Strain effects on transport properties of Si nanowire devices

We study the effects of strains on the performances of (001) and (110) oriented gate-all-around silicon nanowire (Si NW) transistors within a Non-Equilibrium Green´s Functions framework. In agreement with previous works, we show that uniaxial strains can significantly improve the carrier mobility in the channel. However, we find that besides the enhancement of the carrier mobility, the ballistic resistance must be simultaneously optimized to achieve good performances in short channel devices. The response of the ballistic resistance to strains is different in [001] and [110] strained devices. Our study shows that the ballistic resistance is improved more consistently with the mobility in [110] Si NWs, providing the best opportunities for strain engineering in ultimate short channel transistors.