Transport in TriGate nanowire FET: Cross-section effect at the nanometer scale

We hereby present a study of electron mobility in Tri-gate SOI Nanowire (TGNW) transistors in a wide range of temperature from 20K up to 425K. We compared the temperature dependence for different values of the NW cross-section (width and height) and different crystallographic orientations of the conduction channel. We demonstrate that the electron mobility in narrow TGNWs is limited by surface roughness in the sidewall inversion surface whatever the NW orientation [110]/(100) or [100]/(100). We have also evidenced an enhanced temperature dependence, attributed to phonon scattering, as the cross-section of the NW decreases below a critical dimension (≈80nm).