Correlation between low-field mobility and high-field carrier velocity in quasi-ballistic-transport MISFETS scaled down to Lg=30 nm

Mobility (μ) and L
g
dependence of high-field velocity (v) is systematically investigated. A wide variety of μ characteristics are realized with various gate dielectrics of SiO
2
, SiON, HfLaSiON, and HfLaAlSiON. At L
g
=30nm, the sensitivities of v to μ and scaling in L
g
, (δv/v)/(δμ/μ) and (δv/v)/(δL
g
/L
g
), are 0.43 and −0.45, respectively: in quasi-ballistic transport regime, μ and scaling in L
g
still play an important role on I
on
improvement with v enhancement. High-k MISFETs do not show any particular v degradation in high-energy carrier transport. μ-T
inv
characteristics of MG/high-k gate-stacks required for 22nm-node and beyond is discussed based on the experimental data for μ and L
g
dependence of v.