Plasma processing apparatus and method for generating plasma

An apparatus for plasma processing comprising:

• a chamber;
• a radio-frequency power supply configured to output a pulsed radio-frequency power or a combined radio-frequency power in order to generate plasma from a gas in the chamber, wherein the combined radio-frequency power is a combined power of the pulsed radio-frequency power with a correction radio-frequency power that oscillates in a reverse phase with respect to a reflected wave of the pulsed radio-frequency power;
• and
• a correction signal generator configured to generate a correction signal that oscillates in a reverse phase with respect to a reflected wave monitor signal representing the reflected wave of the pulsed radio-frequency power,
• wherein the radio-frequency power supply is configured to output the pulsed radio-frequency power in a first period,
• the correction signal generator is configured to generate the correction signal from the reflected wave monitor signal in the first period, and
• the radio-frequency power supply is configured to output the combined radio-frequency power generated using the correction signal in each of one or more second periods after the first period, and alternately repeat output of the pulsed radio-frequency power in the first period and output of the combined radio-frequency power in the one or more second periods.