Gap States at the Interface of Ultra-Thin Oxide and Organic Films on Si(100)

摘要

The formation of gap states during the initial oxidation of Si(100)-2xl and the adsorption of maleic anhydride on Si(100)-2xl at room temperature have been followed with photoluminescence measurements and high resolution electron energy loss spectroscopy. We observe that gap states are already induced after the adsorption of 0.002 L of molecular oxygen on Si(100)-2xl. Prolonged exposures to molecular oxygen results in a marked increase of the gap state density. In contrast, repeated cycles of water adsorption and heating to 530°C leads to a thicker oxide film, which exhibits a reduced gap state density. The adsorption of the unsaturated organic molecule maleic anhydride on Si(100)-2xl does not induce the formation of gap states.