Role of point defects in the growth of the oxidation-induced stacking faults in silicon. II. Retrogrowth, effect of HCl oxidation and orientation

A new mechanism, describing the growth of the oxidation-induced stacking faults (OISF) in silicon was described earlier. The length of the fault was given by the equation $L=k^{\prime }{p}_{{\mathrm{O}}_2}^m{t}^n\exp (-\frac{Q}{\mathrm{kT}})$. In this paper, two new concepts are introduced which, without changing the basic formulation of the above mechanism, account for the observed temperature dependence of $m$ and $n$ and for the effect of chlorinecontaining oxidizing ambients on the fault growth. (a) It is postulated that, in addition to the $p_{\mathrm{O}2}$ dependence, the concentration of the interstitial silicon $\left[{\mathrm{Si}}_I\right]$, generated in silicon at the Si${\mathrm{O}}_2$-Si interface, decreases with the increasing rate at which the Si${\mathrm{O}}_2$-Si interface moves in the silicon. It is then assumed that $\left[{\mathrm{Si}}_I\right]\propto {\left(\mathrm{oxidation}\mathrm{rate}\right)}^{-q}$. $q$ is a number which is found to be related to the difference between the parabolic oxidation-rate constant and the self-diffusion coefficient of silicon. Incorporation of this concept leads to the equation of the length of the OISF which is similar to above equation but which predicts temperature-dependent $m$ and $n$. In addition, a retrogrowth phenomenon is postulated to occur when $q$ changes from being positive to negative. Negative $q$ values lead to very small values for $k^{\prime }$. (b) In the presence of chlorine-containing species, the interstitial silicon concentration decreases either due to direct consumption of the interstitial or due to generation of vacancies at the Si${\mathrm{O}}_2$-Si interface. In either case, a SiCl complex is formed, leading to a reduced OISF growth rate (or shrinkage of existing faults) or to a nogrowth condition. A comparison with the available data leads to the conclusion that, for the reduced-growth conditions in HCl-${\mathrm{O}}_2$ ambients, $L\propto p_{\mathrm{HCl}}^{-\frac{3}{8}}$, and that one silicon atom complexes with two chlorine atoms. Finally, the orientation dependence of the OISF growth is also discussed.