Abstract
The Schottky diode behaviors of the TiWNx and the WNx Schottky contacts to n-GaN were investigated at different annealing temperatures. Both TiWNx and WNx films were deposited by the reactive DC sputtering method. The WNx/n-GaN contact exhibited excellent electrical characteristics even after rapid-thermal annealing up to 850°C for 10 s. The ideality factor and barrier height remained 1.09 and 0.80 eV, respectively, after 850°C annealing. However, the TiWNx/n-GaN contact was thermally stable only up to 650°C annealing; the values of the ideality factor and the barrier height were 1.14 and 0.76 eV, respectively, after 650°C annealing and started to degrade when annealed at higher temperatures. The deterioration of the TiWNx/n-GaN contact at higher temperatures was due to the inter-diffusion of the TiWN film and the GaN material.