Stability of HF-etched Si(100) surfaces in oxygen ambient

In situ multiple internal reflection infrared absorption spectroscopy of H-passivated silicon surfaces in controlled oxygen environments reveals that direct oxygen incorporation into the surface Si–Si bonds occurs without surface hydrogen removal, in the temperature range of 550–590 K for 1–20 mTorr O2 pressures. The kinetics of the O2 insertion process display overall effective activation energies of 1.6 to 1.7 eV and prefactors controlled primarily by Si–H steric hindrance for O2 to access Si–Si backbonds.