Amorphous silicon prepared from silane-hydrogen mixture

Amorphous silicon films prepared from a d.c. discharge of 10% SiH4 - 90% H2 mixture are found to have properties similar to those made from 100% SiH4. These films are found to be quite stable against prolonged light exposure. The effect of nitrogen on the properties of these films was investigated. It was found that instead of behaving as a classical donor, nitrogen introduces deep levels in the material. Field effect experiments on a-Si:H films at the bottom (film-substrate interface) and the top (film-vacuum interface) of the film are also reported. (author)