High Transport Si/SiGe Heterostructures for CMOS Transistors with Orientation and Strain Enhanced Mobility

Jungwoo OH  Jeff HUANG  Injo OK  Se-Hoon LEE  Paul D. KIRSCH  Raj JAMMY  Hi-Deok LEE  

Publication
IEICE TRANSACTIONS on Electronics   Vol.E94-C   No.5   pp.712-716
Publication Date: 2011/05/01
Online ISSN: 1745-1353
DOI: 10.1587/transele.E94.C.712
Print ISSN: 0916-8516
Type of Manuscript: INVITED PAPER (Special Section on Fundamentals and Applications of Advanced Semiconductor Devices)
Category: 
Keyword: 
high transport,  SiGe,  orientation,  strain,  heterostructure,  

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Summary: 
We have demonstrated high mobility MOS transistors on high quality epitaxial SiGe films selectively grown on Si (100) substrates. The hole mobility enhancement afforded intrinsically by the SiGe channel (60%) is further increased by an optimized Si cap (40%) process, resulting in a combined ∼100% enhancement over Si channels. Surface orientation, channel direction, and uniaxial strain technologies for SiGe channels CMOS further enhance transistor performances. On a (110) surface, the hole mobility of SiGe pMOS is greater on a (110) surface than on a (100) surface. Both electron and hole mobility on SiGe (110) surfaces are further enhanced in a <110> channel direction with appropriate uniaxial channel strain. We finally address low drive current issue of Ge-based nMOSFET. The poor electron transport property is primarily attributed to the intrinsically low density of state and high conductivity effective masses. Results are supported by interface trap density (Dit) and specific contact resistivity (ρc).