AVS 59th Annual International Symposium and Exhibition
    MEMS and NEMS Monday Sessions
       Session MN-MoA

Paper MN-MoA6
Fabrication and Testing of Suspended Piezoelectric Nanocomposite Membranes

Monday, October 29, 2012, 3:40 pm, Room 10

Session: Multi-scale Interactions of Materials and Fabrication at the Micro- and Nano-scale
Presenter: J.R. Fox, Ducommun Miltec
Authors: J.R. Fox, Ducommun Miltec
S.B. Horowitz, Ducommun Miltec
J.P. Cortes, Ducommun Miltec
M.S. Allen, Ducommun Miltec
A.D. Mathias, Ducommun Miltec
L.A. Barkett, Ducommun Miltec
M. Sanghadasa, U.S. Army Aviation and Missile Research Development and Engineering Center
Correspondent: Click to Email
The fabrication and testing of a novel piezoelectric microphone consisting of a suspended nanocomposite membrane of oriented hydrothermally-grown ZnO nanorods in a matrix of SU-8 photopolymer is detailed. High aspect ratio ZnO nanorods (0.5 – 1 microns long) were grown using a low temperature hydrothermal process on a patterned gold electrode on a wet-oxidized wafer. Then SU-8 photoresist was spin-coated over the rods to a thickness of approximately 1 micron and subsequently exposed and developed to reveal access to the bottom bond pads of the structure. A top electrode was deposited via sputtering and patterned on the SU-8 polymer. Finally a deep reactive ion etch (Bosch process) through-wafer silicon etch was used to release the nano-piezo-membranes in diameters of 50-400 microns. The infiltration of SU-8 photopolymer into the nanorods was observed to improve during long post-exposure bakes of the polymer as well as produce an improvement in vacuum compatibility of the polymer. Laser Doppler vibrometry (LDV) was used to characterize the actuation of the nano-piezo-membrane both under application of a driving potential as well as during acoustic load from a plane-wave tube.