THERMAL-DECOMPOSITION OF NATIVE-OXIDE ON SI(100)

We investigated the thermal decomposition of native oxide on Si(100) u nder ultrahigh vacuum using high-resolution x-ray photoelectron spectr oscopy (XPS). The native oxide was formed by wet chemical treatment (H Cl/H2O2/H2O), a widely employed procedure for preparing atomically cle an surfaces. XPS measurements revealed that high temperature heating ( > 700-degrees-C) leads to a remarkable alteration in Si 2p and O 1s sp ectra. After heating to 700-degrees-C, the Si3+ structure increases an d the O 1s full-width-at-half-maximum decreases. After heating to 800- degrees-C, the Si4+ and O 1s intensity decreases but the Si2+ intensit y remains almost unchanged. We suggest that the formation of volatile SiO is related to the Si3+ Structure produced by high temperature anne aling.