Plasma processing apparatus and plasma processing method

摘要

A plasma processing apparatus includes a plasma-generation high-frequency power supply which generates plasma in a processing chamber, a biasing high-frequency power supply which applies high-frequency bias electric power to an electrode on which a sample is placed, a monitor which monitors a peak-to-peak value of the high-frequency bias electric power applied to the electrode, an electrostatic chuck power supply which makes the electrode electrostatically attract the sample, a self-bias voltage calculating unit which calculates self-bias voltage of the sample by monitoring the peak-to-peak value of the high-frequency bias electric power applied to the electrode, and an output voltage control unit which controls output voltage of the electrostatic chuck power supply based on the calculated self-bias voltage.

主权项

1. A plasma processing apparatus comprising:
a processing chamber in which a sample is processed by plasma generated therein; a first radio-frequency power supply which supplies a first radio-frequency electric power for generating the plasma in the processing chamber; a second radio-frequency power supply which applies a second radio-frequency bias electric power to a stage on which the sample is placed; a monitor which monitors a peak-to-peak value of the second radio-frequency bias electric power applied to the stage; an electrostatic chuck power supply which makes an electrode disposed inside the stage electrostatically attract the sample; a self-bias voltage calculating unit which calculates self-bias voltage of the sample by monitoring the peak-to-peak value of the ratio-frequency bias-electric power applied to the electrode; and an output voltage control unit which is configured to control output voltage of the electrostatic chuck power supply based on the calculated self-bias voltage, wherein the output voltage control unit is configured to set the output voltage of the electrostatic chuck power supply unit at a first negative value during an initial period of generating plasma which is from after plasma ignition until a plasma potential becomes stable, and thereafter set the output voltage at a second negative value for processing of the sample which is greater than both of a self-bias voltage of the sample and the first negative value, the second negative value being determined based upon an output from the monitor.