A new metallization scheme has been developed to form Ohmic contacts ton-GaN. Contacts were fabricated by sputtering the intermetallic compound,PtIn2on metal–organic vapor phase epitaxy grownn-GaN(n∼5×1017 cm−3)with some of the contacts subjected to rapid thermal annealing. Contacts in the as-deposited state exhibited nearly Ohmic behavior with a specific contact resistance of1.2×10−2 &OHgr; cm2. Contacts subjected to rapid thermal annealing at 800 °C for 1 min exhibited linear current–voltage characteristics and had specific contact resistances less than1×10−3 &OHgr; cm2. Auger depth profiling and glancing angle x-ray diffraction were used to examine the interfacial reactions of thePtIn2/n-GaNcontacts. Consistent with estimated phase diagram information, the results from Auger depth profiling and glancing angle x-ray diffraction indicated the formation of(InxGa1−x)Nat the contact interface, which could be responsible for the Ohmic behavior ofPtIn2contacts. ©1997 American Institute of Physics.