physica status solidi (a) · 2017 · 64 citations · 28 references
EngineeringMaterials EngineeringMaterials ScienceElectronic MaterialsSemiconductor DevicesSemiconductor MaterialsSemiconductor Device MaterialsSemiconductor HeterostructuresSemiconductor InterfacesWide Band Gap SemiconductorsWide-bandgap Semiconductor DevicesWide-bandgap SemiconductorsFabricationHeterostructure DevicesMetallizationOhmic ConductionOhmic ContactsOhmic MaterialsSchottky BarriersSchottky Contacts
Due to the ultra-wide bandgap of Al-rich AlGaN, up to 5.8 eV for the structures in this study, obtaining low resistance ohmic contacts is inherently difficult to achieve. A comparative study of three different fabrication schemes is presented for obtaining ohmic contacts to an Al-rich AlGaN channel. Schottky-like behavior was observed for several different planar metallization stacks (and anneal temperatures), in addition to a dry-etch recess metallization contact scheme on Al0.85Ga0.15N/Al0.66Ga0.34N. However, a dry etch recess followed by n+-GaN regrowth fabrication process is reported as a means to obtain lower contact resistivity ohmic contacts on a Al0.85Ga0.15N/Al0.66Ga0.34N heterostructure. Specific contact resistivity of 5 × 10−3 Ω cm2 was achieved after annealing Ti/Al/Ni/Au metallization.
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Low resistance ohmic contacts on wide band-gap GaN
Mao Lin, Zhenqiang Ma, Fengyi Huang et al. · Applied Physics Letters · 1994 · 438 citations
InAlN/AlN/GaN HEMTs With Regrown Ohmic Contacts and $f_{T}$ of 370 GHz
Yuanzheng Yue, Zongyang Hu, Jia Guo et al. · IEEE Electron Device Letters · 2012 · 336 citations
A survey of ohmic contacts to III-V compound semiconductors
Albert G. Baca, F. Ren, J.C. Zolper et al. · Thin Solid Films · 1997 · 236 citations · Full text