Interuniversitair Micorelektronica Centrum (Imec, Vzw)

Alessandro Goldoni

Ward Aime De Ceuninck

Luc Irena De Schepper

Jan Van Olmen

A method for measuring resistance changes is described to study electromigration induced failures in conductive patterns. This method can provide a basis for lifetime predictions based on low value failure criteria, i.e. small resistance changes in the conductive patterns in a limited period of time. Two essentially identical so-called test and reference structures are placed close to each other on the same substrate and submitted to at least one sequence of a stress period and a measurement period. During a stress period, a DC current with a high current density is applied to the test structure thereby enhancing electromigration, while substantially simultaneous an AC current is applied to the reference structure leading to the same amount of power dissipation in said reference structure as the amount of power dissipation in said test structure, introduced by said DC stress current. The method of the present invention makes it possible to distinguish in a very accurate way between resistance changes induced by electromigration and resistance changes induced by other disturbances.

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Parma, Italy

Alessandro Goldoni