Carbon Nanotubes Power Grid: Electrical and Thermal Analysis

Abstract

Resistivity, current density, and electromigration make copper less feasible for interconnect in future VLSI generations. Carbon Nanotubes (CNT) have attractive properties to overcome these problems. This talk investigates the feasibility of using CNT for on- chip power grid network. It compares the electrical and thermal attributes of copper with a practical implementation of CNT using an architectural model of chip-level multiprocessor (CMP). Electrical analysis consists of impedance comparison, IR drop in power grid, impact of di/dt, and needs for decoupling capacitance to deliver the same amount of current. Thermal analysis provides the on-chip temperature distribution.

The results of electrical analysis show that CNT can improve the voltage drops due to IR by 2%, and due to di/dt by 3%. The size requirement for on-chip decoupling capacitance is reduced by 50%. Thermal analysis shows that the CNT power grid reduces on-chip peak temperatures and improves heat spreading.