US5576240A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for making a metal to metal capacitor
Assignee: Nokia of America Corp
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Filing: 1994-12-09
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Granted: 1996-11-19
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Expires: 2014-12-09
Abstract
Abstract A method for making a metal-to-metal capacitor for an integrated circuit includes forming a layer of titanium/titanium nitride on a polysilicon which has been patterned with interlevel dielectrics. A capacitor dielectric is then deposited, followed by patterning with photoresist to delineate the capacitor, etching to remove extraneous dielectric, deposition of aluminum, further patterning and etching to define the capacitor and access area, and removal of photoresist.
Inventors
- 👤 Joseph R. Radosevich
- 👤 Ranbir Singh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:56
CPC Classifications
H; H10; H10B; H10B12/00; H10D; H10D1/00; H10D1/60; H10D1/68; Y; Y10; Y10S; Y10S148/00; Y10S148/014
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
179 words
A method for fabricating a capacitor comprising: a) forming a field dielectric layer on a silicon substrate; b) forming a conductive first layer in contact with said field dielectric layer; then c) depositing interlevel dielectric on said conductive first layer as a patterned layer, said interlevel dielectric having at least one window having at least one side wall; then d) forming a bottom plate of the capacitor comprising a conductive second layer including a first metal in electrical contacting relation with said conductive first layer by depositing said first metal in said window such that a portion of said first metal is deposited on said at least one side wall and overlies said interlevel dielectric; e) forming a layer of capacitor dielectric in contact with said bottom plate of the capacitor, said first metal remaining on said at least one side wall of the window and overlying the interlevel dielectric when said capacitor dielectric layer is formed; and f) forming a top plate of the capacitor comprising a conductive third layer including a second metal onto said capacitor dielectric.
Claim 2
Independent Claim
179 words
A method for fabricating a capacitor comprising: a) forming a field dielectric layer on a silicon substrate; b) forming a conductive first layer in contact with said field dielectric layer; then c) depositing interlevel dielectric on said conductive first layer as a patterned layer, said interlevel dielectric having at least one window having at least one side wall; then d) forming a bottom plate of the capacitor comprising a conductive second layer including a first metal in electrical contacting relation with said conductive first layer by depositing said first metal in said window such that a portion of said first metal is deposited on said at least one side wall and overlies said interlevel dielectric; e) forming a layer of capacitor dielectric in contact with said bottom plate of the capacitor, said first metal remaining on said at least one side wall of the window and overlying the interlevel dielectric when said capacitor dielectric layer is formed; and f) forming a top plate of the capacitor comprising a conductive third layer including a second metal onto said capacitor dielectric.
Claim 3
Dependent Claim
33 words
The method of claim 1 wherein said step of forming the bottom plate of the capacitor further includes forming a layer of conductive etch stop on top of said layer of first metal.
Claim 4
Dependent Claim
11 words
The method of claim 2 wherein said first metal is titanium.
Claim 5
Dependent Claim
13 words
The method of claim 2 wherein said conductive etch stop is titanium nitride.
Claim 6
Dependent Claim
11 words
The method of claim 1 wherein said second metal is aluminum.
Claim 7
Dependent Claim
12 words
The method of claim 1 wherein said capacitor dielectric is silicon dioxide.
Claim 8
Dependent Claim
14 words
The method of claim 1 wherein said interlevel dielectric is formed from silicon dioxide.
Claim 9
Independent Claim
165 words
A method for fabricating a capacitor on an integrated circuit comprising: a) forming a field dielectric layer on a silicon substrate; b) forming a conductive first layer in contract with said field dielectric layer; c) depositing a pattern of interlevel dielectric on said conductive first layer; d) forming overall a conductive second layer including a first metal; e) forming an overall layer of capacitor dielectric in contact with said conductive second layer overlying the interlevel dielectric; f) applying a first photoresist to cover a selected portion of said capacitor dielectric to delineate the capacitor; g) removing portions of the capacitor dielectric not covered by said first photoresist; h) removing said first photoresist; i) applying an overall layer of second metal; j) applying a second photoresist to selected portions of said overall layer of second metal, said second photoresist being patterned to define areas for etching; k) applying an etchant to said areas for etching defined by said second photoresist; and l) removing said second photoresist.
Claim 10
Independent Claim
165 words
A method for fabricating a capacitor on an integrated circuit comprising: a) forming a field dielectric layer on a silicon substrate; b) forming a conductive first layer in contract with said field dielectric layer; c) depositing a pattern of interlevel dielectric on said conductive first layer; d) forming overall a conductive second layer including a first metal; e) forming an overall layer of capacitor dielectric in contact with said conductive second layer overlying the interlevel dielectric; f) applying a first photoresist to cover a selected portion of said capacitor dielectric to delineate the capacitor; g) removing portions of the capacitor dielectric not covered by said first photoresist; h) removing said first photoresist; i) applying an overall layer of second metal; j) applying a second photoresist to selected portions of said overall layer of second metal, said second photoresist being patterned to define areas for etching; k) applying an etchant to said areas for etching defined by said second photoresist; and l) removing said second photoresist.
Claim 11
Dependent Claim
20 words
The method of claim 8 further including forming a conductive etch stop on top of said layer of first metal.
Claim 12
Dependent Claim
11 words
The method of claim 9 wherein said first metal is titanium.
Claim 13
Dependent Claim
13 words
The method of claim 10 wherein said conductive etch stop is titanium nitride.
Claim 14
Dependent Claim
11 words
The method of claim 8 wherein said second metal is aluminum.
Claim 15
Dependent Claim
12 words
The method of claim 8 wherein said capacitor dielectric is silicon dioxide.
Claim 16
Dependent Claim
26 words
The method of claim 1 wherein said conductive first layer comprises a material selected from the group consisting of aluminum, copper, silver, titanium and noble metal.
Claim 17
Dependent Claim
14 words
The method of claim 1 wherein said conductive first layer is fabricated from polysilicon.
Claim 18
Independent Claim
162 words
A method for fabricating a capacitor comprising: a) forming a field dielectric layer on a silicon substrate; b) forming a conductive first layer on said field dielectric; c) forming a bottom plate of the capacitor comprising a layer of conductive material including a first metal in electrical contacting relation with said conductive first layer; then d) forming a layer of capacitor dielectric in contact with said bottom plate of said capacitor, wherein the first metal overlies an interlevel dielectric; e) applying a first photoresist to cover a selected portion of said capacitor dielectric to delineate the capacitor; f) removing portions of the capacitor dielectric not covered by the first photoresist; g) removing the first photoresist; h) applying a layer of second metal; i) applying a patterned layer of second photoresist, said layer of second photoresist defining areas for etching; j) applying an etchant to said areas for etching the second metal defined by said second photoresist; and k) removing said second photoresist.
Claim 19
Independent Claim
162 words
A method for fabricating a capacitor comprising: a) forming a field dielectric layer on a silicon substrate; b) forming a conductive first layer on said field dielectric; c) forming a bottom plate of the capacitor comprising a layer of conductive material including a first metal in electrical contacting relation with said conductive first layer; then d) forming a layer of capacitor dielectric in contact with said bottom plate of said capacitor, wherein the first metal overlies an interlevel dielectric; e) applying a first photoresist to cover a selected portion of said capacitor dielectric to delineate the capacitor; f) removing portions of the capacitor dielectric not covered by the first photoresist; g) removing the first photoresist; h) applying a layer of second metal; i) applying a patterned layer of second photoresist, said layer of second photoresist defining areas for etching; j) applying an etchant to said areas for etching the second metal defined by said second photoresist; and k) removing said second photoresist.
Claim 20
Dependent Claim
27 words
The method of claim 16 wherein said conductive first layer comprises a material selected from the group consisting of polysilicon, aluminum, copper, silver, titanium, and noble metal.
Claim 21
Dependent Claim
34 words
The method of claim 16 wherein said step of forming the bottom plate of the capacitor further includes forming a layer of conductive etch stop on top of said layer of said first metal.
Claim 22
Dependent Claim
11 words
The method of claim 18 wherein said first metal is titanium.
Claim 23
Dependent Claim
13 words
The method of claim 19 wherein said conductive etch stop is titanium nitride.
Claim 24
Dependent Claim
30 words
The method of claim 16 further comprising the step of depositing a pattern of interlevel dielectric on said conductive first layer prior to forming the bottom plate of the capacitor.
Claim 25
Dependent Claim
34 words
The method of claim 1 wherein said step (e) of forming a layer of capacitor dielectric is performed directly after step (d) of forming a bottom plate of the capacitor, with no intervening steps.
Claim 26
Dependent Claim
34 words
The method of claim 8 wherein said step (e) of forming an overall layer of capacitor dielectric is performed directly after step (d) of forming overall a conductive second layer, with no intervening steps.
Claim 27
Independent Claim
207 words
A method for fabricating a capacitor comprising: a) forming a dielectric layer on a substrate; b) forming a conductive first layer in contact with said dielectric layer; then c) depositing interlevel dielectric on said conductive first layer as a patterned layer, said interlevel dielectric having at least one window having at least one side wall; then d) forming a bottom plate of the capacitor comprising a conductive second layer including a first metal in electrical contacting relation with said conductive first layer by depositing said first metal in said window such that a portion of said first metal is deposited on said at least one side wall and overlies said interlevel dielectric; e) forming a layer of capacitor dielectric in contact with said bottom plate of the capacitor, said first metal remaining on said at least one side wall of the window and overlying the interlevel dielectric when said capacitor dielectric layer is formed, and said capacitor dielectric not completely filling the window and at least partially defining therein a concave space; and f) forming a top plate of the capacitor comprising a conductive third layer including a second metal onto said capacitor dielectric and at least partially filling said concave space defined by the capacitor dielectric.
Claim 28
Independent Claim
207 words
A method for fabricating a capacitor comprising: a) forming a dielectric layer on a substrate; b) forming a conductive first layer in contact with said dielectric layer; then c) depositing interlevel dielectric on said conductive first layer as a patterned layer, said interlevel dielectric having at least one window having at least one side wall; then d) forming a bottom plate of the capacitor comprising a conductive second layer including a first metal in electrical contacting relation with said conductive first layer by depositing said first metal in said window such that a portion of said first metal is deposited on said at least one side wall and overlies said interlevel dielectric; e) forming a layer of capacitor dielectric in contact with said bottom plate of the capacitor, said first metal remaining on said at least one side wall of the window and overlying the interlevel dielectric when said capacitor dielectric layer is formed, and said capacitor dielectric not completely filling the window and at least partially defining therein a concave space; and f) forming a top plate of the capacitor comprising a conductive third layer including a second metal onto said capacitor dielectric and at least partially filling said concave space defined by the capacitor dielectric.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-11-19 | 2000-05-20 | 2000-11-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-11-19 | 2004-05-20 | 2004-11-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-11-19 | 2008-05-20 | 2008-11-19 | $7700.00 | Window Closed / Lapsed |