Hostname: page-component-7479d7b7d-wxhwt Total loading time: 0 Render date: 2024-07-11T22:48:35.729Z Has data issue: false hasContentIssue false
  • English
  • Français

Surface Smoothing of Polycrystalline Si Waveguides With Gas-Cluster Ion Beams

Published online by Cambridge University Press:  10 February 2011

N. Toyoda ,
K. K. Lee ,
H-C. Luan ,
D. R. Lim ,
A. M. Agarwal ,
K. Wada ,
L. C. Kimerling ,
L. P. Allen ,
D. B. Fenner  and
A. R. Kirkpatrick
N. Toyoda
Affiliation:
Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, ntoyoda@mit.edu Epion Corporation, 37 Manning Road, Billerica, MA 01821
K. K. Lee
Affiliation:
Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, ntoyoda@mit.edu
H-C. Luan
Affiliation:
Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, ntoyoda@mit.edu
D. R. Lim
Affiliation:
Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, ntoyoda@mit.edu
A. M. Agarwal
Affiliation:
Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, ntoyoda@mit.edu
K. Wada
Affiliation:
Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, ntoyoda@mit.edu
L. C. Kimerling
Affiliation:
Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, ntoyoda@mit.edu
L. P. Allen
Affiliation:
Epion Corporation, 37 Manning Road, Billerica, MA 01821
D. B. Fenner
Affiliation:
Epion Corporation, 37 Manning Road, Billerica, MA 01821
A. R. Kirkpatrick
Affiliation:
Epion Corporation, 37 Manning Road, Billerica, MA 01821
Get access

Abstract

Polycrystalline Si (poly-Si) waveguides offer design flexibility and multilayered structures in Si-integrated photonic devices. However, as-deposited poly-Si surfaces are rough compared with single-crystalline Si, and a rough surface causes significant waveguide scattering loss at the surface. In this study, surface smoothing of poly-Si waveguides with a gas-cluster ion beam (GCIB) was demonstrated as a new smoothing technique. As the GCIB process is a directional ion-beam process, in principle it can be applied not only to plane surfaces but also to three-dimensional or non-flat structures, such as waveguide ridges.

The initial average roughness of as-deposited poly-Si films (625°C, 1 μm thick) ranged from 15 nm to 22 nm, and the grain sizes were distributed from 0.2 to 0.4μm. This rough surface was dramatically smoothed to a roughness of 1.5 nm by Ar cluster ion irradiation. From the relation between the sputtered depth and the surface roughness, the sputtered depth must be greater than the height difference of the roughness (peak-to-valley) to obtain smooth surfaces. Optical transmission losses at λ =1.54 μm were measured using cutback measurement from samples before and after the smoothing by GCIB. After surface smoothing with GCIB, the optical loss decreased from 85 dB/cm to 54 dB/cm.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 597: Symposium PP – Thin Films for Optical Waveguide Devices & Materials … , 1999 , 51
Copyright
Copyright © Materials Research Society 2000

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

[1] Jackson, W.B., Johnson, N.M. and Biegelsen, D.K., Appl. Phys. Lett. 66, 2016(1995).Google Scholar
[2] Jones, R.E. Jr. and Wesolowski, S.P., J. Appl. Phys. 56, 1791(1984).Google Scholar
[3] Foresi, J.S., Black, M.R., Agarwal, A.M. and Kimerling, L.C., Appl. Phys. Lett. 68, 2052(1996).Google Scholar
[4] Agarwal, A.M., Liao, L., Foresi, J.S., Black, M.R., Duan, X. and Kimerling, L.C., J. Appl. Phys. 80, 6120 (1996).Google Scholar
[5] 1. Yamada, I., Matsuo, J., Insepov, Z., Takeuchi, D., Akizuki, M. and Toyoda, N., J. Vac. Sci. Technol. A14, 781 (1996).Google Scholar
[6] Matsuo, J., Toyoda, N. and Yamada, I., J. Vac. Sci. Technol. B 14, 3951(1996).Google Scholar
[7] Yoshida, A., Deguchi, M., Kitabatake, M., Hirao, T., Matsuo, J., Toyoda, N. and Yamada, I., Nucl.Instr. and Meth. B 112, 248(1996).Google Scholar
[8] Toyoda, N., Saito, M., Hagiwara, N., Matsuo, J. and Yamada, I., Proc. of the 12th International conference on Ion Implantation Technology, June 1998 (to be published).Google Scholar
[9] Takeuchi, D., Seki, T., Aoki, T., Matsuo, J. and Yamada, I., Mat. Chem. and Phys. 54, 76(1998).Google Scholar
[10] Seki, T., Kaneko, T., Takeuchi, D., Aoki, T., Matsuo, J., Insepov, Z. and Yamada, I., Nucl. Instrand Meth. B 121, 498(1997).Google Scholar
[11] Toyoda, N., Kitani, H., Hagiwara, N., Aoki, T., Matsuo, J. and Yamada, I., Mat. Chem. and Phys. 54, 262 (1998).Google Scholar