Silicon lifetime enhancement by SiNx:H anti-reflective coating deposed by PECVD using SiH4 and N2 reactive gas

Hydrogenated films of silicon nitride SiNx:H are largely used as antireflective coating as well as passivation layer for industrial crystalline and multicrystalline silicon solar cells. In this work, we present a low cost plasma enhanced chemical vapor deposition (PECVD) of this thin layer by using SiH4 and N2 as a reactive gases. A study was carried out on the variation effect of the ratio silane (SiH4) to nitrogen (N2) and time deposition on chemical composition, morphologies, reflectivity and carrier lifetime. The thickness was varied, in order to obtain a homogeneous antireflective layer. The Fourier transmission infrared spectroscopy (FTIR) shows the existence of Si–N and Si–H bonds. The morphologies of the sample were studied by Atomic Force Microscopy (AFM). The resulting surface of the SiNx:H shows low-reflectivity less than 5% in wavelength range 400–1200 nm. As a result, an improvement in minority carrier lifetime has been achieved to about 15 ls. 2012 Elsevier Ltd. All rights reserved