DISCONTINUOUS TRANSITIONS BETWEEN ALPHA-REGIME AND GAMMA-REGIME OF RFCAPACITIVE DISCHARGE

A one-dimensional self-consistent fluid model has been used to analyse a capacitive rf discharge at various applied voltages and frequencies . Within a limited range of applied conditions the model provides two distinct stable stationary solutions. These correspond to two differen t modes of rf discharge which are termed according to the prevailing m echanism of ionization as alpha and gamma regimes of rf discharge. Tra nsitions between these states are discontinuous and result in jumps in the discharge V-I characteristic. The alpha-to-gamma transition occur s when the transition voltage is reached and de-like breakdown conditi on of sheaths is satisfied. The reversed transition from gamma to alph a regime occurs when the sheath voltage decreases under the minimal ma intaining value of secondary electron ionization feedback.