Carrier mobility characteristics of (100), (110), and (551) oriented atomically flattened Si surfaces for fin structure design of multi-gate metal–insulator–silicon field-effect transistors

Abstract

This paper reports on the carrier mobility characteristics of (100), (110), and (551) oriented atomically flattened Si surfaces for the fin structure design of multi-gate metal–insulator–silicon FETs (MuGFETs). At the atomic scale flatness level, the hole mobility is sensitive at the relatively high effective electric field region around 1 MV/cm and the hole mobility improvement is more than the that of electron. On the flattened (551) surface, both electron and hole mobility values are higher than those of the (110) surface. The mobility-based MuGFET assessment on speed and noise margin is proposed, and its result indicates that the (551) facet (100) top surfaces fin type has the best figure-of-merit of all the investigated combinations of fin types at the intermediate facet height to top surface width ratio of 1.2 to 7.5.