The Structure and Composition of Silicon Oxides Grown in HCl / O 2 Ambients

Abstract

The structure and composition of silicon oxides thermally grown in ambients were investigated for various oxidation conditions. Oxides were grown in at 1150°–1300°C for times of 15 min–6 hr. Transmission electron microscopy in conjunction with x‐ray microanalysis has indicated the presence of an additional condensed phase at the oxide‐silicon interface, which appears after a certain oxidation time has elapsed. Scanning electron microscopy has shown that after further oxidation, a gaseous compound accumulates at the interface, lifting the oxide from the silicon, and preferentially etching the silicon. A model of the growth mechanisms of oxides, accounting for the additional phase formation, is proposed.