Stress evolution due to electromigration in confined metal lines

Abstract

Electromigration is an important concern in very large scale integrated circuits. In narrow, confined metal interconnects used at the chip level, the electromigration flux is resisted by the evolution of mechanical stresses in the interconnects. Solutions for the differential equation governing the evolution of back stresses are presented for several representative cases, and the solutions are discussed in the light of experimental as well as theoretical developments from the literature.