Title :
Stress engineering in (100) and (110) nMOSFETs
Author :
Uchida, Ken ; Saitoh, Masumi
Author_Institution :
Dept. of Phys. Electron., Tokyo Inst. of Technol., Tokyo, Japan
Abstract :
The physical mechanisms of electron mobility (¿e) enhancement by uniaxial stress are investigated for nMOSFETs with surface orientations of (100) and (110). From full band calculations, uniaxial-stress-induced split of conduction band edge (¿EC) and effective mass change (¿m*) are quantitatively evaluated. It is experimentally and theoretically demonstrated that the energy surface of 2-fold valleys in Si (100) nMOSFETs is warped due to uniaxial <110> stress, resulting in lighter mT of 2-fold valleys parallel to the stress. By using calculated ¿EC and ¿m*, experimental ¿e enhancement is accurately modeled for biaxial, uniaxial <100>, and uniaxial <110> stress for (100) and (110) nMOSFETs. The limits of ¿e enhancement are also discussed.
Keywords :
MOSFET; conduction bands; elemental semiconductors; silicon; Si; conduction band edge; effective mass change; electron mobility; full band calculations; nMOSFET; stress engineering; surface orientations; uniaxial-stress-induced split; CMOS technology; Compressive stress; Effective mass; Electron mobility; FETs; MOSFETs; Strain measurement; Tensile strain; Tensile stress; Uniaxial strain;
Conference_Titel :
Solid-State and Integrated-Circuit Technology, 2008. ICSICT 2008. 9th International Conference on
Conference_Location :
Beijing
Print_ISBN :
978-1-4244-2185-5
Electronic_ISBN :
978-1-4244-2186-2
DOI :
10.1109/ICSICT.2008.4734485
