US5438012A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of fabricating capacitor element in super-LSI
Assignee: NEC Electronics Corp
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Filing: 1993-08-05
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Granted: 1995-08-01
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Expires: 2013-08-05
Abstract
Abstract A capacitor element of a semiconductor device used for a super-LSI is formed by the steps including (a) removing a natural oxide film on a surface of a lower electrode of polysilicon, (b) forming on the surface of the lower electrode an impurity-doped tantalum oxide film, and (c) forming an upper electrode with at least a bottom thereof constituted by titanium nitride. The steps may further include (d) nitriding the surface of the lower electrode after the removal of the natural oxide film, and (e) densifying the tantalum oxide film by way of a high temperature heat treatment after the formation of the tantalum oxide film. In this way, it is possible to reduce thickness of a capacitive insulating film and to form the capacitor element in which the leakage current characteristics are improved.
Inventors
- 👤 Satoshi Kamiyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 23:47
CPC Classifications
H; H10; H10D; H10D1/00; H10D1/60; H10D1/68; H10D1/692; H10P; H10P14/00; H10P14/60; H10P14/69; H10P14/692; H10P14/6938; H10P14/6939; H10P14/69393; H10P14/69394
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
63 words
A method of fabricating a semiconductor device comprising the steps of: removing a natural oxide film on a surface of a lower electrode of polysilicon; forming on the surface of said lower electrode a tantalum oxide film doped with impurities; and forming on said tantalum oxide film an upper electrode with at least a bottom of said upper electrode constituted by titanium nitride.
Claim 2
Independent Claim
63 words
A method of fabricating a semiconductor device comprising the steps of: removing a natural oxide film on a surface of a lower electrode of polysilicon; forming on the surface of said lower electrode a tantalum oxide film doped with impurities; and forming on said tantalum oxide film an upper electrode with at least a bottom of said upper electrode constituted by titanium nitride.
Claim 3
Dependent Claim
27 words
The method of fabricating a semiconductor device according to claim 1, wherein said step of removing the natural oxide film is a treatment using anhydrous hydrofluoric acid.
Claim 4
Dependent Claim
35 words
The method of fabricating a semiconductor device according to claim 1, wherein said impurity is at least a member of the group consisting of titanium (Ti), silicon (Si), boron (B), phosphorus (P) and germanium (Ge).
Claim 5
Dependent Claim
31 words
The method of fabricating a semiconductor device according to claim 1, wherein said step of forming said tantalum oxide film is performed by chemical vapor deposition using an organic tantalum material.
Claim 6
Dependent Claim
35 words
The method of fabricating a semiconductor device according to claim 1, wherein said step of forming the tantalum oxide film is performed by impurity doping through a chemical vapor phase reaction using an organic material.
Claim 7
Dependent Claim
63 words
The method of fabricating a semiconductor device according to claim 1, in which said process of forming the capacitor element further comprises the steps of: nitriding the surface of said lower electrode of polysilicon after said step of removing said natural oxide film; and densifying said tantalum oxide film through a high temperature heat treatment after the formation of said tantalum oxide film.
Claim 8
Dependent Claim
39 words
The method of fabricating a semiconductor device according to claim 6, wherein said step of nitriding the surface of said lower electrode of polysilicon is performed by a quick temperature raise heat treatment using ammonia gas (NH 3 ).
Claim 9
Dependent Claim
35 words
The method of fabricating a semiconductor device according to claim 6, wherein said high temperature heat treatment is carried out by a quick temperature raise heating system using an electric furnace or a lamp heating.
Claim 10
Dependent Claim
25 words
The method of fabricating a semiconductor device according to claim 6, wherein said high temperature heat treatment is carried out in an inert gas atmosphere.
References Cited (Backward Citations)
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