INTERACTION BETWEEN THE PLASMA THE THE WORKPIECE SURFACE IN THE PROCESS OF PLASMA SOURCE ION-IMPLANTATION

Plasma source ion implantation (PSII) is a method that allows ion impl antation of all surfaces at normal incidence. The workpiece to be trea ted is placed directly in the plasma and is successively pulse biased to a high negative voltage in a given duty cycle in the PSII device. W hen the workpiece is not biased, the plasma behaviour around the workp iece is calculated using the numerical solution of the plasma-sheath e quations, established by means of ambipolar diffusion physics processe s. When the workpiece is biased to a high negative voltage, a simplifi ed energy profile model of the ions accelerated toward the workpiece i s proposed, and the sheath-edge propagation as a function of time is a lso calculated. The calculation and analysis in this paper clearly exp lain the effective mechanisms on the workpiece surface caused by the p lasma, and provide a foundation for the investigation of PSII physics processes.