SiO2-Si interface formation by catalytic oxidation using alkali metals and removal of the catalyst species

We studied the catalytic action of adsorbed cesium or sodium on the oxidation of Si(100)2×1 by core-level photoemission using synchrotron radiation. At room temperature, a large enhancement of the silicon oxidation rate was observed with formation of high oxidation states. By moderate thermal annealing, we were able to remove the catalyst species from the surface and to form a clean SiO2-Si interface at lower temperatures than with other processes.