Effect of Plasma Treatment on Crystallization Behavior of Amorphous Silicon Films

Abstract

ABSTRACTThe crystallization of amorphous silicon (a-Si:H) deposited by plasma enhanced chemical vapor deposition (PECVD) by thermal annealing is of great interest for display and silicon-on-insulator (SOI) technologies, though long anneal times (about 20 hrs) at 600 °C are typically required. We report that a room temperature hydrogen plasma exposure in a parallel plate diode type Reactive Ion Etcher (RIE) can reduce this crystallization time by a factor of five. This plasma enhanced crystallization can be spatially controlled by masking with patterned oxide, so that both amorphous and polycrystalline areas can be realized simultaneously at desired locations. This effect is due to the creation of seed nuclei at the surface, which enhance crystallization rates.