Surface Activated Si-Si Wafer Bonding Using Different Ion Species

Abstract

Surface activated bonding on wafer level is enabled by an advanced direct wafer bonding system for irradiation with different ion species. In this process, the native oxide of 200 mm Si wafers is sputter-removed and an amorphous layer is generated. After ion treatment, the wafers are bonded in ultra-high vacuum at room temperature. The impact of Ar, Kr and Xe ion irradiation on the amorphous layer thickness was investigated with the goal of optimizing the bonding process for establishing interfaces with electronic functionality. This was i.a. motivated by the fact, that the presence of an amorphous layer reduces the electrical conductivity across the wafer interface.