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The Maxwell–Wagner effect, the enhanced charge migration to the interface of a stack of two dielectrics with different conductances, is shown to cause asymmetric leakage current and electrical breakdown behavior for different electrode polarities. For this purpose, metal-insulator-silicon capacitors were fabricated consisting of bilayered silicon dioxide–lanthanum zirconate dielectric stacks. Maxwell–Wagner instability and Debye polarization can be distinguished upon comparing electron injection from both sides of the stack. The Maxwell–Wagner charges have relaxation times that are nearly five orders of magnitude larger than the Debye polarization, suggesting the long-lasting influence of these trapped charges in nanolaminated dielectric systems. [ABSTRACT FROM AUTHOR]

The use of aluminum as an electrode in metal-insulator-semiconductor devices containing lanthanum oxide is impaired by unacceptable leakage current levels. Time of flight secondary ion mass spectroscopy depth profiling shows a significant amount of silicon out-diffusion from the substrate and aluminum in-diffusion towards the oxide. By using titanium nitride as the electrode, the silicon out-diffusion is suppressed, which improves the device performance. This indicates that, despite the larger coordination number of the lanthanum ions in the oxide, aluminum acts as a sink for silicon, thus driving the out-diffusion of silicon. [ABSTRACT FROM AUTHOR]