Modeling of Temperature Increase Due to Joule Heating During Electromigration Measurements

Electromigration (EM), the mass transport phenomenon under applied electrical field, is known to cause degradation in interconnections and thus to compromise the devices' reliability. High current density and high temperature conditions are usually adopted to evaluate the EM lifetime. Such high current density will raise the temperature at the test sites because of Joule heating. Thus the actual temperature on the test surface, not the ambient temperature, is an important parameter affecting the lifetime of the metallization. A simple model is proposed here to predict the temperature rise in such interconnections and the calculated values agree well with the experimentally measured rise in temperature. Only heat conduction and convection are considered and illustrative equivalent electrical analogy technique is used to solve the problem. This model, using a commercially available spreadsheet and its iteration functions, is shown to match closely with experimental results.