摘要
In contrast with Au/Ni/Al0.25Ga0.75N/GaN Schottky contacts, this paper systematically investigates the effect of thermal annealing of Au/Pt/Alo.25Ga0.75N/GaN structures on electrical properties of the two-dimensional electron gas in Alo.25Ga0.75N/CaN heterostructures by means of temperature-dependent Hall and temperature-dependent current-voltage measurements. The two-dimensional electron gas density of the samples with Pt cap layer increases after annealing in N2 ambience at 600℃ while the annealing treatment has little effect on the two-dimensional electron gas mobility in comparison with the samples with Ni cap layer. The experimental results indicate that the Au/Pt/Al0.25Ga0.75N/GaN Schottky contacts reduce the reverse leakage current density at high annealing temperatures of 400-600 ℃. As a conclusion, the better thermal stability of the Au/Pt/Alo.25Gao.75N/GaN Schottky contacts than the Au/Ni/Al0.25Ga0.75N/GaN Schottky contacts at high temperatures can be attributed to the inertness of the interface between Pt and AlxGa1-xN.
In contrast with Au/Ni/Al0.25Ga0.75N/GaN Schottky contacts, this paper systematically investigates the effect of thermal annealing of Au/Pt/Alo.25Ga0.75N/GaN structures on electrical properties of the two-dimensional electron gas in Alo.25Ga0.75N/CaN heterostructures by means of temperature-dependent Hall and temperature-dependent current-voltage measurements. The two-dimensional electron gas density of the samples with Pt cap layer increases after annealing in N2 ambience at 600℃ while the annealing treatment has little effect on the two-dimensional electron gas mobility in comparison with the samples with Ni cap layer. The experimental results indicate that the Au/Pt/Al0.25Ga0.75N/GaN Schottky contacts reduce the reverse leakage current density at high annealing temperatures of 400-600 ℃. As a conclusion, the better thermal stability of the Au/Pt/Alo.25Gao.75N/GaN Schottky contacts than the Au/Ni/Al0.25Ga0.75N/GaN Schottky contacts at high temperatures can be attributed to the inertness of the interface between Pt and AlxGa1-xN.
基金
Project supported by the National Natural Science Foundation of China (Grant Nos. 60906041,10774001,60736033,and 60890193)
the National Basic Research Program of China (Grant Nos. 2006CB604908 and 2006CB921607)
