Copper thin films have been deposited onto silicon substrates by means of two different deposition techniques, resulting in metallizations with different microstructure. In particular, transmission electron microscopy (TEM) observations have shown that the two types of films are characterized by different distributions of the grain size. Lifetime and SARF (Spectral Analysis of Resistance Fluctuations) tests have been performed on lines obtained from the two metallizations in order to compare their resistance to electromigration. The results of the tests confirm those already obtained in Al based lines; in fact, a clear correlation exists among the average grain size, the lifetime and the level of electromigration noise.
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