In Situ Removal of Native Oxides from Silicon Surfaces Using Anhydrous Hydrogen Fluoride Gas

摘要

An in situ, anhydrous hydrogen fluoride (AHF)-based native oxide removal technique is developed, in which the wafer is subjected to AHF at low temperatures for a few minutes and/or followed by a hydrogen spike at high temperature immediately prior to polysilicon deposition. Auger electron spectroscopy analysis shows that this process sequence is able to remove native oxides grown by standard wet cleans such as hydrochloric acid/hydrogen peroxide solution and hydrofluoric acid solution. No moisture is used in this study.