Thermal characterization of planar interconnect architectures under different rapid transient currents using the transmission line matrix and finite element methods

Considering the increasing level of integration and high current densities, the quality and reliability of interconnects in microelectronics is a major challenge. This work studied the problem of transient Joule heating in 180 nm by 360 nm interconnects in a two-dimensional (2D) inhomogeneous model. Specifically, the effects of the duration and amplitude of rapid square-wave source current pulses (100 ns and 1 μs) were investigated. The transmission line matrix (TLM) method was implemented with the link-resistor (LR) formulation and the results were compared with a finite element (FE) model that was developed in LS-DYNA^®. This comparison showed that the overall behavior of the TLM models were in good agreement with the corresponding FE models while, near the heat source, the transient TLM solutions developed slower than the FE solutions. Overall, computational efficiency of the TLM method and its ability to accept non-uniform 2D and 3D mesh and variable time-step make it a good candidate for multi-scale analysis of Joule heating in interconnects.