Comparison of temperature dependent carrier transport in FinFET and gate-all-around nanowire FET

Abstract

The temperature dependent carrier transport characteristics of n-type gate-all-around nanowire field effect transistors (GAA NW-FET) on bulk silicon are experimentally compared to bulk fin field effect transistors (FinFET) over a wide range of temperatures (25-125 °C). A similar temperature dependence of threshold voltage (VTH) and subthreshold swing (SS) is observed for both devices. However, effective mobility (μeff) shows significant differences of temperature dependence between GAA NW-FET and FinFET at a high gate effective field. At weak Ninv (= 5 x 1012 cm2/V. s), both GAA NW-FET and FinFET are mainly limited by phonon scattering in μeff. On the other hand, at strong Ninv (= 1.5 x 1013 cm2/V. s), GAA NW-FET shows 10 times higher dμeff/dT and 1.6 times smaller mobility degradation coefficient (ff) than FinFET. GAA NW-FET is less limited by surface roughness scattering, but FinFET is relatively more limited by surface roughness scattering in carrier transport.