Patent ID: 8382999
Filing Date: 2013-02-26
Classification: H01J,H01L

Abstract:
1. A method of processing a workpiece supported on a workpiece support facing a ceiling in a reactor chamber, comprising: introducing into the chamber a polymerizing etch gas, an electronegative gas and an oxidizer gas; applying source power in the VHF range to the ceiling and applying bias power in the HF or MF range to the wafer support; pulsing said source power and pulsing said bias power, while establishing a phase lag between source and bias power pulses; applying a positive D.C. pulse to the workpiece support and/or a negative D.C. pulse to the ceiling during the pulse off time of the source power; adjusting an average accumulation of electric charge on the workpiece by adjusting the voltage of the D.C. pulse; adjusting the etch rate by adjusting the phase lag between the pulses of the source and bias power; adjusting etch rate distribution between center-high and edge-high by adjusting the pulse duty cycles of the VHF source power and of the RF bias power relative to one another, said adjusting etch rate distribution comprising at least one of: