EFFECT OF TARGET SIZE ON DOSE UNIFORMITY IN PLASMA-BASED ION-IMPLANTATION

Plasma-based ion implantation of a square bar is modeled using a parti cle-in-cell plasma simulation for three different size bars. When the sheath width is significantly greater than the bar width, it is found that the incident ion dose is largest at the center of the bar and dec reases precipitously at the corners. When the sheath width is comparab le to the bar width, the incident dose is largest near to, but not at, the corners. It may be possible to optimize dose uniformity by stradd ling these two regimes. (C) 1997 American Institute of Physics.