Applied Physics Letters · 2003 · 14 citations · 18 references
EngineeringMaterials EngineeringMaterials ScienceElectronic MaterialsSemiconductor DevicesSemiconductor MaterialsDopingMetal-semiconductor ContactsSemiconductor InterfacesSemiconductor SurfacesSurface PhysicsX-ray Photoelectron SpectroscopyContact FormationContact ResistanceFermi LevelFermi SurfaceGallium NitrideGallium Nitride (Gan) MaterialsMolecular Beam EpitaxyOhmic Contacts
The pronounced effect of in situ Mg surface treatment of p-type GaN grown by ammonia-molecular-beam epitaxy on Ohmic contact formation is reported. The surface of the Mg-doped p-type GaN layer was held at the growth temperature following the growth, and exposed to a Mg beam under a NH3 flow for 15 min. With such a treatment, a specific contact resistance in the low 10−4 Ω cm2 was obtained with as-deposited Ni/Au contacts and without any ex situ treatment. In contrast, contacts on similar p-type layers without such an in situ treatment were highly rectifying even after annealing. A surface Fermi level shift as a result of the in situ treatment was observed by x-ray photoemission studies, and is ascribed, together with the high surface doping concentration, to be the mechanisms behind the effective Ohmic contact formation.
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p- GaN surface treatments for metal contacts
Jingxi Sun, K. A. Rickert, Joan M. Redwing et al. · Applied Physics Letters · 2000 · 156 citations
Natural Sciences, Materials Engineering, Materials Science +17
GaN/AlGaN high electron mobility transistors withf <sub>τ</sub> of 110 GHz
M. Micovic, Nam Nguyen, P. Janke et al. · Electronics Letters · 2000 · 112 citations