Characterization of anodic bonding induced diaphragm deflection in pressure sensor

This paper discussed the anodic bonding induced diaphragm deflection in the ultra-sensitive piezoresistive pressure sensor and its effect on the zero-offset output of the sensor. After anodic bonding, upward deflection of the diaphragm was measured by a 3D optical profiler as well as the large negative zero-offset voltage. The difference of thermal expansion coefficient (TEC) between Si and glass wafers was believed responsible for phenomena. Finite Element Analysis (FEA) was applied to study the diaphragm deflection and the residue stress, the simulation results were in good agreement with experimental measurements.