Effect of chamber pressure on red emission from silicon thin films deposited by means of hot-wire CVD

Abstract

Nanocrystalline silicon (nc-Si) embedded in amorphous silicon oxide (a-SiOx) films were prepared by hot wire chemical vapor deposition (HW-CVD), also known as catalytic CVD (Cat-CVD) method. In this study, Tungsten (W) filament material was employed for decomposing the source gases in the reaction chamber. Effect of chamber pressure on the phase transition in silicon oxide (SiOx) has been studied by using X-Ray diffraction (XRD) and Raman spectroscopy techniques. A relationship between phase transition of thin film and Si-H bonding has been recognized and explained by using Fourier transform infrared (FTIR) spectroscopy. The samples deposited at low substrate temperature of 200°C, has shown photoluminescence spectra in the red region and emission of spectra has been found to be in correlation with the size of nc-Si and/or defects present in the thin film.