Influence of Discharge Geometry on Power Dissipation and Sheath Impedances in Silane Discharges

The influence of the interelectrode distance on the power consumed in rf silane glow discharges, for two different electrode sizes and at two different silane pressures is reported. The effect of the increasing grounded surface area in contact with the discharge is analysed by using a simplified calculation of the rf and grounded sheath impedances. At all cases the power consumed in the discharge increases with interelectrode distance and is higher for higher pressures, for a constant excitation voltage. The sheath impedances are always higher for lower pressures except for the case of the ground sheath when using the large electrode set.