Applied Physics B

, Volume 89, Issue 2–3, pp 311–318

Fabrication of low-loss channel waveguides in Al2O3 and Y2O3 layers by inductively coupled plasma reactive ion etching



Etching of amorphous Al2O3 and polycrystalline Y2O3 films has been investigated using an inductively coupled reactive ion etch system. The etch behaviour has been studied by applying various common process gases and combinations of these gases, including CF4/O2, BCl3, BCl3/HBr, Cl2, Cl2/Ar and Ar. The observed etch rates of Al2O3 films were much higher than Y2O3 for all process gases except for Ar, indicating a much stronger chemical etching component for the Al2O3 layers. Based on analysis of the film etch rates and an investigation of the selectivity and patterning feasibility of possible mask materials, optimized optical channel-waveguide structures were fabricated in both materials. In Al2O3, channel waveguides were fabricated with BCl3/HBr plasma and using a standard resist mask, while in Y2O3, channel waveguides were fabricated with Ar and using either a resist or a sputter deposited Al2O3 mask layer. The etched structures in both materials exhibit straight sidewalls with minimal roughness and sufficient etch depths (up to 530 nm for Al2O3 and 250 nm for Y2O3) for defining waveguides with strong optical confinement. Using the developed etch processes, low additional optical propagation losses (on the order of 0.1 dB/cm) were demonstrated in single-mode ridge waveguides in both Al2O3 and Y2O3 layers at 1550 nm.


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  1. 1.
    A. Polman, J. Appl. Phys. 82, 1 (1997)CrossRefADSGoogle Scholar
  2. 2.
    G.N. van den Hoven, E. Snoeks, A. Polman, J.W.M. van Uffelen, Y.S. Oei, M.K. Smit, Appl. Phys. Lett. 62, 3065 (1993)CrossRefADSGoogle Scholar
  3. 3.
    T.H. Hoekstra, P.V. Lambeck, H. Albers, T.J.A. Popma, Electron. Lett. 29, 581 (1993)CrossRefGoogle Scholar
  4. 4.
    S. Musa, H.J. van Weerden, T.H. Yau, P.V. Lambeck, IEEE J. Quantum Electron. QE-36, 1089 (2000)CrossRefADSGoogle Scholar
  5. 5.
    A. Suarez-Garcia, R. Serna, M. Jimenez de Castro, C.N. Afonso, I. Vickridge, Appl. Phys. Lett. 84, 2151 (2004)CrossRefADSGoogle Scholar
  6. 6.
    C.E. Chryssou, A.J. Kenyon, T.M. Smeeton, C.J. Humphreys, D.E. Hole, Appl. Phys. Lett. 85, 5200 (2004)CrossRefADSGoogle Scholar
  7. 7.
    O. Pons-Y-Moll, J. Perdiere, E. Million, R.M. Defourneau, D. Defourneau, B. Vincent, A. Essahiaoui, A. Boudrioua, J. Appl. Phys. 92, 4885 (2002)CrossRefADSGoogle Scholar
  8. 8.
    S. Bär, G. Huber, J. Gonzalo, A. Perea, M. Munz, Appl. Phys. A 80, 209 (2005)CrossRefADSGoogle Scholar
  9. 9.
    A.O.G. Dikovska, P.A. Atanasov, M. Jiménez de Castro, A. Perea, J. Gonzalo, C.N. Afonso, J. Garcia López, Thin Solid Films 500, 336 (2006)CrossRefADSGoogle Scholar
  10. 10.
    M.B. Korzenski, P. Lecoeur, B. Mercey, P. Carny, J.L. Doualan, Appl. Phys. Lett. 78, 1210 (2001)CrossRefADSGoogle Scholar
  11. 11.
    K. Wörhoff, J.D.B. Bradley, F. Ay, M. Pollnau, in Conference on Lasers and Electro-Optics, Technical Digest 2007 (Optical Society of America, Washington, DC, 2007), paper CMW5Google Scholar
  12. 12.
    G.N. van den Hoven, R.J.I.M. Koper, A. Polman, C. van Dam, J.W.M. van Uffelen, M.K. Smit, Appl. Phys. Lett. 68, 1886 (1996)CrossRefADSGoogle Scholar
  13. 13.
    K. Solehmainen, M. Kapulainen, P. Heimala, K. Polamo, IEEE Photon. Technol. Lett. 16, 194 (2004)CrossRefGoogle Scholar
  14. 14.
    T.H. Hoekstra, Erbium-Doped Y2O3 Integrated Optical Amplifiers (University of Twente, Enschede, 1994)Google Scholar
  15. 15.
    B.J.H. Stadler, M. Oliver, J. Appl. Phys. 84, 93 (1998)CrossRefADSGoogle Scholar
  16. 16.
    W.G.M. Van den Hoek, Mater. Res. Soc. Symp. Proc. 68, 71 (1986)Google Scholar
  17. 17.
    Y.H. Lee, Z.H. Zhou, D.A. Danner, P.M. Fryer, J.M. Harper, J. Appl. Phys. 68, 5329 (1990)CrossRefADSGoogle Scholar
  18. 18.
    J.W. Kim, Y.C. Kim, W.J. Lee, J. Appl. Phys. 78, 2045 (1995)CrossRefADSGoogle Scholar
  19. 19.
    J.W. Lee, B. Pathangey, M.R. Davidson, P.H. Holloway, E.S. Lambers, B. Davydov, T.J. Anderson, S.J. Pearton, J. Vac. Sci. Technol. A 16, 2177 (1998)CrossRefADSGoogle Scholar
  20. 20.
    D.P. Kim, J.W. Yeo, C.I. Kim, Thin Solid Films 459, 122 (2004)CrossRefADSGoogle Scholar
  21. 21.
    S. Tegen, P. Moll, J. Electrochem. Soc. 152, G271 (2005)CrossRefGoogle Scholar
  22. 22.
    Y.C. Kim, C.I. Kim, J. Vac. Sci. Technol. A 19, 2676 (2001)CrossRefADSGoogle Scholar
  23. 23.
    S.I. Shim, Y.S. Kwon, S.I. Kim, Y.T. Kim, J.H. Park, Solid-State Electron. 49, 497 (2005)Google Scholar
  24. 24.
    E. van der Drift, B.A.C. Rousseeuw, J. Romijn, E.C.M. Pennings, F.H. Groen, Microelectron. Eng. 9, 499 (1989)CrossRefGoogle Scholar
  25. 25.
    D.R. Lide (ed.), CRC Handbook of Chemistry and Physics, 82nd edn. (CRC, Boca Raton, FL, 2001)Google Scholar
  26. 26.
    B.S. Bokstein, M.I. Mendelev, D.J. Srolovitz, Thermodynamics and Kinetics in Materials Science: A Short Course (Oxford University Press, Oxford, 2005)Google Scholar
  27. 27.
    C.H. Jeong, D.W. Kim, H.Y. Lee, H.S. Kim, Y.J. Sung, G.Y. Yeom, Surf. Coat. Technol. 171, 280 (2003)CrossRefGoogle Scholar
  28. 28.
    D.W. Kim, C.H. Jeong, K.N. Kim, H.Y. Lee, H.S. Kim, Y.J. Sung, G.Y. Yeom, Thin Solid Films 435, 242 (2003)CrossRefADSGoogle Scholar
  29. 29.
    A. Crunteanu, M. Pollnau, G. Jänchen, C. Hibert, P. Hoffmann, R.P. Salathe, R.W. Eason, C. Grivas, D.P. Shepherd, Appl. Phys. B 75, 15 (2002)CrossRefADSGoogle Scholar
  30. 30.
    C. Grivas, D.P. Shepherd, T.C. May-Smith, R.W. Eason, M. Pollnau, A. Crunteanu, M. Jelinek, IEEE J. Quantum Electron. QE-39, 501 (2003)CrossRefADSGoogle Scholar
  31. 31.
    C. Grivas, D.P. Shepherd, T.C. May-Smith, R.W. Eason, M. Pollnau, Opt. Express 13, 210 (2005)CrossRefADSGoogle Scholar
  32. 32.
    S. Bär, H. Scheife, K. Petermann, G. Huber, Top. Appl. Phys. 106, 401 (2007)CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2007

Authors and Affiliations

  • J.D.B. Bradley
    • 1
  • F. Ay
    • 1
  • K. Wörhoff
    • 1
  • M. Pollnau
    • 1
  1. 1.Integrated Optical MicroSystems (IOMS) Group, MESA+ Institute of NanotechnologyUniversity of TwenteEnschedeThe Netherlands

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