Density Profile of Thermal Oxide Thin Films on Si(100)

Abstract

We investigated the density profile of thermally grown SiO2 thin films on a Si(100) using X-ray reflectivity. Samples were grown at 750 and 1000 °C with a slow ramp process and at 1000 and 1100 °C with a rapid thermal process. A SiO2 thin film was reconfirmed to have a two-layer structure: a dense transition layer of about 1 nm and an overlayer. The density profile was affected by the ramp rate and the growth temperature. The SR samples had some complicated features in the overlayer such as an inversion accompanying a density jump at 750 °C or a dense part near the transition layer at 1000 °C. The transition layer maintained a constant density from 750 to 1000 °C. The RTP samples showed a simple two-layer structure with a smaller density than the SR ones. The density was classified into four discrete groups according to its value.