Improvement in electrical characteristics of high-k Al_2O_3 gate dielectric by field-assisted nitric oxidation

摘要

The authors perform a simple technique for the improvements in both current density reliability of high-k Al_2O_3 gate dielectrics. An Al_2O_3 was prepared by chemical oxidation at an appropriate electrical field in nitric acid at room temperature then furnace annealed at 650℃ in N_2. The interface trap-induced capacitance was used to investigate the interfacial property between the gate dielectric Si substrate. On the other hand the stress induced leakage current (SILC) was measured for characterizing the property of bulk oxide. It was found that the electrical characteristics of bulk oxide including leakage breakdown field SILC, were much improved without sacrificing interfacial property. The improvement can be ascribed to the compensation oxidation process.