Structural-phase transformations in SiOx films in the course of vacuum heat treatment

Abstract

A thermally stimulated structural transformation of the Si-O phase in the SiO x layers, which leads to the formation of Si nanoinclusions, was investigated using gravimetry, infrared spectroscopy, multiple-angle ellipsometry, and atomic-force microscopy. It is demonstrated that vacuum heat treatment leads to an increase in the concentration of O bridges in the structural network of oxide. Oxide is compacted, and its surface roughness is smoothened. Silicon and SiO 2 phases are precipitated due to the transfer of O atoms from lightly oxidized molecular clusters (SiOSi 3 ) to heavily oxidized ones (SiO 3 Si). An analysis of ellipsometry data in the context of the effective medium model made it possible to estimate the fractions of the precipitated Si and SiO 2 phases.