As a result of aggressive downscaling, short-channel effects (SCEs) become a major threat for future downscaling especially in the sub-100nm region. In order to extend the International Technology Road-map for Semiconductors (ITRS) road-map beyond 100nm, Double-Gate (DG) MOSFET evinces himself as a major promising candidate due to its higher scaling capability. In this book, modelling using a pseudo- two-dimensional (2D) analysis was presented to explore the effect of scaling especially for subthreshold characteristics of short-channel DG and conventional single gate MOSFET.