Patent ID: 11887817
Assignee: TOKYO ELECTRON LIMITED
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. A plasma processing apparatus comprising:
a chamber;
a substrate support having an electrode and configured to support a substrate in the chamber; and
a DC power source system electrically connected to the electrode and configured to apply a bias voltage to the electrode to draw ions from a plasma in the chamber into the substrate on the substrate support,
wherein the power source system is configured to periodically output a first pulse to the electrode at a frequency of 100 kHz or more and 1 MHz or less in a first period and periodically output a second pulse to the electrode at a frequency of 100 kHz or more and 1 MHz or less in a second period after the first period, as the bias voltage,
each of the first pulse and the second pulse is a pulse of a negative voltage, and
a voltage level of the first pulse is different from a voltage level of the second pulse,
wherein
a controller is configured to control the power source system to output a single pulse of a positive voltage to the electrode before start of the first period within a subsequent cycle of two cycles, each of which includes the first period and the second period.