Patent ID: 11942307
Assignee: TOKYO ELECTRON LIMITED
Field: Electrical machinery, apparatus, energy (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. A method for plasma processing comprising:
sustaining a plasma in a plasma processing chamber, the plasma processing chamber comprising a first radio frequency (RF) electrode and a second RF electrode, wherein sustaining the plasma comprises:
coupling an RF signal source to the first RF electrode; and
applying a bias signal between the first RF electrode and the second RF electrode, the bias signal having a bipolar DC (B-DC) waveform comprising a plurality of B-DC pulses, each of the B-DC pulses comprising:
a negative bias duration during which the pulse has negative polarity relative to a reference potential,
a positive bias duration during which the pulse has positive polarity relative to the reference potential, and
a neutral bias duration during which the pulse has neutral polarity relative to the reference potential, wherein the bias signal has a B-DC-burst waveform comprising a train of B-DC-burst pulses, wherein each of the B-DC-burst pulses has a plurality of consecutive B-DC pulses that is present during a B-DC-burst duration followed by a B-DC-burst separation time during which there is no bias signal, a sum of the B-DC-burst duration and the B-DC-burst separation time being defined as a burst period.