POWER SUPPLY DEVICE AND METHOD FOR PLASMA GENERATION

摘要

A power supply device includes: an oscillation unit for outputting a high frequency signal; a modulation unit for outputting a pulsed high frequency signal; a level adjustment unit for adjusting and outputting a level of the pulsed high frequency signal; a power amplifier for amplifying a power outputted from the level adjustment unit; an output power detection unit for detecting an output power value from the power amplifier; and a control unit. The control unit corrects and outputs a level control signal for controlling the level of the pulsed high frequency signal based on a corresponding correction factor at each of elapsed times in an on state of the pulsed high frequency signal, and compares comparison values in a current pulse and a previous pulse to update the correction factor such that comparison result between the set power value and the output power value becomes smaller at each reflection coefficient.

主权项

1. A power supply device for plasma generation using a pulse modulation system which supplies a pulsed high frequency power to a plasma generation unit for generating plasma provided outside, the power supply device comprising:
an oscillation unit configured to output a high frequency signal of a predetermined frequency; a modulation unit configured to modulate the high frequency signal outputted from the oscillation unit to a pulse shape in which on and off states are repeated and output the modulated high frequency signal as a pulsed high frequency signal; a level adjustment unit configured to adjust a level of the pulsed high frequency signal outputted from the modulation unit and output the level-adjusted pulsed high frequency signal; a power amplifier configured to amplify a power of the pulsed high frequency signal outputted from the level adjustment unit and output a pulsed high frequency power; an output power detection unit configured to detect an output power value of the pulsed high frequency power outputted from the power amplifier; a storage unit that stores a plurality of elapsed times in an on-state of the pulsed high frequency signal outputted from the modulation unit, a plurality of correction factors respectively corresponding to the elapsed times, and a set power value that is previously set as a value of an output power; and a control unit configured to receive the output power value detected by the output power detection unit, and output to the level adjustment unit a level control signal for controlling the level of the pulsed high frequency signal adjusted in the level adjustment unit based on the received output power value and the set power value, wherein the control unit corrects and outputs the level control signal at each of the elapsed times based on the correction factors respectively corresponding to the elapsed times, and compares a comparison value in a current pulse with a comparison value in a previous pulse to update the correction factors such that a comparison result between the set power value and the output power value becomes smaller at each reflection coefficient.