Silicon-Germanium interdiffusion and its impacts on enhanced mobility MOSFETs

As complementary metal-oxide-semiconductor field-effect transistors (MOSFETs) scale, strained Si and SiGe technology have received more attention as a means of enhancing performance via improved carrier mobility. One of the biggest challenges for strained Si and SiGe technology is Si-Ge interdiffusion during thermal processing. Two different aspects of Si-Ge interdiffusion are explored in this work. The first part of this work demonstrates that Si-Ge interdiffusion and ion implantation damage during the fabrication of strained Si MOSFETs have significant impact on electron mobility and thus device performance. Long channel n-MOSFETs with different thermal processing and implant conditions were fabricated on both CZ Si wafers and strained Si/relaxed Sio.8Geo.2 heterostructures. In order to avoid scattering by ionized dopant impurities, neutral Si and Ge were implanted into the channel at six different doses ranging from 4 x 1012 cm-2 to 1 x 1015 atoms/cm2. It is shown that the mobility enhancement factor is degraded by RTA and ion implantation. For each RTA condition, there is a threshold implantation dose, above which the strained Si mobility starts to degrade significantly. The degradation is larger for devices with higher thermal budgets or implantation doses.

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

2006

Author dc:creator

• Xia, Guangrui, 1976-

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/1721.1/37840

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/37840