This article describes a new negative-tone photoresist, SU-8, for ultrathick layer applications. An aspect ratio of 10:1 has been achieved using near-ultraviolet lithography in a 200-μm-thick layer. The use of this resist for building tall micromechanical structures by deep silicon reactive-ion etching and electroplating is demonstrated. Using SU-8 stencils, etched depths of ≳200 μm in Si and electroplated 130-μm-thick Au structures with near-vertical sidewalls have been achieved.

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This paper presents the design of DC-contact RF switch fabricated by 0.18μm CMOS-MEMS which has the advantages of small area、easy fabrication、low-voltage、low Insertion Loss and high RF performance. The switch is compatible with CMOS process. The switches are actuated by electrostatic force that drove the tail of the cantilever beam contact with the transmission line. The DC and RF signal are separated by SiO 2 that avoid RF signal loss. The simulation results show that SiO 2 could avoid the loss of RF signal. In the MEMS post-process, the device is based on aluminum as the cantilevers and the scarified layer. The structure is released by wet-etching. Electroless Nickel immersion gold (EN/IG) is applied for better Insertion Loss. At last, supercritical CO 2 drying is used to release the structure.