Investigating Capacitance Behavior of Nanomaterials through Split-tip Scanning Capacitance Microscopy

ORAL

Abstract

A split-tip Near-field Scanning Optical Microscope (NSOM) probe is used to measure capacitance. We build a model for the instrument by solving Poisson's equation for a simplified system using the finite element program Femlab. The governing equations and boundary conditions are paramount in obtaining a converging solution. Values obtained from a simple capacitor model are compared to calculated values found from the Scanning Capacitance setup. The split-tip capacitance values will be compared with measured values from the Scanning Conductivity Microscopy (SCM) experimental setup. This scanning probe microscope uses two electrically-isolated electrodes fabricated on one split-tip probe to investigate local electrical behavior of nanostructures. The split-tip probe, which we have recently developed, is optimized for light coupling into a particular region of a nanostructure while non-contact capacitance measurements are simultaneously made between the two electrodes. The capacitance is influenced by the presence of a conducting region on the surface beneath the electrodes. The capacitance coupled or scanning conductivity mode allows rapid characterization of large areas of the sample so that regions of interest can be identified for further study. The finite element model aids in the quantification and understanding of the data.

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Authors

  • Beverly Clark III

    NCSU Near-field Optics Lab

  • Jaetae Seo

    NC A\&T State University, Penn State University, The Ohio State University, Wright State University, AFRL/RYHC Hanscom AFB MA 01731, Harvard University, The College of William \& Mary, NCSU Near-field Optics Lab, University of North Carolina at Chapel Hill, Weizmann, PTB, Braunschweig, UMass, TUNL/Duke, UConn, UConn/TUNL, University of North Carolina, Chapel Hill, North Carolina State University, Brimrose Corporation of America, Hampton University, Elizabeth City State University, Department of Physics, Florida A\&M University, Tallahassee, Florida-32307, Department of Physics, University of Rajshahi, Rajshahi-6205, Bangladesh, Department of Physics, University of Rajshahi, Rajshah-6205, Bangladesh, Department of Physics, University of Rajshahi, Rajshahi-6250, Bangladesh, Department of Physics, University of Rajshahi-6205, Bangladesh, Alabama A\&M University, Fachbereich C-Mathematik und Naturwissen-Schaften, Bergische Universitat Wuppertal, D-42097, Wuppertal, Germany, NC State University, College of William and Mary, Department of Physics, N.C. State Univeristy, Research Triangle Institute, NCSU Physics, Pennsylvania State University, Tsinghua University, Lawrence Berkeley National Laboratory, Vanderbilt University, LSU, UNIRIB, U. Tenn., ORNL, Miss. St., University of North Carolina at Chapel Hill and Triangle Universities Nuclear Laboratory, NCA\&T, Duke, NCCU, UNC-Chapel Hill, Department of Physics, North Carolina State University, Department of Chemistry, North Carolina State University, Department of Physics and Astronomy, University of North Carolina, Chapel Hill, Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hil, North Carolina School of Science and Mathematics, Department of Physics, Elon University, Dept. of Physics - UNC - Chapel Hill, Nanyang Technological University, School of Materials Sciences and Engineering, Singapore, Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-3255, USA, Argonne National Laboratory, Department of Physics, Hampton University, Hampton, VA 23668, Korea Research Institute of Standards and Science, Daejeon, 305-600, South Korea, Department of Chemistry, Gyeongsang National University, Jinju 660-701, South Korea, Electronics and Telecommunications Research Institute, Daejeon, 305-700, South Korea, Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, MA 01609