Structural and Optical Properties of Luminescent Silicon Carbonitride Thin Films

The composition, structure, and optical characteristics of amorphous hydrogenated silicon carbonitride (a-SiCN:H) thin films were investigated as a function of nitrogen content. The electron cyclotron resonance plasma enhanced chemical vapor deposition (ECR PECVD) technique was utilized to fabricate two different types of a-SiCN:H thin films including films with varying nitrogen contents and films co-doped with cerium and terbium. The intensity and position of the photoluminescence (PL) peak could be tuned in the visible range by controlling the film composition, deposition conditions, and post-deposition thermal treatment. Near edge X-ray absorption fine structure (NEXAFS) spectroscopy at the Si K- and N K-edge were used to perform a comparative structural study on a series of CVD grown a-SiCN:H thin films. A correlation was obtained between the amount of nitrogen in the matrix and the PL behaviour, which also supported the trend in the NEXAFS results.