Correlation between Low-Field Mobility and High-Field Carrier Velocity in Quasi-Ballistic-Transport MISFETs scaled down to L_g=30 nm

摘要

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.