Low Temperature Fabrication Process for High-Aspect-Ratio and Multi-Compliant MEMS

The presented process technology enables the fabrication of 3D high-aspect-ratio microstructures featuring the integration of multiple materials. The technology offers the possibility to benefit from unique material properties for optimized MEMS functionality and performance. The fabrication process relies on wafer stacking by low temperature plasma activated direct bonding, SOI layer transfer and SU-8 structuring. The proposed process flow is validated by the fabrication of micro mirrors featuring a soft polymeric suspension and a high-aspect-ratio vertical comb-drive actuator. The devices are characterized and confirm the expected performance with dynamic resonant optical deflection angles of 59deg at 50V.