Non-destructive electrical measurement of interconnect degradation in early states by the use of RF signals

Abstract

This paper presents the electrical measurement of interconnect degradation in micrometer scale. For this approach the changes in a RF measurement signal under artificial interconnect aging conditions are used. Therefore, scattering parameters (S-parameters) are measured and evaluated. This technique overcomes the drawbacks in sensitivity of the more traditional measurement approaches. Test samples consisting of coplanar transmission lines are cut in with a focused ion beam. Cracks in micrometer dimensions are created and measured electrically and non-destructive. In the second part of the paper a measurement method is presented that is able to use a lower signal frequency by getting the same information about the early degradation state. The used method is passive intermodulation distortion measurement (PIM). Finally, both methods are compared to the traditional four-wire-resistance measurement method. The electrical measurement of early degradation states is the first step to a novel generation of reliability monitoring systems.