ELECTRICAL-PROPERTIES OF CRYSTALLIZED SEMIINSULATING POLYCRYSTALLINE SILICON FILMS

The electrical characteristics of the crystallized semiinsulating polycrystalline silicon (SIPOS) film were studied, and its electrical conduction was investigated. It is found that the electrical characteristics of the SIPOS film can be explained by the thermionic emission mechanism. Since the oxygen concentration in the film is higher, the band gap is wider and the resistivity and activation energy are increased. By considering the segregation effect of phosphorus, the surface density of grain boundary traps of the crystallized SIPOS film was derived and the relationship was clarified between the oxygen concentration and the surface density of traps. As the oxygen concentration is increased, the surface density of traps increases. The electrical characteristics of the SIPOS film can be explained better if a Gaussian distribution rather than a single level is assumed for the energy of the grain boundary trap.