Observing electromagnetic migration

Integrated circuits have become increasingly more reliable as the technology has progressed, but even a perfectly produced processor operated under the most rigorously maintained environment will fail eventually. The culprit is often electromagnetic (EM) migration slowly degrading the interconnects. Past research has shown that careful tuning of the microscopic grains of a metal interconnect can slow this process significantly—and now researchers have successfully imaged the process in copper—watching individual atoms move around under an electrical current.

To understand just what exactly the researchers observed, one must understand the mechanisms at work in EM-induced migration. On a fundamental level, diffusion is the perpetrator, while electrical current is the motivator. Diffusion is simply stuff moving—notice that even in seemingly stagnant air, smells will disperse themselves evenly through a room. Atoms can and will do the same thing under the proper conditions. Energy is needed to drive diffusion which would include things like heat, and in our case, electromagnetic energy.