Fabrication and Characterization of High Aspect Ratio Silicon Plate Springs with High Out-of-Plane Stiffness

In this work we present the fabrication and characterization of high aspect ratio silicon plate springs. The springs are fabricated using a combination of two technologies: high precision dual side wafer stepper alignment and deep reactive ion etching. Several process issues are discussed.and the optimum masking layer configuration to realize these structures is defined. Particularly the DRIE process characteristics that affect the manufacturing accuracy are studied as they form the limiting factor in accurate dual side bulk micromachining of these very high aspect ratio structures.