마이크로전자및패키징학회지 (Journal of the Microelectronics and Packaging Society)

  • 제18권3호
  • /
  • Pages.25-32
  • /
  • 2011
  • /
  • 1226-9360(pISSN)
  • /
  • 2287-7525(eISSN)
한국마이크로전자및패키징학회 (The Korean Microelectronics and Packaging Society)
권호 표지
DOI QR코드

DOI QR Code

비극성 a-GaN용 R-면 사파이어 기판의 제조

Fabrication of R-plane Sapphire wafer for Nonpolar a-plane GaN

  • 투고 : 2011.07.26
  • 심사 : 2011.09.20
  • 발행 : 2011.09.30
PDF 다운로드
⟨ 이전 논문 다음 논문 ⟩

초록

초고휘도 비극성 a-GaN LED를 위한 양질의 R-면 사파이어 기판을 제조하기 위해 절단, 연마공정에 대해서 연구하였다. 사파이어는 이방성이 큰 물질로서 R-면과 c-면의 기계적인 특성의 차이에 의해 기판 제조공정 조건이 영향을 받으며, c-면에 비해서 R-면은 이방성 크며 각 결정학적인 면에서의 이방성은 연마공정에는 큰 영향을 미치지 않으나 절단공정에 큰 영향을 미치는 것으로 나타났다. R-면 잉곳의 절단방향이 a-flat에 대해 $45^{\circ}$인 경우에 절단이 가장 효과적으로 이루어졌으며 양호한 절단품질을 얻을 수 있었다. 기계적인 연마가 이루어지는 래핑과 DMP(Diamond mechanical polishing) 공정에서는 c-면 기판과 연마율이 큰 차이가 나타나지 않았으나, 화학반응이 수반되는 CMP(Chemical mechanical polishing) 공정에서는 c-면 기판의 연마율이 R-면 기판의 약 2배 이상 큰 값을 가졌으며, 이는 c-면의 수화반응층 형성에 의한 영향으로 보여진다.

We have studied on the slicing and polishing processes of R-plane sapphire wafers for the substrates of UHB nonpolar a-plane GaN LED. The fabrication conditions of the R-plane and c-plane wafers were influenced by the large anisotropic properties (mechanical properties) of the sapphire. The slicing process was more affected by the anisotropic properties of R-plane than the polishing process. When the slicing direction was $45^{\circ}$ to the a-flat, the slicing time was shorter and the quality of as-slicing wafers was better than the slicing direction of normal to the a-flat. The MRR(Material removal rate) of mechanical polishing processes such as lapping and DMP(Diamond mechanical polishing) did not show significant differences between the R-plane and c-plane. The MRR of the c-plane was about two times higher than that of R-planes at the CMP(Chemical mechanical polishing) process due to the formation of hydrolysis reaction layers on the surface of the c-plane.

키워드

참고문헌

  1. D. Miller, T. C. Damen, A. C. Gossard, W. Wiegmann, T. H. Wood, C. A. Burrus, "Electric field dependence of optical absorption near the band gap of quantum-well structures", Phys. Rev. Lett., 32(2) 1043(1985)
  2. P. Waltereit, O. Brandt, A. Trampert, H. Y. Grahn, J. Menniger, M. Ramsteiner, M. Reiche, K. H. Ploog, "Nitride semiconductors free of electrostatic fields for efficient white lightemitting diodes", Nature, 406(24), 865 (2000). https://doi.org/10.1038/35022529
  3. M. D. Craven, S. H. Lim, F. Wu, J. S. Speck, and S. P. Den- Baars, "Structural characterization of nonpolar (11-20) a-plane GaN thin films grown on (1-102) r-plane sapphire", Appl. Phys. Lett., 81(3), 469 (2002). https://doi.org/10.1063/1.1493220
  4. B. A. Haskell and F. Wu, "Structural and morphological characteristics of planar (11-20) a-plane gallium nitride grown by hydride vapor phase epitaxy", Appl. Phys. Lett., 83(8), 1554 (2003). https://doi.org/10.1063/1.1604174
  5. M. D. Craven, P. Waltereit, J. S. Speck, S. P. DenBaars, "Microstructural evolution of a-plane GaN grown on a-plane SiC by metalorganic chemical vapor deposition", Appl. Phys. Lett., 84(8), 1281 (2004). https://doi.org/10.1063/1.1650545
  6. Masataka IMURA, Akira HOSHINO, Kiyotaka NAKANO, Michinobu TSUDA, Motoaki IWAYA, Satoshi KAMIYAMA, Hiroshi AMANO and Isamu AKASAKI, "Flat (11-20) GaN Thin Film on Precisely Offset-Controlled (1-102) Sapphire Substrate", Jpn. J. Appl. Phys., 44(10), 7418 (2005). https://doi.org/10.1143/JJAP.44.7418
  7. Masahiro ARAKI, Noriaki MOCHIMIZO, Katsuyuki HOSHINO, and Kazuyuki TADATOMO, Jpn. "Effect of Misorientation Angle of r-Plane Sapphire Substrate on a-Plane GaN Grown by Metalorganic Vapor Phase Epitaxy", Jpn. J. Appl. Phys., 47(1), 119 (2008). https://doi.org/10.1143/JJAP.47.119
  8. Sung-Min Hwang, Yong Gon Seo, Kwang Hyeon Baik, In- Sung Cho,,Jong Hyeob Baek, Sukkoo Jung, Tae Geun Kim, and Meoungwhan Cho, "Demonstration of nonpolar a-plane InGaN/GaN light emitting diode on r-plane sapphire substrate", Appl. Phys. Lett. 95, 071101 (2009). https://doi.org/10.1063/1.3206666
  9. R.E. Newnham, Y.M. De Haan, Z. Kristallogr., "Refinement of the a-$Al_2O_3$, $Ti_2O_3$, $V_2O_3$ and$ Cr_2O_3 $structures", 117(2-3), 235 (1962).
  10. C. A. Brookes, J.B. O'Neil, B.A. Redfern, "Anisotropy in the Hardness of Single Crystals", Proc. Soc. A, 322, 73 (1971). https://doi.org/10.1098/rspa.1971.0055
  11. E.R. Dobrovinskaya, L.A. Lytvynov, V. Pishchik, "Sapphire- Material, Manufacturing, Applications", 381, Sprinnger Science+ Business Media, New York (2009).
  12. E.R. Dobrovinskaya, L.A. Lytvynov, V. Pishchik, "Sapphire- Material, Manufacturing, Applications", 386, Sprinnger Science+ Business Media, New York (2009).
  13. H.L. Zhu, L.A. Tessaroto, R. Sabia, V.A. Greenhut, M. Smith, D.E. Niesz, "Chemical mechanical polishing (CMP) anisotropy in sapphire", Appl. Surf. Sci. 236, 120 (2004). https://doi.org/10.1016/j.apsusc.2004.04.027
  14. X.K. Hu, Z.T. Song, Z.C. Pan, W.L. Liu, L.C. Wu, "Study on sapphire removal for thin-film LEDs fabrication using CMP and dry etching", Appl. Surf. Sci. 255, 8230 (2009). https://doi.org/10.1016/j.apsusc.2009.05.056
  15. N.H. De Leeuw, S.C. Parker, J. Am. Ceram. Soc. "The eect of chemi- and physi-sorption of water on the surface structure and stability of a-alumina", J. Am. Ceram. Soc., 82(11), 3209 (1999).