Doping effects in off-stoichiometric glow discharge amorphous silicon nitride

Abstract

The effects of boron and phosphorus doping on the electrical properties of a‐SiN_x:H films are studied. The material is obtained by the glow discharge of SiH₄ and N₂ mixtures. It is found that for Si‐rich materials boron doping produces large conductivity variations while phosphorus appears to be a much less efficient dopant. A phenomenological explanation is given assuming that phosphorus prefers to form bonds in accordance with its own valence configuration; i.e., it will go substitutionally to threefold coordinated N sites. Experimental evidence of such behavior obtained from published IR transmission measurements confirms this assumption.