Hydrogen dissociation and incorporation into amorphous silicon produced by electron beam evaporation

A simple and efficient source of atomic hydrogen to be used for reactive evaporation or ionized cluster beam deposition of amorphous silicon films was developed. The intensity of the H beam over a large area of substrates is known and can easily reach 1016 atoms cm−2 s−1. Using this source, a series of films was grown by electron gun evaporation of Si and variable H beam flux. The main objective was to study the fundamental and practical aspects of hydrogen incorporation in a-Si and not to produce device quality films. It is found that the growing films retain atomic H with a probability close to 1 for H/Si atomic ratios lower than 1%. The role of the excess H flux and the reaction products of atomic hydrogen and silicon on the walls, in determining film quality, is discussed.