Polycrystalline silicon thin films on glass substrate

Abstract

The formation of high-quality polycrystalline silicon (poly-Si) on low cost substrates has important applications in the development of thin film solar cells, transistors, image sensors, etc. In this study, we present the results of an investigation of poly-Si and poly-SiGe films on glass, formed by aluminum induced crystallization (AIC). The process is based on the isothermal annealing at temperatures between 500 and 540 °C of co-sputtered Si+Al, Si+Ge or sputtered a-Si films on glass, with and without thermally evaporated or sputtered Al film. The crystallized films were investigated by Raman spectroscopy, optical microscopy, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). Raman spectra demonstrate the crystalline structure of the poly-Si and poly-SiGe films prepared by AIC. The grain sizes of the poly-Si films estimated from the SEM and optical microscopy images are up to 25 μm for the different annealing conditions.