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Optics Express

Optics Express

  • Editor: C. Martijn de Sterke
  • Vol. 17, Iss. 23 — Nov. 9, 2009
  • pp: 20891–20899

Propagation losses in undoped and n-doped polycrystalline silicon wire waveguides

Shiyang Zhu, Q. Fang, M. B. Yu, G. Q. Lo, and D. L. Kwong  »View Author Affiliations


Optics Express, Vol. 17, Issue 23, pp. 20891-20899 (2009)
http://dx.doi.org/10.1364/OE.17.020891


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Abstract

Polycrystalline silicon (polySi) wire waveguides with width ranging from 200 to 500 nm are fabricated by solid-phase crystallization (SPC) of deposited amorphous silicon (a-Si) on SiO2 at a maximum temperature of 1000°C. The propagation loss at 1550 nm decreases from 13.0 to 9.8 dB/cm with the waveguide width shrinking from 500 to 300 nm while the 200-nm-wide waveguides exhibit quite large loss (>70 dB/cm) mainly due to the relatively rough sidewall of waveguides induced by the polySi dry etch. By modifying the process sequence, i.e., first patterning the a-Si layer into waveguides by dry etch and then SPC, the sidewall roughness is significantly improved but the polySi crystallinity is degraded, leading to 13.9 dB/cm loss in the 200-nm-wide waveguides while larger losses in the wider waveguides. Phosphorus implantation causes an additional loss in the polySi waveguides. The doping-induced optical loss increases relatively slowly with the phosphorus concentration increasing up to 1 × 1018 cm−3, whereas the 5 × 1018 cm−3 doped waveguides exhibit large loss due to the dominant free carrier absorption. For all undoped polySi waveguides, further 1–2 dB/cm loss reduction is obtained by a standard forming gas (10%H2 + 90%N2) annealing owing to the hydrogen passivation of Si dangling bonds present in polySi waveguides, achieving the lowest loss of 7.9 dB/cm in the 300-nm-wide polySi waveguides. However, for the phosphorus doped polySi waveguides, the propagation loss is slightly increased by the forming gas annealing.

© 2009 OSA

OCIS Codes
(130.3120) Integrated optics : Integrated optics devices
(230.3990) Optical devices : Micro-optical devices
(230.7370) Optical devices : Waveguides

ToC Category:
Integrated Optics

History
Original Manuscript: July 28, 2009
Revised Manuscript: September 8, 2009
Manuscript Accepted: September 9, 2009
Published: October 30, 2009

Citation
Shiyang Zhu, Q. Fang, M. B. Yu, G. Q. Lo, and D. L. Kwong, "Propagation losses in undoped and n-doped polycrystalline silicon wire waveguides," Opt. Express 17, 20891-20899 (2009)
http://www.opticsinfobase.org/oe/abstract.cfm?URI=oe-17-23-20891


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References

  1. A. Liu, R. Jones, L. Liao, D. Samara-Rubio, D. Rubin, O. Cohen, R. Nicolaescu, and M. Paniccia, “A high-speed silicon optical modulator based on a metal-oxide-semiconductor capacitor,” Nature 427(6975), 615–618 (2004). [CrossRef] [PubMed]
  2. K. Preston and M. Lipson, “Slot waveguides with polycrystalline silicon for electrical injection,” Opt. Express 17(3), 1527–1534 (2009). [CrossRef] [PubMed]
  3. K. Preston, B. Schmidt, and M. Lipson, “Polysilicon photonic resonators for large-scale 3D integration of optical networks,” Opt. Express 15(25), 17283–17290 (2007). [CrossRef] [PubMed]
  4. K. Preston, S. Manipatruni, A. Gondarenko, C. B. Poitras, and M. Lipson, “Deposited silicon high-speed integrated electro-optic modulator,” Opt. Express 17(7), 5118–5124 (2009). [CrossRef] [PubMed]
  5. T. Kamins, Polycrystalline Silicon for Integrated Circuits and Displays, 2nd ed., (Kluwer, 1998).
  6. A. Säynatjoki, J. Riikonen, H. Lipsanen, and J. Ahopelto, “Optical waveguides on polysilicon-on-insulator,” J. Mater. Sci. Mater. Electron. 14(5/7), 417–420 (2003). [CrossRef]
  7. J. S. Foresi, M. R. Black, A. M. Agarwal, and L. C. Kimerling, “Losses in polycrystalline silicon waveguides,” Appl. Phys. Lett. 68(15), 2052–2054 (1996). [CrossRef]
  8. L. Liao, D. R. Lim, A. M. Agarwal, X. Duan, K. K. Lee, and 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). [CrossRef]
  9. Q. Fang, J. F. Song, S. H. Tao, M. B. Yu, G. Q. Lo, and D. L. Kwong, “Low loss (approximately 6.45dB/cm) sub-micron polycrystalline silicon waveguide integrated with efficient SiON waveguide coupler,” Opt. Express 16(9), 6425–6432 (2008). [CrossRef] [PubMed]
  10. Y. A. Vlasov and S. J. McNab, “Losses in single-mode silicon-on-insulator strip waveguides and bends,” Opt. Express 12(8), 1622–1631 (2004). [CrossRef] [PubMed]
  11. F. P. Payne and J. P. R. Lacey, “A theoretical analysis of scattering loss from planar optical waveguides,” Opt. Quantum Electron. 26(10), 977–986 (1994). [CrossRef]
  12. A. Saynatjoki, S. Arpiainen, J. Ahopelto, and H. Lipsanen, “High-index-contrast optical waveguides on silicon”, AIP Conf. Proc. 772, 27th Intern. Conf. on the Physics of Semiconductors, 1537–1538 (2005).
  13. A. Harke, M. Krause, and J. Mueller, “Low-loss single mode amorphous silicon waveguides,” Electron. Lett. 41(25), 1377–1379 (2005). [CrossRef]
  14. R. A. Soref and B. R. Bennett, “Kramers-Kronig analysis of E-O switching in silicon,” SPIE Integr. Opt. Circuit Eng. 704, 32–37 (1986).

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