Silicon Oxidation Studies: Measurement of the Diffusion of Oxidant in SiO2 Films

Abstract

A method for the measurement of the diffusion of oxidant through a growing film is presented. The procedure is based on so‐called lag‐time diffusion methods in which the time to achieve steady‐state oxidation is measured using in situ ellipsometry. Two different modes of oxidant transport were observed over the range of temperatures investigated (600°–1000°C). At temperatures of 900°C and below, no lag‐time was observed, and steady‐state oxidation was seen at the outset of oxidation. At 1000°C, a lag‐time was measured which yielded a value for the diffusion constant, for dry , and this value increased to for 1000 ppm in . This study provides clear evidence for different dominant modes of oxidation at higher and lower oxidation temperatures.