Effect of the Thermal Annealing Temperature on the Composition and Luminescent Properties of Silicon Rich-Nitride (SRN) and -Oxide (SRO) Films

In this work, a study of the optical properties of silicon rich oxide (SRO) and silicon rich nitride (SRN) films deposited by low-pressure chemical vapor deposition (LPCVD) is presented. Silicon excess in SRO and SRN was obtained by changing the flow ratio between N<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>O/SiH<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</inf> and NH<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf>/SiH<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</inf>, respectively. The effect of the annealing temperature on both Si-rich dielectric films was studied. Infrared spectroscopy showed microstructural changes within the SRO and SRN films after thermal annealing. Transmittance measurements exhibit variations in the bandgap of SRN and SRO by changing the silicon excess. Maximum luminescence intensity was observed in as-deposited SRN films while SRO films need to be annealed at 1150°C. Therefore, SRN films are a potential candidate for optoelectronic devices.