Collaborative Applying the Ultra-low-k Dielectric and the High-k Dielectric Materials for Performance Enhancement in Coupled Multilayer Graphene Nanoribbon Interconnects

Based on transmission line modeling, a new technology of collaborative applying the ultralow-k dielectric and the high-k dielectric materials in coupled multilayer graphene nanoribbon (MLGNR) interconnects (i.e., case 4) to reduce propagation delay and to expand 3-dB bandwidth of the conventional pristine (undoped) MLGNR interconnects is proposed in this paper. By using the decoupling technique and ABCD parameter matrix approach, the transfer function of the equivalent circuit model for coupled MLGNR interconnects is derived to obtain step response, propagation delay, transfer gain and 3-dB bandwidth under in-phase and out-of-phase crosstalk modes at global level of 7.5 nm technology node, which is based on the defined four cases. The results show that the maximum reduction of propagation delay between the proposed new technology (case 4) and the conventional MLGNR interconnects (case 1) can reach 15.911 ns at out-of-phase crosstalk mode for an interconnect length of 4000 μm. The corresponding 3-dB bandwidth for them can be expanded over 2.978 times in the same length as the former. It is demonstrated that the proposed case 4 can obviously reduce the propagation delay and enhance the transfer gain and 3-dB bandwidth compared with the conventional case 1. Moreover, it is found that the coupled MLGNR interconnect under in-phase mode outperform that under out-of-phase mode in terms of propagation delay, transfer gain and 3-dB bandwidth at the same condition. In addition, it is manifested that the victim line of two-line coupled MLGNR interconnects have lesser propagation delay, higher transfer gain and larger 3-dB bandwidth, as compared to three-line coupled MLGNR interconnects at the same case. The proposed new technology in this paper would be beneficial to improve the performance of MLGNR interconnects and to provide the guidelines for the design of next generation on-chip MLGNR interconnect system.