Void nucleation at a sequentially plasma-activated silicon/silicon bonded interface

Two 4 inch silicon wafers were directly bonded using a sequentially plasma-activated bonding method (i.e. O2 reactive ion etching (RIE) plasma followed by N2 microwave (MW) radicals) at room temperature. The bonded wafers were annealed from 200 to 900 °C in order to explore the nucleation of voids at the interface. The plasma-induced void nucleation was dominated by O2 RIE power over O2 RIE activation time. The thermal-induced void nucleation …