Etching characteristics of Si and SiO 2 with a low energy argon/hydrogen d.c. plasma source

Abstract

The effect of a low energy argon/hydrogen arc discharge on the etch rate of silicon and silicon dioxide is investigated with respect to ultrahigh vacuum (UHV) wafer cleaning. At room temperature, the reaction speed depends on the partial pressure of the H radicals and the discharge current. Furthermore, the etch rates show Arrhenius dependence versus substrate temperature with negative activation energies of −1.7 kcal mol −1 and −0.7 kcal mol −1 for Si and SiO 2, respectively. The process window to operate the plasma source is very large, thereby showing a high grade of reliability for standard wafer cleaning under UHV conditions.