High-quality SiO 2 film deposition using active reaction by oxygen radical

Abstract

A novel film deposition method called radical shower chemical vapor deposition (RS-CVD) has been developed for high-quality gate-oxide (SiO 2) film formation on low-temperature poly-Si TFT-LCD. RS-CVD is characterised by a plasma damage-free deposition on a large area substrate at a low temperature, although discharge is used to generate the activated species of oxygen radicals. In film deposition, by using a reaction of SiH 4 with oxygen radicals, it is possible to grow SiO 2 films under low substrate temperature at low deposition pressure. Dependencies of film properties on deposition parameters are investigated to optimize the RS-CVD process. The parameter dependencies are interpreted with consideration of the gas phase reaction mechanisms, which account for the observable consequences of Si–OH bonds quantity incorporated in the films. Throughout this study, it is concluded that it is necessary for the film quality to reduce the contamination of intermediate species containing Si–OH bonds in the films and to control the excess reaction in the gas phase. Besides, the increase in the oxygen radical quantity is effective for the improvement of film properties.