A Study of the Performance of Ballistic Nanoscale MOSFETS Using Classical and Quantum Ballistic Transport Models

Using the nanoMOS 2.5 simulator, we study the impact of varying the channel length, gate oxide thickness and dielectric constant, drain voltage, and temperature on the performance of a ballistic nanoscale MOSFET using quantum ballistic and classic ballistic transport models. Our key results show that the quantum ballistic (QB) transport model typically predicts a lower on-state current compared to the classical ballistic (CB) model except for a 5nm channel length where source-to-drain tunneling contributes approximately 35% to the on-state current. We also show that the off-state current is significantly affected by the gate oxide thickness, whereas the influence of varying the oxide dielectric constant on the off-state current was not as pronounced for a 1.5nm oxide thickness. Finally, we show that room temperature operation (T=300K) leads to an excessively high off-state current and a degraded subthreshold slope. For low temperatures, (T=100K), the QB and CB models predicts a seven orders of magnitude difference in the off-state current.