y. mizoguchi1 and m. esashi2
DESCRIPTION
Design and Fabrication of a Pure -Rotation Microscanner with Self-Aligned Electrostatic Vertical Combdrives in Double SOI wafer. Y. Mizoguchi1 and M. Esashi2 1NEMS Platform Research Division, Leading-Edge Technology Development Headquarters, CANON Inc. - PowerPoint PPT PresentationTRANSCRIPT
Y. Mizoguchi1 and M. Esashi21NEMS Platform Research Division, Leading-Edge Technology Development Headquarters, CANON Inc. TRANDUCERS’05The 13th International Conference on Solid-State Sensors, Actuators and Microsystems, Seoul, Korea, June 5-9, 2005, Vol. 1, pp 65-68
Design and Fabrication of a Pure -Rotation Microscanner with Self-Aligned ElectrostaticVertical Combdrives in Double SOI wafer
ReporterReporter ：： CHEN CHIH CHUNGCHEN CHIH CHUNG
2
OutlineOutline
Motivation
Design and Fabrication
Experimental Results
Conclusion
Motivation
Vertical combdrive actuators commonly face the requirement of placing two sets of comb electrodes at different vertical positions, and require critical alignment of the comb electrodes
A tilt motion without unwanted vertical and lateral piston motions of a mirror is very important for a scanning device for high resolution
Increasing the rigidity of the torsional springs helps decreace the unwanted vertical and lateral piston motions, but increases the driving voltages
Design -Schematic view of the pure-rotation microscanner
Schematic cross-sectional view of the layout of the comb electrodes
Schematic cross-sectional view of the pure-rotation actuation.
a) clockwise rotation is achieved by applyingvoltages to electrodes E1,E2,E3,and E6.
b) anticlockwise rotation is achieved by applyingvoltages to electrodes E1,E2,E4,and E5.
Fabrication process
Thermal fusion bonding
etching out with TMAH solution
patterned by DRIE
self-aligned DRIE
Fabrication process
DRIE and BHF etching
SEM of the fabricated device
a) Top view of the device.
b) Close-up view of the torsional springs and the movable and fixed comb electrodes.
Shows the interferometric image of the surface of the fabricated device measured by WYKO
The measured characteristics of the devicein static scanning using the pure-rotation actuation
7.6 degrees at 150 Vdc
CONCLUSION
The pure-rotation microscanner has the following features
(a) The layout of the comb electrodes makes it possible to apply pure torque to the torsional springs.
(b) The fabrication process includes self-alignment and thickness control of the structure in the DRIE
(c) The static optical deflection angle was measured as 7.6 degrees at 150Vdc.
The improvement of the mirror flatness is our current interest