Application of the quadrat counts method to the analysis of the spatial breakdown spots pattern in metal gate/MgO/InP structures

The breakdown spots spatial distribution in NiSi/MgO/InP structures is analyzed using the quadrat counts method, a classical statistical technique aimed to evaluate the deviation from complete spatial randomness. The spots appear as black dots spread over the gate electrode area and are the result of important local thermal effects occurring during the current runaway associated with the formation of the percolation paths across the dielectric film. Using image analysis techniques and specialized statistical software it is shown that the spots' locations follow a homogeneous 2D Poisson distribution, what can be regarded as an indirect indicator of the quality and uniformity of the samples under investigation.