INSITU ULTRAVIOLET-LASER TREATMENT DURING PLASMA DEPOSITION FOR THE IMPROVEMENT OF FILM QUALITIES IN HYDROGENATED AMORPHOUS-SILICON

Hydrogenated amorphous silicon (a-Si:H) films were prepared with ultraviolet laser irradiation to modify the growing surface during the plasma-enhanced chemical vapor deposition. Using this treatment, the photoconductivity was improved by three to four orders of magnitude in films deposited at substrate temperatures below 100-degrees-C. Additionally, the optical band gap remained unchanged with the in-situ laser treatment. Consequently, high quality a-Si:H films, characterized by high photoconductivity and wide optical gap, were obtained at low substrate temperatures.