Influence of Deposition Conditions on Silicon Nanoclusters in Silicon Nitride Films Grown by Laser-Assisted CVD Method

Crystalline-silicon-nanocluster-embedded silicon nitride films were deposited at low temperature using a laser-assisted CVD (LACVD) system with various reactant gas flow rates and assisting laser power densities. The photoluminescence (PL) performances of the resultant films were studied, showing a systematic spectra blue shift, and the enhancement of PL intensity with the increase of the reactant NH
₃
/SiH
₄
gas flow rate ratio and the assisting laser power density used in the film deposition. The spectra blue shift can be ascribed to the decrease of the size of the nanoclusters in the films. It is also deduced that both the reduction of the amount of nonradiative centers in the nanoclusters and the increase of the number density of the nanoclusters in the film are responsible for the enhancement of the PL intensity. The film growth process is also briefly discussed.