US5508221A
Expired / Lapsed
US
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Method for forming capacitor element of DRAM
Assignee: NEC Electronics Corp
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Filing: 1994-12-01
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Granted: 1996-04-16
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Expires: 2014-12-01
Abstract
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.
Inventors
- 👤 Satoshi Kamiyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 05:24
CPC Classifications
H; H10; H10B; H10B12/00; H10D; H10D1/00; H10D1/60; H10D1/68
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
119 words
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.
Claim 2
Independent Claim
119 words
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.
Claim 3
Dependent Claim
35 words
The method for fabricating a stacked capacitor element according to claim 1, in which said step of removing the naturally oxidized film is a treatment using one of hydrofluoric anhydride and a diluted hydrofluoric acid.
Claim 4
Dependent Claim
32 words
The method for fabricating a stacked capacitor element according to claim 1, in which the step of forming said tantalum oxide film is a chemical vapor deposition using an organic tantalum material.
Claim 5
Dependent Claim
61 words
The method for fabricating a stacked capacitor element according to claim 1, in which said densifying treatment of said tantalum oxide film is a treatment carried out in one of an oxygen atmosphere and a nitrous oxide atmosphere using at least one of an electric furnace heat treatment, a rapid thermal treatment using lamp heating, and a plasma assisted heat treatment.
Claim 6
Dependent Claim
40 words
The method for fabricating a stacked capacitor element according to claim 1, in which said conductive film constituting said capacitor upper electrode contains at least one of a titanium nitride film, a tungsten nitride film, and a molybden nitride film.
Claim 7
Dependent Claim
39 words
The method for fabricating a stacked capacitor element according to claim 1, in which said nitriding treatment of said conductive film is a plasma treatment in one of an ammonium atmosphere, a nitride atmosphere and a nitrous oxide atmosphere.
References Cited (Backward Citations)
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