Jun 30 (Tue) @ 1:30pm: "Engineering Two-Dimensional Materials for Future Electronics: From CMOS to Quantum Computing," Ankit Kumar, ECE PhD Defense

Location: Elings Hall (CNSI), Room 1601

Abstract

As the semiconductor industry confronts fundamental limits in transistor scaling, energy consumption, and interconnect performance, two-dimensional (2D) materials have emerged as one of the most promising candidates for sustaining future advances in computing. Owing to their atomically thin nature and diverse electronic properties spanning semiconducting, insulating, and metallic behavior, 2D materials offer unique opportunities for innovation across multiple layers of the semiconductor technology stack.

This dissertation develops a comprehensive modeling and design framework to evaluate and exploit 2D materials for next-generation digital electronics. At the device level, a multiscale simulation methodology combining density-functional theory (DFT) and non-equilibrium Green's function (NEGF) techniques is established to assess the performance limits of 2D field-effect transistors (FETs). Using this framework, strategies for enhancing carrier transport through strain engineering and for simultaneously achieving superior electrostatic control and low gate leakage through optimized gate-dielectric selection are systematically investigated.

Beyond transistors, the dissertation examines the circuit- and system-level implications of intercalated multilayer graphene (I-MLG) interconnect technologies for future computing platforms. Through comprehensive benchmarking against state-of-the-art Cu and Ru interconnects under realistic design constraints, the study demonstrates the strong scalability potential of I-MLG interconnects in advanced technology nodes, particularly at sub-10-nm interconnect dimensions, and identifies contact resistance as the principal barrier limiting the realization of their full performance advantages. The results indicate that, as dimensions continue to shrink beyond the limits of conventional metals, I-MLG interconnects offer a promising pathway toward overcoming the resistance, IR-drop, power-delivery, energy-dissipation, and signal-delay challenges that increasingly constrain next-generation integrated circuits. Recent independent studies by leading semiconductor manufacturers, together with the subsequent inclusion of I-MLG in future interconnect technology roadmaps, have further underscored its potential as a scalable interconnect technology for advanced semiconductor nodes while highlighting the importance of continued advances in contact engineering. The dissertation further establishes the potential of graphene-based interconnects for cryogenic interface electronics, an emerging technological requirement for large-scale quantum computing systems. Complementing these studies, contributions to the development of CMOS-compatible graphene synthesis and integration technologies help establish pathways toward practical implementation.

Collectively, this work provides a holistic assessment of the opportunities, limitations, and technology-enablement strategies required for incorporating 2D materials into future semiconductor platforms. By spanning atomistic materials modeling, device engineering, circuit analysis, and system-level evaluation, the dissertation establishes a comprehensive framework for leveraging 2D materials to address critical scaling challenges in next-generation CMOS technologies while enabling emerging computing paradigms, including large-scale quantum information systems.

Bio: Ankit Kumar is a PhD candidate in the Department of Electrical and Computer Engineering at the University of California, Santa Barbara, where he conducts research under the supervision of Professor Kaustav Banerjee. He received dual degrees—a B.E. (Hons.) in Electrical and Electronics Engineering and an M.Sc. (Hons.) in Physics—from the Birla Institute of Technology and Science (BITS), Pilani, India. His research focuses on the modeling, synthesis, and characterization of two-dimensional (2D) materials and devices, with applications spanning next-generation CMOS technologies, advanced interconnects, and emerging computing platforms.

Hosted By: ECE Professor Kaustav Banerjee

Submitted By: Ankit Kumar <ankitkumar@ucsb.edu>