Characterization and Tolerance of QCA Full Adder under Missing Cells Defects

Quantum-dot Cellular Automata (QCA) is a promising nanotechnology that offers significant improvement over CMOS. QCA is limited by the high fault rate in manufacturing. In this paper, a novel QCA adder structure is presented which is more robust in compare with previous reported designs. Different types of defects in this technology are presented. The full adder is simulated under missing cell defects and its effects in outputs are investigated. It shows that there are some sensitive points in this circuit under missing cell defects. Some solutions for increasing the fault tolerance of the circuit under this specified defects is presented.