SEMICONDUCTOR DEVICE HAVING A SPACER LAYER DOPED WITH SLOWER DIFFUSING ATOMS THAN SUBSTRATE

摘要

A semiconductor device includes a silicon substrate heavily-doped with phosphorous. A spacer layer is disposed over the substrate and is doped with, dopant atoms having a diffusion coefficient in the spacer layer material that is less than the diffusion coefficient of phosphorous in silicon. An epitaxial layer is also disposed over the substrate. A device layer is disposed over the substrate, and over the epitaxial and spacer layers.