Development of a Integrated Dry/Wet Hybrid Cleaning System

Abstract

With scaling of ULSI devices, the process temperatures are continuously lowered. The oxide films, which were deposited at low temperature, show fast etching rates during wet etching compared to high temperature films. Also, the etch rates differ largely from other film deposition conditions. In order to overcome these etch rate differences during surface preparation, dry cleaning processes had been introduced where the etch selectivity of the soft oxide films to the thermal oxide are very similar, regardless of the film deposition conditions and the deposition temperature.