Model of Si–SiO2 interfaces based on ARXPS measurements

Abstract

Angle-resolved x-ray photoelectron spectroscopy (ARXPS) results in a very detailed analysis of minor amounts (≥0.3 nm) of interface compounds and their spatial distribution. First experimental results on the Si–SiO2 interface used in microelectronics, are presented. The ARXPS results on plane, single crystalline (100) Si, oxidized to about 5 nm SiO2, indicate a planar Si surface connected by about one monolayer Si∗ to a compressed SiO∗2 layer coated by SiO2. Separated from this interface region, Si clusters stabilized by a compressing SiO∗2 coating have been found in SiO2. Dehydrogenation is showing up in binding energy changes in SiO2 indicating that H or OH is not only saturating Si∗ but is also bonded to SiO2. The O deficiency of amorphous SiO2,x is increasing toward the outer SiO2 surface.