Micromechanical light modulator array fabricated on silicon

Abstract

A micromechanical device is described which consists of a thin metal-coated SiO2 membrane fabricated on an ordinary silicon wafer using techniques compatible with IC processing. The membrane can be deflected electrostatically over large angles (≳5°), at high frequencies (≳40kHz), at least 1010 times without breaking or any noticeable deterioration due to fatigue. A number of adjacent devices have been used as a 16-element light modulator array in a small display system. Calculations of performance parameters are in good agreement with experiment. Advantages of this device over similar previous deformagraphic systems are IC compatibility, good voltage sensitivity, high speed, higher deflections with less fatigue, well-established fabrication techniques, and the possibility of integrating driving and decoding circuitry on the same chip as the modulators. In addition, the complexities of a vacuum environment and e-beam addressing are avoided.