Electrostatic micromirror arrays fabricated with bulk and surface micromachining techniques

High-density micromirror arrays have been fabricated with a process that combines the benefits of both bulk and surface micromachining. Arrays fabricated with this technique are characterized by flat mirrors, high spring constant uniformity, and high yield. Each pixel consists of a mirror-in-gimbal structure that allows the mirror to rotate about two orthogonal axes when a bias is placed on electrodes residing beneath the mirror. A new dry release process is introduced as a simple, effective alternative to critical point drying for releasing the structures.