Power transfer device coupling RF power and DC pulse voltage and transferring to load

Abstract

A power transfer device according to one embodiment of the present invention comprises: an impedance matching network for transferring RF power of an RF generator to a load; a band elimination filter which transfers the DC pulse voltage of the DC pulse generator to a load and suppresses transfer of the RF power to the DC pulse generator; the DC blocking capacitor is connected to the output end of the impedance matching network and used for inhibiting the DC pulse voltage passing through the output end of the band elimination filter from being transmitted to the impedance matching network; and an impedance converter connected to the output end of the band elimination filter and changing the impedance of the RF power incident to the band elimination filter. The output end of the impedance converter and the output end of the DC blocking capacitor are connected with each other and then are connected to the load through a transmission line.

Description

Technical Field

[0001] The present invention relates to a semiconductor device manufacturing apparatus, and more specifically, to an apparatus for delivering RF power and DC pulse voltage in order to generate plasma in a plasma process chamber used in semiconductor manufacturing. Background Technology

[0002] Plasma etching apparatuses employ a combination of high-frequency RF source power for generating plasma and low-frequency RF bias power for modulating the energy of ions incident on the substrate. Typically, the RF source power uses a frequency above 3 MHz to achieve high plasma density. On the other hand, the RF bias power uses a relatively low bias frequency, less than 3 MHz.

[0003] In plasma etching processes utilizing semiconductor device miniaturization technology, problems such as etching uniformity, etching selectivity, and anisotropic etching characteristics constantly arise. To address these issues, periodically modulated RF pulse waves are used instead of continuous waves.

[0004] Figure 1 and Figure 2 This is a diagram illustrating the traditional power transfer structure.

[0005] Reference Figure 1 and Figure 2 US Patent 11462389 B2 discloses a technique that uses DC pulse bias instead of RF bias power. In this plasma etching apparatus 10, a DC pulse bias from a DC pulse generator 21 is applied to a first electrode 24 (or electrostatic electrode) disposed on a substrate support 30, and an RF source power from an RF generator 11 is applied to a second electrode 14 disposed below the first electrode 24. The first electrode 24 and the second electrode 14 are separated by a dielectric to form a base capacitor Cbase. The DC pulse generator 21 applies the DC pulse bias to the first electrode through a band-stop filter 22 and a power line 23. The RF generator 11 applies RF power to the second electrode 14 through an impedance matching network 12 and a power line 13.

[0006] However, as the DC pulse bias voltage increases to several kV to tens of kV, a high voltage is applied between the first electrode 24 and the second electrode 14, causing the substrate support 30 to be damaged due to insulation breakdown or abnormal discharge of the base capacitor Cbase. Therefore, a novel power transfer method is needed to suppress damage to the substrate support 30. Summary of the Invention

[0007] [The problem the invention aims to solve]

[0008] The present invention aims to solve a technical problem by providing a power transmission device that suppresses insulation breakdown or abnormal discharge between a first electrode on a substrate and a second electrode on which a DC voltage is applied and an RF power is applied.

[0009] The technical problem to be solved by the present invention is to provide a substrate processing apparatus that integrates electrodes mounted on a substrate support to be subjected to DC pulse voltage and RF power into one unit, and arranges a blocking capacitor within an impedance matching network.

[0010] The technical problem to be solved by the present invention is to provide a power transmission device, the power transmission device including a band-stop filter, the band-stop filter including an impedance converter that suppresses the transmission of RF power from an RF generator to a DC pulse generator through an impedance matching network.

[0011] The technical problem to be solved by the present invention is to provide an impedance matching network and a band-stop filter, wherein the impedance matching network transfers the RF power of the RF generator to the load, and the band-stop filter transfers the DC pulse voltage of the DC pulse generator to the load while preventing the RF power from flowing into the DC pulse generator.

[0012] The technical problem to be solved by the present invention is to provide a band-stop filter that transmits the DC pulse voltage of the DC pulse generator to the load while suppressing overshoot and preventing the RF power of the RF generator from flowing into the DC pulse generator.

[0013] [Technical means to solve the problem]

[0014] An embodiment of the power delivery device of the present invention includes: an impedance matching network for delivering RF power from an RF generator to a load; a band-stop filter for delivering DC pulse voltage from a DC pulse generator to the load and suppressing the delivery of RF power to the DC pulse generator; a DC blocking capacitor connected to the output terminal of the impedance matching network to suppress the delivery of the DC pulse voltage through the output terminal of the band-stop filter to the impedance matching network; and an impedance converter connected to the output terminal of the band-stop filter to change the impedance of the RF power incident on the band-stop filter. The output terminals of the impedance converter and the DC blocking capacitor are connected to each other and then connected to the load via a transmission line.

[0015] In one embodiment of the present invention, the DC blocking capacitor may be disposed inside the impedance matching network, and the DC blocking capacitor may be a high-voltage vacuum capacitor or a high-voltage ceramic capacitor.

[0016] In one embodiment of the invention, the DC blocking capacitor is replaceable.

[0017] In one embodiment of the present invention, the DC blocking capacitor may be multiple and connected in series to increase the voltage withstand capability.

[0018] In one embodiment of the present invention, the impedance converter may be configured inside the band-stop filter, and the impedance converter may be an inductor with a reactance of 25 ohms to 500 ohms.

[0019] In one embodiment of the present invention, the load may include an electrode, a dielectric disposed on the electrode, a substrate disposed on the dielectric, and a plasma formed on the substrate.

[0020] In one embodiment of the present invention, the absolute value of the reactance of the impedance converter may be greater than or equal to the absolute value of the reactance of the load.

[0021] In one embodiment of the present invention, the band-stop filter may be a π-type band-stop filter with three or more stages.

[0022] In one embodiment of the present invention, the band-stop filter may include a series resonator, the series resonator including an inductor and a capacitor connected in parallel with each other, and the reactance of the inductor of the series resonator may be less than 200 ohms.

[0023] In one embodiment of the invention, the band-stop filter may include a shunt resonator, which includes an inductor and a capacitor connected in series with each other. The shunt resonator may be grounded.

[0024] In one embodiment of the present invention, the RF generator may be a frequency-variable RF generator, and the band-stop filter may be a three-stage or higher π-type band-stop filter. The band-stop filter may include a series resonator, which includes an inductor and a variable capacitor connected in parallel. The variable capacitor of the series resonator may vary according to the driving frequency of the RF generator, and the capacitance of the variable capacitor is variable, such that the resonant frequency of the series resonator is consistent with the driving frequency of the RF generator.

[0025] In one embodiment of the present invention, the device may further include: an RF sensor disposed between the band-stop filter and the DC pulse generator; and a control unit that receives the output signal of the RF sensor and calculates the RF transmission power. If the RF transmission power is above a threshold value, the control unit may provide an interrupt signal to the RF generator.

[0026] In one embodiment of the present invention, the band-stop filter may be a π-type band-stop filter with three or more stages, and the band-stop filter may include a first shunt resonator, which includes an inductor and a fixed capacitor connected in series.

[0027] An embodiment of the plasma substrate processing apparatus of the present invention includes: a substrate support including electrodes supporting the substrate and a dielectric disposed on the electrodes; a chamber disposed surrounding the substrate support; an RF generator providing RF power to the electrodes and forming plasma on the substrate; a DC pulse generator providing a DC pulse voltage to the electrodes; and a power transmission unit transmitting the RF power and the DC pulse voltage to the electrodes. The power transmission unit includes: an impedance matching network transmitting the RF power from the RF generator to the electrodes; a band-stop filter transmitting the DC pulse voltage from the DC pulse generator to the electrodes and suppressing the transmission of RF power to the DC pulse generator; a DC blocking capacitor connected to the output terminal of the impedance matching network to suppress the transmission of DC pulses through the output terminal of the band-stop filter to the impedance matching network; and an impedance converter connected to the output terminal of the band-stop filter to change the impedance of the band-stop filter. The output terminals of the impedance converter and the DC blocking capacitor are connected to each other and then connected to the electrodes via a transmission line.

[0028] In one embodiment of the present invention, the DC blocking capacitor may be disposed inside the impedance matching network, and the DC blocking capacitor may be a high-voltage vacuum capacitor or a high-voltage ceramic capacitor.

[0029] In one embodiment of the invention, the DC blocking capacitor is replaceable.

[0030] In one embodiment of the present invention, the DC blocking capacitor may be multiple and connected in series to increase the voltage withstand capability.

[0031] In one embodiment of the present invention, the impedance converter may be configured inside the band-stop filter, and the impedance converter may be an inductor with a reactance of 25 ohms to 500 ohms.

[0032] In one embodiment of the present invention, the absolute value of the reactance of the impedance converter may be greater than or equal to the absolute value of the reactance of the load.

[0033] An embodiment of the power delivery device of the present invention includes: an impedance matching network for delivering RF power from an RF generator to a load; a band-stop filter for delivering DC pulse voltage from a DC pulse generator to the load and suppressing the delivery of RF power to the DC pulse generator; and a DC blocking capacitor connected to the output of the impedance matching network to suppress the delivery of DC pulse voltage through the output of the band-stop filter to the impedance matching network. The outputs of the band-stop filter and the DC blocking capacitor are connected to each other and then connected to the load via a transmission line.

[0034] [Invention Effects]

[0035] An embodiment of the power delivery device of the present invention suppresses insulation breakdown or abnormal discharge between a first electrode on a substrate under which a DC voltage is applied and a second electrode under which an RF power is applied.

[0036] One embodiment of the power delivery device of the present invention integrates electrodes on a substrate support that are subjected to DC pulse voltage and RF power into one unit, and arranges a blocking capacitor within an impedance matching network, thereby providing a compact power delivery structure.

[0037] One embodiment of the power transfer device of the present invention may provide a band-stop filter, the band-stop filter including an impedance converter, the impedance converter suppressing the transmission of RF power from an RF generator to a DC pulse generator side through an impedance matching network.

[0038] An embodiment of the power transfer device of the present invention may provide an impedance matching network and a band-stop filter. The impedance matching network transfers the RF power of the RF generator to the load, and the band-stop filter transfers the DC pulse voltage of the DC pulse generator to the load while preventing the RF power from flowing into the DC pulse generator.

[0039] An embodiment of the power transfer device of the present invention may provide a band-stop filter that transmits the DC pulse voltage of a DC pulse generator to a load while suppressing overshoot and preventing RF power from an RF generator from flowing into the DC pulse generator. Attached Figure Description

[0040] Figure 1 and Figure 2 This is a diagram illustrating the traditional power transfer structure.

[0041] Figure 3 This is a conceptual diagram illustrating a plasma substrate processing apparatus and a power transfer device according to an embodiment of the present invention.

[0042] Figure 4 This is an explanation Figure 3 Circuit diagram of the plasma substrate processing device and power transmission device.

[0043] Figure 5 This is a diagram showing the connection relationship of the blocking capacitor according to another embodiment of the present invention.

[0044] Figure 6 This is a diagram showing the impedance as seen from the load direction toward the power transmission section in an embodiment of the present invention.

[0045] Figure 7 This indicates the impedance change when an impedance converter is added to the power transmission section.

[0046] Figure 8 This represents the simulation results showing the operating range of the impedance matching network corresponding to the reactance of the impedance converter in an embodiment of the present invention.

[0047] Figure 9a and Figure 9b This describes the transmission characteristics of a band-stop filter corresponding to the inductance of an impedance converter according to an embodiment of the present invention.

[0048] Figure 10a and Figure 10b This indicates the operating range of the impedance matching network in a power transfer device where a band-stop filter has been removed, according to an embodiment of the present invention.

[0049] Figures 11a to 11c This indicates the operating range of the impedance matching network in a power transfer device including a band-stop filter, according to an embodiment of the present invention.

[0050] Figures 12a to 12c This is a diagram illustrating the characteristics of a band-stop filter according to an embodiment of the present invention.

[0051] Figures 13a to 13e This is a diagram illustrating the characteristics of a band-stop filter according to an embodiment of the present invention.

[0052] Figure 14 This is a simulation result showing the overshoot of the series inductor in the band-stop filter of a power transfer device according to an embodiment of the present invention. Detailed Implementation

[0053] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments described herein are provided to ensure a complete and thorough understanding of the invention and to enable those skilled in the art to fully grasp the spirit of the invention. In the drawings, constituent elements are exaggerated for clarity. Throughout the specification, parts indicated by the same reference numerals represent the same constituent elements. Figure 3 This is a conceptual diagram illustrating a plasma substrate processing apparatus and a power transfer device according to an embodiment of the present invention.

[0054] Figure 3 This is a conceptual diagram illustrating a plasma substrate processing apparatus and a power transfer device according to an embodiment of the present invention.

[0055] Figure 4 This is an explanation Figure 3 Circuit diagram of the plasma substrate processing device and power transmission device.

[0056] Reference Figure 3 and Figure 4According to an embodiment of the present invention, a plasma substrate processing apparatus 100 includes a substrate support 130, a chamber 101, an RF generator 111, and a power transmission unit 130.

[0057] The plasma substrate processing apparatus 100 may be a plasma etching apparatus. The chamber 101 may be a cylindrical or rectangular chamber made of metal. The chamber 101 may also include a vacuum system and a gas injection system. The chamber 101 is capable of maintaining a low pressure (hundreds to several millitors) for plasma formation. The plasma substrate processing apparatus 100 is capable of anisotropically etching a silicon oxide or silicon nitride film on the substrate. The chamber 101 may be configured to surround the substrate support 130.

[0058] The substrate can be a semiconductor substrate. The semiconductor substrate can be a silicon substrate for forming semiconductor devices.

[0059] The substrate support 130 supports the substrate and includes electrodes 124 and a dielectric 125 disposed on the electrodes 124. The substrate support 130 can be disposed inside the chamber 101. The electrodes 124 can receive RF power and DC pulse voltage. The electrodes 124 can also function as electrostatic electrodes of an electrostatic chuck.

[0060] RF generator 111 provides RF power to electrode 124, thereby enabling plasma generation on the substrate. RF generator 111 is capable of generating a sine wave. The driving frequency of RF generator 111 can be tens of MHz or higher. The RF power of RF generator 111 is transferred to electrode 124, thereby enabling plasma formation on the substrate.

[0061] The DC pulse generator 121 is capable of outputting a DC pulse voltage. The DC pulse voltage can be a bipolar voltage waveform. The DC pulse voltage can have a fixed period and include both positive and negative voltages. Furthermore, during the application of the negative voltage, the voltage waveform can have a ramp voltage where the negative voltage decreases over time. The DC pulse voltage creates an electric field between the electrode 124 and the substrate, thereby providing an electrostatic force for adsorbing the substrate. The DC pulse voltage can create a strong electric field in the plasma sheath layer present between the substrate and the plasma, and provide a bias voltage to accelerate ions from the plasma through the electric field of the plasma sheath layer and allow them to be incident on the substrate. The energy of the ions can improve the anisotropic etching characteristics of the substrate.

[0062] The power delivery unit 130 delivers the RF power and the DC pulse voltage to the electrode 124. The power delivery unit 130 couples the RF power and the DC pulse voltage and delivers the power to the electrode 124. The DC pulse voltage is primarily applied to the blocking capacitor 133 and the substrate capacitor Cs between the electrode 124 and the substrate. The blocking capacitor 133 is disposed in the impedance matching network 132, rather than inside the substrate support 130. Therefore, when the DC pulse voltage of several kV to tens of kV is applied to the blocking capacitor 133, the blocking capacitor 133 can use a high-voltage vacuum capacitor to provide stable operation without abnormal operation such as insulation breakdown. The RF power and the DC pulse voltage are coupled and then applied to the electrode 124 through a transmission line 113. On the other hand, when using multiple transmission lines or power lines, multiple transmission lines or power lines may cause abnormal operation within the chamber or the substrate support. Therefore, by using a single transmission line 113, abnormal operation can be reduced, thereby improving operational stability.

[0063] The power transmission unit 130 may include an impedance matching network 132, a band-stop filter 134, a DC blocking capacitor 132, and an impedance converter 135.

[0064] Impedance matching network 132 transmits the RF power of the RF generator 111 to the electrode 124. Impedance matching network 132 can be L-type, inverse L-type, T-type, or π-type. The impedance matching network 132 may include at least two variable reactive power elements. The variable reactive power elements may be vacuum variable capacitors.

[0065] Examplely, the impedance matching network 132 includes a first variable capacitor C1 and a second variable capacitor C2 connected to the output of an RF generator. One end of the first variable capacitor C1 can be connected to the output of the RF generator 111, and the other end of the first variable capacitor C2 can be grounded after being connected in series with a first inductor L1. One end of the second variable capacitor C2 is connected to the output of the RF generator 111, and the other end of the second variable capacitor C2 is connected to one end of a second inductor L2 and one end of a third inductor L3. The other end of the second inductor L2 is grounded. The other end of the third inductor L3 is connected to the output of the impedance matching network 132.

[0066] DC blocking capacitor 133 is connected to the output of impedance matching network 132 to suppress DC pulses transmitted through the output of band-stop filter 134 to impedance matching network 132. DC blocking capacitor 133 is disposed inside impedance matching network 132 and can be a high-voltage vacuum capacitor or a high-voltage ceramic capacitor. DC blocking capacitor 133 is a separate component from substrate support 130 and is replaceable. In particular, DC blocking capacitor 133 can be easily replaced if damaged by DC pulse voltage. Multiple DC blocking capacitors (C4, C5) can be connected in series to increase voltage withstand capability.

[0067] A band-stop filter 134 transmits the DC pulse voltage from the DC pulse generator 121 to the electrode 124 and suppresses the transmission of RF power to the DC pulse generator 121. The band-stop filter 134 may be a three-stage or higher π-type band-stop filter. In the case of a three-stage π-type band-stop filter 134, it may include a first-stage resonator 134a, a second-stage resonator 134b, and a third-stage resonator 134c. The first-stage resonator 134a may include an inductor La and a capacitor Ca connected in series. The second-stage resonator 134b may include an inductor Lb and a capacitor Cb connected in parallel. The third-stage resonator 134c may include an inductor Lc and a capacitor Cc connected in series. The resonant frequencies of the first to third-stage resonators 134a, 134b, and 134c may be consistent with the driving frequency of the RF power. The third-stage resonator 134c may be connected to the output terminal of the DC pulse generator 121. One end of the second-stage resonator 134b can be connected to the output of the DC pulse generator 121. The first-stage resonator 134a can be connected to the other end of the second-stage resonator 134b. The first-stage resonator 134a and the third-stage resonator 134c can be shunt resonators. The second-stage resonator 134b can be a series resonator. The band-stop filter 134 suppresses RF power from traveling to the DC pulse generator 121, thereby maintaining RF power below a few watts at the output of the DC pulse generator 121.

[0068] The band-stop filter 134 may include a series resonator 134b, which includes an inductor Lb and a capacitor Cb connected in parallel with each other. The reactance of the inductor Lb of the series resonator 134b may be less than 200 ohms.

[0069] The band-stop filter 134 may include a shunt resonator 134a, which includes an inductor La and a capacitor Ca connected in series. The shunt resonator 134a may be grounded, and the absolute value of the reactance of the capacitors Ca and Cc of the shunt resonators 134a and 134c may be less than 200 ohms.

[0070] The band-stop filter 134 can be designed to minimize the distortion of the DC pulse waveform. Distortion of the DC pulse waveform (e.g., overshoot) can damage the substrate support 130 and the power delivery device 130. If the order of the band-stop filter 134 increases, the overshoot increases, and the RF transmitted power (e.g., scattering coefficient S21) decreases. Furthermore, series connection of the band-stop filter 134 (or increasing the order) increases the overshoot. Therefore, a suitable order (or number of stages) needs to be selected. According to the invention, the order of the band-stop filter 134 is preferably 3 to 5 stages. In the configuration of the band-stop filter 134, the π-type configuration is advantageous in terms of overshoot compared to the T-type configuration.

[0071] An impedance converter 135 is connected to the output of the band-stop filter 134 to change the impedance of the band-stop filter 134. The impedance converter 135 can be connected to the junction of the first-stage resonator 134a and the second-stage resonator 134b. The impedance converter 135 can change the impedance of the first-stage resonator 134a with a high impedance. RF power incident on the impedance converter 135 can be reflected by the high impedance. The impedance converter 135 can be configured inside the band-stop filter 134. The impedance converter 135 can be an inductor L4, and the reactance of the inductor L4 can be from 25 ohms to 500 ohms.

[0072] The output terminal of the impedance converter 135 is connected to the output terminal of the DC blocking capacitor 133, and then connected to the electrode 124 via a transmission line 113. The transmission line 124 can be a high-voltage coaxial cable. The characteristic impedance of the transmission line 113 can be 50 ohms.

[0073] The load may include an electrode 124, a dielectric 125 disposed on the electrode 124, a substrate disposed on the dielectric 125, and plasma formed on the substrate. The load may include a negative reactive component. RF power incident at the junction of the output terminal of the impedance converter 135 and the output terminal of the DC blocking capacitor 133 travels primarily in the direction of lower impedance. Therefore, the absolute value of the reactance of the impedance converter 135 may be greater than the absolute value of the reactance of the load. Thus, the RF power can travel primarily in the load direction.

[0074] An RF sensor 136 may be configured between the band-stop filter 134 and the DC pulse generator 121. The RF sensor 136 may include a current sensor and a voltage sensor.

[0075] The control unit 137 can receive the output signal of the RF sensor 136 and calculate the RF transmission power. If the RF transmission power is above a threshold, the control unit 137 can provide an interrupt signal to the RF generator 111 or a warning signal to the user.

[0076] A voltage sensor 139 may be configured at the output of the band-stop filter 134. The voltage sensor 139 is capable of measuring the waveform of a DC pulse voltage and providing it to a control unit 137. The control unit 137 is capable of analyzing the waveform of the DC pulse voltage and displaying it to the user. The waveform analysis may be overshoot.

[0077] The RF generator 111 may be a frequency-variable RF generator, and the band-stop filter 134 may be a three-stage or higher π-type band-stop filter. The band-stop filter 134 may include a series resonator, which includes an inductor Lb and a variable capacitor Cb connected in parallel. The variable capacitor Cb of the series resonator may vary according to the driving frequency of the RF generator 111. The capacitance of the variable capacitor Cb is variable, such that the resonant frequency of the series resonator is consistent with the driving frequency of the RF generator. The first-stage resonator 134a may include an inductor La and a capacitor Ca connected in series. The second-stage resonator 134b may include an inductor Lb and a capacitor Cb connected in parallel. The third-stage resonator 134c may include an inductor Lc and a capacitor Cc connected in series. The capacitances of the capacitor Ca of the first-stage resonator 134a and the capacitor Cc of the third-stage resonator 134c can vary in a manner consistent with the driving frequency of the RF generator.

[0078] According to a modified embodiment of the present invention, when the RF generator 111 is a frequency-variable RF generator, the capacitor Ca of the first-stage resonator 134a can also use a fixed value.

[0079] Figure 5 This is a diagram showing the connection relationship of a DC blocking capacitor according to another embodiment of the present invention.

[0080] Reference Figure 5 The DC blocking capacitor 133 may include a plurality of capacitors connected in series with each other. Thus, the applied voltage is evenly distributed to the capacitors, thereby reducing the insulation breakdown voltage of each capacitor.

[0081] The DC blocking capacitor 133 may include multiple capacitors connected in parallel with each other. Thus, the RF power can increase its current drive capability through the low impedance of the DC blocking capacitor.

[0082] The DC blocking capacitor 133 may include multiple capacitors connected in series and in parallel. This reduces the current drive capability and insulation breakdown voltage. The maximum capacitance of the DC blocking capacitor 133 may be 50 pF.

[0083] Figure 6 This is a diagram showing the impedance as seen from the load direction toward the power transmission section in an embodiment of the present invention.

[0084] Figure 7 This indicates the impedance change when an impedance converter is added to the power transmission section.

[0085] Reference Figure 6 and Figure 7 The RF power reflected by the load depends on the impedance of the impedance matching network 132 and the impedance of the band-stop filter 134. If the impedance converter 135 were not present, the impedance of the band-stop filter 134 would be almost zero. Therefore, the reflected wave from the load would be transmitted through the band-stop filter 134. Therefore, to increase the impedance of the band-stop filter 134, an impedance converter 135 is required. The reactance of the impedance converter 135 can be 200 ohms or more. For example, at 60 MHz, the inductance of the impedance converter 135 can be 500 nH or more. When the impedance of the impedance converter 135 is very large, the impedance of the band-stop filter 134 changes from a short-circuit circuit to an open circuit in the Smith chart.

[0086] On the other hand, if the inductance of the impedance converter 135 is increased, the distortion (e.g., overshoot) of the DC pulse waveform may increase. Therefore, the absolute value of the reactance of the impedance converter 135 can be set to be greater than the absolute value of the reactance of the load.

[0087] Figure 8 This represents the simulation results showing the operating range of the impedance matching network corresponding to the reactance of the impedance converter in an embodiment of the present invention.

[0088] Reference Figure 8 When the impedance converter 135 is an inductor L4 and the reactance of the inductor L4 is 25 ohms, 50 ohms, 100 ohms, 200 ohms, and 500 ohms, the operating range of the impedance matching network is marked on the Smith chart respectively. Therefore, in order for the impedance matching network 132 to operate efficiently, the reactance of the impedance converter 135 can be from 50 ohms to 500 ohms.

[0089] Figure 9a and Figure 9b This describes the transmission characteristics of a band-stop filter corresponding to the inductance of an impedance converter according to an embodiment of the present invention.

[0090] Reference Figure 9a and Figure 9b S12 is the transmission coefficient or scattering coefficient between RF generator 111 and DC pulse generator 121. If the resonant frequency of band-stop filter 134 is consistent with the driving frequency of 60 MHz, then the RF power of RF generator 111 decreases from 60 MHz to below -200 dB.

[0091] On the other hand, when the inductance of the impedance converter 135 is 1 nH, the transmittance under harmonics (120 MHz, 180 MHz) remains unchanged. However, when the inductance of the impedance converter 135 is 500 nH, the transmittance under harmonics (120 MHz, 180 MHz) changes. The impedance converter 135 operates as a low-pass filter, thereby suppressing high-frequency components. However, if the inductance of the impedance converter 135 increases, the distortion of the DC pulse waveform (e.g., overshoot) increases. Therefore, the absolute value of the reactance of the impedance converter 135 can be set to be greater than the absolute value of the reactance of the load.

[0092] Figure 10a and Figure 10b This indicates the operating range of the impedance matching network in a power transfer device where a band-stop filter has been removed, according to an embodiment of the present invention.

[0093] Reference Figure 10a and Figure 10b With the band-stop filter 134 removed from the power transfer device 130, the power transfer device 130 operates as a normal impedance matching network. If a load impedance exists in the marked area, the power generated by the power source can be transferred to the load without loss.

[0094] Figures 11a to 11c This indicates the operating range of the impedance matching network in a power transfer device including a band-stop filter, according to an embodiment of the present invention.

[0095] Reference Figures 11a to 11b In the simulation, Ca, Cb, and Cc = 40, 50, and 60 pF, respectively. When the power transfer device 130 includes a band-stop filter 134, if the inductance of the impedance converter 135 is 1 nH, the operating range of the impedance matching network 132 is very narrow. However, if the inductance of the impedance converter 135 is 500 nH, the operating range of the impedance matching network 132 is very wide. Therefore, stable impedance matching operation can be performed according to the load.

[0096] Reference Figures 11a to 11c In the simulation, Cb, Cc = 40, 50, 60 pF, and Ca = 50 pF. When the power transfer device 130 includes a band-stop filter 134, if the inductance of the impedance converter 135 is 1 nH, the operating range of the impedance matching network 132 is very narrow. However, if the inductance of the impedance converter 135 is 500 nH, the operating range of the impedance matching network 132 is very wide. Therefore, stable impedance matching operation can be performed according to the load.

[0097] Figures 12a to 12c This is a diagram illustrating the characteristics of a band-stop filter according to an embodiment of the present invention.

[0098] Reference Figures 12a to 12c The band-stop filter 134 includes resonators 134a to 134e from stage 1 to stage 5, and can be π-type. The band-stop filter with only stage 1 resonator 134a exhibits relatively high transmittance (or scattering matrix S21) at a resonant frequency of 60 MHz. On the other hand, as the stage number (or order) of the band-stop filter 134 increases to two or three stages, it exhibits relatively low transmittance at a resonant frequency of 60 MHz. Therefore, the band-stop filter 134 can be a π-type filter with three or more stages.

[0099] On the other hand, regarding the waveform of the DC pulse voltage, the first-stage band-stop filter exhibits the best overshoot characteristics. That is, as the order (or number of stages) of the band-stop filter 134 increases, the overshoot increases. Therefore, if overshoot is taken into account, the band-stop filter 134 can be a π-type filter with five stages or less.

[0100] Figures 13a to 13e This is a diagram illustrating the characteristics of a band-stop filter according to an embodiment of the present invention.

[0101] Reference Figures 13a to 13e The band-stop filter 134 can be a five-stage band-stop filter. The band-stop filter 134 includes a series inductor, a series capacitor, a shunt inductor, and a shunt capacitor.

[0102] Reference Figure 13b If the series capacitors are changed to 100 pF, 200 pF and 300 pF, the waveform of the DC pulse voltage remains almost unchanged.

[0103] Reference Figure 13c If the series inductor is changed to 100 nH, 200 nH, and 300 nH, then in the waveform of the DC pulse voltage, the overshoot increases with the increase of inductance. Therefore, the inductance of the series inductor can be below 200 nH.

[0104] Reference Figure 13d If the shunt capacitor is changed to 100 pF, 200 pF, and 300 pF, then in the waveform of the DC pulse voltage, the overshoot decreases slightly as the capacitance increases. Therefore, the capacitance of the shunt capacitor can be 100 pF or more.

[0105] Reference Figure 13e If the shunt inductor is changed to 100 nH, 200 nH and 300 nH, then in the waveform of DC pulse voltage, the overshoot does not change with the increase of inductance.

[0106] Figure 14 This is a simulation result showing the overshoot of the series inductor in the band-stop filter of a power transfer device according to an embodiment of the present invention.

[0107] Reference Figure 14 With the reactance of the series inductor below 200 ohms, the overshoot was kept within 5%. A three-stage π-type band-stop filter was used in the simulation. The DC pulse voltage frequency was 400 kHz, the duty cycle was 50%, the rise and fall times were 250 nsec, and the maximum voltage was 10 kV. The actual resistance of the load ranged from 50 to 200 ohms, and the capacitance ranged from 500 pF to 2500 pF.

[0108] To keep the overshoot less than 5%, the reactance of the series inductor can be kept below 200 ohms.

[0109] While specific preferred embodiments of the invention have been illustrated and described, the invention is not limited to these embodiments, but includes various embodiments that can be practiced by those skilled in the art without departing from the technical spirit of the invention as claimed in the claims.

[0110] Symbol Explanation

[0111] 111RF Generator

[0112] 121 pulse generator

[0113] 130 power transmission device

[0114] 132 Impedance Matching Network

[0115] 134 band-stop filter

[0116] 133DC blocking capacitor

[0117] 135 impedance converter.

Claims

1. A power transmission device, characterized in that, include: Impedance matching network transfers the RF power from the RF generator to the load; A band-stop filter delivers the DC pulse voltage from the DC pulse generator to the load and suppresses the RF power from being delivered to the DC pulse generator. A DC blocking capacitor is connected to the output of the impedance matching network to suppress the DC pulse voltage transmitted through the output of the band-stop filter to the impedance matching network. An impedance converter, connected to the output of the band-stop filter, changes the impedance of the RF power incident on the band-stop filter; The output terminals of the impedance converter and the DC blocking capacitor are connected to each other and then connected to the load via a transmission line.

2. The power transmission device according to claim 1, characterized in that, The DC blocking capacitor is disposed inside the impedance matching network, and the DC blocking capacitor is a high-voltage vacuum capacitor or a high-voltage ceramic capacitor.

3. The power transmission device according to claim 1, characterized in that, The DC blocking capacitor is replaceable.

4. The power transmission device according to claim 1, characterized in that, The DC blocking capacitors are multiple and connected in series to increase voltage resistance.

5. The power transmission device according to claim 1, characterized in that, The impedance converter is configured inside the band-stop filter. The impedance converter is an inductor. The reactance of the inductor is from 25 ohms to 500 ohms.

6. The power transmission device according to claim 1, characterized in that, The load includes an electrode, a dielectric disposed on the electrode, a substrate disposed on the dielectric, and a plasma formed on the substrate.

7. The power transmission device according to claim 1, characterized in that, The absolute value of the reactance of the impedance converter is greater than or equal to the absolute value of the reactance of the load.

8. The power transmission device according to claim 1, characterized in that, The band-stop filter is a π-type band-stop filter with three or more stages.

9. The power transmission device according to claim 8, characterized in that, The band-stop filter includes a series resonator, which comprises an inductor and a capacitor connected in parallel with each other. The reactance of the inductor in the series resonator is less than 200 ohms.

10. The power transmission device according to claim 8, characterized in that, The band-stop filter includes a shunt resonator, which comprises an inductor and a capacitor connected in series with each other. The shunt resonator is grounded.

11. The power transmission device according to claim 1, characterized in that, The RF generator is a frequency-variable RF generator. The band-stop filter is a π-type band-stop filter with three or more stages. The band-stop filter includes a series resonator, which comprises an inductor and a variable capacitor connected in parallel. The variable capacitor of the series resonator can vary according to the driving frequency of the RF generator. The capacitance of the variable capacitor is variable, so that the resonant frequency of the series resonator is consistent with the driving frequency of the RF generator.

12. The power transmission device according to claim 1, characterized in that, Also includes: An RF sensor is configured between the band-stop filter and the DC pulse generator; as well as The control unit receives the output signal from the RF sensor and calculates the RF transmitted power; When the RF transmission power is above a threshold, the control unit provides an interrupt signal to the RF generator.

13. The power transmission device according to claim 1, characterized in that, The band-stop filter is a π-type band-stop filter with three or more stages. The band-stop filter includes: The first shunt resonator consists of an inductor and a fixed capacitor connected in series.

14. A plasma substrate processing apparatus, characterized in that, include: A substrate support includes electrodes supporting the substrate and a dielectric disposed on the electrodes; The chamber is configured to surround the substrate support; An RF generator provides RF power to the electrodes and forms plasma on the substrate; A DC pulse generator provides a DC pulse voltage to the electrodes; as well as The power transmission unit transmits the RF power and the DC pulse voltage to the electrodes; The power transmission unit includes: An impedance matching network is used to transfer the RF power of the RF generator to the electrodes; A band-stop filter transmits the DC pulse voltage from the DC pulse generator to the electrode and suppresses the transmission of RF power to the DC pulse generator. A DC blocking capacitor is connected to the output of the impedance matching network to suppress the DC pulse transmitted through the output of the band-stop filter to the impedance matching network. An impedance converter is connected to the output of the band-stop filter and changes the impedance of the band-stop filter. The output terminals of the impedance converter and the DC blocking capacitor are connected to each other and then connected to the electrode via a transmission line.

15. The plasma substrate processing apparatus according to claim 14, characterized in that, The DC blocking capacitor is disposed inside the impedance matching network, and the DC blocking capacitor is a high-voltage vacuum capacitor or a high-voltage ceramic capacitor.

16. The plasma substrate processing apparatus according to claim 14, characterized in that, The DC blocking capacitor is replaceable.

17. The power transmission device according to claim 14, characterized in that, The DC blocking capacitors are multiple and connected in series to increase voltage resistance.

18. The plasma substrate processing apparatus according to claim 14, characterized in that, The impedance converter is configured inside the band-stop filter. The impedance converter is an inductor. The reactance of the inductor is from 25 ohms to 500 ohms.

19. The plasma substrate processing apparatus according to claim 14, characterized in that, The absolute value of the reactance of the impedance converter is greater than or equal to the absolute value of the reactance of the load.

20. A power transmission device, characterized in that: Impedance matching network transfers the RF power from the RF generator to the load; A band-stop filter delivers the DC pulse voltage from the DC pulse generator to the load and suppresses the RF power from being delivered to the DC pulse generator. A DC blocking capacitor is connected to the output of the impedance matching network to suppress the DC pulse voltage transmitted through the output of the band-stop filter to the impedance matching network. The output terminals of the band-stop filter and the DC blocking capacitor are connected to each other and then connected to the load via a transmission line.

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