Physical and Electrical Properties of Polycrystalline Silicon Thin Films

Abstract

ABSTRACTPhysical and electrical properties of chemically-vapordeposited polycrystalline silicon films have been investigated. Effects of deposition parameters, doping, and high temperature processing on grain size and orientation, carrier concentration, carrier mobility and electrical resistivity, have been studied. By relating the physical and electrical properties to each other it has been shown that electrical conduction is controlled by dopant segregation, carrier tunneling, and trapping at grain boundaries. Models for these three mechanisms have been developed and by combining them a generalized model for electrical conduction has been developed. Presence of grain boundaries has also been shown to strongly influence the thermal oxidation and dopant diffusion in polycrystalline silicon.