A method manufactures a capacitor having polycrystalline dielectric layer between two metallic electrodes. The dielectric layer is formed by a polycrystalline growth of a dielectric metallic oxide on one of the metallic electrodes. At least one polycrystalline growth condition of the dielectric oxide is modified during the formation of the polycrystalline dielectric layer, which results in a variation of the polycrystalline properties of the dielectric oxide within the thickness of said layer.