Crosstalk analysis of multilayer graphene nanoribbon interconnects in GHz regime: Unraveling scattering induced effects

This paper analyzes the impact of high-frequency phenomena on the operational characteristics of intercalation-doped horizontal top-contact multilayer graphene nanoribbon (D-HTC-MLGNR) interconnects. The purpose is to explore their viability for utilization in high-frequency circuit design. A methodology incorporating the scattering-limited realistic mean free path and a finite thickness-dependent skin effect model is proposed for extracting the frequency-dependent impedance of MLGNR interconnects. By employing the proposed methodology, the frequency-dependent characteristics of scattering-limited impedance parameters and crosstalk effects in d-HTC-MLGNR interconnects are examined and compared with undoped MLGNR (viz. HTC and vertical top-contact) and copper (Cu) counterparts (smooth and rough). The findings indicate that Cu variants outperform scattering-limited MLGNR variants placed on SiO₂ substrate in terms of crosstalk effects. However, Li-doped HTC-MLGNR without surface polar phonons (SPPs) and edge roughness (ER) placed on SiC and BN substrates demonstrates superior crosstalk-induced performance than Cu counterparts. Furthermore, in the absence of SPPs and ER, Li-D HTC-MLGNR placed on SiC has a minimum average percentage increase in overshoot peak amplitude, overshoot width, and delay of 6.6%, 0.18%, and 15.6%, respectively, for the entire frequency range, implying minimum impact of frequency variations and skin effect.