Wide Bandgap Semiconductors for Sensing Applications

by Fan Ren

Monday, May 13, 2013 | Toronto, Ontario, Canada

The biosensor market is forecasted to reach $4.4 billion by 2014 in the U.S. This growth will be sustained especially by a high demand for biosensors that can be used for medical applications such as glucose monitoring, biomarker detection for infectious diseases, and cancer diagnosis. In addition, there will be strong demand for biosensors with applications in biodefense, environmental monitoring, food, and pharmaceutical industries. There is currently great interest in developing sensors that could be used in point-of-care applications or on-field measurements to reduce medical costs and emergency room visits. Transistor based sensors are promising for these applications. These sensors need to have high precision, compact size, fast response time, and be sensitive to small amounts of biological material.

Semiconductor properties including current, potential, and impedance characteristics that can be used to directly measure chemical or physical stimuli on the semiconductor surface. The wide energy bandgap semiconductor gallium nitride (GaN) material system is attracting much interest for commercial applications of green, blue, and UV light emitting diodes (LEDs), laser diodes, as well as high speed and high frequency power devices. Due to the wide-bandgap nature of the material (3.2 eV for GaN as compared to 1.12eV for Si), it is very thermally stable, and electronic devices can be operated at temperatures up to 500ºC. The GaN based materials are also chemically stable, and no known wet chemical etchant can etch these materials; this makes them very suitable for operation in chemically harsh environments. GaN based sensors for gas and chemical detection as well as medical applications will be presented.

Fan Ren received a BS degree in applied chemistry from Feng Chia University in 1975; an MS degree in chemical engineering from National Cheng Kung University in 1978; an MS degree in polymer science and engineering, and a PhD in inorganic chemistry from Brooklyn Polytechnic in 1991. He joined the University of Florida (UF) in 1998 where he is a Distinguished Professor in the Department of Chemical Engineering and an ExxonMobil Gator Chemical Engineering Alumni Chair Professor. Prior to joining UF, Ren worked at Bell Labs where he was a key figure in developing GaAs metal semiconductor field effect transistors grown on silicon substrate, carbon-doped InGaP/GaAs heterojunction bipolar transistors, and enhancement mode GaAs and InGaAs metal oxide semiconductor (MOS) field effect transistors. At UF, Dr. Ren has primarily focused on fabrication processes for high breakdown voltage GaN based Schottky and MOS diodes, as well as AlGaN/GaN high electron mobility transistor based sensors.

Dr. Ren’s publications have been cited over 13,500 times in the literature. He is a Fellow of ECS, APS, AVS, IEEE, MRS, and SPIE. He is the co-author of more than 820 journal publications and co-inventor of 31 issued patents. He received the 2008 Electronics and Photonics Division Award from ECS, the 2010 Albert Nerken Award from AVS and the 2010 NASA Tech Brief Initial Award.

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