18 April 2017 Erdem Alaca

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KOÇ UNIVERSITY PHYSICS SEMINAR
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Speaker : Erdem Alaca, Koç University
Title :Monolithic Silicon Nanowires in Thick SOI: Device Integration Aspects
Date : April 18, 2017 Tuesday
Time : 4:00 P.M.
Cookie & Tea : SCI 103 3:45 P.M.
Place : SCI 103

Abstract:
Si nanowires have been shown to impart significant operational enhancement to microelectromechanical systems (MEMS) as piezoresistive building blocks. Their use is especially promising in next-generation, miniature and low-power sensor platforms for physical and biological applications. However, the need for anchoring suspended nanowires to the surrounding microscale architecture with a two-order-of-magnitude scale difference poses significant integration challenges. Alignment accuracy, interfacial effects in addition to throughput are leading concerns for batch production. In this talk, a monolithic technology is presented providing registration between nano and microscale components up to a thickness of 50 micrometers. Utilizing a combination of a two-stage etch process with a suitable protection technology the silicon nanowire is obtained, while the surrounding microscale architecture is formed within the same silicon crystal. As nanowires are fabricated at the wafer surface – as opposed to lying underneath the thick MEMS layer, the technique is also compatible with surface processes such as contact formation and doping. The implications of the technique are discussed in the case of both passive (double-anchored) and active (MEMS-integrated) devices. Characterization results of the associated mechanical and piezoresistive behavior are presented.

Bio: Erdem Alaca received the B.S. degree in mechanical engineering from Boğaziçi University, Istanbul, Turkey, in 1997, and the M.S. and Ph.D. degrees in mechanical engineering from the University of Illinois at Urbana–Champaign in 1999 and 2003, respectively.

He is currently an Associate Professor in the Department of Mechanical Engineering at Koç University, where he serves as head of Mechanical Characterization Laboratory and manages micro/nanofabrication facilities. His research interests include small-scale mechanical behavior, fabrication technologies and precision instruments based on nanoelectromechanical devices.

Prof. Alaca is a member of the Turkish National Committee on Theoretical and Applied Mechanics and the Institute of Electrical and Electronics Engineers (IEEE). He was a recipient of the 2009 Distinguished Young Scientist Award from the Turkish Academy of Sciences.