Practical realization of low-power, high-speed transistor technologies for future generation nano- electronics can be achieved with novel structures, such as FinFET, tri-gate or with the integration of exotic channel materials,such as Gallium Nitride (GaN), into Fully-Depleted SOI(FDSOI) transistor architectures. Novel Structures are the most promising candidates for logic devices with sub-20nm gate length. They can increase gate control and suppress short channel effects. To compare the feasibility of these different structures and to project the device performance, technology CAD (TCAD) simulation is a reasonable method. The III-V semiconductors, such as Gallium Nitride (GaN), have high maximum electron drift velocities and ballistic mean free paths, which would enable high-speed transistor operation at very low voltages with gate lengths below 10nm. Since it s impractical for experiments currently, TCAD simulation can be used to project performance goals for aggressively scaled devices. This research focus on the methodology to compare different technologies for alternative to Silicon based traditional logic device using TCAD simulations.