Analytical Studies of the Capping Layer Effect on Aluminum Induced Crystallization of Amorphous Silicon

Abstract

The effect of capping layer on metal induced crystallization of amorphous silicon was studied. Three sets of samples were prepared in this study. All samples had the basic layer structure of amorphous silicon layer deposited on a glass substrate. This was followed by a thin aluminum layer deposition. The second and third sets, however, had a third layer of amorphous silicon with thicknesses of 20 and 50 nm, respectively. These layers were deposited on top of the aluminum. The samples were annealed at 400°C for 15, 30 and 45 minutes. The resultant films were characterized using X-Ray diffraction, scanning electron microscopy, energy dispersive x-ray spectroscopy, and atomic force microscopy. It was observed that the capping layer reduces protrusion formation and therefore improving the smoothness of the crystallized polysilicon films.