QUASI-THREE-DIMENSIONAL DEVICE SIMULATION OF FULLY DEPLETED MOSFET/SOI FOCUSING ON SURFACE ROUGHNESS

摘要

A novel simulation method using TCAD is proposed to investigate the effects of surface roughness on operational characteristics of FD MOSFETs/SOI. The method provides guidelines for estimating surface roughness of an SOI substrate with an ultrathin top Si layer. A quasi-three-dimensional device simulation was performed by employing topographical data on SOI substrates from AFM measurements and a device model with divided structures in appropriate dimensions along a channel. A decrease in the drain current at a high effective normal field, and an increase in the subthreshold current were observed. The results imply a numerical requirement for determining the surface roughness of SOI wafers from the perspective of FD MOSFETs.