AlGaN/GaN Schottky-Gate HEMTs with low thermal budget V/Al/Mo/Au ohmic contacts

We have fabricated and characterized AlGaN/GaN Schottky-Gate HEMTs using V/Al/Mo/Au metal stack for drain and source ohmic electrodes. The metal stack was annealed at relatively low temperature of 700 degrees C for 30 seconds. A very low contact resistance value of 0.34 Omega.mm was realized as measured from transfer length method test structures. For HEMT devices with gate-to-drain spacing of 10 mu m, a highly competitive value of on-resistance of about 9 Omega.mm was achieved, demonstrating the promise of low-thermal budget V/Al/Mo/Au ohmic contacts for improving the performance of GaN-based devices.