3D morphology reconstruction of high aspect ratio MEMS structure by using autofluorescence of Parylene C

This paper reported a MEMS fabrication compatible, damage free method for in-process 3D morphology reconstruction of high aspect ratio microstructure. As a novel morphology tracer, Parylene C thin film was conformally deposited onto the structure and annealed at high temperature under N₂. The autofluorescence of Parylene C was considerably enhanced by the annealing, which made it possible to image the microstructure. By scanning with a confocal microscopy, 3D morphology of the microstructure was reconstructed. The preliminary result indicated that microstructure with width of 8 μm and depth of 34 μm (34.1 μm actual depth by SEM) was successfully and accurately measured by this method.