Plasma ion implantation, an alternative to conventional beam-line ion implantation, is a sheath-acceleration ionbombardment technique and the initial sheath is crucial to the process efficacy and surface properties. The initialspatial potential distribution in the plasma sheath around a trench-shaped target is simulated using a two-dimensionalmodel in this work. The results demonstrate that the sheath structure depends very much on the trench width. Thepotential drop in the trench may be quite small and the sheath expands outward if the width is small. This leadsto a smaller incident ion dose into the sidewalls of the trench. In contrast, the initial potential distribution in thecentral region is quite similar to that without a trench if the trench width is larger than twice the ion-matrix sheaththickness for an infinite plane. Consequently, a higher ion dose into the sidewalls is possible.
Xiubo Tian Chunbei Wei Shiqin Yang Paul K. Chu Ricky K.Y. Fu
