Patent ID: 8891227

Claim:
A process of forming a dielectric thin film comprising: preparing a composition consisting of Ba 1−x Sr x Ti y O 3 obtained by dissolving an organic barium compound, an organic strontium compound and a titanium alkoxide in an organic solvent at a molar ratio of Ba:Sr:Ti of 1-x:x:y; coating and drying onto a support the composition to form a coated film; and baking the support on which the coated film has been formed for forming a Ba 1−x Sr x Ti y O 3 thin film, wherein the process from coating to baking is carried out two to nine times, the thickness of the thin film formed after initial baking is 20 nm to 80 nm, the thickness of each thin film formed after the second baking and beyond is 20 nm to less than 200 nm, each baking from the first time to the second to ninth times is carried out by heating to a prescribed temperature within a range of 500° C. to 800° C. at a heating rate of 1° C. to 50° C./minute in an atmosphere at atmospheric pressure, the total thickness of the dielectric thin film is 100 nm to 600 nm, the values of x and y indicating the composition of the dielectric thin film are such that 0.2<x<0.6 and 0.9<y<1.1, the organic barium compound and the organic strontium compound are metal salts of a carboxylic acid represented by the general formula C n H 2n+1 COOH (where, 3≦n≦7), and the metal salts of the carboxylic acid have a structure shown in a following formula: (wherein R 1 to R 6 represent hydrogen atoms, methyl groups or ethyl groups, and M represents Ba or Sr in the formula (2)), and in a thin film capacitor having the dielectric thin film, the changing rate T of capacitance according to an applied voltage as indicated with the following formula (1) is 60% or more: T =( C 0V −C 5V )/ C 0V ×100 (1) (wherein, C 0v represents capacitance in the absence of an applied voltage, and C 5v represents capacitance during an applied voltage of 5 V).