The Ground Plane in Buried Oxide for Controlling Short-Channel Effects in Nanoscale SOI MOSFETs

The ground plane (GP) concept is one of the techniques used to reduce the drain-induced barrier lowering (DIBL) in nanoscale MOSFETs and is effective only when the distance between the GP and the drain is small as compared with the channel length. Therefore, if the GP is placed in the substrate (GPS), the buried oxide (BOX) thickness should be kept as small as possible which, however, results in an increased subthreshold slope. As a result, for sub-100-nm channel lengths, it is not possible to achieve both reduced DIBL and steep subthreshold slope using GPS. In this brief, a new device structure with the GP BOX is proposed to overcome the aforementioned shortcomings so that a reduced DIBL as well as an improved subthreshold slope can be obtained. Two-dimensional simulation is used to understand the efficacy of the proposed method.