Performance comparison of Pt/Au and Ni/Au Schottky contacts on Al_xGa_(1-x)N/GaN heterostructures at high temperatures  

作　　者：林芳 沈波 卢励吾 马楠 许福军 苗振林 宋杰 刘新宇 魏珂 黄俊 

机构地区：[1]State Key Laboratory of Artificial Microstructure and Mesoscopic Physics,School of Physics,Peking University [2]Institute of Microelectronics,Chinese Academy of Sciences

出　　处：《Chinese Physics B》2010年第12期478-483,共6页中国物理B（英文版）

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)

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.

关 键 词：gate leakage current high temperature Frenkel-Poole emission 

分 类 号：O522.2[理学—高压高温物理]