Patent ID: 8822345

Claim:
A method of controlling plasma etching, comprising: heating a showerhead electrode in a plasma etching chamber at a temperature of at least 80° C.; supplying process gas comprising a fluorocarbon and/or hydrofluorocarbon gas to a plasma etching chamber through the showerhead electrode, the process gas flowing into a gap between the showerhead electrode and a bottom electrode on which a semiconductor substrate is supported; and etching the semiconductor substrate in the plasma etching chamber by applying RF power to the showerhead electrode and energizing the process gas into a plasma state, wherein the heating of the showerhead electrode reduces striations on a photoresist on the semiconductor substrate by controlling fluorine radical density in the process gas; the RF power and the process gas are supplied to the showerhead electrode by a gas distribution member electrically isolated from other parts of the plasma etching chamber; and supplying gas comprises supplying gas from the gas distribution member to one or more plenums at the backside of the showerhead electrode.