Steady-state, direct-current (DC) plasma immersion ion implantation (PIII) for planar samples

A new direct current (DC) plasma immersion ion implantation (PIII) technique by using a grounded conduction grid positioned between the plasma source and sample chuck is described in this paper. DC-PIII is simulated employing the particle-in-cell (PIC) method. Our simulation shows that the ion paths do not change with the negative voltage applied to the wafer stage as well as the mass and charge states of the ions. The ion dose and impact energy uniformity is determined by the internal ratio between the r (radius of sample platen), R (radius of vacuum chamber), H (distance between the grid and bottom of the vacuum chamber), and D (thickness of sample platen). Our simulation suggests that the best ratio is r:R:H:D=1:4:2.5:2. Our experimental results show that high voltage DC-PIII can be realized by using a conducting grid in a conventional PIII system.