Breakdown Energy of Metal (BEM) - A New Technique for Monitoring Metallization Reliability at Wafer Level

This paper presents a new technique for production monitoring of VLSI thin film metallization reliability at wafer level. By measuring the Median-Energy-to-Fail of properly designed structures during a ramp current stress, the long term electromigration reliability of metallization can be determined in a test taking a few seconds. Process variables such as metal width, thickness, step coverage, defect density, etc., have been monitored by measuring critical MEF in a production environment.