Advanced materials, process, and designs for silicon photonic integration

The copper (Cu) interconnect has become the bottleneck for bandwidth scaling due to its increasing RC time constant with the decreasing gate line width. Currently, silicon based optical interconnect is widely pursued as the most promising technology to replace Cu in microprocessor chips. Silicon optical interconnect is based on integrated silicon nanophotonic technologies. It can leverage the large scale and low cost of CMOS technology and deliver higher bandwidth with no EMI and low heat dissipation. Passive photonic component, such as waveguides, couplers, filters, splitters, are the backbone of integrated photonic circuit. This thesis is dedicated to the development of low loss, high performance, high index contrast optical waveguides and couplers via materials, processes engineering, development, and device designs. We primarily focus on SOI single crystalline silicon (c-Si or SOI), PECVD amorphous silicon (a-Si:H, or simplified as a-Si), and PECVD silicon nitride (SiNxHy) based single mode channel waveguides.We have previously identified that sidewall roughness scattering is the dominant loss mechanism for the TE mode in high index contrast single mode channel waveguides. In this thesis, we provide a comprehensive understanding of the roughness scattering and its positive correlations with (1) sidewall optical intensity; (2) sidewall RMS roughness; and (3) sidewall index contrast. Novel processes and designs, such as hard mask and chemical oxidation, are developed based on the above understanding. In single mode, 500 x 200 nm2 c-Si channel waveguides, we have achieved world-record 2.7 dB/cm and 0.7 dB/cm transmission loss coefficients for the TE mode and the TM mode, respectively.For deposited waveguides, bulk absorption loss is also important for both TE and TM modes.For PECVD a-Si, we adapt hydrogen passivation to reduce dangling bond density.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Materials Science and Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2009

Author dc:creator

• Sun, Rong, Ph. D. Massachusetts Institute of Technology

Advisor dc:contributor.advisor

• Lionel C. Kimerling.

• Materials Science and Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/46678

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/46678