High-resolution, high-speed microscanner in single-crystalline silicon actuated by self-aligned dual-mode vertical electrostatic combdrive with capability for phased array operation

Abstract

We present micromirrors actuated by self-aligned, high aspect ratio, vertical electrostatic combdrives with multi-level electrical isolation that allows bi-directional and dual-mode (independent rotation and piston motion) operation. The fabrication process is based on self-aligned DRIE of SOI wafers with two device layers. The two oxide layers provide electrode isolation and etch stops for thickness control. Only front-side processing is required. We demonstrate micromirrors of this type with ±9 degrees of optical scanning and 7.5 μm of piston motion under static actuation. Micromirrors designed for resonant scanning have optical scan angles up to ±25 degrees at 13.5 kHz.