中国物理B ›› 2011, Vol. 20 ›› Issue (6): 67303-067303.doi: 10.1088/1674-1056/20/6/067303

• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇    下一篇

Thermal stability of tungsten and tungsten nitride Schottky contacts to AlGaN/GaN

刘芳, 秦志新, 许福军, 赵胜, 康香宁, 沈波, 张国义   

  1. State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China
  • 收稿日期:2010-11-09 修回日期:2011-02-24 出版日期:2011-06-15 发布日期:2011-06-15

Thermal stability of tungsten and tungsten nitride Schottky contacts to AlGaN/GaN

Liu Fang(刘芳), Qin Zhi-Xin(秦志新)†, Xu Fu-Jun(许福军), Zhao Sheng(赵胜), Kang Xiang-Ning(康香宁), Shen Bo(沈波), and Zhang Guo-Yi(张国义)   

  1. State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China
  • Received:2010-11-09 Revised:2011-02-24 Online:2011-06-15 Published:2011-06-15

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摘要： Thin tungsten nitride (WNx) films were produced by reactive DC magnetron sputtering of tungsten in an Ar-N2 gas mixture. The films were used as Schottky contacts on AlGaN/GaN heterostructures. The Schottky behaviours of WNx contact was investigated under various annealing conditions by current-voltage (I-V) measurements. The results show that the gate leakage current was reduced to 10-6 A/cm2 when the N2 flow is 400 mL/min. The results also show that the WNx contact improved the thermal stability of Schottky contacts. Finally, the current transport mechanism in WNx/AlGaN/GaN Schottky diodes has been investigated by means of I-V characterisation technique at various temperatures between 300 K and 523 K. A TE model with a Gaussian distribution of Schottky barrier heights (SBHs) is thought to be responsible for the electrical behaviour at temperatures lower than 523 K.

Abstract: Thin tungsten nitride (WNx) films were produced by reactive DC magnetron sputtering of tungsten in an Ar-N2 gas mixture. The films were used as Schottky contacts on AlGaN/GaN heterostructures. The Schottky behaviours of WNx contact was investigated under various annealing conditions by current-voltage (I-V) measurements. The results show that the gate leakage current was reduced to 10-6 A/cm2 when the N2 flow is 400 mL/min. The results also show that the WNx contact improved the thermal stability of Schottky contacts. Finally, the current transport mechanism in WNx/AlGaN/GaN Schottky diodes has been investigated by means of I-V characterisation technique at various temperatures between 300 K and 523 K. A TE model with a Gaussian distribution of Schottky barrier heights (SBHs) is thought to be responsible for the electrical behaviour at temperatures lower than 523 K.

Key words: AlGaN/GaN heterostructures, tungsten nitride, Schottky contacts

中图分类号:  (III-V semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions)

  • 73.40.Kp
73.40.Sx (Metal-semiconductor-metal structures) 73.30.+y (Surface double layers, Schottky barriers, and work functions)