Effect of SiH4 fragments and H radicals on nc-Si:H film deposition in an inductively coupled plasma PECVD

• nc-Si:H films were prepared in a radio frequency inductively coupled plasma using SiH 4 . • The deposition and plasma characteristics were comprehensively analyzed for gas fractions and power. • The deposition rate exhibited a strong dependence on the density of SiH 4 fragments. • The density of SiH 4 fragments was governed by SiH 4 dissociation, which, in turn was influenced by the SiH 4 fraction, electron density, and H radical density. Hydrogenated nanocrystalline silicon (nc-Si:H) has garnered considerable interest due to its exceptional properties and ease of accessibility. Typically, nc-Si:H films are deposited using SiH 4 via plasma-enhanced chemical vapor deposition, facilitating large-scale processing at a low cost. In SiH 4 -based plasmas, neutrals and ions of SiH 4 fragments are generated, and their interaction with the surface leads to film deposition. Therefore, a process development and optimization approach incorporating an in-depth understanding of plasma-surface interactions is essential. This necessitates a comprehensive analysis of both plasma properties and process outcomes. In this study, we investigated the deposition characteristics of the nc-Si:H film and the film alongside the plasma properties under varying SiH 4 or H 2 fractions and input power in inductively coupled plasma. The deposition results were analyzed in relation to plasma parameters such as electron density, electron temperature, and neutral and ion densities. Among these parameters, the deposition of nc-Si:H films was primarily influenced by the density of neutral SiH 4 fragments. The SiH 4 fragments density, in turn, was determined by the dissociation of SiH 4 , which depended on the SiH 4 fraction, electron density, and H density.