Prototype of a unidirectional magnetic field-applied fast atom beam source for surface-activated bonding

Abstract

Surface-activated bonding is a wafer bonding technology where the wafer surface is activated by irradiation with a fast atom beam in a vacuum. We have demonstrated that it can improve the irradiation efficiency and reduce bonding defects caused by carbon emissions by controlling the motion of charged particles with a bidirectional magnetic field applied to the beam source. In recent years, there has been a growing need for a beam source that can irradiate a larger area. In this study, we propose a prototype of a unidirectional magnetic field-applied fast atom beam source that can be lengthened or enlarged. The proposed fast atom beam source achieved more than 1.5 times higher oxide film removal performance compared to the conventionally used fast atom beam source. In a long-term irradiation experiment, the proposed fast atom beam source emitted no carbon particles even after more than twice as many irradiations as the conventional fast atom beam source.