Novel fabrication method for high-aspect-ratio suspended parylene structures

This paper is to present a novel and easy fabrication method for suspended high-aspect-ratio parylene structures on a standard silicon wafer. The process employs the concept of creating parylene beams by multiple parylene deposition/removing steps in the trench, releases the structures at the same side of the silicon wafer, and then fabricates soft beams for the requirement of high sensitivity and low stiffness in in-plane motion. By using the proposed process, a test device of free-standing parylene beams with 20 μm in width, 3000μm in span, and 50μm in thickness is fabricated to verify the feasibility of the suspended parylene-based structure design.