Contacts to group III nitride semiconductor alloys

In group III nitride semiconductor alloys, such as Al_xGa_1-xN, most contacts are very similar to those for GaN. In this presentation, we have explored a special consideration of the contact metallurgy alloy semiconductors and how interfacial reactions with metals can lead to compositional shifts in the semiconductor alloys beneath the contacts. High temperature annealing of the late transition Ni and Pd on Al_xGa_1-xN leads to compositional shift in the semiconductor immediately beneath the contact metal, as determined by X-ray photoelectron spectroscopy and scanning transmission electron microscopy. It has also been reported that a significant reduction in the resistance of ohmic contacts to n-type Al_xGa_1-xN with x>0.4 takes place using a contact metallurgy. In addition to describing these contacts, we offer a possible explanation for the advantage of using V-based contacts, developed by considering the metallurgy of contacts to the Al_xGa_1-xN semiconductor alloy.