FORMATION OF DIFFERENT TYPES OF POLYSILICON FILM STRUCTURES AND THEIR GRAIN-GROWTH UNDER ANNEALING

The microstructure of undoped and phosphorus-doped polycrystalline silicon films obtained by low-pressure chemical vapor deposition is investigated using transmission electron microscopy. A classification of structural types of polysilicon films (fibrous, dendritic, equiaxed) is made and the forming conditions of these structure types are analysed. It is found that "toothed" interfaces exist in films with fibrous structure. Driving forces and grain growth mechanisms in polysilicon films under annealing are studied.