Oxidation, Impurity Diffusion, and Defect Growth in Silicon—An Overview

As a result of a large body of literature on oxidation, impurity diffusion, and defect growth in silicon, a consistent picture has emerged of oxidation-enhanced diffusion (OED) and oxidation-induced, stacking fault growth (OISF). It is believed that silicon self-interstitials can be generated at an oxidizing Si/SiO2 interface as a result of an incomplete half-cell reaction involving silicon and oxygen. Those interstitials that do not participate in surface regrowth participate in raising the steady-state concentration of self-interstitials in the surface region. OED can be explained in terms of a partial interstitialcy mechanism involving the surface-generated self-interstitials. The growth of OISF will occur if the relative steady-state self-interstitial concentration around the fault exceeds the emitted concentration of interstitials from the fault line. It is shown that this model predicts that OISF growth is limited by the production rate of self-interstitials at the Si/SiO2 interface. The retrogrowth of OISF and the reduction of OED both occur when the concentration of generated self-interstitials decreases. The introduction of chlorine-bearing compounds into the oxidation tube can also cause retrogrowth. The reaction of chlorine with silicon at the interface creates vacancies which can recombine with generated self-interstitials and reduce their concentration. Calculations show that the chlorine compound formed at the interface is SiCl. © 1981, The Electrochemical Society, Inc. All rights reserved.

Duke Scholars

Author Richard B. Fair Electrical and Computer Engineering