Pulsed bias plasma process to control microloading

摘要

A method for etching a conductive layer through a mask with wider and narrower features is provided. A steady state etch gas is flowed. A steady state RF power is provided to form a plasma from the etch gas. A pulsed bias voltage is provided during the steady state etch gas flow, wherein the pulsed bias voltage has a frequency between 1 to 10,000 Hz. Wider and narrower features are etched into the conductive layer using the plasma formed from the etch gas.