The influence of filament temperature on crystallographic properties of poly-Si films prepared by the hot-wire CVD method

Abstract

This paper presents the deposition and characterization of polycrystalline silicon (poly-Si) films by the hot-wire chemical vapor deposition (HWCVD) method. The filament temperature was determined to be a critical parameter for the deposition of large-grained Si films. Poly-Si films with a moderate lateral grain-size of ∼1 μm and a vertical grain size approximately the same as the film thickness (approx. 3 μm) could be deposited on a glass substrate at a substrate temperature of less than 550°C by increasing the filament temperature to 2000°C. The surface of the films has a natural textured structure, which is believed to give some positive effects on solar cell performance. Some experimental results are presented in order to elucidate these improvements in crystalline properties of the Si films deposited at high filament temperature.