Simplified process for dot sequential lateral solidification of sputtered amorphous silicon thin films

Abstract

In this work we demonstrated an improved method to obtain large grain Si islands matrix with the use of dot sequential lateral solidification. Amorphous Si thin films were deposited on glass plates and Si wafers with thin oxide layer by magnetron sputter. Dot sequential lateral solidification (dot-SLS) was applied on the selected areas of the films by a 248nm excimer laser. The laser beam was patterned by a stainless steel mask. The setup is designed such that the dot-SLS process can be carried out by having the samples move against the laser beam and patterned mask in a uniform motion, which greatly simplified the dot-SLS process. Single crystalline Si grains with an average size of 10μm were obtained and further characterized by an optical microscope, scanning electronic microscope (SEM) and Raman spectrometer. The research work showed a simple method to achieve single crystalline Si islands matrix, which could be used as a seed layer to produce large grain sized Si films for high efficiency polycrystalline Si thin film solar cells and high performance flat panel displays.