FREQUENCY-EFFECTS IN CAPACITIVELY COUPLED RADIOFREQUENCY GLOW-DISCHARGES - A COMPARISON BETWEEN EXPERIMENTS AND A 2-DIMENSIONAL FLUID MODEL

The results of a two-dimensional fluid model for argon rf discharges i n a closed cylindrical vacuum chamber are compared with experimental d ata from an amorphous silicon deposition reactor. Good agreement is ob tained for the relation between the dc autobias voltage and the dissip ated power in the frequency range 50-100 MHz at pressures between 12 a nd 90 Pa. A scaling law is presented for the relation between the powe r, the dc bias voltage, the rf excitation frequency, and the backgroun d pressure. The model yields a linear relation between the applied rf voltage and the dc bias voltage. This relation depends only on the geo metry of the discharge chamber and shows an offset.