Low-Voltage, Large-Scan Angle MEMS Analog Micromirror Arrays With Hidden Vertical Comb-Drive Actuators

Abstract

This paper reports on novel polysilicon surface-micromachined one-dimensional (1-D) analog micromirror arrays fabricated using Sandia's ultraplanar multilevel MEMS technology-V (SUMMiT-V) process. Large continuous DC scan angle (23.6/spl deg/ optical) and low-operating voltage (6 V) have been achieved using vertical comb-drive actuators. The actuators and torsion springs are placed underneath the mirror (137/spl times/120 /spl mu/m/sup 2/) to achieve high fill-factor (91%). The measured resonant frequency of the mirror ranges from 3.4 to 8.1 kHz. The measured DC scanning characteristics and resonant frequencies agree well with theoretical values. The rise time is 120 /spl mu/s and the fall time is 380 /spl mu/s. The static scanning characteristics show good uniformity (</spl plusmn/3.2%) for a 1 /spl times/ 10 array with a mirror pitch of 150 /spl mu/m. The mechanical crosstalk between adjacent mirrors is less than 37 dB. These micromirror arrays have applications in 1/spl times/N wavelength-selective switches and N/spl times/N wavelength-selective crossconnects in wavelength-division multiplexing (WDM) networks.