Hydrogenated amorphous silicon (a-Si:H) and hydrogenated amorphous silicon carbide (a-SiC:H) films of different compositions were deposited by plasma enhanced chemical vapor deposition (PECVD). For a-Si:H thin films, we have investigated the effect of the rf power on the microstructural properties, such as crystal structure and crystallinity. A diffraction peak (Si (111)) positioned at about 2 theta = 28 degrees appeared from a thin film grown on a Si (100) substrate at rf power of 300 W, suggesting a local crystallization of the film. For a-SiC:H thin films, the predominant peak is ascribed to (200) of beta-SiC structure, which confirms the formation of beta-SiC upon 900 annealing. No peak corresponding to the (111) or (220) planes of beta-SiC is detected, suggesting that the films might exist in a single crystalline state.

Keywords: plasma enhanced chemical vapor deposition; amorphous silicon; amorphous silicon carbide; crystallinity