Point and Swirl Defects in Silicon

Abstract

In the previous paper [Jpn. J. Appl. Phys. 32 (1993) L856], vacancy and silicon self-interstitial thermal equilibrium concentrations, i.e., C V0= 2.1×1017 cm-3 and C I0= 3.4×1016 cm-3, were determined at 1100°C from an analysis of experimental data of P and Sb diffusions in silicon during thermal oxidation. From the relationship between these values and the Boltzmann factor, C V0 and C I0 are obtained as functions of the absolute temperature, T. Vacancy and self-interstitial diffusivities, D V and D I, are also given as functions of T by using the equation of D VC V0 or D IC I0 derived from Au diffusion experiments in silicon. Furthermore, the silicon self-diffusion mechanism is discussed and a successful model on the swirl defect formation mechanism is also proposed, using the obtained C V0, C I0, D V and D I. Consequently, C I0<C V0 and D V<D I relations hold for arbitrary T. That is, the dominant thermal equilibrium defects in silicon are vacancies. It was also found that self-diffusion is mainly governed by the interstitialcy or vacancy mechanism for T>1158 K or T≤1158 K.