The creation of a buried collector layer, by As diffusion from oxidized As-implanted amorphous Si, and the effect of solid-phase epitaxial layer formation upon the quality of the As-diffused buried collector, were clarified. In order to break up the native oxide and to grow the solid-phase epitaxial layer at the interface, As pile-up during the oxidation of As-implanted chemical vapor deposited Si was necessary. The crystallinity of a buried layer which was formed by As diffusion from oxidized As-implanted amorphous Si, was greater than that which was formed from oxidized As-implanted polysilicon.

Y.Tsunoda: Japanese Journal of Applied Physics, 1990, 29[10], L1926-8