AVS 53rd International Symposium
    Electronic Materials and Processing Thursday Sessions
       Session EM-ThP

Paper EM-ThP8
Metal Oxide Gas Microsensors for Sensing & Recognition of Low Concentrations of Hazardous Chemicals

Thursday, November 16, 2006, 5:30 pm, Room 3rd Floor Lobby

Session: Electronic Materials and Processing Poster Session
Presenter: J.K. Evju, National Institute of Standards and Technology
Authors: J.K. Evju, National Institute of Standards and Technology
B. Raman, National Institute of Standards and Technology
Z. Boger, OPTIMAL - Industrial Neural Systems, Israel
D.C. Meier, National Institute of Standards and Technology
K.D. Benkstein, National Institute of Standards and Technology
C.B. Montgomery, National Institute of Standards and Technology
S. Semancik, National Institute of Standards and Technology
Correspondent: Click to Email
Considerable motivation exists for developing solid-state microdevices that can reliably detect chemical hazards. We describe our efforts on metal oxide-based conductometric sensor arrays, where the semiconducting oxides on the elements transduce surface chemical interactions into measurable electronic signals. The temperature dependent adsorption, desorption and reaction processes on the thin metal oxide sensing film surfaces give rise to carrier concentration changes that are readily measured on our microhotplate chemical sensor arrays. By utilizing addressable heating of individual sensor elements, together with thermally activated chemical vapor deposition (CVD), we grow different types of oxides onto our microhotplate gas sensor array elements in a self-lithographic process. The selectivity offered by these oxides, coupled with rapid temperature modulation of individual sensor elements, provides a basis of tunability that we take advantage of for gas sensing and recognition. We will illustrate how we harness information from the physical surface processes on our individually addressable sensor array elements, that are comprised of controlled temperature MEMS based microhotplate devices. Our focus will be on challenges associated with recognition of chemical warfare simulants (CWSs) and toxic industrial chemicals (TICs) at low concentrations (ppt to ppb) in air.