An MIM capacitor or an MIS capacitor in semiconductor devices is formed of a thin dielectric layer having a total film thickness less than 100-nm and including a high-dielectric-constant amorphous insulating film, high-breakdown-voltage amorphous films such as of SiO2, and high-dielectric-constant amorphous buffer films between an upper electrode and a lower electrode. The thin high-dielectric-constant amorphous insulation film is formed of a material having a property resistant to fracture although having properties of a large leakage current and a low breakdown voltage, to enhance reliability of the thin dielectric layer and to reduce the footprint thereof in the semiconductor device.