Removal of post etch residuals on wafer surface

Abstract

The present invention provides a method of plasma chamber etching of a semiconductor structure having a base layer, an etch stop layer, a dielectric material layer and a patterned photoresist layer. Among other things, the method may include etching selected portions of the dielectric material layer through the photoresist layer using a plasma etchant containing at least one of fluorine and sulfur in a compound such that portions of the photoresist layer may be contaminated with ions of the at least one of the fluorine and sulfur. The method may further include the steps of exhausting the etchant from the plasma chamber, introducing an oxygen containing gas into the plasma chamber, energizing the plasma reactor to create at least oxygen ions for bombarding the photoresist surface to remove at least a portion of the photoresist containing a majority of the contaminating one of the fluorine and sulfur ions whereby the fluorine and sulfur ions combine with other ions in the oxygen containing gas during at least exhaustion of the gas from the chamber, and removing the semiconductor structure containing a remaining portion of the photoresist from the plasma chamber.