High-resolution microelectromechanical scanners for miniaturized dual-axes confocal microscopes

Abstract

In this paper we present scanning micromirrors, actuated by self-aligned, bidirectional, vertical electrostatic combdrives, for dual-axes confocal microscopy. The fabrication process, which is based on Deep Reactive Ion Etching (DRIE) of Silicon-on-insulator (SOI) wafers with two silicon device layers, requires only three lithography steps for one-dimensional scanners, while an additional two lithography steps must be performed to create two-dimensional scanners. Only front side processing is required and the two oxide layers of the double SOI wafers provide efficient and reliable etch stops. These features combined with the fact that the combs are self aligned, enable high-speed, high-resolution microscanners with stable and reliable operation as required for endoscopic implementations of confocal microscopes.