A MODEL OF PLASMA SOURCE ION-IMPLANTATION FOR INNER SURFACE MODIFICATION

The conclusions of Sun et al concerning the expansion of the plasma sh eath in a cylindrical bore are shown to be incorrect and unphysical. I n particular, the sheath accelerates as it nears the centre of the bor e rather than slowing and, under the same conditions, the sheath expan ds more rapidly for inner surface implantation than it does for outer surface implantation.