Patent ID: 9305803
Filing Date: 2016-04-05
CPC Classification: H01J,H01L

Claim Text:
1. A plasma processing apparatus, comprising: a vacuum vessel in which a sample is plasma treated; a first radio-frequency power supply supplying a first radio frequency power to generate a plasma in the vacuum vessel; a sample stage installed in the vacuum vessel and mounted with the sample; a second radio-frequency power supply supplying a second radio-frequency power to the sample stage; and a D/A converter converting a digital signal into an analog signal, a control unit configured to convert a first digital value which is a value within a first frequency band in a set repetition frequency of a pulse for time-modulating the second radio-frequency power to a first analog value and a second digital value which is a value within a second frequency band wider than the first frequency band in the repetition frequency to a second analog value by the D/A converter; wherein the second radio-frequency power supply includes an A/D converter converting the first analog value and the second analog value transmitted by the control unit to the first digital value and the second digital value each; a signal processing unit configured to select the first digital signal converted by the A/D converter or the second digital value converted by the A/D converter based on a signal received at the A/D converter; and a pulse generator generating pulses having a repetition frequency corresponding to the first digital value or the second digital value selected by the signal processing unit.