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Characterization study of GaN-based epitaxial layer and light-emitting diode on nature-patterned sapphire substrate

  • H.Y. Lin (a1), Y.J. Chen (a1), C.L. Chang (a1), X.F. Li (a1), C.H. Kuo (a2), S.C. Hsu (a3) and C.Y. Liu (a4)...

Abstract

Chemical wet etching on c-plane sapphire wafers by three etching solutions (H3PO4, H2SO4, and H3PO4/H2SO4 mixing solution) was studied. Among these etching agents, the mixing H3PO4/H2SO4 solution has the fastest etching rate (1.5 μm/min). Interestingly, we found that H2SO4 does not etch the c-plane sapphire wafer in thickness; instead, a facet pyramidal pattern is formed on the c-plane sapphire wafer. GaN light-emitting diode (LED) epitaxial structure was grown on the sapphire wafer with the pyramidal pattern and the standard flat sapphire wafer. X-ray diffraction and photoluminescence measurement show that the pyramidal pattern on the sapphire wafer improved crystalline quality but augmented the compressive stress level in the GaN LED epilayer. The horizontal LED chips fabricated on the pyramidal-patterned sapphire wafer have a larger light output than the horizontal LED chips fabricated on the standard flat sapphire wafer by 20%.

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Corresponding author

a)Address all correspondence to this author. e-mail: chengyi@cc.ncu.edu.tw

References

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1.Koike, M., Shibata, N., Kato, H., and Takahashi, Y.: Development of high efficiency GaN-based multiquantum-well light-emitting diodes and their applications. IEEE J. Sel. Top. Quantum Electron. 8, 271 (2002).
2.Lydecker, S.H., Leadford, K.F., and Ooyen, C.A.: Lighting industry acceptance of solid state lighting. Proc. SPIE Int. Soc. Opt. Eng. 5187, 22 (2004).
3.LEDs Magazine, December 21, 2006. Available athttp://ledsmagazine.com/news/3/12/19/1.
4.Narukawa, Y., Narita, J., Sakamoto, T., Deguchi, K., Yamada, T., and Mukai, T.: Ultra-high efficiency white light emitting diodes. Jpn. J. Appl. Phys. 45, L1084 (2006).
5.Lee, Y.J., Kuo, H.C., Lu, T.C., Su, B.J., and Wang, S.C.: Fabrication and characterization of GaN-Based LEDs grown on chemical wet-etched patterned sapphire substrates. J. Electrochem. Soc. 153(12), G1111 (2006).
6.Wuu, D.S., Wang, W.K., Shih, W.C., Horng, R.H., Lee, C.E., Lin, W.Y., and Fang, J.S.: Enhanced output power of near-ultraviolet InGaN-GaN LEDs grown on patterned sapphire substrates. IEEE Photonics Technol. Lett. 17, 288 (2005).
7.Yamada, M., Mitani, T., Narukawa, Y., Shioji, S., Niki, I., Sonobe, S., Deguchi, K., Sano, M., and Mukai, T.: InGaN-based near-ultraviolet and blue-light-emitting diodes with high external quantum efficiency using a patterned sapphire substrate and a mesh electrode. Jpn. J. Appl. Phys. 41, L1431 (2002).
8.Feng, Z.H. and Lau, K.M.: Enhanced luminescence from GaN-based blue LEDs grown on grooved sapphire substrates. IEEE Photonics Technol. Lett. 17, 1812 (2005).
9.Tadatomo, K., Okagawa, H., Ohuchi, Y., Tsunekawa, T., Imada, Y., Kato, M., and Taguchi, T.: High output power InGaN ultraviolet light-emitting diodes fabricated on patterned substrates using metalorganic vapor phase epitaxy. Jpn. J. Appl. Phys. 40(Pt 2), L583 (2001).
10.Lee, Y.J., Tseng, H.C., and Kuo, H.C.: Improvement in light-output efficiency of AlGaInP LEDs fabricated on stripe patterned epitaxy. IEEE Photonics Technol. Lett. 17(12), 2532 (2005).
11.Chen, J.J., Su, Y.K., Lin, C.L., Chen, S.M., Li, W.L., and Kao, C.C.: Enhanced output power of GaN-based LEDs with nano-patterned sapphire substrates. IEEE Photonics Technol. Lett. 20(13), 1193 (2008).
12.Tsai, P.C., Ricky, W., and Su, Y.K.: Lifetime tests and junction-temperature measurement of InGaN light-emitting diodes using patterned sapphire substrates. J. Lightwave Technol. 25(2), 591 (2007).
13.Wuu, D.S., Wang, W.K., Wen, K.S., Huang, S.C., Horng, R.H., Yu, Y.S., and Pan, M.H.: Fabrication of pyramidal patterned sapphire substrates for high-efficiency InGaN-based light emitting diodes. J. Electrochem. Soc. 153(8), G765 (2006).
14.Dwikusuma, F., Saulys, D., and Kuech, T.F.: Study on sapphire surface preparation for III-nitride heteroepitaxial growth by chemical treatments. J. Electrochem. Soc. 149(11), G603 (2002).
15.Simon, J., Langer, R., Barski, A., and Pelekanos, N.T.: Spontaneous polarization effects in GaN/AlxGa1-xN quantum wells. Phys. Rev. B 61, 7211 (2000).
16.Li, Y.L., Huang, Y.R., and Lai, Y.H.: Efficiency droop behaviors of InGaN/GaN multiple-quantum-well light-emitting diodes with varying quantum well thickness. Appl. Phys. Lett. 91, 181113 (2007).
17.Törmä, P.T., Svensk, O., Ali, M., Suihkonen, S., Sopanen, M., Odnoblyudov, M.A., and Bougrov, V.E.: Maskless roughening of sapphire substrates for enhanced light extraction of nitride based blue LEDs. Solid-State Electron. 53, 166 (2009).
18.Zhao, D.G., Jiang, D.S., Zhu, J.J., Liu, Z.S., Wang, H., Zhang, S.M., Wang, Y.T., and Yang, H.: Role of edge dislocation and Si impurity in linking the blue luminescence and yellow luminescence in n-type GaN films. Appl. Phys. Lett. 95, 041901 (2009).
19.Lee, J.H., Oh, J.T., Kim, Y.C., and Lee, J.H.: Stress reduction and enhanced extraction efficiency of GaN-based LED grown on cone-shape-patterned sapphire. IEEE Photonics Technol. Lett. 20(18), 1563 (2008).

Keywords

Characterization study of GaN-based epitaxial layer and light-emitting diode on nature-patterned sapphire substrate

  • H.Y. Lin (a1), Y.J. Chen (a1), C.L. Chang (a1), X.F. Li (a1), C.H. Kuo (a2), S.C. Hsu (a3) and C.Y. Liu (a4)...

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