Advanced Techniques in 3D Photolithography for MEMS

摘要

Three dimensional (3D) MEMS fabrication is essential to many power MEMS applications important to today's soldier. We present two advanced techniques to realize 3D structures in photoresist. Both technologies are based on gray-scale photolithography, which is a method to modulate the light intensity incident on photoresist to control the development rate. We compare a commercial technique, HEBS glass, to a technique developed in-house called double-exposure gray-scale. HEBS glass has a better horizontal resolution and is more suited to small structures that require high vertical resolution. Double exposure gray-scale technology has a comparable vertical resolution to HEBS glass, but is better suited to large MEMS structures over 100 m.