Resume

• 1981

  Doctor of Philosophy (PhD)

  Chemical Engineering

  University of Florida

• 1978

  Bachelor of Science (BS)

  Chemical Engineering

  University of Kansas

• Materials Science

  Nitride semiconductors

  Nanotechnology

  Crystal Growth

  Wet Chemical Etching

  Chemical Engineering

  Semiconductor Process

  Physics

  Defect Identification

  Teaching

  Higher Education

  Thermodynamics

  Boron compound semiconductors

  Experimentation

  Excellent electronic transport in heterostructures of graphene and monoisotopic boron-nitride grown at atmospheric pressure

  The properties of hBN single crystals produced by an atmospheric pressure process are compared to the best ever reported in the literature.

  Excellent electronic transport in heterostructures of graphene and monoisotopic boron-nitride grown at atmospheric pressure

  M.J. Kirkham

  Clinton Whiteley

  ournal of Physics and Chemistry of Solids

  The coefficients of thermal expansion for icosahedral boron arsenide are reported.

  The coefficient of thermal expansion of boron arsenide (B12As2) between 25 °C and 900 °C

  Takao Mori

  Isao Ohkubo

  Clint D. Frye

  Journal of the Physical Society of Japan

  The electrical conductivity and thermoelectric properties of B12As2 were measured as a function of temperature.

  Seebeck coefficient and electrical resistivity of single crystal B12As2 at high temperatures

  The properties of the insulator-gallium nitride interface are being optimized by developing an understanding of how process conditions impact the properties. Insulators with high dielectric constants such as alumina (Al2O3) and titanium dioxide (TiO2) are deposited on GaN by atomic layer deposition

  and their morphology

  structure

  and composition of the oxides are thoroughly characterized. Then the electrical properties are measured by capacitance-voltage measurements

  trends are identified

  and these are interpreted based on the physical and chemical properties. The goal is to establish the most important properties that are necessary

  so the oxides and nitrides can be combined to achieve high quality electronic device performance.

  N.Y. Garces

  N. Nepal

  Charles R. Eddy Jr.

  Daming Wei

  Tashfin Hossain

  Boron Phosphide Epitaxy on Silicon Carbide Substrates

  Boron phosphide is a semiconductor potentially useful for neutron detection. It is one of the few boron compound semiconductors for which both n- and p-type conductivity have been reported. In this project

  the epitaxy of BP on 4H-silicon carbide substrates is under study. This is a superior substrate to silicon

  as the lattice constants and coefficients of thermal expansion of BP and 4H-SiC are similar. Characterization of the structural and electrical properties are underway.

  Michael Dudley

  Balaji Raghothamachar

  Balabalaji Padavala

  Clint D. Frye

  Hexagonal Boron Nitride Crystal Growth

  Hexagonal boron nitride (hBN) is a wide band gap semiconductor that is structurally similar to graphite. hBN crystals are grown from metal solutions saturated with boron and nitrogen

  ie the flux growth method

  specifically

  from a combination of hBN

  nickel

  and chromium sources. A saturated molten solution is prepared by heating these components to 1525 °C. Crystals are then formed on the solution surface by slow cooling

  2-4 °C/h. Crystals form with their (0001) planes parallel to the solution surface. The maximum crystal size is approximately 2 mm in diameter that were 10 to 30 microns thick. The crystals have a single Raman peak at 1366 cm-1 with a narrow FWHM of 8 cm-1. The peak room temperature photoluminescence energy centered at 5.5 eV

  with a maximum energy at 5.75 eV. Etch pit densities from etching in molten potassium hydroxide for 1 minute at 430 °C were on the order 10e6 cm-2 to 10e7 cm-2.

  J.Y. Lin

  H.X. Jiang

  T.B. Hoffman

  K Snow

  B. Clubine

  Edgar

  James H.

  Edgar

  National Science Foundation (NSF)

  Radboud University Nijmegen

  Naval Research Laboratory

  Kansas State University

  Naval Research Laboratory

  National Science Foundation (NSF)

  Alexandria

  VA

  Temporary position as a director of the Electronic and Photonic Materials Program in the Division of Materials Research Division of the National Science Foundation.

  Program Director

  Kansas State University

  Guest Lecturer

  At Radboud University

  I investigated the hydride vapor phase epitaxy of scandium nitride on silicon carbide substrates. This semiconductor has applications as a thermoelectric material.

  Radboud University Nijmegen