Quantum-mechanical suppression and enhancement of SCEs in ultrathin SOI MOSFETs

This paper simulates the transport characteristics of ultrathin silicon-on-insulator MOSFETs, and evaluates the influence of the quantum-mechanical mechanism on the short-channel effects on the basis of the density-gradient model. It is clearly shown that the quantum-mechanical mechanism suppresses the buried-insulator-induced barrier lowering with regard to the subthreshold swing because the surface dark space yields a high-field region in the source region adjacent to the channel. It is also suggested that the quantum-mechanical mechanism enhances the impact of the apparent charge-sharing effect on the threshold voltage because the surface dark space effectively increases the thickness of the gate-oxide layer and buried-oxide layer.