Effects of hydrogen passivation on the electrical conduction in undoped polycrystalline silicon films

Abstract

The influence of the hydrogenation treatment on the conduction mechanism in the undoped polycrystalline silicon films near room temperature was investigated. The two current components are predicted from the temperature dependence of the conductivity in the films. We consider the hopping current in addition to the conventional thermionic (or drift) current. We have also found the hydrogenation induced increase phenomena of resistivity in the undoped polycrystalline silicon films and its activation energy, and qualitatively explain those by the decrease of the hopping current, which would relate to the band tail states, and that of the thermionic current, which would relate to the midgap states. From the analysis of the current components, it takes longer time for the passivation of the band tail states than that of the midgap states. © 1997 American Institute of Physics.