Plasma Processing Apparatus and Plasma Processing Method

A plasma processing apparatus comprising:

• a processing chamber which plasma-processes a sample;
• a first high-frequency power supply which supplies first high-frequency power at a first high-frequency for plasma generation to the processing chamber;
• a second high-frequency power supply which supplies second high-frequency power at a second high-frequency to a sample stage on which the sample is placed;
• and
• a pulse generation device, including a control device, which generates a first pulse to modulate the first high-frequency power and a second pulse to modulate the second high-frequency power,
• wherein the control device is configured to control a frequency of repetition of the first pulse and a frequency of repetition of the second pulse so that the frequency of repetition of the first pulse is higher than the frequency of repetition of the second pulse, and
• wherein the on-period of the second pulse coincides with, or is contained within, the on-period of the first pulse.

A plasma processing method, comprising:

• providing, by a first high-frequency power supply, a first high-frequency power at a first high-frequency to a processing chamber for plasma generation;
• providing, by a second high-frequency power supply, a second high-frequency power at a second high-frequency to a sample stage;
• generating, by a pulse generation device, a first pulse to modulate the first high-frequency power and a second pulse to modulate the second high-frequency power, a frequency of repetition of the first pulse being higher than a frequency of repetition of the second pulse;
• modulating the first high-frequency power using the first pulse;
• modulating the second high-frequency power using the second pulse;
• and
• while the modulated second high-frequency power is being provided to the sample stage, processing a sample using plasma generated by the modulated first high-frequency power,
• wherein the on-period of the second pulse coincides with, or is contained within, the on-period of the first pulse.