Modeling and performance analysis of coupled multilayer graphene nanoribbon (MLGNR) interconnects with intercalation doping

Abstract

This paper investigated the temperature‐dependent performance of coupled top contact multilayer graphene nanoribbon interconnects (TC-MLGNRs) with different intercalation doping (viz., AsF5-, FeCl3-, and Li-doped) considering edge roughness and crosstalk effect, compared with SC-MLGNR, MWCNT, and copper (Cu) interconnects for 13.4 nm technology nodes at the global level. Based on the equivalent single conductor (ESC) modeling, a distributed transmission line model for coupled doped TC-MLGNRs is presented to obtain the crosstalk delay, step response, transfer gain, and 3-dB bandwidth, which considers in-phase and out-of-phase crosstalk modes and verified with the Hspice simulation. It is demonstrated that all interconnects at room temperature in the in-phase crosstalk mode outperform those in the out-of-phase crosstalk mode in terms of crosstalk delay, transfer gain, and 3-dB bandwidth, and Li-doped TC-MLGNR significantly reduces crosstalk delay and enhances transfer gain and 3-dB bandwidth compared to other interconnects. Moreover, it is found that the victim line of two-line coupling for doped TC-MLGNRs exhibits less crosstalk delay, greater transfer gain, and 3-dB bandwidth compared to the center line of three-line coupling for doped TC-MLGNRs in the same condition. Furthermore, we analyze the crosstalk delay and 3 dB-bandwidth for two- and three-line doped TC-MLGNRs at varying temperatures and compare them with SC-MLGNR, MWCNT, and Cu interconnects. Simulation results show that crosstalk delay and bandwidth performance are temperature dependent, and they both degrade with increasing temperature. Also, Li-doped TC-MLGNRs still exhibit the best crosstalk delay and bandwidth performance of all interconnects. The numerical calculation results show that decreasing interconnect temperature, increasing line spacing, and reducing edge roughness are efficient methods to reduce crosstalk delay and enhance 3-dB bandwidth for Li-doped TC-MLGNRs. In addition, the results obtained by the proposed model are well matched with the Hspice simulation. Hence, our performance analysis demonstrates that Li-doped TC-MLGNR can be a promising material for global interconnect applications in a thermally variable environment.