Catalytic role of Au in Ni/Au contact on GaN(0001)

We investigated the structural behavior of the Ni/Au contact on GaN(0001) a nd found the catalytic role of Au during annealing, using in situ x-ray sca ttering. The oxidation kinetics of Ni during annealing in air was greatly a ffected by the presence of Au. The accelerated GaN decomposition and Ni nit ride formation during annealing in N-2 also provide evidence of the catalyt ic role of Au. The results suggest that oxidized Ni/Au ohmic contact exhibi t better thermal stability than that of the N-2 annealed Ni/Au contacts. (C ) 2001 American Institute of Physics.