Correlation between microstructure and temperature dependent electrical behavior of annealed Ti/Al/Ni/Au Ohmic contacts to AlGaN/GaN heterostructures

Journal Article · Mon Nov 11 00:00:00 EST 2013 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4828839· OSTI ID:22254074

Iucolano, Ferdinando ^[1]; Greco, Giuseppe; Roccaforte, Fabrizio ^[2]

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1. IPD R and D, STMicroelectronics, Stradale Primosole 50, 95121 Catania (Italy)
2. CNR-IMM, Strada VIII, n. 5, Zona Industriale, 95121 Catania (Italy)

This letter reports on the temperature behavior of the structural and electrical properties of Ti/Al/Ni/Au contacts to AlGaN/GaN heterostructures. While Ohmic contacts formed at 750 °C showed a decreasing temperature behavior of the specific contact resistance ρ{sub C}, which was explained by a thermionic field emission mechanism, an increasing trend is observed in the contacts formed at 850 °C. In this case, ρ{sub C} exhibits a “metal-like” behavior, i.e., describable by a T{sup 1.8} dependence. The microstructural analysis of the interfacial region allowed to explain the results with the formation of metallic intrusions contacting directly the two dimensional electron gas.

• OSTI ID: 22254074
• Journal Information: Applied Physics Letters, Vol. 103, Issue 20; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
36 MATERIALS SCIENCE
ANNEALING
CORRELATIONS
ELECTRICAL PROPERTIES
ELECTRON GAS
FIELD EMISSION
GALLIUM NITRIDES
MICROSTRUCTURE
PLUTONIC ROCKS
TEMPERATURE DEPENDENCE