Recent Progress in Physics-Based Modeling of Electromigration in Integrated Circuit Interconnects

Abstract

The advance of semiconductor technology not only enables integrated circuits with higher density and better performance but also increases their vulnerability to various aging mechanisms which occur from front-end to back-end. Analysis on the impact of aging mechanisms on circuits’ reliability is crucial for the design of reliable and sustainable electronic systems at advanced technology nodes. As one of the most crucial back-end aging mechanisms, electromigration deserves research efforts. This paper introduces recent studies on physics-based modeling of electromigration aging of on-chip interconnects. At first, the background of electromigration is introduced. The conventional method and physics-based modeling for electromigration are described. Then studies on how electromigration affects powers grids and signal interconnects are discussed in detail. Some of them focus on the comprehensiveness of modeling methodology, while others aim at the strategies for improving computation accuracy and speed and the strategies for accelerating/decelerating aging. Considering the importance of electromigration for circuit reliability, this paper is dedicated to providing a review on physics-based modeling methodologies on electromigration and their applications for integrated circuits interconnects.

A Comparative Study and Analysis of Various Interconnects for Very Large-Scale Integration

“…An overview of physics-based modelling approaches for electro migration and their applications for integrated circuit interconnects has been published by Wen-Sheng Zhao et al 5 The impact of electromigration on power grids and signal interconnects is examined in this research. The conventional method and physics-based modeling for electromigration are described.…”

Recent Trends in Copper Metallization

“…In a Cu damascene structure, the TaN/Ta barrier and the DB act as a boundary for the Cu, and this is where the depletion of metal atoms begins. As a result, Cu EM shifts into the voids through the nucleation, incubation, and growth phases [96]. The dimensions of the vias and metal determine the likelihood that the voids produced in this manner will affect the resistance.…”

Theoretical Understanding of Electromigration-Related Surface Diffusion and Current-Induced Force in Ag–Pd Systems

“…For on-chip interconnects, the scale-down of the chip process leads to a decrease in the cross section of interconnects, which means a higher current density, resulting in a higher wind force and more serious EM. Although some techniques, like the Cu alloy seed layer, are applied to suppress EM, the lifetime of the interconnect is still predicted to be seriously decreased …”