材料期刊网

With a self-consistent fluid model, we study the transport characteristics of the collisionless radio frequency (rf) sheath in a high density plasma and calculate the spatiotemporal ion density and the potential drop across the sheath in one rf cycle for an rf-bias frequency of 13.56 MHz. We also study the effects of the rf frequency on the voltage at the electrode, the sheath width, the ion energy distribution (IED) and the ion angular distribution (IAD) at the electrode. The simulated results indicate that the incidence angles of the ions impinging on the electrode are less than 8 degrees when the ion velocity in the direction perpendicular to the sheath field is assumed to be a Boltzmann distribution. It is concluded that the rf frequency plays a crucial role for the energy and angular distributions of ions impinging on the electrode surface, and the IED and IAD are affected by the plasma density and the rf-bias power.