An investigation of eutectic wafer bonding process for micromachined sensors

Abstract Au/Si eutectic bonding is a promising technology for vacuum packaging and 3D structure in micro-electro-mechanical systems (MEMS). This paper investigates the effect of process parameters on the bonding quality of Au/Si eutectic bonds, with a focus on bonding temperature, bond area, and annealing conditions. A bonding temperature of 450 °C is found to be critical for achieving optimal bonding, with the annealing process further enhancing bond reliability. The study also explores how variations in bond area can reduce parasitic capacitance and improve bond strength. Die shear and pull tests are performed to assess bond strength, providing valuable insights into the feasibility of using Au/Si eutectic bonding for MEMS applications.