Abstract: In a configuration of an isolation circuit using a transformer of a high-frequency-isolation gate driver circuit in the frequency band from 1 to 100 MHz, a period for resetting the exciting current is eliminated, generation of self-resonance phenomenon after resetting is cancelled to reduce generation of noise current, and malfunctions of the switching element due to noise is prevented. In driving plural gate circuits by RF signals, exciting current is allowed to pass through a primary coil of a gate driver transformer alternately in both directions continuously all the time, in a configuration for isolating drive input signals by the gate driver transformer. Accordingly, the reset period that is required when the exciting current flows only in one way becomes unnecessary, and thus generation of self-resonance phenomenon after resetting is canceled. Then, generation of noise current caused by the self-resonance phenomenon is reduced.

Abstract: In an RF power supply for supplying RF power to a plasma load, reflected wave power control is performed in which the reflected wave power of an RF generator is detected and the RF generator is controlled. For a short-time variation in reflected wave power, control is performed based on a peak value variation in the detection value of reflected wave power. For a long-time variation in reflected wave power, control is performed based on a variation in a smoothed value obtained by smoothing detection values of reflected wave power. A reflected wave power control loop system includes a reflected wave power peak value dropping loop system and an arc blocking system that perform control based on a peak variation in reflected wave power and a reflected wave power amount dropping loop system that performs control based on a smoothed power amount of reflected wave power.

Abstract: When RF power is supplied from an RF generator to a load via a power supply unit, (a) the internal impedance of the RF generator is made lower than the characteristic impedance of the power supply unit, and (b) the load-end voltage is increased by selecting the electrical length LE of the power supply unit, which connects between the RF generator and the load to supply RF power, so that the electrical length LE has a predetermined relation with the fundamental wavelength ? of the RF AC. More specifically, the electrical length LE of the power supply unit is selected in such a way that, when the load end, which is the input end of the load, is in an open state, the electrical length LE is (2n?1)·(?/4)?k·??LE?(2n?1)·(?/4)+k·? (n is an integer, k is {??2·cos?1(1/K)}/(4?)) with respect to the fundamental wavelength ? of the RF AC.

Abstract: When RF power is supplied from an RF generator to a load via a power supply unit, (a) the internal impedance of the RF generator is made lower than the characteristic impedance of the power supply unit, and (b) the load-end voltage is increased by selecting the electrical length LE of the power supply unit, which connects between the RF generator and the load to supply RF power, so that the electrical length LE has a predetermined relation with the fundamental wavelength ? of the RF AC. More specifically, the electrical length LE of the power supply unit is selected in such a way that, when the load end, which is the input end of the load, is in an open state, the electrical length LE is (2n?1)·(?/4)?k·??LE?(2n?1)·(?/4)+k·? (n is an integer, k is {??2·cos?1(1/K)}/(4?)) with respect to the fundamental wavelength ? of the RF AC.

Abstract: In an RF power supply for supplying RF power to a plasma load, reflected wave power control is performed in which the reflected wave power of an RF generator is detected and the RF generator is controlled. For a short-time variation in reflected wave power, control is performed based on a peak value variation in the detection value of reflected wave power. For a long-time variation in reflected wave power, control is performed based on a variation in a smoothed value obtained by smoothing detection values of reflected wave power. A reflected wave power control loop system includes a reflected wave power peak value dropping loop system and an arc blocking system that perform control based on a peak variation in reflected wave power and a reflected wave power amount dropping loop system that performs control based on a smoothed power amount of reflected wave power.