Interconnection Reliability on FinFET Devices

Abstract

Reliability issues of semiconductors devices are always related with defects accumulation. Repeatedly switching processes of a semiconductor device could induce the defects accumulation which results in performance degradation. Bulk fin field-effect transistor (FinFET) devices, with a miniaturized three-dimensional structure, have a more complex reliability mechanism that requires detailed research. In this experiment, failure analysis was studied on the same batch of the FinFET devices which suffered performance degradation aging tests at different stress time. During this process, the magnitude of each applied electrical current was not exceeded the operating current. In this work, microstructural and chemical elements differences were characterized by transmission electron microscopy. It is founded that the interconnection part next to the core fin structure was destructed under the electrical over stress (EOS). These phenomena were not observed in the normal FinFET. It can be concluded that the effective contact area of the interconnection part decreased, resulting in the increased internal electrical field. Tungsten (W), as the metal 0 (M0) layer, migrated under defects accumulation. This work paves a guideline for the reliability improvements of FinFET.