Growth and structural properties of hydrogenated silicon films deposited by pulsed laser ablation

Hydrogenated silicon thin films have been deposited by means of pulsed laser ablation. Efficient hydrogenation was obtained by performing the ablation process in a controlled H2 atmosphere. Fluorescence spectroscopy characterization of the plume revealed the presence of both atomic hydrogen and highly ionized silicon atoms. The hydrogen content ranged from 2% to 15% as the H2 pressure was varied between 0.05 and 30 mbar. Infrared spectroscopy measurements showed a monohydride preferential incorporation at low hydrogen pressure. The films' crystalline fraction, obtained by both Raman scattering and x-ray diffraction experiments, was found to show a maximum value of about 60% for H2 pressure values around 1 mbar. These results suggest that crystallinity and hydrogenation of the film, deposited at room temperature, can be properly adjusted as a function of the deposition parameters.