Direct Observation of Current Density Distribution in Contact Area by Using Light Emission Diode Wafer

Theoretically the Laplace equation can be used to calculate the current constriction behavior in electrical contacts. On the actual behavior of current constriction, although there are many reports on the contact resistance measurement, not many reports on the detailed behavior of current density distribution in the contact area experimentally. Therefore, we attempted to observe the behavior of the current density distribution in the contact by using semiconductor wafers in this study. As a result, it was confirmed that electric current is uniformly distributed over the contact area covered by an oxide film, while it is concentrated at the periphery of the contact if there is no oxide film. These results qualitatively agree with the results of the earlier theory and electric field analysis.