Short channel effect of SOI vertical sidewall MOSFET

Abstract

Application of asymmetric sidewall vertical metal oxide semiconductor field effect transistors (MOSFETs) is hindered by the parasitic overlap capacitance associated with their layout, which is considerably larger than for a lateral MOSFET on the same technology node. A simple process simulation has been developed to reduce the parasitic overlap capacitance in the asymmetric sidewalls vertical MOSFETs by using SOI (silicon on insulator) in bottom planar surfaces side. The result shows that while channel length decreases, the threshold voltage goes lower, the DIBL rises and subthreshold swing tends to decrease, for both structures. It is noted that the SVS MOSFET structure generally have better performance in SCE control compared to bulk vertical MOSFET. The presence of buried oxide is believed to increase the performance of vertical MOSFET, essentially in controlling the depletion in subthreshold voltage.