Layout-Driven Robustness Analysis for misaligned Carbon Nanotubes in CNTFET-based standard cells

Carbon Nanotube Field Effect Transistors (CNT-FETs) are being considered as a promising successor to current CMOS technology. Since the alignment of CNTs cannot be fully controlled yet, the layout of CNTFET-based standard cells has to be designed robust against misalignment. As CNTFET-based designs become more prevalent, a systematic methodology for misalignment robustness evaluation becomes crucial. In this work we present a novel EDA tool “Layout-Driven Robustness Analysis” (LDRA) which enables designers to, for the first time, measure the robustness against misalignment. LDRA is validated and applied to various CNTFET-based standard cell layouts. The comparison of these cells reveals that robustness against misalignment is complex and depends on many factors. A CNT curve model is introduced and its influence on the robustness result is discussed. In conclusion, key factors for designing layouts robust against misalignment are proposed.