A metallization scheme has been developed for obtaining low ohmic contacts to n-GaN with a low contact resistance. The metal contact is a Ti/Al/Ti/Au composite with layers that are respectively 30, 100, 30, and 30 nm thick. Contacts with a specific contact resistivity ρ[sub s], as low as 6.0x10[sup -7] Ω cm[sup 2] for a doping level of 1.40x10[sup 20] cm[sup -3] were obtained after annealing the sample for 30 s at 750 °C in a rapid thermal annealer. The Ti placed on top of the traditional Ti/Al contact appears to have the advantage of tying up the excess Al; therefore it does not form a mottled contact. Some of the additional Ti-Al intermetallic alloys that are formed also have beneficial effects. The Ti-Au layer forms a robust upper portion of the composite, which enables the contacts to have high-temperature applications. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]