Abstract: The present invention provides a dielectric thin film capacitor element in which leak current may be suppressed from increasing over time while energizing at high temperature and which has excellent insulating quality and reliability and a manufacturing method thereof. The dielectric thin film capacitor element is constructed by forming a lower electrode, a dielectric thin film and an upper electrode one after another on a substrate, wherein the dielectric thin film capacitor element is characterized in that the dielectric thin film is made of an oxide material composed of at least titanium and strontium and containing erbium.

Abstract: A method for preparing an oxide dielectric thin film, for use in a dielectric thin film device, is described. Briefly, a film forming chamber is heated, and a thin film of dielectric, about 200 nm thick, is formed by sputtering or another deposition method. After the film is formed, evacuation of the film forming chamber is suspended, and oxygen gas is introduced into the chamber. The film is oxidized after its formation by maintaining the film in the oxygen atmosphere for a period of time, which can include cooling steps. The resulting dielectric thin film has excellent dielectric properties, such as a high dielectric constant and great dielectric strength.