Advertisement

Amorphous Silicon in Microphotonics

  • Anuradha M. AgarwalEmail author
  • Jurgen Michel
Chapter
Part of the Springer Handbooks book series (SHB)

Abstract

Amorphous silicon () is an attractive high-refractive-index material for waveguide applications because of its flexible deposition conditions, which do not rely on the existence of crystalline silicon. However, a-Si can exhibit significant propagation losses due to unsaturated bonds in the silicon. Adding hydrogen will reduce those losses, but hydrogen itself can out-diffuse due to elevated processing temperatures. In this chapter, we describe the progress that has been made in the last 20 years with a-Si waveguides and related passive and active photonic devices. We review the basic mechanisms of loss in a-Si and solutions for reducing propagation losses to an acceptable level. We then discuss passive a-Si devices such as ring resonators and multimode interferometer (MMI) power splitters. In the last section, we focus on active devices that use a-Si-based waveguides.

References

  1. J. Mort, J. Knights: Localization and electronic properties in amorphous semiconductors, Nature 290, 659–663 (1981)CrossRefGoogle Scholar
  2. F. Gaspari: Optoelectronic properties of amorphous silicon the role of hydrogen: From experiment to modeling. In: Optoelectronics – Materials and Techniques, ed. by P. Pradeep (InTech, London 2011)Google Scholar
  3. M.H. Cohen, H. Fritzsche, S.R. Ovshinsky: Simple band model for amorphous semiconducting alloys, Phys. Rev. Lett. 22, 1065 (1969)CrossRefGoogle Scholar
  4. F. Orapunt, S.K. O'Leary: Optical transitions and the mobility edge in amorphous semiconductors: A joint density of states analysis, J. Appl. Phys. 104, 073513 (2008)CrossRefGoogle Scholar
  5. L. Banyai: On the theory of electric conduction in amorphous semiconductors. In: Proc. 7th Int. Conf. Phys. Semicond., Paris (1964) p. 417Google Scholar
  6. N.F. Mott: Electrons in disordered structures, Adv. Phys. 16(61), 49–144 (1967)CrossRefGoogle Scholar
  7. E.A. Davis, N.F. Mott: Conduction in non-crystalline systems V. Conductivity, optical absorption and photoconductivity in amorphous semiconductors, Philos. Mag. 22(179), 0903–0922 (1970),  https://doi.org/10.1080/14786437008221061CrossRefGoogle Scholar
  8. A. Madan, P.G. Le Comber, W.E. Spear: Investigation of the density of localized states in a-Si using the field effect technique, J. Non-Cryst. Solids 20, 239–257 (1976)CrossRefGoogle Scholar
  9. N. Mott: The mobility edge since 1967, J. Phys. C Solid State Phys. 20, 3075–3102 (1987)CrossRefGoogle Scholar
  10. M. Green: Thin-film solar cells: Review of materials, technologies and commercial status, J. Mater. Sci. Mat. Electron. 18(1), 15–19 (2007)CrossRefGoogle Scholar
  11. Y. Kuo: Thin film transistor technology – Past, present, and future, Electrochem. Soc. Interface 22(1), 55–61 (2013)CrossRefGoogle Scholar
  12. A.M. Agarwal, L. Liao, J.S. Foresi, M.R. Black, X. Duan, L.C. Kimerling: Low-loss polycrystalline silicon waveguides for silicon photonics, J. Appl. Phys. 80(11), 6120–6123 (1996)CrossRefGoogle Scholar
  13. L. Liao: Low Loss Polysilicon Waveguides for Silicon Photonics, Ph.D. Thesis (Massachusetts Institute of Technology, Cambridge 1997)Google Scholar
  14. L. Liao, D.R. Lim, A.M. Agarwal, X. Duan, K.K. Lee, L.C. Kimerling: Optical transmission losses in polycrystalline silicon strip waveguides: Effects of waveguide dimensions, thermal treatment, hydrogen passivation, and wavelength, J. Electron. Mater. 29(12), 1380–1386 (2000)CrossRefGoogle Scholar
  15. K. Pangal, J.C. Sturm, S. Wagner, T.H. Büyüklimanli: Hydrogen plasma enhanced crystallization of hydrogenated amorphous silicon films, J. Appl. Phys. 85(3), 1900 (1999)CrossRefGoogle Scholar
  16. S.J. Fonash, G. Liu: Low temperature crystallization and patterning of amorphous silicon films on electrically insulating substrates, US Patent 527585 (1994)Google Scholar
  17. W.B. Jackson: Hydrogen in amorphous silicon, Curr. Opin. Solid State Mater. Sci. 1(4), 562–566 (1996)CrossRefGoogle Scholar
  18. A. Harke, M. Krause, J. Mueller: Low-loss single mode amorphous silicon waveguides, Electron. Lett. 41(25), 1377–1379 (2005)CrossRefGoogle Scholar
  19. M.-J. Kim, G.K. Mebratu, J.-Y. Sung, J.H. Shin: Er-doped hydrogenated amorphous silicon: Structural and optical properties, J. Non-Cryst. Solids 315(3), 312–320 (2003)CrossRefGoogle Scholar
  20. F.G. Della Corte, S. Rao: Use of amorphous silicon for active photonic devices, IEEE Trans. Electron Dev. 60(5), 1495–1505 (2013)CrossRefGoogle Scholar
  21. S.K. Selvaraja, W. Bogaerts, D. Van Thourhout, M. Schaekers: Thermal trimming and tuning of hydrogenated amorphous silicon nanophotonic devices, Appl. Phys. Lett. 97(7), 071120-1–1071120-3 (2010)CrossRefGoogle Scholar
  22. L. Cao, A. Aboketaf, Z. Wang, S. Preble: Hybrid amorphous silicon (a-Si:H)–LiNbO3 electro-optic modulator, Opt. Commun. 330, 40–44 (2014)CrossRefGoogle Scholar
  23. P.M. Fauchet, D. Hulin, R. Vanderhaghen, A. Mourchid, W.L. Nighan Jr.: The properties of free carriers in amorphous silicon, J. Non-Cryst. Solids 141, 76–87 (1992)CrossRefGoogle Scholar
  24. K. Ikeda, Y. Shen, Y. Fainman: Enhanced optical nonlinearity in amorphous silicon and its application to waveguide devices, Opt. Express 15(26), 17761–17771 (2007)CrossRefGoogle Scholar
  25. K.-Y. Wang, A.C. Foster: Ultralow power continuous-wave frequency conversion in hydrogenated amorphous silicon waveguides, Opt. Lett. 37(8), 1331 (2012)CrossRefGoogle Scholar
  26. K. Narayanan, S.F. Preble: Optical nonlinearities in hydrogenated amorphous silicon waveguides, Opt. Express 18(9), 8998–9005 (2010)CrossRefGoogle Scholar
  27. J.J. Wathen, V.R. Pagán, R.J. Suess, K.-Y. Wang, A.C. Foster, T.E. Murphy: Non-instantaneous optical nonlinearity of an a-Si:H nanowire waveguide, Opt. Express 22(19), 22730–22742 (2014)CrossRefGoogle Scholar
  28. P.K. Lim, W.K. Tam, L.F. Yeung, F.M. Lam: Effect of hydrogen on dangling bond in a-Si thin film, J. Phys. Conf. Ser. 61, 708–712 (2007)CrossRefGoogle Scholar
  29. K. Tanaka, E. Maruyama, T. Shimada, H. Okamoto: Amorphous Silicon (Wiley, Chichester 1999)Google Scholar
  30. D.K. Sparacin, R. Sun, A.M. Agarwal, M.A. Beals, J. Michel, L.C. Kimerling, T.J. Conway, A.T. Pomerene, D.N. Carothers, M.J. Grove, D.M. Gill, M.S. Rasras, S.S. Patel, A.E. White: Low-loss amorphous silicon channel waveguides for integrated photonics. In: 3rd IEEE Int. Conf. Group IV Photonics (2006),  https://doi.org/10.1109/GROUP4.2006.1708231CrossRefGoogle Scholar
  31. J.M. Fedeli, L. Di Cioccio, D. Marris-Morini, L. Vivien, R. Orobtchouk, P. Rojo-Romeo, C. Seassal, F. Mandorlo: Development of silicon photonics devices using microelectronic tools for the integration on top of a CMOS wafer, Adv. Opt. Technol. 2008, 412518 (2008),  https://doi.org/10.1155/2008/412518CrossRefGoogle Scholar
  32. S.K. Selvaraja, E. Sleeckx, M. Schaekers, W. Bogaerts, D. Van Thourhout, P. Dumon, R. Baets: Low-loss amorphous silicon-on-insulator technology for photonic integrated circuitry, Opt. Commun. 282, 1767–1770 (2009)CrossRefGoogle Scholar
  33. S. Zhu, G.Q. Lo, D.L. Kwong: Low-loss amorphous silicon wire waveguide for integrated photonics: Effect of fabrication process and the thermal stability, Opt. Express 18(24), 25283 (2010)CrossRefGoogle Scholar
  34. K. Furuya, K. Nakanishi, R. Takei, E. Omoda, M. Suzuki, M. Okano, T. Kamei, M. Mori, Y. Sakakibara: Nanometer-scale thickness control of amorphous silicon using isotropic wet-etching and low loss wire waveguide fabrication with the etched material, Appl. Phys. Lett. 100, 251108 (2012)CrossRefGoogle Scholar
  35. P.K. Lim, W.K. Tam: Local vibrational modes and the optical absorption tail of amorphous silicon, Int. J. Mod. Phys. B 20(25–27), 4261–4266 (2006)CrossRefGoogle Scholar
  36. R. Sun, K. McComber, J. Cheng, D.K. Sparacin, M. Beals, J. Michel, L.C. Kimerling: Transparent amorphous silicon channel waveguides with silicon nitride intercladding layer, Appl. Phys. Lett. 94, 141108 (2009)CrossRefGoogle Scholar
  37. T. Lipka, L. Moldenhauer, J. Müller, H.K. Trieu: Photonic integrated circuit components based on amorphous silicon-on-insulator technology, Photonics Res. 4(3), 126 (2016)CrossRefGoogle Scholar
  38. T. Lipka, J. Müller, H.K. Trieu: Systematic nonuniformity analysis of amorphous silicon-on-insulator photonic microring resonators, J. Lightw. Technol. 34(13), 3163 (2016)CrossRefGoogle Scholar
  39. S. Zhu, G.Q. Lo: Vertically stacked multilayer photonics on bulk silicon toward three-dimensional integration, J. Lightw. Technol. 34, 386 (2016)CrossRefGoogle Scholar
  40. K. Narayanan, A.W. Elshaari, S.F. Preble: Broadband all-optical modulation in hydrogenated-amorphous silicon waveguides, Opt. Express 18(10), 9809–9814 (2010)CrossRefGoogle Scholar
  41. S. Rao, C. D'Addio, F.G. Della Corte: All-optical modulation in a CMOS-compatible amorphous silicon-based device, J. Eur. Opt. Soc. Rapid Publ. 7, 12023-1–12023-7 (2012)CrossRefGoogle Scholar
  42. F.G. Della Corte, S. Rao, M.A. Nigro, F. Suriano, C. Summonte: Electro-optically induced absorption in a-Si:H/a-SiCN waveguiding multistacks, Opt. Express 16(10), 7540–7550 (2008)CrossRefGoogle Scholar
  43. S. Rao, F.G. Della Corte, C. Summonte, F. Suriano: Electrooptical modulating device based on a CMOS-compatible \({\upalpha}\)-Si:H/\({\upalpha}\)-SiCN multistack waveguide, IEEE J. Sel. Top. Quantum Electron. 16(1), 173–178 (2010)Google Scholar

Copyright information

© Springer Nature Switzerland AG 2019

Authors and Affiliations

  1. 1.Materials Research LaboratoryMassachusetts Institute of TechnologyCambridge, MAUSA
  2. 2.Materials Research LaboratoryMassachusetts Institute of TechnologyCambridge, MAUSA

Personalised recommendations