Journal of Applied Physics · 2001 · 105 citations · 22 references
EngineeringMaterials EngineeringMaterials ScienceElectronic MaterialsSemiconductor DevicesSemiconductor MaterialsAlloysHigh-temperature MaterialsIii-v SemiconductorsMetal-semiconductor ContactsMetalsSemiconductor Device MaterialsContact AnnealingContact MaterialsContact ResistanceElectrical Contact ResistanceGallium Nitride (Gan) MaterialsMetallizationOhmic ContactsRapid Thermal Annealing
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 ρs, as low as 6.0×10−7 Ω cm2 for a doping level of 1.40×1020 cm−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.
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Very low resistance multilayer Ohmic contact to <i>n</i>-GaN
Zhifang Fan, S. Noor Mohammad, Wook Kim et al. · Applied Physics Letters · 1996 · 455 citations
Low resistance ohmic contacts on wide band-gap GaN
Mao Lin, Zhenqiang Ma, Fengyi Huang et al. · Applied Physics Letters · 1994 · 438 citations