Fluorocarbon high density plasma. VI. Reactive ion etching lag model for contact hole silicon dioxide etching in an electron cyclotron resonance plasma

Abstract

Etching of high aspect ratio patterns induces reactive ion etching (RIE) lag. This effect is studied for oxide features etched in a high density plasma excited by electron cyclotron resonance using different fluorocarbon gases. A new RIE lag model is proposed which depends on the assumption that the oxide etch rate is, as on a blanket sample, strongly influenced by the deposition of fluorocarbon film on the oxide surface during the etching process.