Dependence of the photoemission of amorphous silicon nitride thin films on their composition

Hydrogenated amorphous silicon nitrides (a-Si1−xNx:H) have been obtained by plasma enhanced chemical vapour deposition onto 6″ silicon(100) wafers with different plasma parameters. These samples possess similar amounts of nitrogen and hydrogen with a different distribution of the latter between SiH and NH bonds into the amorphous network. A study of the photoluminescence spectra shows that this different distribution leads to a dramatic change in the sample luminescence features regarding widths and positions. These findings are discussed in terms of the different mechanisms in the dangling bond saturation due to the hydrogen bonding to the thin film structure.