Effects of dry etching on the electrical properties of silicon

Abstract

Dry etching results in the permeation of silicon by etching species; it also results in the better understood residue layer formation and near-surface lattice damage layer formation. The principal species permeating silicon during dry etching exposures is found to be hydrogen. Using doping deactivation as a marker, we study this permeation and show that hydrogen can permeate as much as 10 μ during etching, thereby modifying the electrical properties of Si to that depth. We further demonstrate that this hydrogen permeation, at least in the case of p material, exhibits two distinct regions of behavior and two apparent diffusion coefficients. It is also shown that the doping deactivation anneals out differently in these two permeation regions.