Effects of electrical stress on the leakage current characteristics of multilayer capacitor structures

Abstract

The degradation of a high-k dielectric multilayer was investigated by measuring the time dependent leakage current under a constant voltage stress in metal-insulator-metal capacitor structures. When comparing the two multilayer structures of Al2O3/HfO2/Al2O3 and HfO2/Al2O3/HfO2, the former was characterized by a large fluctuation of the leakage current and the latter had an increased leakage current at the initial stage. These results are related to the different voltage drops of each individual layer as well as the thickness impact on the behavior of the current density versus electric field.