Vacuum Wafer Level Packaged Two-Dimensional Optical Scanner by Anodic Bonding

Vacuum wafer-level packaged two-dimensional optical scanners actuated by vertical electrostatic combs have been developed. A 1 mm-diameter gimbal mirror with high frequency deflection and a surrounding 2.5times3 mm movable frame with low frequency deflection are fabricated in a SOI wafer. Wafer-level packaging with anodically bonded borosilicate glass substrates on both sides together with non-evaporable getters fixed on the lower glass substrate allows hermetic sealing in high vacuum. The gimbal mirror and the movable frame are both deflected mechanically plusmn12 deg. at a resonant frequency of 25.1 kHz with a driving voltage of 18 V, and at a resonant frequency of 78.6 Hz with a driving voltage of 10 V, respectively. The internal pressure of the device is 20 Pa.