INTERFACE ANALYSIS IN POLYSILICON THIN-FILMS AND POLY-SI/SIO2 SYSTEMS

Cross-sectional transmission electron microscopy (TEM) has been used to study interface morphology in undoped and P-doped polysilicon films and poly-Si/SiO2 systems deposited by low-pressure chemical vapour deposition. Two types of polysilicon interface are found: a 'toothed' interface in films with fibrous structure and a flat uniform interface in P-doped polysilicon films. The conditions for the formation of these interface types have been analysed. The morphology of the poly-Si/SiO2 interface is studied in relation to its dependence on both the original structure type of the polysilicon films and the oxidation temperature.