Low-temperature Si/Si wafer bonding using boride treated surface

An approach for Si/Si wafer bonding based on boride-solution treatment was presented. The bonding energy is higher than the Si fracture energy by annealing at 180°C. The properties of the bonded structures were studied in terms of the interface shape, electrical and optical characteristic through scanning electron microscopy (SEM), interface I–V curve, and so on. In this method, the surfaces of two wafers are active by Boride solution, and then following a thermal annealing process. The bonding strength was found to be sufficiently high and could withstand the subsequent etching and polishing procedures of the bonded wafers. This low temperature wafer bonding technology can be used in Optic Electronics Integrated Circuit and this technology with potential to meet a broad range of future telecommunication and computing systems' needs.