Influence of Elastic and Inelastic Phonon Scattering on the Drive Current of Quasi-Ballistic MOSFETs

In this paper, we study the influence of elastic and inelastic phonon scattering on the drive current of Si MOSFETs under quasi-ballistic transport. Inelastic phonon emission involving energy relaxation helps achieve ballistic current, even in the presence of scattering, if the channel length is scaled down to the 10-nm scale. This result agrees with Natori´s previous predictions. However, for longer channel devices, inelastic phonon emission degrades the drain current due to space charge effects caused by charge accumulation. We also demonstrate that source-end potential engineering to electrically reduce the bottleneck barrier length can result in a ballistic current even in longer channel devices.