Defect Formation Behaviors in Heavily Doped Czochralski Silicon

Abstract

To reveal a difference of defect formation behaviors,i.e. grown-in void formation during crystal growth and oxide precipitation in n- and p-type silicon, we have investigated by using heavily boron- and arsenic-doped silicon crystals. The density of void defects in heavily boron doped silicon was decreased with a shrinking OSF-ring, but in arsenic doped silicon were increased with resistivities below 3.3mΩcm. On the other hand, for oxygen precipitation, the nucleation rate in boron doped silicon was enhanced with increasing resistivities, while decreased by one tenth in reference to lightly doped silicon for resistivities up to 4.4mΩcm in arsenic doped silicon. These contrastive phenomena between n- and p-type cannot be explained with a growth model of precipitates by an accelerated diffusion of oxygen in silicon. We believed that the nucleation rate of oxide precipitates related to a dependence of point defects on fermi level closely.