Analysis of grid electrode assisted plasma based ion implantation system and application to ion beam assisted deposition for insulator substrates

摘要

A grid electrode assisted plasma based ion implantation system, which was originally designed only for ion implantation on insulator substrates, was investigated as a system of sputter deposition with high energy ion beam irradiation. When pulses of negative high voltage were applied to grid electrodes immersed in argon plasmas, high energy ions were observed to bombard the surface of the grid electrodes during the rise and plateau times of the pulses, using particle-in-cell (PIC) simulations. The resulting sputter deposition of atoms on the substrate from the stainless steel grid electrodes was confirmed by X-ray photoelectron spectroscopy. During the fall time of the pulses, PIC simulations indicated high energy ion beams of pseudowaves bombarded the surface of the substrate. Thus we verified that by using grid electrodes, ion beams can irradiate the insulator substrate after the sputter deposition within the time scale of a single pulse. In the proposed configuration, problems due to high voltage on insulator can be avoided because the insulator substrates float in plasmas for the entire process. Finally, we discuss potential application of the system for ion beam assisted deposition as a compact plasma based ion implantation and deposition system, which does not require a separate sputtering system.