Model for ion extraction from pulsed plasma source for plasma based ion implantation (PBII)

In plasma based ion implantation, the use of a pulsed plasma source may have some advantages over the conventional dc source, in that a pulsed plasma may easily meet the requirement of high density plasma production in low pressure environment. For the purpose of understanding the ion dynamics, we have developed a one-dimensional model for the ion implantation into a target from a pulsed plasma which expands toward the target with finite velocity. The sheath edge evolution equation and the equations of ion motion are solved, to obtain analytic formulas for the implanted ion current and energy distribution on some assumptions. Influence of the vacuum region and plasma expansion velocity will be discussed. (C) 2000 American Institute of Physics. [S0034-6748(00)68502-7].