Investigation of the initial stages of oxidation of microcrystalline silicon by means of X-ray photoelectron spectroscopy

XPS Si2p spectra of microcrystalline silicon (μc-Si), prepared by plasma chemical transport are reported and the initial stages of oxidation are studied: In comparison with single crystal Si(111) surfaces, μc-Si samples are remarkable resistant to surface oxidation. A short exposure to air results in negligible oxygen adsorption (intensity ratio of 01s to Si2p peaks is less than 0.018 after more than3 × 10¹¹ Langmuirs exposure to air). Intensive oxidation treatment is required to produce an oxide layer and evidence supporting a preferential grain boundary oxidation mechanism is presented. The surface plasmon structure observed in the Si2p spectrum provides complementary information on the remarkably low oxidation rate of the crystallite surfaces as compared to the grain boundaries.