Authors: M. Haris, H. Qu, A. Jain, H. Xie
Affilation: Oakland University, United States
Pages: 203 - 206
Keywords: micromirror, CMOS-MEMS, electrostatic, vertical comb-drives
This paper reports the design and microfabrication of an electrostatically actuated CMOS-MEMS micromirror with elevated electrodes. Device structural design and fabrication process are detailed and device performance such as scanning angles is simulated using CoventorWare. With a 30 V driving voltage applied to the mismatched comb drives alternately, a rotational angle of over plus-minus 12 degree can be realized. The uniqueness of this structure also includes the integration of polysilicon heaters in the bimorph beams. By passing current in these polysilicon heaters, the bimorph beams, which consist of SiO2 and aluminum thin films, can be electrothermally driven to tune the elevation height of the stator comb fingers. A resonant frequency ratio of over 4 is chosen between the bimorph beams and torsional springs to ensure stable operation of the device. The device chips were fabricated using AMI 0.5 µm CMOS technology through MOSIS. Post-CMOS microfabrication has been performed for device release and detailed fabrication process flow is given. More results will be presented in abstract update or full paper.