From Transistors to Quantum Dots: A Comparative Study of CMOS and QCA Paradigms Technologies

Abstract

(CMOS) Complementary-Metal-Oxide Semiconductor technology has been the dominant platform for digital circuit design for decades, enabling high-performance and cost-effective electronics. However, as CMOS devices scale below 5 nm, they face physical and economic challenges such as leakage currents, short-channel effects, and increased fabrication costs. Quantum- dot Cellular Automata (QCA) is an emerging nanotechnology that encodes binary information using electron polarization rather than current flow, offering ultra-low power consumption and extremely high device density. This paper presents a comparative review of CMOS and QCA technologies in terms of power, area, speed, scalability, reliability, and fabrication complexity. Challenges and future trends for both technologies are also discussed, providing an overview of their possible roles in next-generation Nanoelectronics. The paper also discusses current challenges and potential research directions for enabling a transition from CMOS to QCA in the coming decades.