Frequency Dependence of Ion Energy at the Outlet of a Capacitive RF Discharge Placed in an External Magnetic Field with a Predominant Radial Component

The frequency dependence of the energy and ion current at the output of an RF plasma source with SPT geometry has been investigated. It has been shown that the ion energy is maximum when operating at a frequency of 6.8 MHz. An increase in the operating frequency is accompanied by a decrease in ion energy. The ion current depends nonmonotonically on frequency. At frequencies less than 27.12 MHz, an increase in the ion energy is accompanied by a decrease in the current, and a decrease in the energy by an increase in the current. Increasing the frequency to 27.12 MHz does not lead to an increase in the ion current.