| Original Articles |
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Barrier Enhancement Effect of Postannealing in Oxygen Ambient on Ni/AlGaN Schottky Contacts |
| SANG Li-Wen;QIN Zhi-Xin;CEN Long-Bin;CHEN Zhi-Zhong;YANG Zhi-Jian;SHEN Bo;ZHANG Guo-Yi |
| State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, Research Center for Wide Gap Semiconductor, School of Physics, Peking University, Beijing 100871 |
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| Cite this article: |
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SANG Li-Wen, QIN Zhi-Xin, CEN Long-Bin et al 2007 Chin. Phys. Lett. 24 2938-2941 |
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Abstract Al0.2Ga0.8N/GaN samples are grown by metalorganic chemical vapour deposition (MOCVD) method on (0001) sapphire substrates. A 10nm-thick Ni layer is deposited on AlGaN as the transparent Schottky contact. The effect of postannealing in oxygen ambient on the electrical properties of Ni/AlGaN is studied by current--voltage--temperature (I--V--T) measurement. The annealing at a relatively low temperature of 300°C for 90s results in a
decrease of the ideality factor from 2.03 to 1.30 and an increase of the
Schottky barrier height from 0.77eV to 0.954eV. The I--V--T analysis confirms the improvement originated from the formation of NiO, a layer with higher resistance, which could passivate the surface states of AlGaN and suppress the tunnelling current. Furthermore, the annealing also leads to an increase of the transmittance of the contacts from 57.5% to 78.2%, which would be favourable for AlGaN-based photodetectors.
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| Keywords:
73.30.+y
85.30.De
73.61.Ey
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Received: 09 May 2007
Published: 20 September 2007
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| PACS: |
73.30.+y
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(Surface double layers, Schottky barriers, and work functions)
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85.30.De
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(Semiconductor-device characterization, design, and modeling)
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73.61.Ey
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(III-V semiconductors)
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[1] Wang X L, Zhao D G, Yang H and Liang J W 2007 Chin. Phys.Lett. 24 774
[2] Collins C J, Chowdhury U, Wong M M, Yang B, Beck A L, Dupuis R Dand Ampbell J C 2002 Appl. Phys. Lett. 80 3754
[3] Biyikli N, Kimukin I, Kartaloglu T, Aytur O and Ozbay E 2003 Appl. Phys. Lett. 82 2344
[4] Chen C H, Chang S J, Su Y K, Chi G C, Chi J Y, Chang C A, Sheu J Kand Chen J F 2001 IEEE Photon. Technol. Lett. 13 848
[5] Gila B P, Hlad M, Onstine A H, Frazier R, Thaler G T, Herrero A,Lambers E, Abernathy C R and Pearton S J 2005 Appl. Phys. Lett. 87 163503
[6] Bradleya S T and Goss S H 2005 J. Appl. Phys. 97 084502
[7] Chen L C, Chen F R and Kai J J 1999 J. Appl. Phys. 863826
[8] Kim H, Schuette M, Jung H, Song J H, Lee J and Lu W 2006 Appl.Phys. Lett. 89 053516
[9] Sze S M 1969 Physics of Semiconductor Devices (New York:Wiley-Interscience)
[10] Yu L S, Liu Q Z, Xing Q J, Qiao D J and Lau S S 1998 J. Appl.Phys. 84 2099
[11] Kang H C, Seo S H and Jang H W 2003 Appl. Phys. Lett. 83 2139
[12] Hu C Y, Qin Z X, Feng Z X, Chen Z Z, Yang H, Yang Z J, Yu T J, HuX D, Yao S D and Zhang G Y 2005 Chin. J.Semiconduct. 26 1154 (in Chinese)
[13] Sawada T, Ito Y, Imai K, Suzuki K, Tomozawa H and Sakai S 2000 Appl. Surf. Sci. 159/160 449 |
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