Characterization and depth profiles measurements of silicon nitride thin films on silicon and molybdenum substrates by Auger electron spectroscopy

Abstract

Silicon nitride thin films were deposited on Si or Mo substrates using a technique of plasma enhanced chemical vapor deposition (PECVD). Depth profiles measurements were carried out on these Si 3N 4 layers, as well as on the Si 3N 4/Mo and Si 3N 4/Si interlayer by Auger electron spectroscopy, associated with Argon ion sputtering. For the Si 3N 4 films deposited on Mo substrates a sequence of three distinguishable zones were observed: the Si 3N 4 layer; an interlayer containing Si–N, Mo–N, and presumably Mo–Si bonds, a diffusion zone of nitrogen into the Mo substrate. On the Si substrate a more usual depth profile was evidenced involving the sequence of the Si 3N 4 layer, an interlayer zone with the presence of Si–N and Si–Si bonds, and finally the Si substrate.