Interfacial effect of Cu electrode enhanced energy density of amorphous aluminum oxide dielectric capacitor

In this work, a novel dielectric system of Cu/amorphous aluminum oxide/Pt (Cu/AmAO/Pt) is developed for dielectric capacitor applications. The high breakdown strength (425 MV m−1), high dielectric constant (8.6) and improved leakage current density are achieved due to this effective system. Dielectric capacitors with the structure of Cu/AmAO/Pt demonstrate much higher energy density of 6.9 J cm−3 than that of Au/AmAO (2.9 J cm−3). The enhanced performance of Cu/AmAO/Pt stems intrinsically from the interfacial effect under high electric field. The interfacial effect forms copper oxides and compacts the structure of AmAO, contributing to the improvement of breakdown strength and leakage current density. Anodized copper oxide also makes contribution to the increase of dielectric constant. Moreover, the oxidation mechanism is proposed for further understanding electrochemical behaviors. Based on the extensive applications of Cu in integrated circuits, high-energy-density Cu/AmAO/Pt system promises huge potential for the integrated circuit.