Effects of Postdeposition Annealing in Argon Ambient on Metallorganic Decomposed CeO[sub 2] Gate Spin Coated on Silicon

Abstract

Cerium oxide solution was prepared by cerium(III) acetylacetonate hydrate, methanol, and acetic acid as the starting materials via the metallorganic decomposition (MOD) method. Postdeposition annealing was performed onto the MOD-derived films deposited onto n-type Si substrates at different temperatures (600, 800, and ) under the flow of argon gas. A slow cooling rate was then accomplished for samples to cool down to room temperature. Four orientations [(111), (200), (220), and (311)] of films were revealed by X-ray diffraction analysis as well as and cerium silicate . Epitaxial-like behavior was shown in the sample annealed at due to the (200)-oriented film, and the dominance of this plane ceased with the increase in annealing temperature. A negative voltage shift was observed in all of the samples, indicating that positive oxide charges were trapped in the oxide as a result of the presence of oxygen vacancies. An interface trap density was extracted from the capacitance–voltage measurement, and it was related to the current density–voltage characteristics of the investigated samples. The lowest density was perceived by the sample annealed at due to the increment in the layer, reduction in total interface trap density, and effective oxide charge.