This thesis explores the potential of replacing traditional MOSFET technology with FinFET devices, focusing on performance improvements in digital and analog applications. The study analyses FinFET’s advantages over MOSFET, particularly regarding power efficiency, speed, and scalability in advanced semiconductor nodes. Emphasis is placed on FinFET's enhanced control over SCE due to its three-dimensional gate structure, which reduces leakage currents and improves overall device performance. In addition to comparing the fundamental characteristics of MOSFET and FinFET technologies, the thesis also examines the impact of FinFET geometry, including parameters such as hfin, wfin and AR, on device performance. Special attention is given to the implications of these geometric factors on analog circuit design, such as VCO and LNA.