Micro arc welding for electrode gap reduction of high aspect ratio microstructures

This paper presents a novel post-process gap reduction technique for high aspect ratio microstructures. The gap reduction procedure is based on electrostatic deflection of a movable microstructure and micro welding for permanently locking the final position. The gap reduction technique is demonstrated for MEMS devices fabricated by the air gap insulated microstructures technology. The functional principle of the gap reduction mechanism, the fabrication technology and the experimental set-up is presented. As a result, the initial gap width between vertical comb electrodes was decreased from 4500 nm to 385 nm, leading to a final aspect ratio of 150.