Far-Ultraviolet Laser-Induced Oxidation at the Si(111) Surface by Bond Rearrangement

Abstract

The chemical structure of Si(111) exposed to a low coverage of oxygen has been investigated via Auger-electron spectroscopy. We have shown that the irradiation of an adsorbed monolayer of oxygen, by a weak laser beam at $\lambda =248\mathrm{}$ nm, induces important bond rearrangements at the Si(111) surface. This results in a disorderly structured monolayer of oxide, which relaxes into stable $a$-Si${\mathrm{O}}_2$ when heated up to $T_c\sim 949$ K.