Atomic force microscopy and x-ray diffraction studies of aluminum-induced crystallization of amorphous silicon in Al/α-SiM, α-Si:H/Al, and Al/α-Si:H/Al thin film structures

Amorphous silicon (alpha-Si:H) films were deposited on both Corning 7059 glass and single-crystalline, silicon (c-Si) substrates in combination with aluminum to create alpha-Si:H, Al/alpha-Si:H, alpha-Si:H/Al, and Al/alpha-Si:H/Al structures for a study of aluminum-induced crystallization (AIC) of alpha-Si:H. The alpha-Si:H was deposited by high-vacuum plasma-enhanced chemical vapor deposition. The. structures were then annealed at temperatures between 200 and 500 degreesC using radiative heating. Optical microscopy was used to observe macro-scale changes in the surface of the films after annealing. The surface microroughness was investigated using atomic force microscopy. X-ray diffraction analysis was performed to study the crystallization changes of the alpha-Si:H induced by the presence of the Al. The surface roughness, as well as the morphology of these structures exhibit significant changes with annealing. The results show that the smoothest polycrystalline silicon films are obtained for the Al/alpha-Si: H structure. (C) 2003 American Vacuum Society.