Enhanced silicon etching in nitrogen-containing SF6-O2 plasma

Abstract

The effect of addition of small amounts of nitrogen into SF6-O2 plasma has been studied in terms of atomic fluorine concentration and the silicon etch rate. A factor of seven increase in the atomic fluorine concentration is observed when O2 along with 1% N2 is introduced into the SF6 plasma. With oxygen alone in the feed, the increase was less than a factor of 3. Consequently, an enhanced silicon etch rate is achieved in a SF6-O2-N2 plasma.