Ionic transport and barrier effect of anodic oxide layer in a solid-state Al2O3 capacitor under high electric field

Dry anodic oxidation as an effective electrical self-healing method in a solid-state Al2O3 capacitor was investigated in terms of ionic transport study. Sol-gel-derived amorphous aluminum oxide (AmAO) film as dielectric and aluminum (Al) film as top electrode of the capacitor were prepared on platinized silicon substrates. When a negative voltage was applied to the Al electrode pad, the ionic transport would induce the failure of the Al electrode. Nevertheless, such failure could be inhibited by the barrier effect of an anodic aluminum oxide (AAO) layer formed at the Al/AmAO interface when positive voltage was applied to the Al electrode pad previously. The barrier effect of the AAO layer was controlled by the maximum applied positive voltage. An ionic transport model was proposed to explore the dry anodic oxidation in the solid-state Al2O3 capacitor.