Electrical and microstructure analysis of nickel-based low-resistance ohmic contacts to n-GaSb
Nassim Rahimi,
Andrew A. Aragon,
Orlando S. Romero,
Darryl M. Shima,
Thomas J. Rotter,
Sayan D. Mukherjee,
Ganesh Balakrishnan,
Luke F. Lester
Affiliations
Nassim Rahimi
Center for High Technology Materials, University of New Mexico, Albuquerque, New Mexico 87106, USA
Andrew A. Aragon
Center for High Technology Materials, University of New Mexico, Albuquerque, New Mexico 87106, USA
Orlando S. Romero
Center for High Technology Materials, University of New Mexico, Albuquerque, New Mexico 87106, USA
Darryl M. Shima
Center for High Technology Materials, University of New Mexico, Albuquerque, New Mexico 87106, USA
Thomas J. Rotter
Center for High Technology Materials, University of New Mexico, Albuquerque, New Mexico 87106, USA
Sayan D. Mukherjee
Center for High Technology Materials, University of New Mexico, Albuquerque, New Mexico 87106, USA
Ganesh Balakrishnan
Center for High Technology Materials, University of New Mexico, Albuquerque, New Mexico 87106, USA
Luke F. Lester
Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State University, 302 Whittemore, Blacksburg, Virginia, 24061, USA
Ultra low resistance ohmic contacts are fabricated on n-GaSb grown by molecular beam epitaxy. Different doping concentrations and n-GaSb thicknesses are studied to understand the tunneling transport mechanism between the metal contacts and the semiconductor. Different contact metallization and anneal process windows are investigated to achieve optimal penetration depth of Au in GaSb for low resistances. The fabrication, electrical characterization, and microstructure analysis of the metal-semiconductor interfaces created during ohmic contact formation are discussed. The characterization techniques include cross-sectional transmission electron microscopy and energy dispersive spectroscopy. Specific transfer resistances down to 0.1 Ω mm and specific contact resistances of 1 × 10−6 Ω cm2 are observed.
