Impact of scaling channel length on the performances of nanoscale FETs

The investigation of short-channel effects (SCE) due to channel length reduction for four different types of n-channel FETs: Bulk MOSFET, SOI MOSFET, DG MOSFET and CNTFET are carried out in this work. Simulators are used to investigate SCEs like threshold voltage (V
_th
) roll-off, subthreshold Swing (SS) and I
_on
/I
_off
ratio. Our study shows that DG MOSFET, SOI MOSFET and Bulk MOSFET reach their scalable limit at 30 nm, 50 nm and 100 nm channel length respectively due to elevation of leakage power consumption as they exhibit rapid degradation of V
_th
, SS beyond 100mV/decade and less I
_on
/I
_off
ratio. On the contrary, CNTFET can be scaled down below 10 nm as it shows negligible SCEs with stable V
_th
, ideal SS (60mV/decade) and high I
_on
/I
_off
ratio as channel length decreases. Our numerical analysis shows CNTFET creates only 1.11% V
_th
variation whereas DG MOSFET creates 39.33% V
_th
variation. CNTFETs advantages over MOSFET make it viable for faster and enhanced applications in nanoelectronics.