Self-consistent simulation of a parallel-plate rf discharge

A particle-in-cell code with nonperiodic boundary conditions is used to stimulate a rf discharge. The simulations are started with a few ion-electron pairs which can initiate a breakdown after a few rf cycles with the plasma density increasing until a steady state is reached. The average potential of the plasma is greater than that on the boundaries so that ions drift towards the sheaths at the ambipolar rate. The ion loss at equilibrium is balanced mainly by ion creation due to jets of secondary electrons accelerated through the sheaths formed alternately on each electrode. The variation of the sheath width, the negative glow, and the average sheath potential are studied as a function of pressure and compared with Child–Langmuir theory.