CHARACTERIZATION OF EPITAXIAL LAYERS BY THE DEPTH DEPENDENCE OF BORON DIFFUSIVITY

Differences in boron diffusivity have been used to characterize epitaxially grown silicon layers. After oxidation-enhanced diffusion of boron spikes, a decrease in boron diffusivity with increasing depth is observed in epitaxial silicon layers grown by molecular beam epitaxy and fast gas switching vapor deposition, in contrast to layers grown by low-temperature chemical vapor deposition. The reduced boron diffusivity is thought to be caused by an oversaturation of vacancy defects, acting as interstitial traps, suppressing the diffusion of boron.