Preparation of cerium dioxide thin films via Sol-Gel process and their characteristics as electrical buffer layers

摘要

CeO2 thin films were prepared on Si (100) and Si(111) substrates from cerium acetate monohydrate via solgelprocess. The thin films were crystallized at approximately 700℃and had polycrystalline microstructure. Scanning electronmicroscopy (SEM) observation showed that those films consistedof small grains of 60-70 nm in diameter and had even surfaces.SrTiO3 films with a platinum top electrode were formed on Pt/Siand Pt/CeO2/Si substrates. Current voltage (I-V) characteristics ofthe SrTiO3 films were measured on Pt/ SrTiO3/Pt/Si andPt/SrTiO3/Pt/CeO2/Si structures. The leakage current density forthe former sample was approximately 6.6×10 -6 A/cm2 under theapplied electric field of 9.4×10 4 V/cm. An increase in the appliedelectric field above 9.4×10 4 V/cm resulted in a marked increasein the leakage current. The leakage current for the latter samplewas 4.1×10 -6 A/cm2 under 2.5×10 5 V/cm. The I-Vcharacteristics of the SrTiO3 films were improved by the use of theCeO2 film as an intermediate layer.