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Silicon CMOS BEOL Compatible Optical Waveguide Micro-mirrors

Published online by Cambridge University Press:  11 February 2011

Shom Ponoth
Affiliation:
Department of Chemical Engineering, 110 8th St, Rensselaer Polytechnic Institute, Troy, New York 12180.
Navnit Agarwal
Affiliation:
Department of Electrical Engineering and Computer Systems, 110 8th St, Rensselaer Polytechnic Institute, Troy, New York 12180.
Peter Persans
Affiliation:
Department of Physics, 110 8th St, Rensselaer Polytechnic Institute, Troy, New York 12180.
Joel Plawsky
Affiliation:
Department of Chemical Engineering, 110 8th St, Rensselaer Polytechnic Institute, Troy, New York 12180.
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Abstract

Optical waveguides are being explored for on-chip purposes to overcome the speed limitations of electrical interconnects. Passive optical components like waveguides and vertical outcouplers are important components in such schemes. In this study we fabricate planar waveguides with integrated vertical micro-mirrors using standard Back End of the Line silicon (BEOL) CMOS based processes. Around 1.6 μm of a hybrid alkoxy siloxane polymer with a refractive index of ∼ 1.50 at the intended wavelength of 830 nm is used as the core and plasma deposited silicon oxide with a refractive index of ∼ 1.46 is used as the cladding. The angular face in the polymer waveguide that would function as the mirror surface was fabricated by a pattern transfer method which involves transferring the angle in a template to the waveguide using anisotropic reactive ion etching. The sidewall angle realized in a positive resist on patterning was used as the angle template. Exposure and development conditions were adjusted for Shipley® S1813 photoresist to generate a sidewall angle of ∼ 65°. The anisotropic Reactive Ion Etching (RIE) was done using a CF4/O2 plasma chemistry. A gas composition of 50/50 CF4/O2 was chosen in order to minimize the etch related roughness of the polymer and the photoresist. The metallization of the mirror faces was done using a self-aligned maskless technique which ensures metal deposition only on the angular face and also eliminates a lithography step.

Type
Research Article
Copyright
Copyright © Materials Research Society 2003

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References

REFERENCES

1. Savage, N., IEEE Spectrum, 39, 8, 32–6 (2002).Google Scholar
2. Trewhella, J. and Oprysko, M. M., SPIE Proceedings, 1377, 6472 (1990).Google Scholar
3. Hikita, M., Tomaru, S., Enbutsu, K., Ooba, N., Yoshida, R., Usai, M., Yoshida, T., and Imamura, S., IEEE Journal of Selected Topics in Quantum Electronics, 5, 5, p. 12371242 (1999).Google Scholar
4. Hikita, M., Yoshimura, R., Usai, M., Tomaru, S., and Imamura, S., Thin Solid Films, 331, 1–2, 303308 (1998).Google Scholar
5. Van Der Linden, J., De Dobbelaere, P., Van Daele, P., and Diemeer, M., Japanese Journal of Applied Physics Part 1, 37, 6B, 37303735 (1998).Google Scholar
6. Nagata, T., Tanaka, T., Miyake, K., Kurotaki, H., Yokoyama, S., and Koyanagi, M., Japanese Journal of Applied Physics Part 1, 33, 1B, 822826 (1994).Google Scholar
7. Nagata, T., Namba, T, Kuroda, Y., Miyake, K., Miyamoto, T., Yokoyama, S., Miyazaki, S., Koyanagi, M. and Hirose, M., Japanese Journal of Applied Physics, Part 1 (Regular Papers & Short Notes), 34, 2B, 1282–5 (1995).Google Scholar
8. Kagami, M., Hasegawa, K., and Ito, H., Applied Optics, 36, 30, 77007707 (1997).Google Scholar
9. Liu, Y., Lin, L., Choi, C., and Chen, R. T., SPIE Proceedings, 3950, 210219 (2000).Google Scholar
10. Polyset Chemical Company Inc., Mechanicville, NY 12118.Google Scholar
11. MSDS for Microposit S1813 Photo resist, Shipley company (1998).Google Scholar