Properties of silicon nanoparticles embedded in SiNx deposited by microwave-PECVD

In this work, silicon-rich silicon nitride (SRN) layers were deposited on a silicon wafer by microwave-assisted plasma-enhanced chemical vapor deposition (MW-PECVD) using NH3 and SiH4 as precursor gases. The Si excess in the as-deposited layers as determined by the Rutherford backscattering technique was controlled by varying the precursor gas ratio. We were able to produce silicon nanoparticles (Si-nps) in the silicon nitride (SiNx) layers upon thermal annealing at high temperature. Energy-filtered TEM (EFTEM), complemented by photoluminescence measurements, were used to identify the experimental parameters in order to reach a high density of well-separated Si-nps (3 nm). Our results show that the MW-PECVD method is a suitable deposition tool for the formation of Si-nps in thin SRN layers.