Growth process, structure and thermal stability of a-Si 1− xN x:H films

Abstract

The influence of nitrogen content on structure, properties, and thermal stability of a-Si:H and a-Si1−xNx:H films have been investigated. Films were prepared by a rf (13.56 MHz) glow discharge decomposition of gas mixtures with 10% SiH4 + 90% H2 and various amounts of NH3. The infrared, Raman scattering, and electron paramagnetic resonance spectra, dark electrical conductivity and optical absorption of the films have been measured. The structural inhomogeneity was determined by infrared transmission line at 2020 cm−1. It is found that material with low nitrogen content (x = 0.06) possesses higher conductivity and better thermal stability in comparison with a-Si:H. In addition, the structure of such material is shown to be more homogeneous. It is shown that a small amount of ammonia in gaseous phase during film deposition prevents the formation of structural inhomogeneities.