Point defects and diffusion mechanisms in crystalline semiconductors

Abstract

Although point defects are involved in the diffusion processes applied in the fabrication of semiconductor devices, the knowledge on the nature of these point defects as well as on the detailed atomistic diffusion mechanisms is rather limited for most semiconductors. After describing basic concepts of point defects and diffusion mechanisms this article mainly deals with silicon, because considerable progress has been made in understanding point defects and diffusion mechanisms in this material. Experimental results on oxidation-influenced diffusion and the diffusion of gold in silicon are described, which have led to the conclusion that both self-interstitials and vacancies contribute to self-diffusion and most impurity diffusion processes in silicon. As an example of diffusion in III–V compounds the diffusion of Zn in GaAs is discussed in terms of gallium interstitials.