THIN-FILM CAPACITOR AND ITS MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To prevent leakage in a thin-film capacitor via a grain boundary from becoming large, when a ferrodielectric thin film has a columnar structure. SOLUTION: Ferrodielectric thin film grows into a columnar shape, because it tends to inherit the crystallization properties of the first electrode of its underlying layer. However, by making a portion near the interface of the first electrode amorphous, the dielectric thin film is made to have a fine grain structure. This effect can substantially elongate a leakage path via the grain boundary of the upper and lower electrodes and thus realizes thin-film capacitor which has low leakage. A simple method of making the part near the surface of the first electrode amorphous is to form a thin Zr layer on a Pt electrode and to subject it to heat treatment in a nonoxidizing atmosphere.