Applied Physics Letters · 1999 · 79 citations · 13 references
EngineeringMaterials EngineeringMaterials ScienceElectronic MaterialsSemiconductor DevicesSemiconductor MaterialsIii-v SemiconductorsSemiconductor Device MaterialsSemiconductor HeterostructuresSemiconductor InterfacesSemiconductor PhysicsWide Band Gap SemiconductorsContact FormationContact ResistanceElectrical Contact ResistanceHeterostructure DevicesHeterostructure Field-effect TransistorsHeterostructure TransistorsMetallizationOhmic Contacts
The ohmic contact formation of Al/Ti on AlGaN/GaN heterostructure field effect transistors (HFETs) with and without Si implantation was investigated. Direct implantation and implantation through an AlN capping layer were studied. Compared to implantation through AlN, direct implantation is more effective in reducing the contact resistance. An Al(200 Å)/Ti(1500 Å) bilayer structure, called the “advancing” metallization, was used in this investigation to take advantage of consuming nearly all the top AlGaN layers for easy carrier access to the GaN layer underneath. Combining the direct implantation and the advancing metallization, low contact resistance of the order of 0.25 Ω mm (∼5.6×10−6 Ω cm2) can be readily obtained on HFET structures with an AlGaN layer about 340 Å thick and with an Al fraction of at least 22%.
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Microstructure of Ti/Al ohmic contacts for n-AlGaN
S. Ruvimov, Z. Liliental‐Weber, J. Washburn et al. · Applied Physics Letters · 1998 · 131 citations
Ultra-low resistive ohmic contacts on n-GaN using Si implantation
Jinwook Burm, Kenneth K. Chu, William A. Davis et al. · Applied Physics Letters · 1997 · 114 citations
Ni and Ti Schottky barriers on n-AlGaN grown on SiC substrates
L. S. Yu, D. Qiao, S. S. Lau et al. · Applied Physics Letters · 1998 · 98 citations