US6509246B2
Expired / Lapsed
US
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Production of semiconductor integrated circuit
Assignee: Hitachi Ltd
•
Filing: 2001-06-11
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Granted: 2003-01-21
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Expires: 2021-06-11
Abstract
Abstract A semiconductor integrated circuit in which the storage capacitor has an increased capacitance and a decreased leakage current. The storage capacitor is formed by the steps of: forming a polysilicon bottom electrode having semispherical silicon crystals formed thereon; performing plasma nitriding on the surface of said bottom electrode at a temperature lower than 550° C., thereby forming a film of silicon nitride having a film thickness smaller than 1.5 nm; and depositing a film of amorphous tantalum pentoxide and then crystallizing said amorphous tantalum pentoxide. The silicon nitride film has improved resistance to oxidation and also has a reduced leakage current. As a result, the polysilicon bottom electrode becomes resistant to oxidation and the storage capacitor increases in capacitance and decreases in leakage current.
Inventors
- 👤 Hiroshi Miki
- 👤 Yasuhiro Shimamoto
- 👤 Masahiko Hiratani
- 👤 Tomoyuki Hamada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 09:51
CPC Classifications
H; H10; H10B; H10B12/00; H10D; H10D1/00; H10D1/60; H10D1/68; H10D1/692; H10D1/711; H10D1/712; H10D1/01; H10D1/041; H10D1/042; H10D1/716; H10B12/30; H10B12/31; H10B12/315
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
100 words
A process for producing a semiconductor integrated circuit having a capacitive element consisting of an upper electrode and a dielectric film in the form of laminate of silicon nitride film and tantalum pentoxide film, said process comprising: forming a bottom electrode of polysilicon having semispherical silicon crystals formed thereon; forming a silicon nitride film on the surface of said bottom electrode by plasma nitriding method; forming a film of amorphous tantalum pentoxide on said silicon nitride film; performing heat treatment, thereby forming a film of crystalline tantalum pentoxide; and forming an upper electrode on said film of crystalline tantalum pentoxide.
Claim 2
Dependent Claim
100 words
A process for producing a semiconductor integrated circuit having a capacitive element consisting of an upper electrode and a dielectric film in the form of laminate of silicon nitride film and tantalum pentoxide film, said process comprising: forming a bottom electrode of polysilicon having semispherical silicon crystals formed thereon; forming a silicon nitride film on the surface of said bottom electrode by plasma nitriding method; forming a film of amorphous tantalum pentoxide on said silicon nitride film; performing heat treatment, thereby forming a film of crystalline tantalum pentoxide; and forming an upper electrode on said film of crystalline tantalum pentoxide.
Claim 3
Dependent Claim
66 words
The process for producing a semiconductor integrated circuit as defined in claim 1 , wherein the step of forming a silicon nitride film is carried out in an apparatus equipped with a plasma generating part and a semiconductor substrate mounting part which are separated spacewise from each other and further is carried out such that the nitriding employs a reactant supplied from the plasma generating part.
Claim 4
Dependent Claim
40 words
The process for producing a semiconductor integrated circuit as defined in claim 1 , wherein the step of forming a silicon nitride film is carried out such that the silicon nitride film has a film thickness larger than 1 nm.
Claim 5
Dependent Claim
32 words
The process for producing a semiconductor integrated circuit as defined in claim 1 wherein the step of forming an upper electrode is carried out to form the upper electrode from titanium nitride.
Claim 6
Dependent Claim
28 words
The process for producing a semiconductor integrated circuit as defined in claim 4 , wherein the titanium nitride film is formed at least partly by chemical vapor deposition.
Claim 7
Dependent Claim
108 words
A process for producing a semiconductor integrated circuit having a capacitive element consisting of an upper electrode and a dielectric film in the form of laminate of silicon nitride film and tantalum pentoxide film, said process comprising: forming a bottom electrode of polysilicon having semispherical silicon crystals formed thereon; forming a silicon nitride film on the surface of said bottom electrode by directly nitriding said polysilicon at a temperature lower than 700° C.; forming a film of amorphous tantalum pentoxide on said silicon nitride film; performing heat treatment, thereby forming a film of crystalline tantalum pentoxide; and forming an upper electrode on said film of crystalline tantalum pentoxide.
Claim 8
Dependent Claim
108 words
A process for producing a semiconductor integrated circuit having a capacitive element consisting of an upper electrode and a dielectric film in the form of laminate of silicon nitride film and tantalum pentoxide film, said process comprising: forming a bottom electrode of polysilicon having semispherical silicon crystals formed thereon; forming a silicon nitride film on the surface of said bottom electrode by directly nitriding said polysilicon at a temperature lower than 700° C.; forming a film of amorphous tantalum pentoxide on said silicon nitride film; performing heat treatment, thereby forming a film of crystalline tantalum pentoxide; and forming an upper electrode on said film of crystalline tantalum pentoxide.
Claim 9
Dependent Claim
33 words
The process for producing a semiconductor integrated circuit as defined in claim 6 , wherein the step of forming a silicon nitride film is carried out at a temperature lower than 550° C.
Claim 10
Dependent Claim
41 words
The process for producing a semiconductor integrated circuit as defined in claim 6 , wherein the step of forming a silicon nitride film is carried out such that the direct nitriding employs a reactant supplied from a nitrogen radial generating apparatus.
Claim 11
Dependent Claim
40 words
The process for producing a semiconductor integrated circuit as defined in claim 6 , wherein the step of forming a silicon nitride film is carried out such that the silicon nitride film has a film thickness larger than 1 nm.
Claim 12
Dependent Claim
33 words
The process for producing a semiconductor integrated circuit as defined in claim 6 , wherein the step of forming an upper electrode is carried out to form the upper electrode from titanium nitride.
Claim 13
Dependent Claim
28 words
The process for producing a semiconductor integrated circuit as defined in claim 10 , wherein the titanium nitride film is formed at least partly by chemical vapor deposition.
Claim 14
Dependent Claim
95 words
A process for producing a semiconductor integrated circuit having a capacitive element consisting of an upper electrode and a dielectric film in the form of laminate of silicon nitride film and tantalum pentoxide film, said process comprising: forming a bottom electrode of phosphorus-doped polysilicon; forming a silicon nitride film on the surface of said bottom electrode by plasma nitriding method; forming a film of amorphous tantalum pentoxide on said silicon nitride film; performing heat treatment, thereby forming a film of crystalline tantalum pentoxide; and forming an upper electrode on said film of crystalline tantalum pentoxide.
Claim 15
Dependent Claim
95 words
A process for producing a semiconductor integrated circuit having a capacitive element consisting of an upper electrode and a dielectric film in the form of laminate of silicon nitride film and tantalum pentoxide film, said process comprising: forming a bottom electrode of phosphorus-doped polysilicon; forming a silicon nitride film on the surface of said bottom electrode by plasma nitriding method; forming a film of amorphous tantalum pentoxide on said silicon nitride film; performing heat treatment, thereby forming a film of crystalline tantalum pentoxide; and forming an upper electrode on said film of crystalline tantalum pentoxide.
Claim 16
Dependent Claim
65 words
The process for producing a semiconductor integrated circuit as defined in claim 12 , wherein the step of forming a silicon nitride film is carried out in an apparatus equipped with a plasma generating part and a semiconductor substrate mounting part which are separated spacewise from each other and is carried out such that the nitriding employs a reactant supplied from the plasma generating part.
Claim 17
Dependent Claim
40 words
The process for producing a semiconductor integrated circuit as defined in claim 12 , wherein the step of forming a silicon nitride film is carried out such that the silicon nitride film has a film thickness larger than 1 nm.
Claim 18
Dependent Claim
33 words
The process for producing a semiconductor integrated circuit as defined in claim 12 , wherein the step of forming an upper electrode is carried out to form the upper electrode from titanium nitride.
Claim 19
Dependent Claim
28 words
The process for producing a semiconductor integrated circuit as defined in claim 15 , wherein the titanium nitride film is formed at least partly by chemical vapor deposition.
Claim 20
Dependent Claim
103 words
A process for producing a semiconductor integrated circuit having a capacitive element consisting of an upper electrode and a dielectric film in the form of laminate of silicon nitride film and tantalum pentoxide film, said process comprising: forming a bottom electrode of phosphorus-doped polysilicon; forming a silicon nitride film on the surface of said bottom electrode by directly nitriding said polysilicon at a temperature lower than 700° C.; forming a film of amorphous tantalum pentoxide on said silicon nitride film; performing heat treatment, thereby forming a film of crystalline tantalum pentoxide; and forming an upper electrode on said film of crystalline tantalum pentoxide.
Claim 21
Dependent Claim
103 words
A process for producing a semiconductor integrated circuit having a capacitive element consisting of an upper electrode and a dielectric film in the form of laminate of silicon nitride film and tantalum pentoxide film, said process comprising: forming a bottom electrode of phosphorus-doped polysilicon; forming a silicon nitride film on the surface of said bottom electrode by directly nitriding said polysilicon at a temperature lower than 700° C.; forming a film of amorphous tantalum pentoxide on said silicon nitride film; performing heat treatment, thereby forming a film of crystalline tantalum pentoxide; and forming an upper electrode on said film of crystalline tantalum pentoxide.
Claim 22
Dependent Claim
33 words
The process for producing a semiconductor integrated circuit as defined in claim 17 , wherein the step of forming a silicon nitride film is carried out at a temperature lower than 550° C.
Claim 23
Dependent Claim
41 words
The process for producing a semiconductor integrated circuit as defined in claim 17 , wherein the step of forming a silicon nitride film is carried out such that the direct nitriding employs a reactant supplied from a nitrogen radial generating apparatus.
Claim 24
Dependent Claim
40 words
The process for producing a semiconductor integrated circuit as defined in claim 17 , wherein the step of forming a silicon nitride film is carried out such that the silicon nitride film has a film thickness larger than 1 nm.
Claim 25
Dependent Claim
33 words
The process for producing a semiconductor integrated circuit as defined in claim 17 , wherein the step of forming an upper electrode is carried out to form the upper electrode from titanium nitride.
Claim 26
Dependent Claim
28 words
The process for producing a semiconductor integrated circuit as defined in claim 21 , wherein the titanium nitride film is formed at least partly by chemical vapor deposition.
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