Monolithic Silicon Nanowires: A Platform for Electromechanical Characterization
27 April 2016, FENS G015
Abstract: Due to their ability of measuring small forces along with a high-resolution displacement control, microsystems are widely employed as tools for the electromechanical characterization of nanoscale building blocks. However, few challenges remain to be addressed in this field. These include the difficulty of sample-microsystem assembly and the alignment of the sample with respect to the axis of loading. In this talk a monolithic platform is introduced along with a new fabrication technology that has the potential of providing a solution to the challenges of testing in the specific case of top-down silicon nanowires. A two-step Si etching approach is adopted. The first step leads to the formation of a shallow surface protrusion and the second step releases the protrusion in the form of a nanowire. During this second deep etching step, a microsystem –with at least a two-order-of-magnitude scale difference - is also fabricated. The success of integration on SOI wafers is demonstrated via in-situ actuation inside an electron microscope until fracture of the nanowire. The use of the specific technology in the fabrication of micro and nanosystems can potentially lead to a significant reduction in process complexity, as direct access to the nanowire is granted during surface processes such as contact formation and doping.
Bio: B. 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 manages Mechanical Characterization and Microfabrication facilities. Research and development efforts in his group are geared towards mechanical property measurement at micro and nanoscale including the development of accompanying testing devices with specific actuation and readout components. Current focus is placed on batch-compatible fabrication of Si nanowires and development of integration philosophies of these nanowires with micro electromechanical systems, nanowire resonators, development and fabrication of resonant microcantilever-based physical and biological sensors, and characterization of the scale-dependence of mechanical properties. 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.