  The dynamical characteristics of a single frequency low pressure capacitively
coupled plasma (CCP) device under varying applied RF voltages and driving
frequencies are studied using particle-in-cell/Monte Carlo collision
simulations. An operational regime is identified where for a given voltage the
plasma density is found to remain constant over a range of driving frequencies
and to then increase rapidly as a function of the driving frequency. The
threshold frequency for this mode transition as well as the value of the
constant density is found to increase with an increase in the applied voltage.
Over the constant density range, for a given voltage, the sheath width is seen
to increase as a function of the increasing driving frequency, thereby changing
the ion energy without affecting the ion density. Our parametric study thus
indicates that the twin knobs of the applied voltage and driving frequency
offer a means of independently controlling the density and the ion energy in a
low pressure CCP device that may be usefully exploited for plasma processing
applications.
