US 5,508,221 A · Method for forming capacitor element of DRAM

Abstract

A stacked capacitor element for a DRAM cell is formed as follows. After a naturally oxidized film on a surface of a polycrystalline silicon film is removed, the polycrystalline silicon film is subjected to a rapid thermal nitriding treatment using lamp annealing so that a capacitor lower electrode of the capacitor element is formed. A tantalum oxide film is deposited on the polycrystalline silicon film and then densified so that a dielectric film of the stacked capacitor element is formed. A conductive film is formed on the tantalum oxide film and patterned. The conductive film is nittided so that a capacitor upper electrode is formed. The capacitor element thus formed enables the suppression of reduction in the capacitance value of the capacitor element of a DRAM and deterioration of the leakage current characteristics.

Claims6

Dependent claims

A method for fabricating a stacked capacitor element of a semiconductor device, said stacked capacitor element having a capacitor lower electrode and a capacitor upper electrode with a dielectric film being interposed therebetween, said method comprising the steps of:

removing a naturally oxidized film on a surface of a polycrystalline silicon film constituting said capacitor lower electrode, and nitriding said surface of the polycrystalline silicon film by a rapid thermal nitriding treatment using lamp annealing;
forming a tantalum oxide film on said polycrystalline silicon film and densifying said tantalum oxide film to form said dielectric film;
forming a conductive film, on said tantalum oxide film, constituting said capacitor upper electrode;
and
nitriding said conductive film after having been patterned.

2 more elements

Dependencies are inferred from the claim text.

Method for forming capacitor element of DRAM

Life of this patent

Method for forming capacitor element of DRAM

Life of this patent

Abstract

Claims6