Spectroscopic Study of Radiofrequency Oxygen Plasma Stripping of Negative Photoresists. II. Visible Spectrum

Abstract

The rf O₂ plasma-induced stripping of negative photoresists from semiconductor surfaces has been detected and monitored using the optical emission from electronically excited CO product molecules at 483.5 and 519.8 nm. The active species producing the stripping has been identified as electronically excited oxygen atoms. The end point of the stripping process is easily identified as is the final cleanup of the semiconductor surface. The dependence of the stripping time as a function of flow rate and oxygen pressure has also been determined.