Electromigration of submicron Damascene copper interconnects

Abstract

This paper compares the microstructure and reliability of submicron Damascene CVD and electroplated Cu interconnects. For CVD Cu, the electromigration lifetime degrades in the deep submicron range due to fine grains constrained by the deposition process. However, electroplated Cu has relatively large grains in trenches, resulting in no degradation of reliability in the deep submicron range. The electromigration performance of electroplated Cu is superior to that of CVD Cu especially for deep submicron Damascene interconnects.