Improvement in electrical insulating properties of 10-nm-thick Al2O3 film grown on Al/TiN/Si substrate by remote plasma annealing at low temperatures

Abstract

The electrical conduction properties of 10-nm-thick atomic-layer deposited Al2O3 thin films with Al bottom and Pt top electrodes were characterized for use in field emission display. The as-deposited films, grown at 300 °C, exhibited such a high electrical leakage that their electrical properties could not be measured. However, post-treatment at 300 °C under a remote O2 or H2O plasma for 30 min improved the insulating properties of the Al2O3 films. However, the electrical conduction mechanism, particularly in the high field (>4 MV/cm) was not Fowler–Nordheim (F–N) tunneling but was influenced by space charge limited conduction implying that there were many traps inside the dielectric film or the electrode interfaces. Postannealing of the top electrode at 300 °C in an oxygen atmosphere resulted in a F–N conduction mechanism by removing the interfacial traps. The calculated barrier height at the Al/Al2O3 interface from the F–N fitting of the current density versus voltage curves using the electron effective mass (m*) of 0.5 m0 was approximately 2.0 eV.