This document describes the design and simulation of a hybrid full adder circuit for high-speed VLSI applications. Full adders are important components used in arithmetic logic units, floating point units, and address generation. The author first reviews existing full adder designs based on static CMOS, transmission gate, and dynamic logic styles. Then, a previously proposed hybrid CMOS full adder using both transmission gates and CMOS is described. To improve speed, the author proposes a modified full adder design using only 14 transistors instead of 16. Both the existing and proposed designs are simulated in Cadence Virtuoso at 180nm and 90nm technology nodes. Simulation results show the proposed design has lower power consumption and propagation delay compared to the