METHOD OF MANUFACTURING CAPACITOR FOR SEMICONDUCTOR MEMORY ELEMENT THROUGH TWO-STAGE HEAT TREATMENT

摘要

PROBLEM TO BE SOLVED: To provide a method of manufacturing a capacitor for semiconductor memory element by which the electric characteristic of the capacitor can be improved effectively, by suppressing the oxidation of an upper electrode even when the temperature of heat treatment that is performed to improve the leakage current characteristic and dielectric characteristic of the capacitor is not lowered. SOLUTION: A lower electrode is formed on a semiconductor substrate and a dielectric film is formed on the lower electrode. Then the upper electrode made of a noble metal is formed on the dielectric film. The matter resulting from the formation of the upper electrode is subjected to first heat treatment that is performed at a first temperature which is selected out of the range of 200-600 deg.C, and is higher than the oxidizing temperature of the upper electrode in a first atmosphere containing oxygen. In a second atmosphere containing no oxygen, the matter resulting from the first heat treatment is subjected to second heat treatment that is performed at a second temperature which is selected out of the range of 300-900 deg.C and is higher than the first temperature. Since the curing effect of the dielectric film can be obtained sufficiently even when the surface of the upper electrode is not oxidized, the leakage current characteristic and dielectric characteristic of the capacitor are improved. Consequently, the electric characteristic of the capacitor is improved.