Modeling and Analysis of High Frequency Interconnects Using Doped Multilayer Graphene Nanoribbon

Abstract

The increasing need for faster communication and computing systems has created a demand for interconnects capable of handling sharper signal transitions and operating at higher frequencies. At the same time, driven by the need for enhanced performance, the semiconductor industry has aggressively scaled down the size of devices and interconnects. However, the continuous evolution and rapid scaling of device integration technology, have led to significant performance challenges for conventional copper (Cu) based high-speed on-chip interconnects. Hence, researchers are on a quest to find a suitable alternative that addresses these limitations while ensuring efficient and reliable performance in future high-speed, nanoscale systems. Recently, intercalation-doped multilayer graphene nanoribbons (MLGNRs) have emerged as a promising alternative for Cu interconnects, offering remarkable electronic, transport, mechanical, and thermal properties. However, despite the promising enhancements offered by intercalation doping, the practical application of MLGNR as on-chip interconnects is limited by extrinsic scatterers and skin effect at high frequencies, thereby aggravating signal integrity issues and compromising the overall performance, functionality, and reliability of high-speed systems. Further research is crucial to mitigate these challenges and fully realize the potential of MLGNR for high-speed on-chip interconnects. In this thesis, an impedance model is developed by incorporating the scattering-limited realistic effective mean free path (MFP), and#955;R(T), for various configurations of MLGNR interconnects to extract frequency-independent circuit parameters. The MLGNR configurations include undoped MLGNR (viz., horizontal top-contact (HTC), horizontal side-contact (HSC), and vertical top-contact (VTC)), and intercalation-doped HTC-MLGNR (with AsF5, FeCl3, and Li dopants). The optimistic intrinsic-phonon-limited effective MFP, and#955;P(T), for perfect MLGNR is also considered for impedance analysis. The circuit parameters