Ballistic-Mode Plasma-Based Ion Implantation for Surface-Resistivity Modification of Polyimide Film

摘要

Plasma-based ion implantation (PBII) is the well-established technique for material surface modification. In this paper, we described the ballistic-mode PBII process in which repetitive high-voltage pulses are applied to the grid a few centimeters from a polyimide (PI) film target. The high-voltage pulse applied to the grid has the peak values of $-$30 kV, width of 2.5 $muhbox{s}$, rise time of 1.5 $muhbox{s}$ , and fall time of 0.5 or 40 $muhbox{s}$. In this process, ions propagate ballistically from a grid to the PI film and modify the surface resistivity of the PI film. The efficiency of surface-resistivity modification depends on the fall time of the pulse applied to the grid. The ballistic-mode PBII process affects the surface characteristics of PI to a depth of $sim$ 90 nm.