Investigation on Silicon Oxide Films Grown by Using Silicone Oil and Ozone at Low-Temperature

Abstract

High quality silicon oxide (SiO 2 ) films deposited at low-temperature (≤ 200 °C) are needed for TFTs (Thin Film Transistor) as gate dielectric material, inter layer dielectric, inter metal dielectric, etc. In this study, SiO 2 films were grown on silicon substrates by chemical reaction between silicone oil (SO) vapor and ozone gas (O 3 ) at a temperature of 200 °C using Atmospheric Pressure Chemical Vapor Deposition (APCVD) system. The chemical structures of the as-deposited and post-annealed SiO 2 films were studied by Fourier transform infrared (FT-IR) spectroscopy. Laser ellipsometry method was used to measure the thickness and refractive index of the films. FT-IR spectra of the as-deposited films showed similarity to those SiO 2 films found in literature. However, the existence of two weak absorption peaks of Si-OH bonds suggests the presence of very small amount of pores in the sample. The –OH contents of the films created unwanted leakage current. Heat treatment reduced the –OH contents of the film and reduced the leakage current. The experimental results indicate that the APCVD system can be used for successful grown of SiO 2 films by using SO vapor and ozone gas at low temperature.