Low pressure epitaxial growth, fabrication and characterizion of Ge-on-Si photodiodes

In order to facilitate the integration of photonic systems onto an electronic chip, near infrared photodiodes utilizing novel materials such as germanium must be monolithically integrated onto the Si CMOS platform. Such near-infrared photodiodes can be utilized for a plethora of applications such as optoelectronic ADCs, optical interconnects, photonic integrated circuits, and near infrared cameras. In this work, the major focus is on investigating processes utilizing a Low Pressure Chemical Vapor Deposition (LPCVD) Applied Materials Epi CenturaTM system to deposit germanium onto silicon substrates (Ge-on-Si). A growth space is identified to deposit blanket and selective epitaxial 1 to 3 rim-thick Ge-on-Si films via a two-step process. These deposited Ge-on-Si films have a low root-mean-square surface roughness (below 2 nm) and a moderate threading dislocation density (- 107 cm-2) after an annealing process. Utilizing these Ge-on-Si films, vertically illuminated Ge-on-Si pin photodiodes are fabricated in a CMOS compatible process. The best photodiodes fabricated in this work have low dark current values (below 10 mA/cm2), high responsivity (- 0.45 A/W at 1.55 pim wavelengths) and 3-dB frequency response in the gigahertz range.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2007

Author dc:creator

• Olubuyide, Oluwamuyiwa Oluwagbemiga, 1979-

Advisor dc:contributor.advisor

• Judy L. Hoyt.

• Electrical Engineering and Computer Science.

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/1721.1/38685

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/38685