Fullband Study of Ultra-Scaled Electron and Hole SiGe Nanowire FETs

Ultra-scaled SiGe nanowire FETs (NWFETs) are an attractive candidate in achieving faster p-type devices compared to Silicon. This work investigates the performance of SiGe nanowire FETs (NWFETs) using a Virtual Crystal Approximation (VCA) method based on an atomistic Tight-Binding (TB) model. The electronic structure calculation is self- consistently coupled to a 2D Poisson solver. The spatial charge and current distribution in these NWFETs strongly depend on the Ge% as well as on the channel orientation. We predict an improvement in both SiGe n and p FETs in terms of I ON and gate delay (¿
_D
)compared to Silicon. For Ge > 80% the <110> oriented channels show better performance compared to the <100> SiGe n and p-FETs .