Preparation of amorphous Al2O3 thin films from stabilized Al-alkoxides by the sol-gel method

Abstract

Highly transparent amorphous thin films of Al2O3 were prepared by adding some chelating agents such as β-diketones to the Al-alkoxide/alcohol starting solutions. Among the β-diketones examined, ethylacetoacetate was the most effective in stabilizing the alkoxides against water, because of the formation of an Alchelate complex. The Al2O3 films obtained were amorphous and transparent below 700°C, whereas they crystallized in γ-Al2O3 at 900°C, which transformed to a-Al2O3 at 1000°C, accompanying the loss of transparency.