Ultra-low resistance ohmic contacts to GaN with high Si doping concentrations grown by molecular beam epitaxy

Journal Article · Mon Jul 16 00:00:00 EDT 2012 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4738768· OSTI ID:22092044

Afroz Faria, Faiza; Jia, Guo; Pei, Zhao; Guowang, Li; Kumar Kandaswamy, Prem; Wistey, Mark; Huili, Xing; Jena, Debdeep ^[1]

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1. Department of Electrical Engineering, University of Notre Dame, Indiana 46556 (United States)

Ti/Al/Ni/Au ohmic contacts were formed on heavily doped n{sup +} metal-polar GaN samples with various Si doping concentrations grown by molecular beam epitaxy. The contact resistivity (R{sub C}) and sheet resistance (R{sub sh}) as a function of corresponding GaN free carrier concentration (n) were measured. Very low R{sub C} values (<0.09 {Omega} mm) were obtained, with a minimum R{sub C} of 0.035 {Omega} mm on a sample with a room temperature carrier concentration of {approx}5 Multiplication-Sign 10{sup 19} cm{sup -3}. Based on the systematic study, the role of R{sub C} and R{sub sh} is discussed in the context of regrown n{sup +} GaN ohmic contacts for GaN based high electron mobility transistors.

• OSTI ID: 22092044
• Journal Information: Applied Physics Letters, Vol. 101, Issue 3; Other Information: (c) 2012 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALUMINIUM
CARRIER DENSITY
CARRIERS
DOPED MATERIALS
ELECTRIC CONDUCTIVITY
ELECTRIC CONTACTS
ELECTRON MOBILITY
GALLIUM NITRIDES
GOLD
MOLECULAR BEAM EPITAXY
NICKEL
NITROGEN IONS
SEMICONDUCTOR MATERIALS
SILICON ADDITIONS
TEMPERATURE RANGE 0273-0400 K
TITANIUM