KR20200135114A - Plasma control apparatus and plasma processing system comprising the same apparatus - Google Patents

Abstract

The technical idea of the present invention provides a plasma control device for controlling the distribution of plasma in a plasma chamber to be uniform, and a plasma process system including the same. The plasma control device comprises: a transmission line transmitting radio frequency (RF) power to a plasma chamber through at least two frequencies; a matcher adjusting impedance to maximize the transmission of the RF power; and a plasma control circuit selectively and independently controlling harmonics for a very high frequency (VHF) of the at least two frequencies. The plasma control circuit controls the plasma distribution in the plasma chamber by making resonance with respect to the harmonics.

Description

Plasma control apparatus and plasma processing system comprising the same apparatus

The technical idea of the present invention relates to a plasma processing system, and more particularly, to an apparatus for controlling plasma distribution in a plasma chamber and a plasma processing system including the apparatus.

In general, in order to manufacture a semiconductor device, a series of processes such as deposition, etching, and cleaning may be performed. These processes may be performed through a deposition, etching, or cleaning apparatus having a process chamber. Meanwhile, plasma technologies such as capacitive coupled plasma (CCP), inductive coupled plasma (ICP), or a mixture of CCP and ICP are employed to improve selectivity and minimize film damage. Plasma technology includes a direct plasma technology that directly generates plasma in a process chamber, which is a wafer processing space, and a remote plasma technology that generates plasma outside the process chamber and supplies it to the process chamber.

The technical idea of the present invention is to provide a plasma control device for controlling the distribution of plasma in a plasma chamber to be uniform, and a plasma processing system including the control device.

In order to solve the above problems, the technical idea of the present invention is a transmission line for transmitting RF (Radio Frequency) power to the plasma chamber through at least two frequencies; A matcher for adjusting impedance to maximize the transmission of the RF power; And a plasma control circuit for selectively and independently controlling harmonics for a very high frequency (VHF) among the at least two frequencies, wherein the plasma control circuit comprises resonance with respect to the harmonics. ) To control the plasma distribution in the plasma chamber, providing a plasma control apparatus.

In addition, the technical idea of the present invention is, in order to solve the above problem, a resonance circuit for generating resonance with respect to harmonics of the microwave of the frequencies of the RF power transmitted to the plasma chamber; And a filter circuit for filtering fundamental waves and harmonics of the frequencies of the RF power; including, and controlling plasma distribution in the plasma chamber through resonance of the harmonics of the microwave power. .

Further, the technical idea of the present invention is, in order to solve the above problem, an RF power source generating RF power of at least two frequencies; A plasma chamber in which plasma is generated; A transmission line transmitting the RF power to the plasma chamber; A matcher for adjusting impedance to maximize the transmission of the RF power; And a plasma control circuit that selectively and independently controls harmonics for the very short of the at least two frequencies, wherein the plasma control circuit controls plasma distribution in the plasma chamber by making resonance with respect to the harmonics. Provide a process system.

On the other hand, the technical idea of the present invention, in order to solve the above problem, the transmission line for transmitting RF power to the plasma chamber through at least two frequencies; A matcher for adjusting impedance to maximize the transmission of the RF power; A first plasma control circuit for selectively and independently controlling harmonics for VHF among the at least two frequencies; And a second plasma control circuit for controlling a characteristic impedance of an edge region adjacent to an edge ring of the electrostatic chuck in the plasma chamber, wherein the first plasma control circuit is configured to control the harmonics. A plasma control apparatus is provided for controlling plasma distribution in the plasma chamber by making resonance.

Finally, the technical idea of the present invention is, in order to solve the above problem, an RF power source generating RF power of at least two frequencies; A plasma chamber in which plasma is generated; A transmission line transferring the RF power to the plasma chamber; A matcher disposed between the RF power source and the plasma chamber to adjust an impedance to maximize transmission of the RF power; A first plasma control circuit disposed between the matcher and the plasma chamber and connected to an electrode portion of an electrostatic chuck in the plasma chamber; And a second plasma control circuit connected to a conductive ring surrounding the electrode part, wherein the first plasma control circuit includes a first resonance circuit and a first filter circuit, wherein the first resonance circuit includes a variable capacitor and an inductor. Including, wherein the second plasma control circuit includes a second resonance circuit and a second filter circuit, wherein the second resonance circuit provides a plasma processing system including two capacitors, a variable capacitor, and an inductor.

A plasma control device according to the technical idea of the present invention and a plasma processing system including the control device include a plasma control circuit, by making resonance with respect to harmonics of ultra-short among frequencies of RF power transmitted to the plasma chamber, The plasma distribution in the plasma chamber can be uniformly controlled and controlled, and thus, etching of the wafer, which is the target of the plasma process, can be uniformly performed.

In addition, in the plasma control apparatus and the plasma processing system including the control apparatus according to the technical idea of the present invention, the plasma control apparatus does not affect the matcher and the transmission line, and selectively and/or independently controls the harmonics of the microwave. This can create resonance. Accordingly, the plasma control apparatus can effectively control and adjust the plasma distribution in the plasma chamber without affecting the RF power transmission characteristics.

1A to 1C are configuration diagrams and circuit diagrams of a plasma processing system according to an embodiment of the present invention.
2 is a graph showing an etch rate of a wafer in a plasma chamber.
3 is a graph showing the fundamental and harmonic components of a microwave among frequencies of RF power in a transmission line.
4 is a graph showing that harmonics of microwaves among frequencies of RF power affect the plasma distribution in the plasma chamber.
5A and 5B are graphs showing a voltage change of a harmonic and an etch rate change through impedance control by a plasma control circuit.
6 is a graph showing a change in an etch rate of a central portion in a plasma chamber in the plasma processing system of FIG. 1A.
7 to 9 are configuration diagrams and circuit diagrams of a plasma processing system according to exemplary embodiments of the present invention.
10 is a block diagram of a plasma processing system according to an embodiment of the present invention.
FIG. 11A is a conceptual diagram showing a traveling direction of a harmonic component of a microwave in the plasma processing system of FIG. 10.
11B is a graph showing a characteristic impedance of a first transmission line in a plasma chamber in relation to a traveling direction of a harmonic component of the microwave of FIG. 11A.
12A to 12D are configuration diagrams showing a second plasma control circuit in more detail in the plasma processing system of FIG. 10, and detailed circuit diagrams of the second plasma control circuit and the edge circuit.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. The same reference numerals are used for the same components in the drawings, and duplicate descriptions thereof are omitted.

1A to 1C are configuration diagrams and circuit diagrams of a plasma processing system according to an embodiment of the present invention.

1A to 1C, the plasma processing system 1000 of the present embodiment includes a radio frequency (RF) power source 100, a matcher 200, a plasma control circuit 300, a transmission line 400, and A plasma chamber 500 may be included.

The RF power source 100 may generate RF power and supply it to the plasma chamber 500. The RF power source 100 may generate and output RF power of various frequencies. For example, the RF power source 100 may include three sources, for example, a first source 110, a second source 120, and a third source 130. Here, the first source 110 may generate RF power having a first frequency (F1 MHz) ranging from several MHz to several tens of MHz. The second source 120 may generate RF power having a second frequency (F2 MHz) in the range of several hundred kHz to several MHz. The third source 130 may generate RF power having a third frequency (F3 kHz) in the range of several tens of kHz to several hundreds of kHz. In addition, each of the three sources 110, 120, and 130 of the RF power source 100 may generate and output power of hundreds to tens of thousands of watts (W).

In the plasma processing system 1000 of this embodiment, the RF power source 100 includes three sources 110, 120, and 130, but the source included in the RF power source 100 is not limited to three. . For example, the RF power source 100 may include two or four or more sources. In addition, the frequency range and power of the RF power generated by the source are not limited to the above-described values. For example, according to an embodiment, at least one source included in the RF power source 100 may generate RF power having a frequency of several tens of kHz or less or several hundreds of MHz or more. In addition, at least one source included in the RF power source 100 may generate RF power having a power of hundreds of watts or less or thousands of watts or more.

For reference, in the plasma processing system 1000 of the present embodiment, the RF power source 100 may correspond to power supplying power to the plasma chamber 500. In addition, the plasma chamber 500 may be regarded as a kind of load receiving power from the RF power source 100. Accordingly, in the circuit diagram of Fig. 1B, the plasma chamber 500 is indicated by a capacitor element as a load.

In the plasma processing system 1000 of the present embodiment, the RF power source 100 may generate RF power of various frequencies including at least two sources and supply them to the plasma chamber 500. Through this, ion energy and plasma density of the plasma chamber 500 can be independently controlled. For example, to describe in more detail with the RF power source 100 including three sources 110, 120, 130, the high frequency RF power from the first source 110 serves to generate plasma, and , Low frequency RF power from the third source 130 may serve to supply energy to the ions. Meanwhile, the RF power of the intermediate frequency from the second source 120 may have a different function according to embodiments. For example, the RF power of the second source 120 may function to enhance a function of the RF power from the first source 110 and/or the RF power from the third source 130. Meanwhile, in order to improve an etch rate and an etch profile by plasma in the plasma chamber 500, RF power may be applied in the form of a pulse.

The matcher 200 adjusts the impedance so that the RF power from the RF power source 100 can be maximally transmitted to the plasma chamber 500. For example, the matcher 200 may maximize RF power delivery by adjusting the impedance to satisfy a complex conjugate condition based on a maximum power delivery theory. In other words, the matcher 200 drives the RF power source 100 in an environment of 50 Ω so that the reflected power is minimized, so that the RF power from the RF power source 100 is transferred to the plasma chamber 500. It can function to maximize delivery.

The matcher 200 may include three sub-matchers 210, 220, and 230 corresponding to each frequency of the RF power. For example, the matcher 200 is a first sub-matcher 210 corresponding to the first frequency (F1 MHz) of the first source 110, the second frequency corresponding to the second frequency (F2 MHz) of the second source 120 A second sub-matcher 220 and a third sub-matcher 230 corresponding to a third frequency (F3 kHz) of the third source 130 may be included. Each of the three sub-matchers 210, 220, and 230 may adjust the impedance so that the RF power of the corresponding frequency is transmitted to the maximum.

The plasma control circuit 300 can selectively and/or independently control harmonics for very high frequencies (VHF) among the frequencies of RF power to control and adjust the plasma distribution in the plasma chamber 500. have. For example, the plasma control circuit 300 selectively and/or independently controls the harmonics of the first frequency (F1 MHz) of the first source 110 corresponding to the microwave to control and adjust the plasma distribution in the plasma chamber 500. I can. Here, the distribution of plasma may mean a density distribution of plasma. The principle and method of controlling the plasma distribution in the plasma chamber 500 by controlling the harmonics of the microwaves will be described in more detail in the description of FIGS. 2 to 6.

The plasma control circuit 300 may include a filter circuit 310 and a resonance circuit 330. The filter circuit 310 may perform a filtering function of passing only a specific range of frequencies among frequencies of RF power output from the matcher 200. The filter circuit 310 may include, for example, an LPF (310-1, Low Pass Filter) and/or an HPF (310-2, High Pass Filter). The filter circuit 310 blocks harmonic components from the matcher 200 and resonates with the RF power supplied to the plasma chamber 500 and harmonics generated by the nonlinearity of the plasma in the plasma chamber 500. Circuit 330 can be made to create resonance. Here, the frequency of the RF power generating harmonics due to the nonlinearity may be, for example, a very short file of 40 MHz or more. Specifically, in the plasma processing system 1000 of the present embodiment, the RF power of the first frequency (F1 MHz) generated from the first source 110 of the RF power source 100 may correspond to one cause of harmonic generation. I can.

In more detail with respect to the filter circuit 310, the LPF 310-1 is disposed at the output of the matcher 200 to generate a fundamental wave of each of the frequencies of RF power from the matcher 200. It can pass and block other ingredients. In other words, the LPF 310-1 may block harmonic components of each of the frequencies of RF power. Here, the output end of the matcher 200 refers to a portion in which RF power is output from the matcher 200 along the direction in which the RF power is transmitted from the RF power source 100 to the plasma chamber 500, and conversely, the matcher ( The input terminal of 200) may mean a portion in which RF power is input to the matcher 200.

The HPF 310-2 may be disposed with the resonance circuit 330 between the LPF 310-1 and the plasma chamber 500. As described above, most of the harmonic components of the frequencies of RF power may be cut off through the LPF 310-1. However, harmonics may be generated due to the RF power and the nonlinearity of the plasma, and harmonics not blocked by the LPF 310-1 may be present. These harmonics may make the plasma distribution in the plasma chamber 500 non-uniform. The non-uniformity of plasma distribution due to harmonics will be described in more detail in the description of FIGS. 3 and 4. Accordingly, the HPF 310-2 may be disposed together with the resonant circuit 30 to contribute to the resonant circuit 330 making resonance with respect to harmonics.

According to an embodiment, in the plasma control circuit 300, at least one of the LPF 310-1 and the HPF 310-2 may be omitted. For example, each of the three sub-matchers 210, 220, and 230 of the matcher 200 may include an LPF. In such a case, the LPF 310-1 may be omitted from the plasma control circuit 300.

Meanwhile, as shown in FIG. 1C, the LPF 310-1 may have a circuit structure in which a first inductor L1 and a first capacitor C1 are connected in parallel. In addition, the HPF 310-2 may have a circuit structure in which the second inductor L2 and the second capacitor C2 are connected in parallel. However, the circuit structures of the LPF 310-1 and the HPF 310-2 are not limited to the circuit structures shown in FIG. 1C.

The resonance circuit 330 may create resonance for harmonics. The resonant circuit 330 may include a series resonant circuit and/or a parallel resonant circuit. For example, the resonance circuit 330 may include at least one of an LC series resonance circuit, an RLC series resonance circuit, an LC parallel resonance circuit, and an RLC parallel resonance circuit. In addition, according to an embodiment, the resonance circuit 330 may have a series-parallel resonance circuit structure.

Meanwhile, the resonance circuit 330 may include a variable element, for example, a variable capacitor. The resonance circuit 330 may make resonance for each of the harmonics through the variable element. In the circuit diagram of FIG. 1B, in order to emphasize the variable characteristics of the resonance circuit 330, the resonance circuit 330 is shown in the form of a variable capacitor. In addition, a specific example of the resonance circuit 330 in FIG. 1C is a circuit structure in which the first variable capacitor Cv1 and the third inductor L3 are connected in series. However, the circuit structure of the resonance circuit 330 is not limited to the circuit structure shown in FIG. 1C.

The specific circuit structure of the resonance circuit 330 may vary according to the overall circuit characteristics of the plasma processing system 1000 of the present embodiment. For example, the resonance circuit 330 includes not only the plasma chamber 500 corresponding to the load, but also the matcher 200 and the impedance characteristics of the transmission line 400 for transmitting RF power to the RF plasma chamber 500. , It can have a circuit structure that makes resonance for harmonics. In addition, the impedance characteristic of the filter circuit 310 described above may also be included in the resonance circuit 330 to create resonance. For reference, when resonance is made for a specific frequency, the impedance may be minimized for that specific frequency.

In addition, the circuit structure included in the plasma control circuit 300 is not limited to the resonance circuit 330. For example, in the plasma resonance system 1000 of the present embodiment, the plasma control circuit 300 minimizes the impedance in the plasma chamber 500 and has a circuit structure other than the resonance circuit that can effectively control the uniformity of the plasma distribution. Can include. Hereinafter, for convenience of description, the plasma control circuit 300 will be described mainly in embodiments including the resonance circuit 330.

Meanwhile, the plasma control circuit 300 may not affect the matcher 200 and the transmission line 400. In other words, in the plasma processing system 1000 of the present embodiment, the addition of the plasma control circuit 300 may not affect the transmission characteristics of the RF power by the matcher 200 and the transmission line 400. If the transmission characteristics of RF power by the matcher 200 and the transmission line 400 are changed by the addition of the plasma control circuit 300, the matcher 200 and the transmission line 400 are redesigned for maximum RF power transmission. Because I have to.

In the plasma processing system 1000 of the present embodiment, the plasma control circuit 300 does not affect the matcher 200 and the transmission line 400, and selectively and/or independently controls the harmonics of the microwave so that resonance is reduced. Can be made. Accordingly, the plasma control circuit 300 can effectively control and adjust the plasma distribution in the plasma chamber 500 without affecting the RF power transmission characteristics.

Meanwhile, only the plasma control circuit 300 may be treated as a plasma control apparatus (PCA) that controls plasma distribution in the plasma chamber 500. However, since the plasma control circuit 300 creates resonance by including the impedance of the matcher 200 and the transmission line 400 together, according to the embodiment, the plasma control device (PCA) is a matcher together with the plasma control circuit 300. 200 and the transmission line 400 may be included as components. In other words, the plasma control apparatus PCA may include a matcher 200, a plasma control circuit 300, and a transmission line 400.

The transmission line 400 may be disposed between the matcher 200 and the plasma chamber 500 to transmit RF power to the plasma chamber 500. Meanwhile, in this embodiment, since the plasma control circuit 300 is disposed as an output terminal of the matcher 200, the transmission line 400 can be considered to be disposed between the plasma control circuit 300 and the plasma chamber 500. Meanwhile, although not specifically shown, the transmission line 400 may be disposed between the RF power source 100 and the matcher 200.

The transmission line 400 may be implemented with, for example, a coax cable, an RF strap, or an RF rod. The coaxial cable may include a center conductor, an outer conductor, an insulator, and a sheath. The coaxial cable may have a structure in which a center conductor and an outer conductor are arranged coaxially. In general, coaxial cables have less attenuation up to high frequencies, so they are suitable for broadband transmission, and may also have less leakage due to the presence of an external conductor. Accordingly, the coaxial cable can be mainly used as a transmission cable used when the frequency is high. For example, a coaxial cable can effectively transmit RF power having a frequency in the range of several MHz to several tens of MHz without leakage. Meanwhile, there are two types of coaxial cables with characteristic impedances of 50Ω and 75Ω.

The RF strap may include a strap conductor, a ground housing, and an insulator. The strap conductor may have a belt-like shape extending in one direction. The ground housing may have the form of a circular tube surrounding the strap conductor at a predetermined distance. The ground housing can protect the strap conductor from RF radiation. On the other hand, the insulator can fill between the strap conductor and the ground housing. RF rods can be structurally different from RF straps in that they contain rod conductors instead of strap conductors. Specifically, the rod conductor of the RF rod may have a cylindrical shape extending in one direction. Such RF straps or RF loads can, for example, carry RF power with frequencies in the range of several MHz to tens of MHz.

The impedance characteristic of the transmission line 400 may be changed through a change in physical characteristics such as an implemented coaxial cable, an RF strap, and an RF load. For example, when the transmission line 400 is implemented as a coaxial cable, the impedance characteristic of the transmission line 400 may be changed by changing the length of the coaxial cable. In addition, when the transmission line 400 is implemented as an RF strap or an RF rod, the length of the strap conductor or the rod conductor is changed, the space size of the ground housing is changed, or the dielectric constant and/or the permeability of the insulator is changed. The impedance characteristic of can be changed.

The plasma chamber 500 may include a chamber body 510, an electrostatic chuck 530, and a shower head 550. The plasma chamber 500 is a chamber for a plasma process, and plasma P may be generated therein. The plasma chamber 500 may be a CCP (Capacitively Coupled Plasma) chamber, an ICP (Inductively Coupled Plasma) chamber, or a mixed chamber of CCP and ICP. Of course, the plasma chamber 500 is not limited to the above-described chambers. For reference, according to the type of the plasma chamber and the type of RF power applied to the plasma chamber, the plasma processing system can be classified into a CCP method, an ICP method, and a CCP and ICP mixed method. The plasma processing system 1000 of this embodiment may be a CCP method or an ICP method. In addition, the plasma processing system 1000 of this embodiment may be implemented in a mixed CCP and ICP method.

The chamber body 510 may limit the reaction space in which plasma is formed to seal the reaction space from the outside. The chamber body 510 is generally formed of a metal material, and may maintain a grounded state to block noise from outside during a plasma process. Although not shown, a gas inlet, a gas outlet, a view-port, or the like may be formed in the chamber body 510. Process gas required for a plasma process may be supplied through the gas inlet. Here, the process gas may refer to all gases required in the plasma process, such as a source gas, a reaction gas, and a purge gas. After the plasma process through the gas outlet, gases inside the plasma chamber 500 may be exhausted to the outside. In addition, the pressure inside the plasma chamber 500 may be adjusted through the gas outlet. Meanwhile, one or more view-ports may be formed on the chamber body 510, and the inside of the plasma chamber 500 may be monitored through the view-port.

The electrostatic chuck 530 may be disposed in a lower portion of the plasma chamber 500. A wafer 2000 that is an object of a plasma process may be disposed and fixed on the upper surface of the electrostatic chuck 530. The electrostatic chuck 530 may fix the wafer 2000 by the force of static electricity. In addition, the electrostatic chuck 530 may include a bottom electrode for a plasma process. The electrostatic chuck 530 may be connected to the RF power source 100 through the transmission line 400. Accordingly, RF power from the RF power source 100 may be applied into the plasma chamber 500 through the electrostatic chuck 530.

The shower head 550 may be disposed in an upper portion of the plasma chamber 500. The shower head 550 may inject process gases supplied through a gas inlet into the plasma chamber 500 through a plurality of injection holes. Meanwhile, the shower head 550 may include a top electrode. The shower head 550 may be connected to ground, for example, in a plasma process.

Meanwhile, although not shown, the plasma processing system 1000 may include at least one RF sensor. The RF sensor may be disposed at an output terminal of the RF power source 100 or an input terminal or an output terminal of the matcher 200 to measure the RF power delivered to the plasma chamber 500 and/or the impedance of the plasma chamber 500. By monitoring the state of the plasma chamber 500 through the RF sensor, it is possible to effectively manage and control the transmission of RF power to the plasma chamber 500, and accordingly, the plasma process can be accurately performed.

The plasma processing system 1000 of the present embodiment includes the plasma control circuit 300 and creates resonance with respect to the harmonics of the ultra-high frequency among the frequencies of the RF power transmitted to the plasma chamber 500. ) It is possible to uniformly control and adjust the plasma distribution within. Accordingly, etching of the wafer 2000, which is an object of the plasma process, can be uniformly performed.

In addition, in the plasma processing system 1000 of this embodiment, the plasma control circuit 300 selectively and/or independently controls the harmonics of the ultra-short without affecting the matcher 200 and the transmission line 400. Can create resonance. Accordingly, the plasma control circuit 300 can effectively control and adjust the plasma distribution in the plasma chamber 500 without affecting the RF power transmission characteristics.

Meanwhile, although the above description was mainly focused on etching, the plasma processing system 1000 according to the present embodiment may be equipment for a deposition process or a cleaning process. Accordingly, the plasma processing system 1000 according to the present exemplary embodiment may uniformly perform deposition or cleaning of the wafer 2000, which is the target of the plasma process, through uniform plasma distribution. Hereinafter, even if not specifically mentioned, the plasma processing system 1000 can be used not only for an etching process but also for a deposition process or a cleaning process.

2 is a graph showing an etch rate for a wafer in a plasma chamber, where the x-axis represents the radius (R) of the wafer, and the y-axis represents the etch rate (ER).

Referring to FIG. 2, in a general plasma process, an etch rate may be high at a center portion of a wafer, and an etch rate may be lower toward an outer side of a wafer. In this way, a phenomenon in which the etch rate increases at the center of the wafer is referred to as a center hot spot phenomenon, and the center hot spot is displayed as a shadow on the graph.

The center hot spot phenomenon can become more serious as the RF power increases. In addition, punching, NOP (not open), crater, and clogging problems may occur due to the center hot spot. Here, punching or NOP is a problem in which a film is unintentionally opened or a hole is not opened during etching by plasma, and a crater or blockage is a problem in which a surface occurs or the hole entrance is closed due to process gas control to improve the center hot spot. I can.

The specific cause of the center hot spot phenomenon is not clear. However, as shown in FIG. 4 below, harmonic components of the microwave may increase the plasma density at the center of the wafer 2000. Accordingly, it can be predicted that such an increased plasma density acts as a cause of increasing the etch rate at the center of the wafer 2000.

For reference, in the case of existing plasma processing systems. An attempt was made to solve the center hot spot phenomenon by adjusting the amount of process gas for each location in the plasma chamber or by changing the shape of the upper electrode. However, the method of controlling the amount of process gas can cause control problems, and the aforementioned crater or clogging problems. The method of changing the shape of the upper electrode may be inconvenient to change every time according to all process conditions. In addition, there is a problem that a change over time may occur in the upper electrode due to etching, but compensation according to the change over time is impossible, and prediction due to the change over time is also impossible.

3 is a graph showing fundamental and harmonic components of microwaves among frequencies of RF power in a transmission line. The x-axis represents the frequency of the microwave and the y-axis represents the intensity of the microwave.

Referring to FIG. 3, in general, when RF power is applied to the plasma chamber 500, harmonic components among the frequencies of the RF power are cut off through the LPF, so that only the fundamental wave is transmitted to the plasma chamber through the transmission line 400. It can be delivered to 500. However, some harmonics are not completely blocked in the LPF and transmitted to the plasma chamber 500, or, as described above, harmonics of the microwave may occur due to the RF power of the microwave and the nonlinearity of the plasma. These harmonics may serve as a cause of uneven distribution of plasma in the plasma chamber 500.

The graph of FIG. 3 actually shows that microwaves of harmonics are detected in a transmission line 400, for example, a transmission line 400 implemented as an RF load. Here, the peak portions may correspond to a fundamental wave, a second harmonic, a third harmonic, or the like of the microwave, respectively. For reference, the fundamental wave may correspond to the first harmonic.

4 is a graph showing that microwave harmonics among the frequencies of RF power affect the plasma distribution in the plasma chamber, where the x-axis represents the distance in the radial direction of the wafer in the plasma chamber, and the y-axis is the strength of the electric field. Is displayed, but is displayed as normalized.

Referring to FIG. 4, the graph shows the strength of the electric field for each position in the plasma chamber for the second to fifth harmonics using a 60 MHz microwave as a fundamental wave. It can be seen that the intensity of the electric field of the harmonics is higher in the center part than the fundamental wave. For example, in the case of a fundamental wave, when the strength of the electric field in the center portion is 1, the strength of the electric field in the outer portion is approximately 0.8. On the other hand, in the case of the third or fourth harmonic, when the strength of the electric field at the center portion is 1, the electric field strength at the outer portion is about 0.3.

Based on the distribution of the intensity of the electric field, in the case of the fundamental wave, the difference in the intensity of the electric field at the center or the outer portion is not large, so the density of the plasma generated by the fundamental wave may not have a large difference between the center and the outer portion. . Accordingly, the plasma distribution can appear uniformly to some extent within the plasma chamber. On the other hand, in the case of harmonics, since the difference in the intensity of the electric field at the center or the outer portion is large, the plasma density generated by the harmonics may also have a large difference at the center and the outer portion. Thus, the plasma distribution may appear non-uniform within the plasma chamber. As a result, based on the result of the graph of FIG. 4, it can be predicted that the center hot spot phenomenon described in FIG. 2 will be caused by harmonics of microwaves.

5A and 5B are graphs showing a voltage change and an etch rate of a harmonic through impedance control by a plasma control circuit.In FIG. 5A, the x-axis represents the impedance control level by the plasma control circuit, and the y-axis represents the harmonic. Represents voltage or power. In addition, in FIG. 5B, the x-axis represents the radius of the wafer, and the y-axis represents the etch rate. Here, [A.U.] may mean an arbitrary unit representing only a relative size.

Referring to FIG. 5A, when there is no impedance control by the plasma control circuit 300 (w/o Im-Co.), harmonics may be maintained at a certain level of voltage or power. On the other hand, when impedance control is performed through the plasma control circuit 300 (/w Im-Co.), it can be seen that the voltage of the harmonic can be greatly varied. In addition, as can be seen from the enlarged portion of the upper right, it can be seen that the voltage of the harmonic can be reduced through impedance control, so that the voltage of the harmonic can be kept lower than the voltage of the harmonic without impedance control.

Here, the control of the impedance by the plasma control circuit 300 may be, for example, creating a resonance for harmonics through the plasma control circuit 300. In other words, by making resonance for the harmonic through the plasma control circuit 300, it is possible to minimize the impedance or change the impedance for the harmonic. Accordingly, a method of creating resonance with respect to harmonics through the plasma control circuit 300 may correspond to controlling the impedance.

5B, in the graph,'Ref. 'Primary' means the measurement result before impedance control is performed by the plasma control circuit 300, and'Circuit Tuning primary' and'Circuit Tuning secondary' are two times after impedance control by the plasma control circuit 300. It means the measurement result, and'Ref. Secondary' may mean a measurement result after returning to before impedance control.

On the other hand, in the graph, the etch rate is normalized and displayed, and the etch rate of the center portion and the outer portion of the wafer 2000 is relatively displayed with the maximum value of the etch rate as 1. 'Ref. 1st' and'Ref. In'secondary', the difference between the etch rates of the outer portion and the center portion of the wafer 2000 is the etch rate of the outer portion and the center portion of the wafer 2000 in'Circuit Tuning Primary' and'Circuit Tuning Secondary' It can be seen that it appears larger than the difference in

More specifically, the difference between the etch rate of the central part of the wafer 2000 and the etch rate of the outer part of the wafer 2000 before impedance control is about 0.04, while the etch rate of the center part of the wafer 2000 and the etch rate of the outer part of the wafer 2000 after impedance control It can be seen that the difference of is reduced to about 0.02. This, in turn, can reduce the difference between the etch rate of the central part of the wafer 2000 and the etch rate of the outer part of the wafer 2000 by impedance control through the plasma control circuit 300, and thus, the etching of the entire wafer 2000 It can mean that the rate can be made uniform to some extent.

Meanwhile, the difference between the etch rate of the central portion of the wafer 2000 and the etch rate of the outer portion may correspond to a difference between the plasma density at the central portion of the plasma chamber 500 and the plasma density of the outer portion. Accordingly, the difference between the plasma density at the center portion of the plasma chamber 500 and the plasma density at the outer portion can be reduced by impedance control through the plasma control circuit 300, and as a result, plasma in the plasma chamber 500 The distribution of can be made uniform to some extent.

FIG. 6 is a graph showing changes in the etch rate of the central portion of the plasma chamber in the plasma processing system of FIG. 1A. Like FIG. 2, the x-axis represents the radius (R) of the wafer, and the y-axis represents the etch rate (ER). . For convenience of explanation, it will be described with reference to FIG. 1A.

Referring to FIG. 6, in the graph, the thick solid line represents an etch rate in the case of no impedance control by the plasma control circuit 300, and is substantially the same as the graph of FIG. 2, and the thin solid line represents the etch rate by the plasma control circuit 300. It shows the etch rate by impedance control. As can be seen from the graph, the etch rate of the center portion of the wafer 2000 can be greatly reduced by impedance control through the plasma control circuit 300. Accordingly, the plasma processing system 1000 of the present exemplary embodiment can effectively alleviate or eliminate a center hot spot phenomenon that occurs when there is no impedance control by impedance control through the plasma control circuit 300.

7 to 9 are configuration diagrams and circuit diagrams of a plasma processing system according to exemplary embodiments of the present invention. 7 and 8 may correspond to the configuration diagram of FIG. 1A, and FIG. 9 may correspond to the circuit diagram of FIG. 1B. Contents already described in the description of FIGS. 1A to 6 will be briefly described or omitted.

Referring to FIG. 7, the plasma processing system 1000a of this embodiment has a structure in which RF power is applied to the plasma chamber 500a through the shower head 550a of the plasma chamber 500a. It may be different from the plasma processing system 1000. Specifically, in the plasma processing system 1000a of the present embodiment, the shower head 550a of the plasma chamber 500a includes an upper electrode, and the plasma control circuit 300 includes the shower head 550a through the transmission line 400. ) Can be connected. Accordingly, RF power from the RF power source 100 may be applied to the plasma chamber 500a through the matcher 200, the plasma control circuit 300, the transmission line 400, and the shower head 550a. In this case, the electrostatic chuck 530 including the lower electrode may be connected to the ground.

Meanwhile, according to an embodiment, the plasma processing system may have a structure in which RF power can be applied to both the electrostatic chuck 530 and the shower head 550a. In such a structure, the RF power source 100, the matcher 200, and the plasma control circuit 300 may be connected to each of the electrostatic chuck 530 and the shower head 550a. In addition, when the plasma process is performed through a plasma process system having such a structure, RF power may be applied through either the electrostatic chuck 530 or the shower head 550a. Further, according to an embodiment, RF power may be applied while alternately between the electrostatic chuck 530 and the shower head 550a.

Referring to FIG. 8, the plasma processing system 1000b of the present embodiment may be different from the plasma processing system 1000b of FIG. 1A in that the plasma control circuit 300a is disposed inside the matcher 200a. Specifically, in the plasma processing system 1000b of the present embodiment, the plasma control circuit 300a includes a filter circuit 310a and a resonance circuit 330, and the output terminal of the first sub-matcher 210 of the matcher 200a Can be connected to

As described above, the first sub-matcher 210 may adjust the impedance for the first frequency (F1 MHz) from the first source 110 of the RF power source 100. In addition, the first frequency (F1 MHz) from the first source 110 may correspond to a microwave. Accordingly, the plasma control circuit 300a may be connected to the first sub-matcher 210 in order to form resonance with respect to the harmonics of the microwave.

In this way, when the plasma processing system 1000b is implemented with a structure in which the plasma control circuit 300a is disposed inside the matcher 200a, since it is not necessary to separately manufacture and combine the plasma control circuit 300a, the plasma processing system It can be advantageous in terms of compactness of (1000b). In addition, since the resonance circuit 330 only needs to consider the impedance of the first submatcher 210 and the transmission line 400, the plasma control circuit 300a may include a resonance circuit 330 having a simpler configuration.

Meanwhile, the plasma control apparatus PCA may include only the plasma control circuit 300a. However, when considering the aspect that the resonance circuit 330 creates resonance by including the impedance of the matcher 200a and the transmission line 400 together, the plasma control apparatus PCA includes the matcher 200a, the plasma control circuit 300a, and And a transmission line 400.

Referring to FIG. 9, the plasma processing system 1000c of the present embodiment further includes an RF power splitter 600, and also includes four plasma control circuits 300-1 to 300-4 and four plasma chambers ( In terms of including 500-1 to 500-4), it may be different from the plasma processing system 1000 of FIG. 1A. Specifically, in the plasma processing system 1000c of the present embodiment, an RF power splitter 600 for dividing RF power from the RF power source 100 into partial RF powers may be disposed at the output terminal of the matcher 200. The RF power splitter 600 may, for example, divide the RF power into four partial RF powers. In addition, four plasma control circuits 300-1 to 300-4 and four plasma chambers 500-1 to 500- correspond to the number of four partial RF powers by division of the RF power splitter 600. 4) can be placed. In addition, in the plasma processing system 1000c of the present embodiment, four transmissions connecting the four plasma control circuits 300-1 to 300-4 and the four plasma chambers 500-1 to 500-4, respectively. Lines 400-1 to 400-4 may be arranged.

In the plasma processing system 1000c of the present embodiment, the RF power is divided into four partial RF powers by the RF power splitter 600, but the number of partial RF powers is not limited to four. For example, the RF power splitter 600 may divide the RF power into two, three, or five or more partial RF powers. Also, the plasma control circuit 300 and the plasma chamber 500 may be arranged in a number corresponding to the number of partial RF power.

In the plasma processing system 1000c of this embodiment, in order to obtain a gain in terms of mass production, the RF power from one RF power source 100 is converted into four plasma chambers 500-using the RF power splitter 600. 1 ~ 500-4) branch and supply structure. In the case of a system having such a branch structure, a balanced distribution of RF power and a uniform plasma distribution within each of the four plasma chambers 500-1 to 500-4 accordingly may be very important to a plasma process. Accordingly, four plasma control circuits 300-1 to 300-4 may be disposed at the output end of the RF power splitter 600 corresponding to each of the four plasma chambers 500-1 to 500-4.

Each of the four plasma control circuits 300-1 to 300-4 resonates with the harmonics of the ultra-short among the frequencies of RF power applied to each of the corresponding four plasma chambers 500-1 to 500-4 Can be made. Accordingly, each of the four plasma control circuits 300-1 to 300-4 can uniformly control and adjust the plasma distribution inside each of the corresponding four plasma chambers 500-1 to 500-4. . In addition, each of the four plasma control circuits 300-1 to 300-4 is a matcher 200, an RF power splitter 600, and each of the corresponding four transmission lines 400-1 to 400-4. Resonance is made for the harmonics of the microwave including the impedance, but may not affect each of the matcher 200, the RF power splitter 600, and the corresponding four transmission lines 400-1 to 400-4. have.

Meanwhile, when the impedance characteristics of the four transmission lines 400-1 to 400-4 and the corresponding four plasma chambers 500-1 to 500-4 are substantially the same, one plasma control circuit is matched. It may be disposed between 200 and the RF power splitter 600. In other words, it is possible to simultaneously control and adjust the plasma distribution in the four plasma chambers 500-1 to 500-4 through one plasma control circuit.

10 is a block diagram of a plasma processing system according to an embodiment of the present invention.

Referring to FIG. 10, in that the plasma processing system 1000d of the present embodiment further includes a second plasma control circuit 700, the plasma control systems 1000, 1000a to 1000c of FIGS. 1A and 7 to 9 ) May be different. More specifically, the plasma processing system 1000d of the present embodiment includes an RF power source 100, a matcher 200, a first plasma control circuit 300, a first transmission line 400, and a plasma chamber 500. And a second plasma control circuit 700.

The first plasma control circuit 300 may be substantially the same as the plasma control circuit 300 of the plasma processing system 1000 of FIG. 1A. However, the first plasma control circuit 300 is not limited thereto. For example, the plasma processing system 1000d of this embodiment is the first plasma control circuit 300, and the plasma control circuits 300a, 300-1 to 300- of the plasma processing systems 1000b and 1000c of FIG. 8 or 9 4) may be included.

The RF power source 100, the matcher 200, the first transmission line 400, and the plasma chamber 500 are the RF power source 100, the matcher 200, and the transmission of the plasma processing system 1000 of FIG. 1A. As described for the line 400 and the plasma chamber 500. In addition, the connection structure between the first transmission line 400 and the plasma chamber 500 is not limited to the structure of the plasma processing system 1000 of FIG. 1A, and the structure of the plasma processing systems 1000a and 1000c of FIG. 7 or 9 Connection structure can also be adopted. On the other hand, when the plasma processing system 1000d of this embodiment adopts the connection structure of the plasma processing system 1000c of FIG. 9, the plasma processing system 1000d of this embodiment is an RF power splitter, four plasma chambers, and 4 It may include four first plasma control circuits, and four first transmission lines, and may also include four second plasma control circuits. Of course, depending on the number of plasma chambers, the number of RF power divided by the RF power splitter and the number of the first plasma control circuit, the second plasma control circuit, and the first transmission line may vary.

The plasma processing system 1000d of the present exemplary embodiment may further include a second plasma control circuit 700 connected to the conductive ring 538 of the electrostatic chuck 530. Before describing the second plasma control circuit 700, referring to FIG. 10, the structure of the electrostatic chuck 530 in the plasma chamber 500 will be described in more detail,

The electrostatic chuck 530 may include an electrode portion 532, an insulation isolation 534, an edge ring 536, and a conductive ring 538. The electrode unit 532 is disposed at a central portion below the chamber 500 and may include an electrode for applying power for chucking/dechucking of the wafer 2000 and plasma processing, and the like. On the upper surface of the electrode part 532, a wafer 2000 that is an object of a plasma process may be disposed and fixed by an electrostatic force.

The insulating isolation 534 has a structure surrounding the electrode portion 532, and the insulating isolation 534 may be formed of an insulator such as alumina. Of course, the material of the insulation isolation 534 is not limited thereto.

The edge ring 536 may have a structure surrounding the wafer 2000 and may be disposed outside the electrode part 532. The edge ring 536 is formed of silicon and induces an effect of expanding the silicon region of the wafer 2000, thereby preventing the phenomenon that plasma is concentrated on the edge portion of the wafer 2000. Meanwhile, the edge ring 536 has one ring type and two ring types. Usually, one ring type is called a focus ring and two ring types are called a combo-ring.

Meanwhile, the conductive ring 538 may be disposed in a structure surrounding the electrode part 532 inside the insulating isolation 534. The conductive ring 538 may be formed of a metal such as aluminum. Of course, the material of the conductive ring 538 is not limited thereto. The conductive ring 538 is electrically coupled with the edge ring 536 disposed thereon, and may contribute to the control of plasma distribution by the edge ring 536.

For reference, the structure of the electrostatic chuck 530 in the plasma chamber 500 of the plasma processing systems 1000, 1000a, and 1000b of FIGS. 1A, 7, and 8 is the correcting chuck of the plasma processing system 1000d of the present embodiment. It is substantially the same as 530, but is simple and illustrated for convenience because it does not include a second plasma control circuit.

In the plasma processing system 1000d of this embodiment, the second plasma control circuit 700 may be connected to the conductive ring 538. The second plasma control circuit 700 may be connected to the conductive ring 538, for example, through a second transmission line 401. The second plasma control circuit 700 controls the characteristic impedance of the edge region (refer to ER-P3 in FIGS. 11A and 11B) adjacent to the edge ring 536, thereby controlling the plasma distribution in the plasma chamber 500. Can contribute to controlling For example, control of the microwave harmonic components through the first plasma control circuit 300 may be limited due to the presence of the edge ring 536 and the conductive ring 538 disposed in the edge region ER-P3. Accordingly, in the plasma processing system 1000d of the present embodiment, by additionally arranging the second plasma control circuit 700, the problem of the limitation is solved, and the inside of the plasma chamber 500 by the first plasma control circuit 300 Plasma distribution can be controlled more effectively.

The second plasma control circuit 700 may include a predetermined circuit structure and may contribute to impedance control for harmonic components. For example, the second plasma control circuit 700, similar to the first plasma control circuit 700, includes a filter circuit (see 710 in FIG. 12A) and a resonance circuit (see 720 in FIG. 12A). Can contribute to the impedance control for A more detailed structure of the second plasma control circuit 700 will be described in more detail in the description of FIGS. 12A and 12B.

The plasma processing system 1000d of the present embodiment further includes a second plasma control circuit 700 connected to the conductive ring 538 of the edge region ER-PR, so that the edge ring ( By solving the problem caused by the 536 and the conductive ring 538, the plasma distribution in the plasma chamber 500 by the first plasma control circuit 300 can be more effectively controlled.

FIG. 11A is a conceptual diagram showing a traveling direction of a harmonic component of a microwave in the plasma processing system of FIG. 10. 11A schematically shows only portions of the electrode portion 532 and the conductive ring 538 of the correcting chuck 530 for convenience of understanding. In addition, the actual electrode in the electrostatic chuck 530 from the chamber body 510 This arrangement up to the electrode portion 532 is shown as being treated as the first transmission line 400.

Referring to FIG. 11A, in general, harmonic components generated by the RF power supplied to the plasma chamber 500 and the nonlinearity of the plasma in the plasma chamber 500 are indicated by a straight arrow, and the plasma chamber 500 ) It may be transmitted from the inside to the outside through the first transmission line 400. However, due to the presence of the edge ring 536 and the conductive ring 538 present in the edge region ER-P3, harmonic components are reflected by the conductive ring 538 of the edge region ER-P3, etc. A path such as may be formed. The reflected harmonic component is not transmitted to the outside through the first transmission line 400 and may be maintained inside the plasma chamber 500 in the form of, for example, a sinusoidal wave. Therefore, there may be a limit to controlling the harmonic components maintained in the plasma chamber 500 by such reflection through the first plasma control circuit 300.

11B is a graph showing the characteristic impedance of the first transmission line in the plasma chamber with respect to the propagation direction of the harmonic component of the microwave of FIG. And y-axis shows the characteristic impedance for each location of the first transmission line. Meanwhile, the edge area ER-P3 in the graph is also treated as a part of the first transmission line.

Referring to FIG. 11B, it can be seen that the characteristic impedance of the first transmission line 400 from the input terminal TL-P1 of the first transmission line 400 to the connection part TL-P2 is kept constant to some extent. Here, the input terminal (TL-P1) means a portion connected to the first transmission line 400 to the chamber body 510 of the plasma chamber 500, the connection portion (TL-P2) is the first transmission line 400 It may mean a part connected to the electrode part 532. In addition, the connection part TL-P2 may be expanded and analyzed to a central part of the electrode part 532.

On the other hand, as can be seen from FIG. 11B, in the edge region (ER-P3) in which the edge ring 536 and the conductive ring 538 are disposed, the characteristic impedance of the corresponding first transmission line 400 changes significantly. I can. In general, the characteristic impedance of the first transmission line 400 in the plasma chamber 500 is kept constant to some extent. Impedance control of the plasma chamber 500 through the first plasma control circuit 300, and accordingly It can be easy to control plasma distribution. Accordingly, the characteristic impedance of the first transmission line 400 in the edge region ER-P3 is changed from another part, for example, from the input terminal TL-P1 of the first transmission line 400 to the connection part TL-P2. It may be necessary to match the characteristic impedance level.

The plasma processing system 1000d of the present embodiment may perform such a function through the second plasma control circuit 700 connected by the conductive ring 538. That is, the second plasma control circuit 700 adjusts the characteristic impedance of the edge region ER-P3 to the characteristic impedance level from the input terminal TL-P1 of the first transmission line 400 to the connection part TL-P2. Function can be performed.

In FIG. 11B, a graph of a straight line shows a characteristic impedance without control by the second plasma control circuit 700, and a graph of a dotted line in the edge region ER-P3 represents the second plasma control circuit 700. Through this, the characteristic impedance is adjusted to be similar to the characteristic impedance of other parts of the first transmission line 400.

12A to 12D are configuration diagrams showing a second plasma control circuit in more detail in the plasma processing system of FIG. 10, and detailed circuit diagrams of the second plasma control circuit and the edge circuit.

Referring to FIG. 12A, in the plasma processing system 1000d of the present embodiment, the second plasma control circuit 700 may include a filter circuit 710 and a resonance circuit 720. The filter circuit 710 is, for example, an HPF, and may pass only harmonic components of the microwave. That is, the harmonic components of the microwave generated in the plasma chamber 500 are transmitted to the second plasma control circuit 700 through the second transmission circuit 401, and filtered through the filter circuit 710 to the resonance circuit 720. Can be delivered to. 12C, the filter circuit 710 has a circuit structure in which the fourth inductor L4 and the fifth inductor L5 disposed on both sides of the third capacitor C3 are connected in parallel to the third capacitor C3. Can have Of course, the circuit structure of the filter circuit 710 is not limited to the circuit structure shown in FIG. 12C.

The resonant circuit 720 may create resonance for harmonics. The resonance circuit 720 may include a series resonance circuit and/or a parallel resonance circuit. For example, the resonance circuit 720 may include at least one of an LC series resonance circuit, an RLC series resonance circuit, an LC parallel resonance circuit, and an RLC parallel resonance circuit. Further, according to an embodiment, the resonance circuit 720 may have a series-parallel resonance circuit structure.

As illustrated in FIG. 12C, the resonance circuit 720 may include a fourth capacitor C4, a fifth capacitor C5, a sixth inductor L6, and a second variable capacitor Cv2. In addition, in the resonance circuit 720, the sixth inductor L6 and the second variable capacitor Cv2 are connected in series to each other, and may be connected in parallel between the fourth capacitor C4 and the fifth capacitor C5. . However, the circuit structure of the resonance circuit 720 is not limited to the circuit structure shown in FIG. 12C.

Meanwhile, the specific circuit structure of the resonance circuit 720 may vary in various ways according to the characteristic impedance appearing in the edge region ER-P3 in the plasma processing system 1000d of the present embodiment. For example, as described above, the resonance circuit 720 may have a circuit structure such that the characteristic impedance of the edge region ER-P3 is similar to the characteristic impedance of another portion of the first transmission line 400.

In addition, in the plasma resonance system 1000d of this embodiment, the circuit structure included in the second plasma control circuit 700 is not limited to the resonance circuit 720. For example, the second plasma control circuit 700 may include a circuit structure other than the resonance circuit, which can adjust the characteristic impedance of the edge region ER-P3 to a required level.

Referring to FIG. 12B, in the plasma processing system 1000d of this embodiment, the second plasma control circuit 700 is connected in parallel with the edge control circuit 800 for controlling the impedance of the edge region ER-P3. It may be connected to the conductive ring 538. Here, the edge control circuit 800 may include, for example, a filter circuit 810 and an impedance (|Z|) control circuit 820. The filter circuit 810 may block at least some of the plurality of frequencies transmitted to the plasma chamber 500 through the first transmission line 400 and pass only a specific frequency. In addition, the impedance control circuit 820 may adjust the impedance of the edge region ER-P3 by controlling a specific frequency passing through the filter circuit 810. The edge control circuit 800 may be functionally different from the second plasma control circuit 700 in that it controls the frequency transmitted from the RF power source 100 rather than harmonic components.

12D, the edge control circuit 800 may include a filter circuit 810 and an impedance control circuit 820. The filter circuit 810 may include sixth and seventh capacitors C6 and C7, and seventh to ninth inductors L7 to L9, each of which is connected in series and/or parallel to each other as shown. I can. Meanwhile, the impedance control circuit 820 may have a circuit structure in which the tenth inductor L10 and the third variable capacitor Cv3 are connected in series. However, the circuit structure of the filter circuit 810 and the impedance control circuit 820 is not limited to the circuit structure shown in FIG. 12D.

Until now, the present invention has been described with reference to the embodiments shown in the drawings, but this is only exemplary, and those of ordinary skill in the art will understand that various modifications and other equivalent embodiments are possible therefrom. will be. Therefore, the true technical protection scope of the present invention should be determined by the technical spirit of the appended claims.

100: RF power source, 110, 120, 130: first to third source, 200, 200a: matcher, 210, 220, 230: first to third sub-matcher, 300, 300a: plasma control circuit, 310, 310a , 710, 810: filter circuit, 330, 720: resonance circuit, 400: transmission line, 500, 500a: plasma chamber, 510: chamber body, 530; Electrostatic chuck, 550, 550a: shower head, 600: RF power splitter, 700: second plasma control circuit, 800: edge control circuit, 820: impedance control circuit, 1000, 1000a ~ 1000d: plasma processing system

Claims (20)

A transmission line for transmitting radio frequency (RF) power to the plasma chamber through at least two frequencies;
A matcher for adjusting impedance to maximize the transmission of the RF power; And
Including a plasma control circuit for selectively and independently controlling harmonics (harmonics) for a very high frequency (VHF) of the at least two frequencies; and
The plasma control circuit controls plasma distribution in the plasma chamber by creating resonance with respect to the harmonics. The method of claim 1,
Wherein the plasma control circuit includes a resonance circuit and a filter circuit. The method of claim 2,
Wherein the resonance circuit includes a circuit that makes resonance for each of the harmonics. The method of claim 2,
Wherein the filter circuit comprises a circuit for filtering the fundamental waves and harmonics of the at least two frequencies. The method of claim 2,
Wherein the filter circuit includes at least one of a low pass filter (LPF) and a high pass filter (HPF). The method of claim 1,
Wherein the plasma control circuit generates resonance for the harmonics including impedances of the matcher and the transmission line. The method of claim 6,
Wherein the plasma control circuit does not affect the transmission of the RF power by the matcher and the transmission line. The method of claim 1,
The plasma control circuit is disposed between the matcher and the plasma chamber, or is disposed within the matcher. A resonant circuit that makes resonance with respect to harmonics of ultra-high frequency among frequencies of RF power transmitted to the plasma chamber; And
Including; a filter circuit for filtering the fundamental wave and harmonics of the frequencies of the RF power,
The plasma control apparatus for controlling plasma distribution in the plasma chamber through resonance with the harmonics of the microwave. The method of claim 9,
The resonance circuit includes a circuit that makes resonance for each of the harmonics of the microwave,
Wherein the filter circuit includes a circuit for filtering fundamental waves and harmonics of each of the frequencies. The method of claim 9,
Plasma control apparatus, characterized in that the plasma distribution is uniform by lowering the plasma density of the central portion of the plasma chamber through the resonance circuit. An RF power source generating RF power of at least two frequencies;
A plasma chamber in which plasma is generated;
A transmission line transferring the RF power to the plasma chamber;
A matcher for adjusting impedance to maximize the transmission of the RF power; And
Including; a plasma control circuit for selectively and independently controlling harmonics with respect to the microwave of the at least two frequencies,
Wherein the plasma control circuit controls plasma distribution in the plasma chamber by creating resonance with respect to the harmonics. The method of claim 12,
The plasma control circuit includes a resonance circuit and a filter circuit,
The resonance circuit includes a circuit that makes resonance for each of the harmonics,
Wherein the filter circuit comprises a circuit for filtering the fundamental waves and harmonics of the at least two frequencies. The method of claim 12,
Wherein the plasma control circuit is disposed between the matcher and the plasma chamber, or disposed within the matcher. A transmission line for delivering RF power to the plasma chamber through at least two frequencies;
A matcher for adjusting impedance to maximize the transmission of the RF power;
A first plasma control circuit for selectively and independently controlling harmonics for VHF among the at least two frequencies; And
A second plasma control circuit for controlling a characteristic impedance of an edge region adjacent to an edge ring of the electrostatic chuck in the plasma chamber; and
The first plasma control circuit controls plasma distribution in the plasma chamber by making resonance with respect to the harmonics. The method of claim 15,
Wherein the first plasma control circuit comprises a resonance circuit and a filter circuit. The method of claim 15,
And the second plasma control circuit comprises a harmonic impedance control circuit and a filter circuit. The method of claim 15,
Wherein the second plasma control circuit is connected in parallel to an edge control circuit that controls the impedance of the edge region. An RF power source generating RF power of at least two frequencies;
A plasma chamber in which plasma is generated;
A transmission line transmitting the RF power to the plasma chamber;
A matcher disposed between the RF power source and the plasma chamber to adjust an impedance to maximize transmission of the RF power;
A first plasma control circuit disposed between the matcher and the plasma chamber and connected to an electrode portion of an electrostatic chuck in the plasma chamber; And
Including; a second plasma control circuit connected to the conductive ring surrounding the electrode,
The first plasma control circuit includes a first resonance circuit and a first filter circuit, wherein the first resonance circuit includes a variable capacitor and an inductor,
The second plasma control circuit comprises a second resonant circuit and a second filter circuit, wherein the second resonant circuit comprises two capacitors, a variable capacitor and an inductor. The method of claim 19,
The first filter circuit includes a first low pass filter (LPF) and a first high pass filter (HPF),
The first resonance circuit is connected to the first HPF,
The plasma processing system, wherein the second filter circuit includes a second HPF.

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