Compact slanted comb two-axis micro-mirror scanner fabricated by silicon-on-insulator micromachining

摘要

We present a two-axis micro-mirror scanner with compact slanted comb-drive actuator. The slanted comb-drive actuator is analyzed by comparing with a rectangular comb-drive actuator. The angle magnification factor of slanted comb-drive actuator is 1.6 times larger than that of rectangular comb-drive actuator. The slanted comb-drive actuator is designed for operations in both static and dynamic modes. The proposed scanner is realized from silicon-on-insulator (SOI) wafer. Electronic isolation between movable comb electrodes in device layer and fixed comb electrodes in handle layer are performed using isolation trenches, buried oxide layer, and silicon V-shaped conductive hinges. Movable and fixed parts are physically connected via buried oxide layer and silicon frame fabricated from the handle layer of SOI wafer using time-controlled etching process. The resonant frequencies of horizontal and vertical axes are 25.88 kHz and 592 Hz, respectively. The rotation angles are 0.7° and 5.8° at 80V dc voltage in the static mode for inner mirror and gimbal frame, respectively, and 21° and 24° using the differential ac driving method with 80Vbias+70Vac and 25Vbias+12.5Vac voltages.