Potential future generation nanoscale MOS device: Trigate (TG) or Double Gate (DG) FinFETs?

Performance limit of Tri-Gate (TG) and Double Gate (DG) SOI FinFETs have been compared in terms of ballistic current which is calculated using a modified model shown for conventional MOSFET. Such a simple model for calculating ballistic current in nanoscale multigate MOSFETs is yet to be reported. Comparison of the ballistic current for different Si fin thicknesses reveals that for decreasing fin thickness, strong quantum mechanical confinement degrades the ballistic current. The simulation result presented here contradicts with the previously reported result that TG FinFETs show better performance than DG FinFET and reveals that DG FinFET shows slightly better performance below 5 nm fin thickness. This result indicates that in terms of ballistic drive current the tri-gate device is not always favorable than double gate device especially when the device dimension is scaled down deeply.