Surface-micromachined 2-D optical scanners with high-performancesingle-crystalline silicon micromirrors

We have developed a novel batch-fabrication single-crystalline silicon micromirror bonding process to fabricate optically flat micromirrors on polysilicon surface-micromachined two-dimensional (2-D) scanners. The electrostatically actuated 2-D scanner has a mirror area of 460 μm×460 μm and an optical scan angle of ±7.5°. Compared with micromirror made by standard polysilicon surface-micromachining process, the radius of curvature of the micromirror has been improved by 150 times from 1.8 to 265 cm, with surface roughness <10 nm