Abstract: An apparatus which selectively etches a first region with respect to a second region made of a material different from that of the first region. The apparatus is controlled to perform a first step for generating, in a processing container housing a workpiece to be treated, a plasma of a treatment gas from a gas supply including a fluorocarbon gas, an oxygen-containing gas, and an inert gas, and forming a deposit including fluorocarbon on the object to be treated, and a second step for etching the first region with radicals of the fluorocarbon included in the deposit. The apparatus is also controlled to perform the first step and the second step repeatedly.

Abstract: Method for tuning a voltage setpoint for a multi-state pulsed RF signal in a plasma processing system, including: applying RF power from a first generator to an ESC, the RF power from the first generator defining a first multi-state pulsed RF signal; applying RF power from a second generator to an edge electrode that surrounds the ESC and is disposed below an edge ring that surrounds the ESC, the RF power from the second generator defining a second multi-state pulsed RF signal having a first state and a second state, wherein for each state of the second multi-state pulsed RF signal, the second generator automatically introduces a phase adjustment to substantially match phase with a corresponding state of the first multi-state pulsed RF signal; adjusting a voltage setpoint for the second state of the second multi-state pulsed RF signal to tune the phase adjustment to a target phase adjustment setting.

Abstract: Plasma processing systems and methods are disclosed. The system may include at least one modulating supply that modulates plasma properties where the modulation of the plasma properties has a repetition period, T. A synchronization module configured to send a synchronization signal with a synchronization-signal-repetition-period that is an integer multiple of T to at least one piece of equipment connected to the plasma processing system. A waveform-communication module communicates characteristics of a characterized waveform to at least one piece of equipment connected to the plasma system to enable synchronization of pieces of equipment connected to the plasma processing system. The characterized waveform may contain information about the modulation of the plasma or information about a desired waveform of a piece of equipment connected to the plasma processing system.

Abstract: A method of plasma processing a substrate in a plasma chamber is provided. The method includes the steps of supplying a power supply signal to electrodes arranged within the plasma chamber in order to form a plasma in the plasma chamber, monitoring at least one parameter related to the plasma processing, determining a feature related to the at least one monitored parameter, and adjusting the power supply signal during the plasma processing to modify, in particular reduce, the feature. The modification of the feature eliminates or mitigates formation of crazing on the substrate.

Abstract: A high-frequency power supply apparatus includes the following elements. A first power supply outputs a first high-frequency voltage with a first fundamental frequency. A second power supply outputs a second high-frequency voltage with a second fundamental frequency lower than the first fundamental frequency. A second matching device is connected between the second power supply and the load. The second matching device generates a timing control signal with a frequency lower than the second fundamental frequency. The first power supply generates a modulation signal by applying a start phase and a frequency shift amount to a modulation fundamental wave signal whose frequency is equal to the second fundamental frequency. The start phase is applied to the modulation fundamental wave signal in accordance with an input timing of the timing control signal. The first power supply performs frequency modulation on the first high-frequency voltage by using the modulation signal.

Abstract: Method of forming low-k films with reduced dielectric constant, reduced CHx content, and increased hardness are described. A siloxane film is on a substrate surface using a siloxane precursor comprising O—Si—O bonds and cured using ultraviolet light.

Abstract: Embodiments of this disclosure describe a feedback loop that can be used to maintain a nearly constant sheath voltage and thus creating a mono-energetic IEDF at the surface of the substrate. The system described herein consequently enables a precise control over the shape of IEDF and the profile of the features formed in the surface of the substrate.

Abstract: To simplify a process of suppressing an increase in a reflected wave power caused by IMD, provided is a high-frequency power supply system for providing a high-frequency power to a load, including: a first power supply for supplying a first high-frequency power to the load; a second power supply for supplying a second high-frequency power to the load; and a matching device. The matching device provides a system clock to each of the first power supply and the second power supply. The second power supply outputs a second high-frequency voltage at a control period determined based on the system clock provided from the matching device. The first power supply outputs a first high-frequency voltage obtained by frequency modulation of a fundamental wave signal having a first fundamental frequency and through amplification, in each control period determined based on the system clock provided from the matching device.

Abstract: A plasma processing apparatus includes: a plasma processing chamber; a substrate support disposed in the plasma processing chamber and including a lower electrode; a source RF generator coupled to the plasma processing chamber and configured to generate a source RF signal including high states and low states in alternate manner; and a bias DC generator coupled to the lower electrode and configured to generate a bias DC signal including ON states and OFF states in alternate manner. Each ON state includes a plurality of cycles, each cycle including a first sequence of first pulses and a second sequence of second pulses, each first pulse having a first voltage level, and each second pulse having a second voltage level different from the first voltage level.

Abstract: A hollow cathode includes an insulation plate having cathode holes. Bottom electrodes are below the insulation plate. The bottom electrodes define first holes having a width greater than a width of the cathode holes. Top electrodes are at an opposite side of the insulation plate from the bottom electrodes. The top electrodes define second holes aligned with the first holes along a direction orthogonal to the upper surface of the insulation plate.

Abstract: Embodiments disclosed herein include a processing tool for semiconductor processing. In an embodiment, the processing tool comprises a chamber, and a plurality of witness sensors integrated with the chamber. In an embodiment, the processing tool further comprises a drift detection module. In an embodiment, data from the plurality of witness sensors is provided to the drift detection module as input data. In an embodiment, the processing tool further comprises a dashboard for displaying output data from the drift detection module.

Abstract: A sputtering apparatus including a chamber, a stage inside the chamber and configured to receive a substrate thereon, a first sputter gun configured to provide a sputtering source to an inside of the chamber, a first RF source configured to provide a first power having a first frequency to the first sputter gun, and a second RF source configured to provide a second power having a second frequency to the first sputter gun, the second frequency being lower than the first frequency may be provided.

Abstract: Methods and apparatus for plasma processing substrate are provided herein. The method comprises supplying from an RF power source RF power, measuring at the RF power source a reflected power at the first power level, comparing the measured reflected power to a first threshold, transmitting a result of the comparison to a controller, setting at least one variable capacitor to a first position based on the comparison of the measured reflected power at the first power level to the first threshold, supplying from the RF power source the RF power at a second power level for plasma processing the substrate, measuring at the RF power source the reflected power at the second power level, comparing the measured reflected power at the second power level to a second threshold different from the first threshold, transmitting a result of the comparison, setting at the matching network the at least one variable capacitor to a second position.

Abstract: A disclosed etching method includes (a) generating plasma of a processing gas in a chamber of a plasma processing apparatus. The plasma is generated in a state where a substrate is placed on a substrate support having a lower electrode in the chamber. The substrate has a film and a mask. The mask is provided on the film. The etching method further includes (b) etching the film by supplying ions from the plasma to the substrate by periodically applying a pulse of a voltage to a lower electrode. In the operation (b), a level of a voltage of the pulse is changed at least once such that an absolute value of a negative potential of the substrate has a tendency to increase according to progress of etching of the film.

Abstract: A detecting method includes: supplying a bias power to a lower electrode, and supplying a source power to an upper electrode or the lower electrode; and detecting an output value of a sensor attached to a chamber. The detecting the output value of the sensor includes (a) specifying a first phase of a bias waveform for each cycle of the bias waveform, (b) specifying a second phase of a source waveform after a predetermined first time elapses from a timing when the first phase is specified, and (c) sampling the output value of the sensor after a predetermined second time elapses from a timing when the second phase is specified. The steps (a) to (c) are repeated for each cycle of the bias waveform.

Abstract: A system and method for etching workpieces in a uniform manner are disclosed. The system includes a semiconductor processing system that generates a ribbon ion beam, and a workpiece holder that scans the workpiece through the ribbon ion beam. The workpiece holder includes a portion that extends beyond the workpiece, referred to as a halo. The halo may be independently heated to compensate for etch rate non-uniformities. In some embodiments, the halo may be independently biased such that its potential is different from the potential applied to the workpiece. In certain embodiments, the halo may be divided into a plurality of thermal zones that can be separately controlled. In this way, various etch rate non-uniformities may be addressed by controlling the potential and/or temperature of the various thermal zones of the halo.

Abstract: A stage device includes a stage having a copper main body and an electrostatic chuck, a cooling unit disposed below the stage, and a power supply mechanism for supplying power to an attraction electrode of the electrostatic chuck from a DC power supply disposed below the stage. The power supply mechanism includes a pair of terminals disposed at an outer peripheral portion of the stage while being spaced apart from each other, a first power supply line having a pair of metal rods spaced apart from each other while extending toward the stage and being connected to the DC power supply, a second power supply line having a pair of metal rods spaced apart from each other and connected to the terminals, and a connecting unit where the metal rods of the first power supply line and the metal rods of the second power supply line are connected.

Abstract: A method for non-invasively imaging plasma parameters has been invented. Crossed dipole pairs are used to differentiate changes in the measured complex self- and mutual impedances due to plasma density and magnetic field. Measurements of the complex self-impedance and mutual impedance between pairs of antennas over a wide range of frequencies provide spatial information to create an image of the plasma density and magnetic field. The spectral information is acquired simultaneously using a Gaussian monopulse as the driver signal.

Abstract: Power supply devices for generating at least one electric high-frequency power signal for a plasma having at least a first plasma state and a second plasma state are provided. The power supply devices are configured to determine a first variable that characterizes a power reflected by the plasma in the first plasma state, determine a second variable that characterizes a power reflected by the plasma in the second plasma state, generate a third variable based on the first variable and the second variable, and control at least one of a frequency or a power of the high-frequency power signal based on the third variable.

Abstract: A defrosting system includes an RF signal source, two electrodes proximate to a cavity within which a load to be defrosted is positioned, a transmission path between the RF signal source and the electrodes, and an impedance matching network electrically coupled along the transmission path between the output of the RF signal source and the electrodes. The system also includes power detection circuitry coupled to the transmission path and configured to detect reflected signal power along the transmission path. A system controller is configured to modify, based on the reflected signal power, values of variable capacitors of the impedance matching network to reduce the reflected signal power. The impedance matching network may be a single-ended network or a double-ended network.

Abstract: A cleaning method that removes contaminants adhering to a stage in a chamber, includes: setting a pressure in a chamber to a predetermined vacuum pressure; supplying a first gas that forms a shock wave toward the stage; and supplying a second gas that does not form the shock wave toward the stage.

Abstract: A substrate processing apparatus includes: a disk including a plurality of electrostatic chucks periodically disposed at a constant radius from a central axis; a disk support supporting the disk; a DC line electrically connected to the plurality of electrostatic chucks through the disk support; and a power supply configured to supply power to the DC line. The DC line includes: a first DC line penetrating through the disk support from the power supply; a power distribution unit configured to distribute the first DC line to connect the first DC line to each of the plurality of electrostatic chucks; and a plurality of second DC lines respectively connected to the plurality of electrostatic chucks in the power distribution unit.

Abstract: Provided is a technique capable of reducing a variation in processing in an in-plane direction of a sample and improving a yield of processing. A plasma processing apparatus 1 includes a first electrode (a base material 110B) disposed in a sample stage 110, a ring-shaped second electrode (a conductive ring 114) disposed surrounding an outer peripheral side of an upper surface portion 310 (a dielectric film portion 110A) of the sample stage 110, a dielectric ring-shaped member (a susceptor ring 113) that covers the second electrode and is disposed surrounding an outer periphery of the upper surface portion 310, a plurality of power supply paths that supply high frequency power from a high frequency power supply to the first electrode and the second electrode respectively, and a matching device 117 disposed on a power supply path to the second electrode.

Abstract: A substrate processing apparatus of the present disclosure includes a processing container capable of being vacuum-exhausted, a lower electrode, and an upper electrode. A target substrate can be placed on the lower electrode. The upper electrode is disposed in the processing container so as to face the lower electrode. A substrate processing method of the present disclosure includes performing a first process on the target substrate using an AC voltage without using a DC pulse voltage, and performing a second process on the target substrate using the DC pulse voltage.

Abstract: Methods and apparatus for processing a substrate are herein described. For example, a processing chamber for processing a substrate includes a chamber body defining a processing volume; a radio frequency (RF) power source configured to deliver RF energy to the processing volume for processing a substrate; a substrate support comprising an electrode; an AC power supply configured to supply power to the processing chamber; an RF filter circuit connected between the electrode and the AC power supply; and a controller configured to monitor an RF voltage at the RF filter circuit that is indirectly induced into the electrode by the RF power source during operation, and to determine a processing state in the processing volume based on the monitored RF voltage.

Abstract: A physical vapor deposition system may include an RF generator configured to transmit an AC process signal to a physical vapor deposition chamber via an RF matching network. A controller of the RF matching network is configured to receive the DC magnitude and phase error signals and to vary an impedance of the RF matching network in response to the DC magnitude and phase error signals. The matching network operates in a first mode until a tuning dead-zone is determined. Once a tuning dead-zone is determined, the matching network operates in additional modes until the network is tuned. The controller uses a composite value of magnitude and phase error to drive of the variable tuning and load capacitors.

Abstract: Systems and methods for plasma processing are disclosed. An exemplary system may include a plasma processing chamber including a source to produce a plasma in the processing chamber and at least two bias electrodes arranged within the plasma processing chamber to control plasma sheaths proximate to the bias electrodes. A chuck is disposed to support a substrate, and a source generator is coupled to the plasma electrode. At least one bias supply is coupled to the at least two bias electrodes, and a controller is included to control the at least one bias supply to control the plasma sheaths proximate to the bias electrodes.

Abstract: An impedance matching device includes: a variable capacitor in which a plurality of series circuits of capacitors and semiconductor switches are connected in parallel; a calculation unit that calculates an impedance or a reflection coefficient on the load side using information regarding impedance acquired from the outside; and a control unit that determines ON/OFF states to be taken by the semiconductor switches included in the variable capacitor using the impedance or the reflection coefficient calculated by the calculation unit and turns on or off the semiconductor switches based on the determined states. The control unit changes an ON/OFF control timing between one and another of the semiconductor switches.

Abstract: Lighting fixture data hubs and systems and methods for use. An example of a data hub may include an annunciator configured to generate first and second indications; a sensor configured to detect a zone including one or more parking spaces, pedestrians, or other activity areas in a vicinity of the data hub and to determine whether or not one or more vehicles, pedestrians, and/or activities occurring in the activity areas are present within the zone, the sensor further configured to emit signals corresponding to said detection; and a gateway in communication with an on-board processor and the annunciator, the on-board processor configured for EDGE computing and processing to receive and analyze the signals from the sensor, communicate said signals to the gateway, and operable to allow the gateway to direct the annunciator to generate the first indication or the second indication in response to the signals.

Abstract: A plasma processing apparatus includes: a processing container; an electrode that places a substrate thereon within the processing container; a plasma generation source that supplies plasma into the processing container; a bias power supply that supplies bias power to the electrode; a part exposed to the plasma in the processing container; a DC power supply that supplies a DC voltage to the part; a controller that executes a process including a first control procedure in which a first state in which the DC voltage has a first voltage value and a second state in which the DC voltage has a second voltage value higher than the first voltage value are periodically repeated, and the first voltage value is applied in a partial period in each cycle of a potential of the electrode, and the second voltage value is applied such that the first state and the second state are continuous.

Abstract: A carrier system and method carries a plate-like object to an object mounting section. The system imparts vibration to the object that has been moved such that the object is vibrating when the object is placed onto the mounting section.

Abstract: A discharge control apparatus for controlling a flyback power supply circuit which includes a transformer having a primary coil and a secondary coil and performing voltage conversion, and a driver for controlling energization of the primary coil. The power supply circuit supplies electric energy to a plasma reactor. The discharge control apparatus calculates, based on primary current flowing through the primary coil and primary voltage generated in the primary coil, supply energy supplied to the primary coil and regeneration energy which is a portion of the supply energy not used for the discharge in the plasma reactor. The discharge control apparatus controls the power supply circuit based on the calculated supply energy and the calculated regeneration energy. Also disclosed is a method for controlling the flyback power supply circuit.

Abstract: Systems and methods for increasing peak ion energy with a low angular spread of ions are described. In one of the systems, multiple radio frequency (RF) generators that are coupled to an upper electrode associated with a plasma chamber are operated in two different states, such as two different frequency levels, for pulsing of the RF generators. The pulsing of the RF generators facilitates a transfer of ion energy during one of the states to another one of the states for increasing ion energy during the other state to further increase a rate of processing a substrate.

Abstract: Embodiments include a method of processing a substrate. In an embodiment, the method comprises flowing one or more source gasses into a processing chamber, and inducing a plasma from the source gases with a plasma source that is operated in a first mode. In an embodiment, the method may further comprise biasing the substrate with a DC power source that is operated in a second mode. In an embodiment, the method may further comprise depositing a film on the substrate.

Abstract: A detector for detecting an occurrence of a current strength of interest (e.g. zero current) of a current of a signal to be sensed includes a magnetoresistive structure and a detection unit. The magnetoresistive structure varies a resistance depending on a magnetic field caused by the current of the signal to be sensed. Further, the detection unit generates and provides a current detection signal indicating an occurrence of the current strength of interest based on a detected magnitude of the varying resistance of the magnetoresistive structure.

Abstract: A system and method for reduced workpiece adhesion during removal from a semiconductor processing station. The system provides an electrostatic charge detector that measures the residual charge on an electrostatically clamped workpiece prior to removal from a processing station inside the semiconductor processing tool. One embodiment uses an algorithm that to predict when to remove the workpiece without electrostatic adhesion based upon the decay rate of the residual electrostatic charge (Q) on the workpiece. Other embodiments also provide for a processing station static charge buildup health check and an excessive static charge check on incoming workpieces.

Abstract: Examples of a system for generating and compressing magnetized plasma are disclosed. The system comprises a plasma generator with a first closed end and an outlet, and a flux conserving chamber that is in tight fluid communication with the outlet of the plasma generator such that the generated plasma is injected into an inner cavity of the flux conserving chamber. An elongated central axial shaft is also provided such that the central shaft extends through the outlet of the plasma generator into the flux conserver. The end of the central shaft in connected to the flux conserver. A power source that comprises a formation power circuit and a shaft power circuit is provided to provide a formation power pulse to the plasma generator to generate magnetized plasma, and a shaft power pulse to the central axial shaft to generate a toroidal magnetic field into the plasma generator and the flux conserving chamber.

Abstract: Lighting fixture data hubs and systems and methods for use. An example of a data hub may include an annunciator configured to generate first and second indications; a sensor configured to detect a zone including one or more parking spaces, pedestrians, or other activity areas in a vicinity of the data hub and to determine whether or not one or more vehicles, pedestrians, and/or activities occurring in the activity areas are present within the zone, the sensor further configured to emit signals corresponding to said detection; and a gateway in communication with an on-board processor and the annunciator, the on-board processor configured for EDGE computing and processing to receive and analyze the signals from the sensor, communicate said signals to the gateway, and operable to allow the gateway to direct the annunciator to generate the first indication or the second indication in response to the signals.

Abstract: The invention relates to a plasma treatment device with a treatment chamber, at least one pair of microwave plasma sources and at least one voltage source. Each pair of microwave plasma sources consists of a first microwave plasma source and a second microwave plasma source, wherein the first and the second microwave plasma source each have a plasma source wall and, within this, a microwave coupling-in device and a plasma electrode. The first and the second microwave plasma source are arranged within the treatment chamber on the same side of one or more substrates to be processed and adjacently to one another. The plasma electrodes of the first microwave plasma source and the second microwave plasma source are electrically insulated from one another and electrically conductively connected to the at least one voltage source. Here, the at least one voltage source is suitable for supplying the plasma electrodes of the first and the second microwave plasma source with different potentials.

Abstract: A plasma processing apparatus according to one embodiment includes a grounded processing container, a mounting table configured to support a workpiece inside the processing container, a plurality of electrodes arranged to face the mounting table and insulated from one another, a high frequency power supply configured to supply a high frequency power for generating plasma and electrically connected between two different electrodes out of the plurality of electrodes or between one of the plurality of electrodes and the processing container, and an impedance variable circuit configured to control an impedance and electrically connected between two different electrodes out of the plurality of electrodes or between one of the plurality of electrodes and the processing container.

Abstract: A substrate processing method includes supplying RF power from an RF power supply provided with a linear amplifier to a plasma generation apparatus via an electronic matcher, thereby generating plasma and starting a process on a substrate, and stopping the supply of the RF power from the RF power supply when a prescribed time elapses after the generation of plasma starts.

Abstract: An RF generator includes: a modulation circuit outputting a pulsed RF signal; a variable attenuation circuit adjusting the level of the pulsed RF signal; an output power detecting unit detecting an output power value of the power output from the device; a first comparative arithmetic circuit outputting a first level control signal for controlling the level of the adjusted pulsed RF signal on the basis of a first detected voltage value and a set voltage value set in advance; a second comparative arithmetic circuit outputting a second level control signal for controlling the level of the adjusted pulsed RF signal on the basis of a second detected voltage value and the set voltage value; and a switching circuit switching between the value of the first level control signal and the value of the second level control signal depending on a switching timing setting value.

Abstract: A RF control circuit is provided and includes a controller, a divider, and a RF sensor. The controller selects a RF, which is a frequency of a reference LO signal. The divider receives a first RF signal detected in a substrate processing chamber and outputs a second RF signal. The first RF signal is generated by a RF generator and supplied to the substrate processing chamber. The RF sensor includes a lock-in amplifier, which includes: a RF path that receives the second RF signal; a LO path that receives the reference LO signal; a first mixer that generates an IF signal based on the second RF signal and the reference LO signal; and a filter that filters the IF signal. The controller generates a control signal based on the filtered IF signal and transmits the control signal to the RF generator to adjust the first RF signal.

Abstract: A plasma etching method uses, as a processing gas, a mixed gas of at least one fluorocarbon gas and at least one hydrofluoroether gas represented by chemical formula (I).

Abstract: Disclosed inventions are apparatus for supplying power and an apparatus for treating a substrate including the same. The apparatus for supplying power includes a high-frequency power source that provides a high-frequency power; a plasma source including first and second antennas that generates plasma by using the high-frequency power; and a power divider connected between the high-frequency power source and the plasma source to divide the high-frequency power supplied to the first and second antennas. The power divider includes a first variable device that controls the high-frequency power supplied to the first and second antennas; and a second variable device that compensates for non-linearity of the high-frequency power supplied to the first and second antennas.

Abstract: Systems and methods for creating arbitrarily-shaped ion energy distribution functions using shaped-pulse-bias. In an embodiment, a method includes applying a positive jump voltage to an electrode of a process chamber to neutralize a wafer surface, applying a negative jump voltage to the electrode to set a wafer voltage, and modulating the amplitude of the wafer voltage to produce a predetermined number of pulses to determine an ion energy distribution function. In another embodiment a method includes applying a positive jump voltage to an electrode of a process chamber to neutralize a wafer surface, applying a negative jump voltage to the electrode to set a wafer voltage, and applying a ramp voltage to the electrode that overcompensates for ion current on the wafer or applying a ramp voltage to the electrode that undercompensates for ion current on the wafer.

Abstract: A method for producing an arc detection signal on the basis of a plurality of observation signals comprises producing an arc detection part-signal for each of at least two observation signals. Producing each of the part-signals includes correlating the respective observation signal with a correlation signal by influencing the correlation signal with the respective observation, thereby producing a correlation result; producing or modifying a coefficient on the basis of the correlation result; and weighting the respective observation signal with the coefficient. The arc detection part-signals are added to form the arc detection signal.

Abstract: Disclosed is a plasma processing method for generating plasma between an upper electrode connected with a VF power supply and a susceptor disposed to face the upper electrode to perform a plasma processing on a wafer by the plasma. The plasma processing method includes: providing an auxiliary circuit configured to reduce a difference between a reflection minimum frequency of a first route where a high frequency current generated from the VF power supply flows before ignition of the plasma and a reflection minimum frequency of a second route where the high frequency current generated from the VF power supply flows after the ignition of the plasma; igniting the plasma; and maintaining the plasma.

Abstract: A method for cleaning a processing chamber of a substrate processing system includes supplying nitrogen trifluoride (NF3) gas to a remote plasma source (RPS); generating RPS plasma using the RPS; supplying the RPS plasma to the processing chamber; supplying NF3 gas as bypass gas to the processing chamber; striking in-situ plasma in the processing chamber while the RPS plasma is supplied; and cleaning the processing chamber during a cleaning period using both the RPS plasma and the in-situ plasma.

Abstract: A plasma processing apparatus can efficiently perform a pulse modulation method of switching a high frequency power to be used in a plasma process between a high level and a low level alternately according to a duty ratio of a modulation pulse. In this plasma processing apparatus, when performing a high/low pulse modulation on the high frequency power for plasma generation, if a weighted variable K is set to be 0.5<K<1, a constant reflection wave power PRH is generated on a high frequency transmission line of a plasma generation system even during a pulse-on period Ton. Meanwhile, during a pulse-off period Toff, a reflection wave power PRL decreases. By adjusting the value of K, a balance between the reflection wave power PRH during the pulse-on period Ton and the reflection wave power PRL during the pulse-off period Toff can be controlled.