A new design method for imperfection-immune CNFET-based circuit design

Abstract

Abstract CNFETs (Carbon Nanotube Field Effect Transistors) are among the most outstanding candidates to replace with current semiconductor technology. The facing challenges of this newly introduced nanotechnology like metallic CNT (Carbon nanotube) and misaligned and mispositioned CNTs are considered as obstacles in mass production of circuits based on CNFET. In the present article, first, the correlation between methods of CNFET-based designs circuits and misalignment and mispositioning of CNTs occurrence are assessed in the fabrication phase, and then an approach is propose, which may deal with and eliminate the effects of this challenge. This method is introduced at design level, which is immune against misaligned and mispositioned CNTs and due to the lack of complexity in its layout, it is compatible with recent techniques in eliminating metallic CNT, in a sense that, the application of such techniques does not require change in layout. To evaluate circuit parameters in circuits designed with this proposed method, together with evaluating their tolerance against variations in CNT diameter and density and supply voltage variation a full adder is designed based on this proposed method. The various simulations prove the efficiency of this proposed method and the improvement of circuit parameters compared to previous studies.