Investigation on Dislocations in C-Plane Electron-Irradiated GaN Epilayers by Wet Chemical Etching

Abstract:

The dislocations in electron-irradiated c-plane n-GaN epitaxial layers grown on c-plane sapphire substrates by MOCVD were revealed by several different wet chemical etching methods. And the defect-selective etching method combined with SEM was carried out to study the mechanism of dislocations generation of GaN. SEM images of GaN epilayers with several individual methods are in good agreement with each other. Among all the defects, threading dislocations (TDs) dominated in the GaN epilayers and these defects could be divided into three types. In addition, the EPDs after annealing at various temperatures were studied. The experimental results showed that suitable thermal annealing can eliminate some dislocations.

• Periodical: Advanced Materials Research (Volumes 335-336)
• Pages: 531-534
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.335-336.531
• Online since: September 2011
• Authors: Yuan Tian, Li Min Liang, Wen Cheng Wu, Qiu Yan Hao, Cai Chi Liu
• Keywords: Dislocation, Electron-Irradiated Gan, Wet Chemical Etching

References

[1] S. Nakamura, T. Mukai, M. Senoh, Candela-class high-brightness InGaN/AlGaN double- heterostructure blue-light-emitting diodes, Appl. Phys. Lett. 64 (1994) 1687-1689.

DOI: 10.1063/1.111832

[2] S. Nakamura, T. Mukai, M. Senoh, High-brightness InGaN/AlGaN double-heterostructure blue- green-light-emitting diodes, J. Appl. Phys. 76 (1994) 8189-8191.

DOI: 10.1063/1.357872

[3] S. Nakamura, M. Senoh, N. lwasa, S. Nagahama, T. Yamada, T. Mukai, Superbright green InGaN single-quantum-well-structure light-emitting diodes, Jpn. J. Appl. Phys. 34 (1995) L1332-L1335.

DOI: 10.1143/jjap.34.l1332

[4] J.S. Speck, S.J. Rosner, The role of threading dislocations in the physical properties of GaN and its alloys, Physica B. 273/274 (1999) 24-32.

DOI: 10.1016/s0921-4526(99)00399-3

[5] I. Akasaki, Renaissance and progress in crystal growth of nitride semiconductors, J. Cryst Growth. 198/199 (1999) 885-893.

DOI: 10.1016/s0022-0248(98)01227-5

[6] M. Iwaya, T. Takeuchi, S. Yamaguchi, C. Wetzel, H. Amano, I. Akasaki, Reduction of etch pit density in organometallic vapor phase epitaxy-grown GaN on sapphire by insertion of a low-temperature-deposited buffer layer between high-temperature-grown GaN, Jpn. J. Appl. Phys. 37 (1998) L316-L318.

DOI: 10.1143/jjap.37.l316

[7] M.S. Minsky, M. White, E.L. Hu, Room-temperature photoenhanced wet etching of GaN, Appl. Phys. Lett. 68 (1996) 1531-1533.

DOI: 10.1063/1.115689

[8] H.X. Jiang, S.X. Jin, J. Li, J. Shakya, J.Y. Lin, Ⅲ-nitride blue microdisplays, Appl. Phys. Lett. 78 (2001) 1303-1305.

DOI: 10.1063/1.1351521

[9] L. Lu, Z.Y. Gao, B. Shen, F.J. Xu, S. Huang, Z.L. Miao, Y. Hao, Z.J. Yang, G.Y. zhang, X.P. Zhang, J. Xu, D.P. Yu, Microstructure and origin of dislocation etch pits in GaN epilayers grown by metal organic chemical vapor deposition, J. Appl. Phys. 104 (2008) 123525.

DOI: 10.1063/1.3042230

[10] Z.Y. Gao, Y. Hao, J.C. Zhang, J.F. Zhang, H.F. Chen, J.Y. Ni, Observation of dislocation etch pits in GaN epilayers by atomic force microscopy and scanning electron microscopy, Chinese Journal of Semiconductors. 28 (2007) 473-479.