Transport in thin-body MOSFETs fabricated in strained Si and strained Si/SiGe heterostructures on insulator

The combination of channel mobility enhancement techniques such as strain engineering, with non-classical MOS device architectures, such as ultra-thin body or multiple-gate structures, offers the promise of maximizing current drive while maintaining the electrostatic control required for aggressive device scaling in future CMOS technology nodes. Two structures that combine strain engineering and new materials with the ultrathin body silicon-on-insulator (SOI) technology are examined primarily from the point of view of hole mobility: (1) strained Si directly on insulator (SSDOI), and (2) strained Si/SiGe (with 46-55% Ge)/strained Si heterostructure-on-insulator (HOI). In SSDOI, high strain levels are required to obtain hole mobility enhancements at both low and high inversion charge densities. As the strained Si channel thickness is reduced below 8 nm, hole mobility in SSDOI decreases, as in unstrained SOI. The hole mobility of 3.9 nm-thick 30% SSDOI is still enhanced compared to hole mobility in 15 nm-thick unstrained SOI. Below 4 nm thickness, hole mobility in SSDOI decreases rapidly, which is found to be due to scattering from film thickness fluctuations.

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

• Åberg, Ingvar

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/1721.1/37839

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/37839