Patent ID: 7932181
Filing Date: 2011-04-26
Classification: H01J,H01L

Abstract:
1. A method of etching a semiconductor substrate with improved critical dimension uniformity comprising: supporting a semiconductor substrate on a substrate support in an inductively coupled plasma etch chamber; supplying a first etch gas comprising a silicon containing gas to a central region over the semiconductor substrate; supplying a second gas comprising at least one silicon containing gas to a peripheral region over the semiconductor substrate surrounding the central region, wherein a concentration of silicon in the second gas is greater than a concentration of silicon in the first etch gas; adjusting an amount of silicon in the first etch gas relative to an amount of silicon in the second gas; generating a plasma from the first etch gas and second gas by inductively coupling radio frequency energy into the chamber; and plasma etching an exposed surface of the semiconductor substrate with the plasma; at least one passivating species comprising silicon passivates sidewalls of features etched into the semiconductor substrate; and the first etch gas comprises chlorine and the passivating species comprising silicon comprises SiCl