Velocity and Mobility Investigation in 1-nm-EOT HfSiON on Si (110) and (100)—Does the Dielectric Quality Matter?

One of the fundamental questions for gate-stack scaling is whether the low-field mobility measured in long-channel devices is a good proxy for short-channel performance at high field. In this paper, we thoroughly investigate low- and high-field transports (velocity and mobility) in 1-nm-EOT high-kappa materials on Si (100) and (110) down to cryogenic temperature. It is shown that scattering in Si substrate dominates the transport at high field, thus enabling relaxation of the low-field-mobility requirement for future scaling below 1-nm EOT.