论文信息 - Physical mechanisms of electron mobility enhancement in uniaxial stressed MOSFETs and impact of uniaxial stress engineering in ballistic regime

Physical mechanisms of electron mobility enhancement in uniaxial stressed MOSFETs and impact of uniaxial stress engineering in ballistic regime

The physical mechanisms of mue enhancement by uniaxial stress are investigated. From full band calculations, uniaxial-stress-induced split of conduction band edge, DeltaEC and effective mass change, Deltam*, are quantitatively evaluated. It is experimentally and theoretically demonstrated that the energy surface of 2-fold valleys in Si (001) FETs is warped due to uniaxial lang110rang stress, resulting in lighter mT of 2-fold valleys parallel to the stress. By using calculated DeltaEC and Deltam*, experimental (ie enhancement is accurately modeled for biaxial, uniaxial lang100rang, and uniaxial lang110rang stress. The limits of mue enhancement and the effectiveness of uniaxial stress engineering in enhancing nFET ballistic Id,sat are also discussed

K. Saraswat | Y. Nishi | T. Krishnamohan | K. Uchida

[1] J. Hensel,et al. Cyclotron Resonance in Uniaxially Stressed Silicon. II. Nature of the Covalent Bond , 1965 .

[2] James R. Chelikowsky,et al. ELECTRONIC STRUCTURE OF SILICON , 1974 .

[3] Suzuki,et al. Origin of the shear piezoresistance coefficient pi 44 of n-type silicon. , 1991, Physical review. B, Condensed matter.

[4] K. Natori. Ballistic metal-oxide-semiconductor field effect transistor , 1994 .

[5] S. Laux,et al. Band structure, deformation potentials, and carrier mobility in strained Si, Ge, and SiGe alloys , 1996 .