Skip to main content Accessibility help
×
Home

Impact of Small Miscuts of (0001) Sapphire on the Growth of AlxGa1-xN/AlN

  • Zheng Gong (a1), Wenhong Sun (a1), Jianping Zhang (a2), Mikhail E. Gaevski (a1), Hongmei Wang (a1), Jinwei Yang (a1) and M. Asif Khan (a1)...

Abstract

In this paper, using chemical etching, atomic force microscope (AFM) and High- resolution X-ray diffraction (HRXRD), we report a study of the effect of various small miscuts of (0001) sapphire substrate (<1°) and the way to further improve the material quality. A set of AlN epilayers and AlN/AlxGa1-xN Superlattices (SLs) were grown by Migration-enhanced Metalorganic Chemical Vapor Deposition (MEMOCVD) on vicinal (0001) sapphire substrates. The threading dislocation density was found to be very sensitive to the miscut angles. The etch pit density reduced to 7×106 cm-2 for normal-oriented (0°-off) from the starting value of 7×107 cm-2 for 0.5°-off. We found the surface morphologies can be easily controlled by the different substrate miscut angles. The 1-2 Monolayers (MLs) step flow morphology for normal- oriented substrate changed to step bunches of 10 MLs height for 0.5°-off substrate. Correspondingly, AFM Root Mean Square (RMS) increased from 1.52 to 9.15 Å with a 5um×5um scan. This finding may help enhance the quality of full structure UVLED material and eventually improve the lifetime of UVLEDs.

Copyright

References

Hide All
[1] Fischer, A. J., Allerman, A. A., Crawford, M. H., Bogart, K. H. A., Lee, S. R., Kaplar, R. J., Chow, W. W., Kurtz, S. R., Fullmer, K. W., Figiel, J. J., Appl. Phys. Lett. 84 3394 (2004).
[2] Sun, W. H., Zhang, J. P., Adivarahan, V., Chitnis, A., Shatalov, M., Wu, S., Mandavilli, V., Yang, J. W., Khan, M. A., Applied Physics Letters 85, 531(2004).
[3] Advarahan, V., Chitnis, A., Zhang, J. P., Shatalov, M., Yang, J. W., Simin, G., Khan, M. Asif, Shur, M., and Gaska, R., Appl. Phys. Lett. 79, 4240(2001)
[4] Shen, Xu-Qiang, Shimizu, Mitsuaki and Okumura, Hjime, Jpn. J. Appl. Phys. Vol. 42 (2003) pp. L1293– L1295.
[5] Zhang, Jp, Khan, Ma, Sun, Wh, Wang, Hm, Chen, Cq, Fareed, Q, Kuokstis, E, and Yang, Jw, Applied Physics Letters, 81(23):43924394(2002)
[6] Sun, W. H., Yang, J. W., Zhang, J. P., Gaevski, M. E., Chen, C. Q., Li, J. W., Gong, Z., Su, M., and Khan, M. Asif, phys. stat. sol. (c), 1–4 (2005)
[7] Gong, Zheng, Sun, Wenhong, Wang, Hongmei, , Mikhail, Gaevski, E., Yang, Jinwei, and Khan, M. Asif, to be published

Impact of Small Miscuts of (0001) Sapphire on the Growth of AlxGa1-xN/AlN

  • Zheng Gong (a1), Wenhong Sun (a1), Jianping Zhang (a2), Mikhail E. Gaevski (a1), Hongmei Wang (a1), Jinwei Yang (a1) and M. Asif Khan (a1)...

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed