Three-dimensional stress engineering in FinFETs for mobility/on-current enhancement and gate current reduction

In this paper, the first systematic study of uniaxial stress effects on mobility (μ)/on-current (I
on
) enhancement and gate current (I
g
) reduction in FinFETs is described. We demonstrate for the first time that I
g
of (110) side-surface pFinFETs is largely reduced by longitudinal compressive stress due to out-of-plane mass increase. (110) n/pFinFETs are superior to (100) FinFETs in terms of higher μ/I
on
enhancement ratio by longitudinal strain and comparable/higher short-channel I
dsat
. Three-dimensional stress design in FinFETs including transverse and vertical stresses is proposed based on the understanding of stress effects beyond bulk piezoresistance.