Quasi-analytical model-based performance analysis of dual material gate stack strained GAA FinFET

摘要

The evolution of traditional field effect transistor from planar to three-dimensional (3-D) device structure has led to higher package density and high current drive. However, due to continuous scaling, these non-planar devices (FinFET) have been found to suffer from performance degrading short channel effects (SCEs). In this work, a modified field effect device called dual material gate-all-around FinFET with High-K Gate-Oxide stack and strained channel is presented along with its quasi 3-D analytical model to evaluate the SCE immunity. This surface potential-based model includes gate work-function difference, characteristic gate length and equivalent oxide thickness. The channel potential is derived using quasi-3-D scaling equation where the characteristic length is derived using equivalent number of gates model. With the simple expression of potential distribution, threshold voltage and subthreshold swing have been obtained using minimum central potential. The device immunity to SCEs such as drain-induced barrier lowering, hot carriers and subthreshold degradation has also been examined for various structural and material modifications. The proposed analytical model has been verified using the 3-D numerical device simulator ATLAS.