Characterization of silicon films deposited in presence of nitrogen plasma

Abstract

Silicon films are deposited in presence of nitrogen plasma with the technique known as ‘activated reactive evaporation (ARE)’ with a view to deposit silicon nitride films on silicon substrate at room temperature. The in-house fabricated ARE system consists of a high vacuum chamber (e-beam gun housing) and a low vacuum chamber (reaction chamber) separated by a plate with an opening at the center. Silicon was evaporated by an electron beam (e-beam) gun in the presence of nitrogen plasma and films were deposited on a silicon substrate at room temperature. A number of experiments were carried out for testing the system and for checking the repeatability of the deposition of the films. The characterization of the films deposited on silicon substrates was done using X-Ray Diffraction, X-ray Photoelectron Spectroscopy and Energy Dispersive Analysis of X-ray (EDAX). Refractive index of 1.97 obtained from ellipsometric measurements is in good agreement with that of the standard value of silicon nitride. Observation under SEM showed particulates of silicon on the surface of the film. The same was confirmed from spot EDAX analysis. These results indicate that the deposited films are non-stoichiometric and contain both silicon nitride and a phase of silicon oxynitride.