New Long Life Fast Atom Beam Source for Surface Activated Bonding

We clarify a mechanism for longer lifetime of the fast atom beam (FAB) source for surface activated bonding proposed in our previous study. The new FAB source achieves highly efficient FAB irradiation and suppression of generation of fine carbon (C) particles. In this study, the distribution of sputtering and deposition on the inner wall of the C electrodes have been evaluated by measuring the thickness of the electrodes before and after long-time use. In the new source, the C erosion area due to sputtering is localized near the irradiation port and the sputtered C is deposited on other electrode surface, whereas in the conventional one, the erosion occurs on all surfaces of C electrodes. The reduction of electrode erosion due to sputtering contributes significantly to the extension of the lifetime of the new FAB source.