Delay characterization of multilayer graphene nanoribbon interconnects in presence of scattering and thermal effects

Abstract

AbstractScattering source‐based mean free path (MFP) and circuit modeling are proposed for three different configurations of undoped multilayer graphene nanoribbon (U‐MLGNR) (viz. horizontal top‐contact (HTC), horizontal side‐contact (HSC), and vertical top‐contact (VTC)). A similar analysis is carried out for doped HTC‐MLGNR (D‐HTC‐MLGNR) considering dopants viz. Li, FeCl3, and AsF5, for a temperature range of 300–500 K. The optimistic intrinsic‐phonon limited (Λeff,1(T)) and realistic scattering limited (Λeff,2(T)) effective MFP models are considered to derive the equivalent resistance of MLGNR. The performance of MLGNR variants, considering Λeff,1(T) and Λeff,2(T), is compared to copper (Cu) (with smooth and rough surface) in terms of coupled line crosstalk‐induced delay (XT‐D). The results show that the MLGNR variants outperform Cu interconnects in terms of XT‐D, for Λeff,1(T). However, structural edge roughness being the dominant scattering source in Λeff,2(T), severely degrades the performance of MLGNR variants in comparison to Cu counterparts. Moreover, for Λeff,1(T) and Λeff,2(T), Li‐D HTC‐MLGNR outperforms other MLGNR variants. Also, among the MLGNR variants, U‐VTC‐MLGNR exhibits a minimum average relative penalty of 21.58 × 102% in terms of XT‐D, when Λeff,2(T) is considered as against Λeff,1(T). Li‐D HTC‐MLGNR with optimized width exhibits 10.59× lower XT‐D and 8.85× higher XT‐D for Λeff,1(T) and Λeff,2(T), respectively, compared to smooth Cu. The optimized Li‐D HTC‐MLGNR demonstrates a reduction of 85.48% and 74.67% in XT‐D values for Λeff,1 (T) and Λeff,2 (T), respectively, when compared to mixed carbon nanotube (MCNT) bundle interconnects.