Phonon-engineered mobility enhancement in the acoustically mismatched silicon/diamond transistor channels

The authors have shown that the low-field electron drift mobility in the ultrathin silicon films can be enhanced if they are embedded within acoustically hard materials such as diamond. The increase results from phonon spectrum modification in the acoustically mismatched silicon/diamond heterostructure and suppression of the deformation-potential electron-phonon scattering. The room temperature mobility in silicon films with 2 nm thickness can be increased by a factor of 2-3 depending on the hardness and thickness of the barrier layers. The obtained results suggest a new phonon-engineering approach for increasing the speed and drive current of downscaled electronic devices. (C) 2008 American Institute of Physics. [DOI: 10.1063/1.3007986]