Correlation of the structure with electrical and optical properties of thin tin films

Abstract

Thin tin films of thickness in the range 340–3200 Å were prepared by thermal evaporation under a vacuum of 10 −5 Torr. The films were deposited onto amorphous substrates with a deposition rate of 10 Å s −1. Investigation by transmission and scanning electron microscopy showed that the grain size increased with increasing film thickness. The films had a polycrystalline structure. The fitting of the resistivity-thickness relation proved to be in good agreement with Mayadas-Shatzkes theory. The resistivity increased with increasing temperature and the temperature coefficient of resistivity increased with increasing film thickness. The mean free path, mobility and concentration of charge carriers were calculated from the theoretical formulae. The optical properties were studied in the IR region. The mean free path and the specular parameter were determined from the correlation of electrical and optical results.