Testing of "Venetian-Blind" silicon microstructures with optical methods

• Published in: Journal of microelectromechanical systems Vol. 15; no. 3; pp. 588 - 596
• Main Authors: Merlo, S., Annovazzi-Lodi, V., Benedetti, M., Carli, F., Norgia, M.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.06.2006; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Arrays; Camber; Devices; Electric potential; Exact sciences and technology; Gratings; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; interferometry; Laser feedback; Mathematical models; Mechanical instruments, equipment and techniques; Micromechanical devices and systems; microoptoelectromechanical systems (MOEMS); Microstructure; optical diffraction; Optical feedback; Optical interferometry; Performance evaluation; Physics; Resonance; Resonant frequency; Silicon; Studies; Testing; Tilt; Voltage; Integrated optics; Light interferometry; Optical diffraction; Optical interconnections; Semiconductor materials; Capacitive transducer; interferometry; Diffraction pattern; Experimental study; Vibrometer; Inclination; Optical arrays; Laser interferometer; Electrostatic machine; microoptoelectromechanical systems (MOEMS); Feedback; Resonance frequency; Modelling; Gratings; Microelectromechanical device; Electrostatic force
• ISSN: 1057-7157; 1941-0158
• DOI: 10.1109/JMEMS.2006.876664

In this paper, we illustrate the design and testing of new silicon microstructures, fabricated by means of a conventional planar process. These "Venetian-blind" structures consist of arrays of narrow, rectangular suspended masses (width =31 /spl mu/m, length =400 /spl mu/m, thickness =15 /spl mu/m), which can be tilted using electrostatic actuation. Characterization of their static and dynamic behavior was performed with optical methods. The diffraction patterns in monochromatic light were analyzed and vibration measurements were performed by means of semiconductor laser feedback interferometry: experimental data on the tilt angle as a function of the applied voltage and on the resonance frequencies are reported. A maximum tilt angle of approximately 1.9/spl deg/ was obtained with a driving voltage in the range of 70-95 V. All the tested devices showed resonance frequencies higher than 80 kHz, which is fast enough (i.e., switching time in the millisecond range) for future use in optical interconnections. Numerical analyses were performed to evaluate the coupled electromechanical behavior of the microstructures, confirming the observed experimental behavior.