A Monte Carlo computer simulation of electromigration

In this article, a Monte Carlo computer program is used to simulate the motion of atoms during electromigration. In the program, current density is accurately determined in two dimensions and the result of the impressed current is a drift of activated atoms along the grain boundaries in response to an ‘‘electron wind’’ force. The grain structure simultaneously undergoes annealing—atoms are moved so as to minimize the curvature of the grain boundaries. Heat is lost to the back of the substrate and a single temperature of the metal line is used to characterize both thermal conduction and Joule heating. Qualitatively correct predicted results include the dependence of mean lifetime upon current density, temperature and grain size, the distribution of failure times (log normal), and the occurrence of 1/f noise in measured results.