Resistivity study of si-doped GaN nanowires grown by catalyst-free MBE

Published

September 16, 2008

Author(s)

Lorelle Mansfield, Paul T. Blanchard, Devin M. Rourke, Aric W. Sanders, Norman A. Sanford, Kristine A. Bertness

Abstract

GaN nanowires doped with silicon were grown on Si(111) substrates by catalyst-free molecular beam epitaxy (MBE). Contacts were fabricated to single nanowires with a Ti/Al metallization scheme. Low-resistance ohmic contacts were achieved after annealing for 60 seconds at 500 ?C in 5 % hydrogen and 95 % argon ambient. Using current-voltage curves to determine the resistance of several wires from each growth run and SEM to measure the dimensions, we were able to calculate a specific contact resistivity for nanowires with different doping densities. A growth run consisting of highly doped wires had a specific contact resistivity of 1.9 x 10-5 Ω-cm2. We also estimated a bulk resistivity of approximately 0.003 Ω-cm and a free carrier concentration in the nanowires on the order of 1.5 to 2 x 1019 cm-3. Moderately doped nanowires had a higher specific contact resistivity of 3.5 x 10-4 Ω-cm2, an estimated bulk resistivity of 0.01 Ω-cm, and a free carrier concentration on the order of 3.5 x 1018 cm-3.

Proceedings Title

Proc., International Conference of Nitride Semiconductors

Conference Dates

September 16-21, 2007

Conference Location

Las Vegas, NV

Conference Title

International Conference of Nitride Semiconductors

Pub Type

Conferences

Keywords

contact resistance, GaN, molecular beam epitaxy, nanostructures, nanowires, nitrides, resistivity

Citation

Mansfield, L. , Blanchard, P. , Rourke, D. , Sanders, A. , Sanford, N. and Bertness, K. (2008), Resistivity study of si-doped GaN nanowires grown by catalyst-free MBE, Proc., International Conference of Nitride Semiconductors, Las Vegas, NV (Accessed October 5, 2024)