Study of Crosstalk Effect on the Propagation Characteristics of Coupled MLGNR Interconnects

Multi-layer graphene nanoribbons (MLGNRs) material has been a potential solution to replace conventional Cu for next-generation on-chip interconnects. Based on equivalent single conductor model, this paper extracts the equivalent resistance-inductance-capacitance parameters for MLGNRs with consideration of edge roughness and Fermi level. A distributed circuit model for a pair of coupled MLGNR interconnects is provided, with both capacitive and inductive coupling taken into account, and validated against the Spice results and the predicted experiment results in frequency and time domains. Using the proposed model, the impact of various dimensional and technology parameters on the transfer gain and crosstalk delay is investigated for the global MLGNR interconnects at different phase modes. It is demonstrated that MLGNR interconnects with smooth edge exhibit higher transfer gain and lower crosstalk delay in comparison to its Cu counterpart at same dimension. However, edge roughness in the present fabrication technologies is inevitable that significantly deteriorates the propagation performance and the performance difference due to edge roughness is relatively less in wider MLGNR interconnects. Moreover, it is shown that side contact MLGNR interconnects have better electrical performance than that of top contact MLGNR interconnects at short interconnect length in comparison to that at long interconnects due to the domination of in-layer resistance. The results presented in this paper would be helpful to fully understand the propagation characteristics and provide guidelines for signal integrity analysis of MLGNR interconnects.