The Effects of Deposition and Processing Parameters on the Electronic Structure and Photoluminescence from Nitride-Passivated Silicon Nanoclusters

Silicon nanoclusters (Si-ncs) embedded in silicon nitride films have been studied to determine the effect that deposition and processing parameters have on their growth, luminescent properties, and electronic structure. Luminescence was observed from Si-ncs formed in silicon-rich silicon nitride films with a broad range of compositions and grown using three different chemical vapour deposition (CVD) based systems: plasma-enhanced CVD (PECVD), inductively coupled plasma CVD (ICP CVD), and electron cyclotron resonance PECVD (ECR PECVD). Photoluminescence experiments revealed broad, tunable emissions with peaks ranging from the near-infrared across the full visible spectrum. The emission energy was highly dependent on the film composition and changed only slightly with annealing, which primarily affected the emission intensity. X-ray absorption spectra at the Si K- and L3,2-edges exhibited composition dependent phase separation and structural re-ordering of the Si-ncs and silicon nitride host matrix under different post-deposition annealing conditions.