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Integrated germanium optical interconnects on silicon substrates

Nature Photonics volume 8, pages 482–488 (2014)Cite this article

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Abstract

Monolithic integration of optoelectronics with electronics is a much-desired functionality. Here, we demonstrate that it is possible to realize low-loss Ge quantum-well photonic interconnects on Si wafers. We show that Ge-rich Si1–xGex virtual substrates can act as a passive, high-quality optical waveguide on which low-temperature, epitaxial growth of Ge quantum-well devices can be realized. As a proof of concept, the photonic integration of a passive Si0.16Ge0.84 waveguide and two Ge/SiGe multi-quantum-well active devices, an optical modulator and a photodetector was realized to form a photonic interconnect using a single epitaxial growth step. This demonstration confirms that Ge quantum-well interconnects are feasible for low-voltage, broadband optical links integrated on Si chips. Our approach can be extended to any kind of Ge-based optoelectronic device working within telecommunication wavelengths as long as a suitable Ge concentration is selected for the Ge-rich virtual substrate.

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Figure 1: Epitaxial growth and its HR-XRD characterization
Figure 2: Schematic and scanning electron microscopy (SEM) views of the three kinds of photonic device fabricated on the same chip and with the same process flows.
Figure 3: Characterizations of the Si0.16Ge0.84 waveguides.
Figure 4: Characterizations of the stand-alone Ge/Si0.16Ge0.84 MQWs modulator and photodetector.
Figure 5: Characterizations of the integrated optical interconnects of a passive Si0.16Ge0.84 waveguide and active Ge/Si0.16Ge0.84 MQW modulator and photodetector.

References

  1. Kirchain, R. & Kimerling, L. A roadmap for nanophotonics. Nature Photon. 1, 303–305 (2007).

    Article  ADS  Google Scholar 

  2. Miller, D. A. B. Device requirements for optical interconnects to silicon chips. Proc. IEEE 97, 1166–1185 (2009).

    Article  Google Scholar 

  3. Wada, K. A new approach of electronics and photonics convergence on Si CMOS platform: how to reduce device diversity of photonics for integration. Adv. Opt. Technol. 2008, 807457 (2008).

    Article  Google Scholar 

  4. Kuo, Y., Chen, H.-W. & Bowers, J. E. High speed hybrid silicon evanescent electroabsorption modulator. Opt. Express 16, 9936–9941 (2008).

    Article  ADS  Google Scholar 

  5. Fang, A. W. et al. Electrically pumped hybrid AlGaInAs-silicon evanescent laser. Opt. Express 14, 9203–9210 (2006).

    Article  ADS  Google Scholar 

  6. Van Campenhout, J. et al. Electrically pumped InP-based microdisk lasers integrated with a nanophotonic silicon-on-insulator waveguide circuit. Opt. Express 15, 6744–6749 (2007).

    Article  ADS  Google Scholar 

  7. Kuo, Y.-H. et al. Strong quantum-confined Stark effect in germanium quantum-well structures on silicon. Nature 437, 1334–1336 (2005).

    Article  ADS  Google Scholar 

  8. Chaisakul, P. et al. Quantum-confined Stark effect measurements in Ge/SiGe quantum-well structures. Opt. Lett. 35, 2913–2915 (2010).

    Article  ADS  Google Scholar 

  9. Assefa, S. et al. CMOS-integrated high-speed MSM germanium waveguide photodetector. Opt. Express 18, 4986–4999 (2010).

    Article  ADS  Google Scholar 

  10. Liu, J. et al. Waveguide-integrated, ultralow-energy GeSi electro-absorption modulators. Nature Photon. 2, 433–437 (2008).

    Article  ADS  Google Scholar 

  11. Feng, D. et al. High speed GeSi electro-absorption modulator at 1550 nm wavelength on SOI waveguide. Opt. Express 20, 22224–22232 (2012).

    Article  ADS  Google Scholar 

  12. Feng, D. et al. High-speed Ge photodetector monolithically integrated with large cross-section silicon-on-insulator waveguide. Appl. Phys. Lett. 95, 261105 (2009).

    Article  ADS  Google Scholar 

  13. Lim, A. E. J. et al. Novel evanescent-coupled germanium electro-absorption modulator featuring monolithic integration with germanium p–i–n photodetector. Opt. Express 19, 5040–5046 (2011).

    Article  ADS  Google Scholar 

  14. Vivien, L. et al. Zero-bias 40Gbit/s germanium waveguide photodetector on silicon. Opt. Express 20, 1096–1101 (2012).

    Article  ADS  Google Scholar 

  15. DeRose, C. T. et al. Ultra compact 45 GHz CMOS compatible germanium waveguide photodiode with low dark current. Opt. Express 19, 24897–24904 (2011).

    Article  ADS  Google Scholar 

  16. Ren, S. et al. Ge/SiGe quantum well waveguide modulator monolithically integrated with SOI waveguides. IEEE Photon. Technol. Lett. 24, 461–463 (2012).

    Article  ADS  Google Scholar 

  17. Edwards, E. H. et al. Low-voltage broad-band electroabsorption from thin Ge/SiGe quantum wells epitaxially grown on silicon. Opt. Express 21, 867–876 (2013).

    Article  ADS  Google Scholar 

  18. Park, S. et al. Monolithic integration and synchronous operation of germanium photodetectors and silicon variable optical attenuators. Opt. Express 18, 8412–8421 (2010).

    Article  ADS  Google Scholar 

  19. Ren, S., Rong, Y., Kamins, T. I., Harris, J. S. & Miller, D. A. B. Selective epitaxial growth of Ge/Si0.15Ge0.85 quantum wells on Si substrate using reduced pressure chemical vapor deposition. Appl. Phys. Lett. 98, 151108 (2011).

    Article  ADS  Google Scholar 

  20. Klinger, S., Berroth, M., Kaschel, M., Oehme, M. & Kasper, E. Ge-on-Si p–i–n photodiodes with a 3-dB bandwidth of 49 GHz. IEEE Photon. Technol. Lett. 21, 920–922 (2009).

    Article  ADS  Google Scholar 

  21. Chaisakul, P. et al. 23 GHz Ge/SiGe multiple quantum well electro-absorption modulator. Opt. Express 20, 3219–3224 (2012).

    Article  ADS  Google Scholar 

  22. Chaisakul, P. et al. Ge/SiGe multiple quantum well photodiode with 30 GHz bandwidth. Appl. Phys. Lett. 98, 131112 (2011).

    Article  ADS  Google Scholar 

  23. Luan, H.-C. et al. High-quality Ge epilayers on Si with low threading-dislocation densities. Appl. Phys. Lett. 75, 2909–2911 (1999).

    Article  ADS  Google Scholar 

  24. Orcutt, J. S. et al. Nanophotonic integration in state-of-the-art CMOS foundries. Opt. Express 19, 2335–2346 (2011).

    Article  ADS  Google Scholar 

  25. Pinguet, T., Analui, B., Masini, G., Sadagopan, V. & Gloeckner, S. 40-Gbps monolithically integrated transceivers in CMOS photonics. Proc. SPIE 6898, 689805 (2008).

    Article  Google Scholar 

  26. Masini, G., Capellini, G., Witzens, J. & Gunn, C. High-speed, monolithic CMOS receivers at 1550 nm with Ge on Si waveguide photodetectors. Proc. Laser Elect. Opt. Soc., 848–849 (2007).

  27. Bresson, N., Cristoloveanu, S., Mazuré, C., Letertre, F. & Iwai, H. Integration of buried insulators with high thermal conductivity in SOI MOSFETs: thermal properties and short channel effects. Solid-State Electron. 49, 1522–1528 (2005).

    Article  ADS  Google Scholar 

  28. Sherwood-Droz, N., Gondarenko, A. & Lipson, M. Oxidized silicon-on-insulator (OxSOI) from bulk silicon: a new photonic platform. Opt. Express 18, 5785–5790 (2010).

    Article  ADS  Google Scholar 

  29. Pan, H. et al. High-speed receiver based on waveguide germanium photodetector wire-bonded to 90nm SOI CMOS amplifier. Opt. Express 20, 18145–18155 10.1364/OE.20.018145 (2012).

    Article  ADS  Google Scholar 

  30. Zheng, X. et al. A sub-picojoule-per-bit CMOS photonic receiver for densely integrated systems. Opt. Express 18, 204–211 10.1364/OE.18.000204 (2010).

    Article  ADS  Google Scholar 

  31. McComber, K. A., Duan, X., Liu, J., Michel, J. & Kimerling, L. C. Single-crystal germanium growth on amorphous silicon. Adv. Funct. Mater. 22, 1049–1057 (2012).

    Article  Google Scholar 

  32. Braunstein, R., Moore, A. R. & Herman, F. Intrinsic optical absorption in germanium–silicon alloys. Phys. Rev. 109, 695–710 (1958).

    Article  ADS  Google Scholar 

  33. Isella, G. et al. Low-energy plasma-enhanced chemical vapor deposition for strained Si and Ge heterostructures and devices. Solid-State Electron. 48, 1317–1323 10.1016/j.sse.2004.01.013 (2004).

    Article  ADS  Google Scholar 

  34. Falub, C. V. et al. Scaling hetero-epitaxy from layers to three-dimensional crystals. Science 335, 1330–1334 (2012).

    Article  ADS  Google Scholar 

  35. Frigerio, J. et al. Electro-refractive effect in Ge/SiGe multiple quantum wells. Appl. Phys. Lett. 102, 061102 (2013).

    Article  ADS  Google Scholar 

  36. Spiekman, L. H. et al. Ultrasmall waveguide bends: the corner mirrors of the future? IEE Proc. Optoelectron. 142, 61–65 (1995).

    Article  Google Scholar 

  37. Akiyama, S. et al. Air trench waveguide bend for high density optical integration. Proc. SPIE 5355, 14–21 (2004).

    Article  ADS  Google Scholar 

  38. Schaevitz, R. K. et al. Simple electroabsorption calculator for designing 1310 nm and 1550 nm modulators using germanium quantum wells. IEEE J. Quantum Electron. 48, 187–197 (2012).

    Article  ADS  Google Scholar 

  39. Chaisakul, P. et al. 10-Gb/s Ge/SiGe multiple quantum-well waveguide photodetector. IEEE Photon. Technol. Lett. 23, 1430–1432 (2011).

    Article  ADS  Google Scholar 

  40. Lever, L. et al. Modulation of the absorption coefficient at 1.3 µm in Ge/SiGe multiple quantum well heterostructures on silicon. Opt. Lett. 36, 4158–4160 (2011).

    Article  ADS  Google Scholar 

  41. Lever, L., Ikonic, Z., Valavanis, A., Cooper, J. D. & Kelsall, R. W. Design of Ge-SiGe quantum-confined Stark effect electroabsorption heterostructures for CMOS compatible photonics. J. Lightwave Technol. 28, 3273–3281 (2010).

    ADS  Google Scholar 

  42. Hofrichter, J. et al. A low-power high-speed InP microdisk modulator heterogeneously integrated on a SOI waveguide. Opt. Express 20, 9363–9370 (2012).

    Article  ADS  Google Scholar 

  43. Tang, Y. et al. 50 Gb/s hybrid silicon traveling-wave electroabsorption modulator. Opt. Express 19, 5811–5816 (2011).

    Article  ADS  Google Scholar 

  44. Harris, N. C. et al. Noise characterization of a waveguide-coupled MSM photodetector exceeding unity quantum efficiency. J. Lightwave Technol. 31, 23–27 (2013).

    Article  ADS  Google Scholar 

  45. Cassan, E., Marris-Morini, D., Rouvière, M., Vivien, L. & Laval, S. C. Comparison between electrical and optical global clock distributions for CMOS integrated circuits. Opt. Eng. 44, 105402 (2005).

    Article  ADS  Google Scholar 

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Acknowledgements

This research received funding from the French ANR under project GOSPEL (Direct Gap Related Optical Properties of Ge/SiGe Multiple Quantum Wells) and from the European Commission (EC) through project Green Silicon. The fabrication of the device was performed at the nano-center CTU-IEF-Minerve, which is partially funded by the ‘Conseil Général de l'Essonne’. This work was partly supported by the French RENATECH network.

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Authors and Affiliations

  1. Institut d'Electronique Fondamentale, Université Paris-Sud, CNRS UMR 8622, Bâtiment 220, Orsay Cedex, 91405, France

    Papichaya Chaisakul, Delphine Marris-Morini, Mohamed-Said Rouifed, Paul Crozat & Laurent Vivien

  2. Dipartimento di Fisica del Politecnico di Milano, L-NESS, Polo di Como, Via Anzani 42, Como, I-22100, Italy

    Jacopo Frigerio, Daniel Chrastina, Stefano Cecchi & Giovanni Isella

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  1. Papichaya Chaisakul
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  2. Delphine Marris-Morini
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  3. Jacopo Frigerio
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  5. Mohamed-Said Rouifed
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  9. Laurent Vivien
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Contributions

P.Ch., D.M.-M. and L.V. conceived the project. P.Ch. designed and fabricated the tested devices, conducted the experiments and performed optical simulations. P.Ch. and D.M.-M. analysed the experimental data. J.F. carried out epitaxial growth and band diagram calculations. D.C. and S.C. performed HR-XRD measurements and analysis. S.C. participated in the epitaxial growth. P.Cr. participated in device characterization. All authors contributed to manuscript preparation. D.M.-M., G.I. and L.V. supervised the project.

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Correspondence to Delphine Marris-Morini.

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Chaisakul, P., Marris-Morini, D., Frigerio, J. et al. Integrated germanium optical interconnects on silicon substrates. Nature Photon 8, 482–488 (2014). https://doi.org/10.1038/nphoton.2014.73

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