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

Claim 12:
13. A plasma processing method comprising:
preparing a substrate on a substrate support provided in a chamber of a plasma processing apparatus, wherein the substrate support includes an electrode;
periodically outputting a first pulse from a DC power source system to the electrode at a frequency of 100 kHz or more and 1 MHz or less in a first period as a bias voltage to draw ions from plasma in the chamber into the substrate; and
periodically outputting a second pulse as the bias voltage from the power source system to the electrode at a frequency of 100 kHz or more and 1 MHz or less in a second period,
wherein 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, and
wherein the plasma processing method further comprises outputting 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.