Process temperature dependence of sputtered MgO/<i>n</i>-type GaN metal–oxide–semiconductor capacitors
Abstract
The temperature dependence of epitaxial growth of MgO on n-type (0001)-oriented GaN by radio frequency magnetron sputtering is investigated. Epitaxial growth is obtained for growth temperatures of 550 °C and above, but polycrystalline films are observed for 500 °C and below. For all process temperatures, it is demonstrated that an interfacial phase is present that ranges from 2 to 3 nm in thickness and does not increase in thickness with temperature. The presence of the interfacial phase is shown to originate from ion bombardment during the initial growth. The electronic properties of metal–oxide–semiconductor capacitor devices are measured. Wider hysteresis is seen in capacitance–voltage measurements for devices fabricated at lower deposition temperatures. The less stable electrical performance of films grown at lower temperatures is shown to be related to both interface and bulk defects.
Article Details
Journal Info
Journal of Applied Physics
American Institute of Physics
Authors (10)
Liron Shvilberg
Department of Materials Science and Engineering, University of Virginia 1 , Charlottesville, Virginia 22904,
Haotian Xue
Department of Electrical and Computer Engineering, North Carolina State University 2 , Raleigh, North Carolina 27612,
Elia J. Palmese
Department of Electrical and Computer Engineering, North Carolina State University 2 , Raleigh, North Carolina 27612,
Helge H. Heinrich
Nanoscale Materials Characterization Facility, University of Virginia 6 , Charlottesville, Virginia 22904,
Joanne Kuan
Department of Materials Science and Engineering, University of Virginia 1 , Charlottesville, Virginia 22904,
Gabrielle C. Abad
Department of Materials Science and Engineering, University of Virginia 1 , Charlottesville, Virginia 22904,
Nikhil Shukla
Department of Electrical and Computer Engineering, University of Virginia 1 , Charlottesville, Virginia 22904,
Stephen J. McDonnell
Department of Materials Science and Engineering, University of Virginia 1 , Charlottesville, Virginia 22904,
Jonathan J. Wierer
Department of Electrical and Computer Engineering, North Carolina State University 1 , Raleigh, North Carolina 27606,
Jon F. Ihlefeld
Department of Materials Science and Engineering, University of Virginia 2 , Charlottesville, Virginia 22904,