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Fluidic measurement of electric field sensitivity of Ti-GaAs Schottky junction gated field effect biosensors

Chang, Woo-Jin and Suk, Ho-Jun and Newaz, A. K. M. and Wallace, Kirk D. and Wickline, Samuel A. and Solin, Stuart A. and Bashir, Rashid (2010) Fluidic measurement of electric field sensitivity of Ti-GaAs Schottky junction gated field effect biosensors. Biomedical Microdevices, 12 (5). pp. 849-854.

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Official URL: http://www.springerlink.com/content/b71u1p53565w64...

Abstract

We report the electric field and pH sensitivity of fluid gated metal-semiconductor hybrid (MSH) Schottky structures consisting of a Titanium layer on n-type GaAs. Compared to standard field-effect sensors, the MSH Schottky structures are 21 times more sensitive to electric field of −46.6 V/cm and show about six times larger resistance change as pH of the solution is decreased from 8.17 to 5.54. The potential change at the fluidic gate and passivation layer interface by bias voltages and pH are mirrored by the metal shunt, resulting in larger depletion widths under the Schottky junction and resistance change as compared to sensors with no Schottky junction. 2D numerical simulation results are in good agreement with the measured data and suggest thinner mesa with lower doping density can further increase device sensitivity.

Item Type:Article
Subjects:Physical Science > Nanophysics
Physical Science > Nano objects
Material Science > Nanochemistry
Material Science > Nanostructured materials
Divisions:Faculty of Engineering, Science and Mathematics > School of Physics
Faculty of Engineering, Science and Mathematics > School of Chemistry
ID Code:9502
Deposited By:JNCASR
Deposited On:22 Sep 2010 06:52
Last Modified:22 Sep 2010 06:52

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