Self-aligned electrostatic angular vertical comb actuators assembled on-chip using in-plane electrothermal actuators

We have designed, fabricated and tested self-aligned angular vertical comb-drive (AVC) actuators by on-chip assembly technique using in-plane electrothermal actuators. The AVC actuators are fabricated on a silicon-on-insulator (SOI) wafer using three photomasks and three times of deep etching steps. The maximum optical scan angle of 30.7deg is achieved at 4.56 kHz under the sinusoidal driving voltage of 0~80 V applied to the AVC actuator. After the reliability test performed by operating the actuator for 1.6 times 10⁸ cycles, the measured optical scan angle variation and resonant frequency change were within 8 Hz and 1.1%, respectively.