Electrical properties of fluorinated amorphous carbon films

We have studied the capacitance-voltage (C-V), conductance-voltage (G-V), and current-voltage characteristics of fluorinated amorphous carbon (a-C:F-x) films using metal/a-C:F-x/Si and metal/a-C:F-x/metal structures, respectively. Samples annealed in a vacuum were also studied. The C-V curves of the as-deposited sample are stretched about the voltage axis. Interface state density of 4.1x10(11) cm(-2) eV(-1) at the midgap was calculated. Annealing the sample deposited on Si in a vacuum caused more frequency dispersion in the C-V and G-V curves, probably due to the diffusion of carbon into silicon. The bulk density of states for samples deposited on metal, measured by space-charge-limited current technique, decreased from 4x10(18) eV(-1) cm(-3) for the as-deposited sample, to 7x10(17) eV(-1) cm(-3) for the annealed sample. (C) 2001 American Institute of Physics.