2D Asymmetric Silicon Micro-Mirror Fabricated with Anodic Bonding between an Ultra-thin Silicon Film by Laser Micro-Processing and a Glass Substrate

Abstract

Asymmetric silicon micro-mirrors are fabricated by the anodic bonding of an ultra-thin silicon film on a glass substrate, followed by the fabrication of ultra-thin silicon microelectromechanical systems (MEMS) mirror structures by laser micro-processing. Laser micro-processing, which merges the direct laser fabrication of ultra-thin silicon and anodic bonding, is easier than the silicon-on-insulator-MEMS process. Typically, polished ultra-thin silicon warps under residual stress. However, a flat surface profile was achieved on the scanning mirror of the silicon micro-mirror by anodic bonding and uniform pressure application. By vibrating the asymmetric silicon micro-mirror with an external vibrating element, we obtained a horizontal operation of 118 Hz and a vertical operation of 11040 Hz at the resonance frequency. The Lissajous pattern was also projected on the screen using the horizontal and vertical operations.