Share Email Print
cover

Journal of Micro/Nanolithography, MEMS, and MOEMS

Amorphous TiAl films for micromirror arrays with stable analog deflection integrated on complementary metal oxide semiconductors
Author(s): Jan-Uwe Schmidt; Martin Friedrichs; Andreas Gehner
Format Member Price Non-Member Price
PDF $20.00 $25.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

Large micromechanical mirror arrays (MMA) with analog pixel deflection integrated onto active CMOS address circuitry require both high-quality planar reflective optical surfaces and a stable deflection versus voltage characteristic. However, for implementing a CMOS-compatible surface-micromachining process, certain obstacles such as a restricted thermal budget and a limited selection of suitable materials must be overcome. Amorphous TiAl is presented as a new actuator material for monolithical MEMS integration onto CMOS circuitry. TiAl films may be sputter deposited at room temperature, have an x-ray amorphous structure, and a low stress gradient. The glassy structure and high melting point make TiAl less vulnerable to stress relaxation, which makes TiAl an ideal spring material. One-level actuators with TiAl or Al-TiAl-Al structural layers and two-level actuators with separate TiAl spring and Al-alloy mirror layers were fabricated and tested with respect to their drift stability. The stability of TiAl-based actuators was found to be superior in comparison to one-level Al-alloy actuators. Two-level actuators with TiAl hinges emerge as the most promising design.

Paper Details

Date Published: 1 April 2008
PDF: 8 pages
J. Micro/Nanolith. 7(2) 021012 doi: 10.1117/1.2945230
Published in: Journal of Micro/Nanolithography, MEMS, and MOEMS Volume 7, Issue 2
Show Author Affiliations
Jan-Uwe Schmidt, Fraunhofer-Institut für Photonische Mikrosysteme (Germany)
Martin Friedrichs, Fraunhofer-Institut für Photonische Mikrosysteme (Germany)
Andreas Gehner, Fraunhofer-Institut für Photonische Mikrosysteme (Germany)


© SPIE. Terms of Use
Back to Top