Preoxidation treatment using HCl/HF vapor

Replacement of the conventional two-step sequence of aqueous HF dummy oxide strip and wet clean by a one-step vapor phase HCl/HF/H/sub 2/O strip was investigated. Results indicated improvements in the electrical endurance of grown silicon dioxide and that the vapor mixture containing HCl was effective in reducing the detrimental effects caused by deliberately introduced contaminants. Compared with the conventional wet cleans, a 20% improvement in oxide lifetime was observed. Further improvements should be possible with proper optimization of the quantative composition or the constituents of the vapor.<>