IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    NBS-NIST Centennial Sunday Sessions
       Session NB-SuP

Paper NB-SuP5
Application-Tunable Chemical Microsensors: Multicomponent Research for New Measurement Technology

Sunday, October 28, 2001, 6:20 pm, Room 121

Session: NBS/NIST Centennial
Presenter: S. Semancik, National Institute of Standards and Technology
Authors: S. Semancik, National Institute of Standards and Technology
R.E. Cavicchi, National Institute of Standards and Technology
M.C. Wheeler, National Institute of Standards and Technology
N.O. Savage, National Institute of Standards and Technology
C.J. Taylor, National Institute of Standards and Technology
Correspondent: Click to Email
For more than 15 years, NIST has been involved in fundamental surface science, thin film science, and sensor science studies directed at advancing solid state chemical sensing technology toward new levels of performance and reliability. Adsorption-induced property changes occurring at the surfaces of thin films have been investigated and employed for detecting and quantifying a wide range of gases and vapors with microscale devices. Tunability for varied applications has been realized through the use of multielement arrays with sensing films of differing composition, and individually adjustable operating temperatures. In this presentation we review efforts in our program, with an emphasis on key interfacial phenomena, as well as on vacuum-based materials processing and characterization. Research to be described includes examination of: vacancy defects in oxide semiconductors (which set base conductance levels for conductometric gas sensing films), micromachining of Si (to produce low power device platforms - "microhotplates"), thermally-activated CVD (to incorporate sensing materials into microscale structures), correlations between adsorbed species and interfacial electronic transport, temperature-driven adsorbate transient phenomena, and microscale chemical cross-talk. In addition, we illustrate the utility of the microhotplate array platforms as research tools for combinatorial optimization of the compositions and microstructures of sensing film materials, and investigation of gas-surface interactions.