Strained silicon

Strained silicon is a layer of silicon in which the silicon atoms are stretched beyond their normal interatomic distance. This can be accomplished by putting the layer of silicon over a substrate of silicon germanium (SiliconGermanium). As the atoms in the silicon layer align with the atoms of the underlying silicon germanium layer (which are arranged a little farther apart, respect the ones of a bulk silicon crystal), the links between the silicon atoms become stretched - thereby leading to strained silicon. Moving these silicon atoms farther apart reduces the atomic forces that interfere with the movement of electrons through the transistors and thus better mobility, resulting in better chip performance and lower energy consumption. These electrons can move 70% faster allowing strained silicon transistors to switch 35% faster.

More recent advances include deposition of strained silicon using metalorganic vapor phase epitaxy (MOVPE) with metalorganics as starting sources, e.g. silicon sources (silane and dichlorosilane) and germanium sources (germane, germanium tetrachloride, and isobutylgermane).

External links

* [http://www.onr.navy.mil/sci_tech/31/312/ncsr/glossary.asp#S A brief description of strained silicon technology from National Compound Semiconductor Roadmap]
* [http://www.amberwave.com/tech_silicon.html A corporate website's short description of this technology]
* [http://www.research.ibm.com/resources/press/strainedsilicon/ descriptive images from IBM]
* [http://www.technologyreview.com/read_article.aspx?id=17237&ch=infotech&sc=&pg=1 High-Performance Flexible Silicon] - A new way to make bendable high-speed strained silicon.
* [http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TJ6-4HNSJS8-X&_user=10&_handle=V-WA-A-W-AUY-MsSWYWW-UUA-U-AAZBCYVDBE-AAZAAZCCBE-WUWZDAWZE-AUY-U&_fmt=summary&_coverDate=01%2F25%2F2006&_rdoc=103&_orig=browse&_srch=%23toc%235302%232006%23997129997%23614855!&_cdi=5302&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=b727a26cf1d2921d65096fc1f93658bb Designing Novel Organogermanium OMVPE Precursors for High-purity Germanium Films] ; Presentation at ACCGE-16, Montana, USA, July 11, 2005; Shenai-Khatkhate et al, Journal of Crystal Growth, January 25, 2006.
* [http://www.reed-electronics.com/semiconductor/article/CA6319057?industryid=3102 Ge Precursors for Strained Si and Compound Semiconductors] ; "Semiconductor International"; April 1, 2006.
* [http://www.compoundsemi.com/documents/view/news.php3?id=5899 Rohm and Haas Electronic Materials Devises Germanium Film Growth Process] ; "CompoundSemi News", September 23, 2005.
* [http://www.three-fives.com/equipment_materials_news/Sept05_mats_news/230905Rohm&Haas_Hi_purity_Ge_film.htm High Purity Germanium Film] ; "III-Vs Review", September 23, 2005.
* [http://ecsmeet2.peerx-press.org/ms_files/ecsmeet2/2006/03/13/00040125/00/40125_0_art_file_1_1142292562.pdf Development of New Germanium Precursors for SiGe Epitaxy] ; Presentation at 210th ECS Meeting (SiGe Symposium), Cancun, Mexico, October 29, 2006.
* [http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TJ6-4MS9K7M-1&_user=10&_coverDate=01%2F31%2F2007&_alid=571098462&_rdoc=1&_fmt=summary&_orig=search&_cdi=5302&_sort=d&_docanchor=&view=c&_ct=12&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=393a7a045ea6a5beee881039c2cf98e5 Safer alternative liquid germanium precursors for relaxed graded SiGe layers and strained silicon by MOVPE] ; "Deo V. Shenai, Ronald L. DiCarlo, Michael B. Power, Artashes Amamchyan, Randall J. Goyette and Egbert Woelk"; Journal of Crystal Growth, Volume 298, Pages 172-175, January 7, 2007.