In this study, we fabricated the electrolyte-insulator-metal sensor on the base of Si3N4 film-coated AAO template with variation of the heat treatment time. The structural and electrochemical properties of AAO sensor were investigated for applications in chemical sensors. Si3N4 layer was uniformly coated with the thickness of about 10 nm. Alumina layer, heat-treated for 10 h, crystallized from the amorphous phase to crystalline phase of γ-Al2O3, and the spacing of lattice plane of the oxide layer was about 2.638 Å. The AAO sensor heat-treated for 10 h showed the good normalized C-V properties, and the set values of the capacitance and the pH sensitivity were −0.3 V and 54.1 mV/pH, respectively.

Keywords: Anodic Aluminium Oxide, Crystallization, capacitive EIS, biosensor.