Diffusivity of oxygen in silicon during steam oxidation

Abstract

The diffusivity of oxygen in silicon during steam oxidation at 700–1240 °C was measured on as-oxidized Si wafers. To provide greater analytical sensitivity 18O was introduced into the float-zone Si wafers from 1-atm H2 18O steam, and the 18O depth profiles were measured by Cs+ secondary ion mass spectrometry. Over the entire temperature range studied, the diffusivity is governed by a single activation energy, 2.44 eV, and the prefactor is 7×10−2 cm2 s−1. Our results are compared with previous literature values measured only at high temperature.