Abstract:MEMS(Micro Electro Mechanical System) inertial sensors are significantly affected by micromachining stress. Using wafer probes to perform wafer level electrical testing may introduce extra stress. A push-pull differential MEMS wafer PCM(Process Control Monitor) stress characterization structure is designed, which realizes the measurement of stress at different positions of the MEMS wafer and avoids the use of wafer probes during electrical testing. The numerical simulation model of the stress characterization structure is established, and the dimensional parameters of the structure are optimized according to the simulation results. The push-pull differential MEMS wafer stress characterization structure is actually processed. The stress characterization structure characterizes the stress magnitude, direction and stress distribution at different positions in the actual processed MEMS wafer. The test results show that the MEMS wafer is dominated by tensile stress as a whole, and at the same time, it presents a state of central extrusion deformation and peripheral tensile deformation. The maximum tensile stress along the (100) crystal direction produces a displacement of 18.9μm on the characteristic structure, and the maximum compressive stress produces a displacement of -34.2μm; the maximum tensile stress along the (110) crystal direction produces a displacement of 15.0μm on the characteristic structure, and the maximum compressive stress produces a displacement of -57.8μm.