through a mesh ground plate (320) structure and configured to perform impedance matching for the fundamental frequency component of the RF signal, while simultaneously absorbing or suppressing the second or third harmonic components included in the RF signal, thereby transmitting only the frequency components necessary for the formation and maintenance of the plasma to the plasma chamber (150).

[0085] The device (unit) described above may be implemented as a hardware element and / or a software element. For example, the hardware element may include a microphone, an amplifier, a bandpass filter, an A / D converter, and a processing device. The processing device may be implemented using one or more general-purpose or special-purpose computers, such as a processor, a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable gate array (FPGA), a programmable logic unit (PLU), a microprocessor, or other devices capable of responding to and executing instructions in a defined manner. The processing device may operate an operating system (OS) and one or more software applications running on the operating system. Additionally, the processing device may access, store, manipulate, process, and generate data in response to the execution of the software. For the sake of brevity, the processing unit may be described as a single unit; however, those skilled in the art will understand that the processing unit may include multiple processing elements and / or multiple types of processing elements. For example, the processing unit may include multiple processors or a processor and a controller. Additionally, other processing configurations, such as parallel processors, are also possible.

[0086] Software, including computer programs, code, instructions, or combinations thereof, may configure or command a processing unit independently or collectively to operate as desired. Software and data may be embodied permanently or temporarily as propagated signal waves that can be interpreted by the processing unit or provide instructions or data to the processing unit, or as various types of machines, components, physical devices, virtual equipment, computer storage media or devices, etc. Software may be distributed over networked computer systems and may be stored and executed in a distributed manner. Software and data may be stored on one or more computer-readable recording media, which include data storage devices that store data and allow the computer system or processing unit to read it later. The method according to the embodiment may be implemented in the form of program instructions that can be executed through various computer means and recorded on a computer-readable medium. Examples of computer-readable recording media include ROM, RAM, CD-ROM, magnetic tape, floppy disk, and optical data storage devices. It includes magnetic media such as hard disks, floppy disks, and magnetic tapes, optical media such as CD-ROMs and DVDs, magneto-optical media such as floptical disks, and hardware devices specifically configured to store and execute program instructions such as ROM, RAM, and flash memory.In addition, functional programs, code, and code segments that fulfill the examples disclosed herein can be easily understood and implemented by a programmer with ordinary knowledge in the technical field related to these examples based on or using the flowcharts and block diagrams of the drawings and the descriptions provided herein.

[0087] Although various embodiments have been described above, it should be understood that various modifications are possible. For example, suitable results may be achieved even if the described techniques are performed in a different order, and / or the elements of the described system, structure, device, circuit, etc. are combined in a different way, or are replaced or supplemented by other elements or equivalents. Accordingly, other embodiments fall within the scope of the claims set forth below. Explanation of the symbols

[0088] 110: RF power 120: AC filter 130: TC filter 140: Matching Network 150: Plasma chamber 210: First trap circuit 220: Second trap circuit 310: LC Resonance Network 320: Mesh Ground Plate 410: First series resonant circuit 420: First parallel resonant circuit 430: Second series resonant circuit 440: Second parallel resonant circuit

Claims

Claim 1 An RF plasma generating device that generates plasma using an RF (Radio Frequency) power source, comprising: an AC (Alternating Current) filter that blocks harmonic components included in an RF signal applied from the RF power source and external power noise; a TC (Trap Circuit) filter that forms a path configured to have a relatively lower impedance compared to the output impedance of the RF power source and induces harmonic components of a specific frequency band among the RF signal to ground through the path; and a matching network that matches the output impedance of the RF power source with the load impedance of the plasma chamber to which the RF signal is applied, so as to compensate for the mismatch between the output impedance of the RF power source and the load impedance of the plasma chamber to which the RF signal is applied, wherein the TC filter includes an LC resonant circuit that resonates in the specific frequency band and short-circuits the harmonic components of the corresponding frequency band. Claim 2 An RF plasma generator according to claim 1, wherein the AC filter is a low-pass filter (LPF) configured to pass low-frequency components introduced from the RF power source while blocking harmonic components and external power noise. Claim 3 delete Claim 4 An RF plasma generating device according to claim 1, wherein the specific frequency band comprises at least one of 13.56 MHz and 27.12 MHz. Claim 5 An RF plasma generating device according to claim 4, wherein the LC resonant circuit has a structure in which an inductor and a capacitor are connected in series, and includes a first trap circuit that resonates at 13.56 MHz to short-circuit harmonic components of the corresponding frequency band, and a second trap circuit that resonates at 27.12 MHz to short-circuit harmonic components of the corresponding frequency band. Claim 6 An RF plasma generating device that generates plasma using an RF (Radio Frequency) power source, comprising: an AC (Alternating Current) filter that blocks harmonic components included in an RF signal applied from the RF power source and external power noise; a TC (Trap Circuit) filter that forms a path configured to have a relatively lower impedance compared to the output impedance of the RF power source and induces harmonic components of a specific frequency band among the RF signal to ground through the path; and a matching network that matches the output impedance of the RF power source with the load impedance of the plasma chamber to which the RF signal is applied, so as to compensate for a mismatch between the output impedance of the RF power source and the load impedance of the plasma chamber to which the RF signal is applied, wherein the matching network comprises: a vacuum variable capacitor configured to adjust a resonant frequency corresponding to the operating frequency of the RF power source according to a change in the load impedance; and an inductor connected in series or parallel with the vacuum variable capacitor. Claim 7 An RF plasma generating device according to claim 6, wherein the matching network comprises a series resonant circuit and a parallel resonant circuit corresponding to each of the first frequency band and the second frequency band among the specific frequency bands, the series resonant circuit is composed of the vacuum variable capacitor and an inductor connected in series with the vacuum variable capacitor, and the parallel resonant circuit is composed of the vacuum variable capacitor and an inductor connected in parallel with the vacuum variable capacitor. Claim 8 An RF plasma generating device according to claim 7, wherein the matching network is formed as a mesh ground plate structure combined with an LC resonant network in which the series resonant circuit and the parallel resonant circuit are cross-connected. Claim 9 An RF plasma generating device according to claim 8, wherein the matching network is electrically connected to the plasma chamber through the mesh ground plate structure and is configured to perform impedance matching for the fundamental frequency component of the RF signal, while simultaneously absorbing or suppressing the second or third harmonic components included in the RF signal to transmit only the frequency components necessary for the formation and maintenance of the plasma to the plasma chamber. Claim 10 An RF plasma generating device that generates plasma using an RF (Radio Frequency) power source, comprising: an AC (Alternating Current) filter that blocks harmonic components included in an RF signal applied from the RF power source and external power noise; a TC (Trap Circuit) filter that forms a path configured to have a relatively lower impedance compared to the output impedance of the RF power source and induces harmonic components of a specific frequency band among the RF signal to ground through the path; and a matching network that matches the output impedance of the RF power source with the load impedance of the plasma chamber to which the RF signal is applied, so as to compensate for the mismatch between the output impedance of the RF power source and the load impedance of the plasma chamber to which the RF signal is applied, wherein the AC filter, the TC filter, and the matching network are integrated within a single housing to form a single module.

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