Hydrogen Assisted Remote Plasma Enhanced Chemical Vapor Deposition of Amorphous Silicon Nitride Films

Abstract

AbstractWe show that in the RPECVD process the addition of a small upstream flow of H2 gas, combined with the He injected into the plasma region of the reactor, promotes chemical exchange between H and D when the material was deposited from deuterated Silane and ammonia and densifies the a- Si:N:H network. We have deposited hydrogenated stoichiometric nitrides with and without H2 injected into the plasma region. For small H2 flows, the deuterated samples show Fourier transform infrared (FTIR) N-D and N-H stretching and bending modes that interchange their populations, as the total bonded hydrogen content in the films remain constant. The hydrogen assisted grown films show, for small H2 flows, a constant amount of bonded-H, an optical index of refraction n=1.85, and reduced etch rate.