Patent US5582971A successfully refreshed from Google Patents.
US5582971A
Expired / Lapsed
US
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Method of forming submicron contacts
Assignee: STMicroelectronics lnc USA
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Filing: 1995-05-03
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Granted: 1996-12-10
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Expires: 2015-05-03
Abstract
Abstract A method is provided for patterning a submicron semiconductor layer of an integrated circuit, and an integrated circuit formed according to the same. A conductive structure is formed on the integrated circuit. A dielectric layer is formed over the integrated circuit. A contact opening is formed in the dielectric layer exposing a portion of the underlying first conductive structure. A barrier layer is formed on the dielectric layer and in the contact opening. A substantially conformal layer is formed over the barrier layer and in the contact opening. The conformal layer is partially etched away wherein the conformal layer remains only in a bottom portion of the contact opening. A second conductive layer is formed over the barrier layer and the remaining conformal layer.
Inventors
- 👤 Fusen E. Chen
- 👤 Robert O. Miller
- 👤 Girish A. Dixit
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 17:44
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/032; H10W20/047; H10D; H10D64/00; H10D64/01; H10D64/011; H10D64/0111; H10D64/0112; H10D64/01125; H10W20/033; H10W20/034; H10W20/056; Y; Y10; Y10S; Y10S257/00; Y10S257/915
Claims Analysis
Total Claims: 39
Claim 1
Independent Claim
94 words
A method of forming submicron contacts of an integrated circuit, comprising the steps of: forming a contact opening in a first dielectric layer exposing a portion of an underlying first conductive layer; forming a conductive barrier layer over the integrated circuit and in the contact opening; forming a dielectric plug in only the bottom part of the contact opening, such that said dielectric plug is formed substantially below an upper surface of said first dielectric layer; and forming a second conductive layer over the barrier layer and said dielectric plug in the contact opening.
Claim 2
Independent Claim
94 words
A method of forming submicron contacts of an integrated circuit, comprising the steps of: forming a contact opening in a first dielectric layer exposing a portion of an underlying first conductive layer; forming a conductive barrier layer over the integrated circuit and in the contact opening; forming a dielectric plug in only the bottom part of the contact opening, such that said dielectric plug is formed substantially below an upper surface of said first dielectric layer; and forming a second conductive layer over the barrier layer and said dielectric plug in the contact opening.
Claim 3
Dependent Claim
28 words
The method of claim 1, further comprising the steps of: forming a polysilicon sidewall on the sides of the contact opening before the forming a barrier layer step.
Claim 4
Dependent Claim
46 words
The method of claim 1, further comprising the steps of: performing an etch back of the second conductive layer to form a conductive plug in the contact opening over the dielectric plug; and forming a third conductive layer over the barrier layer and the conductive plug.
Claim 5
Independent Claim
130 words
A method of forming submicron contacts of an integrated circuit, comprising the steps of: forming a first conductive structure on the integrated circuit; forming a first dielectric layer over the integrated circuit; forming a contact opening in the first dielectric layer exposing a portion of the underlying first conductive structure; forming a barrier layer on the first dielectric layer and in the contact opening; forming a substantially conformal dielectric layer over the barrier layer and in the contact opening; partially etching the conformal layer wherein the conformal layer remains only in a bottom portion of the contact opening, such that said dielectric plug is formed substantially below an upper surface of said first dielectric layer; and forming a second conductive layer over the barrier layer and the remaining conformal layer.
Claim 6
Independent Claim
130 words
A method of forming submicron contacts of an integrated circuit, comprising the steps of: forming a first conductive structure on the integrated circuit; forming a first dielectric layer over the integrated circuit; forming a contact opening in the first dielectric layer exposing a portion of the underlying first conductive structure; forming a barrier layer on the first dielectric layer and in the contact opening; forming a substantially conformal dielectric layer over the barrier layer and in the contact opening; partially etching the conformal layer wherein the conformal layer remains only in a bottom portion of the contact opening, such that said dielectric plug is formed substantially below an upper surface of said first dielectric layer; and forming a second conductive layer over the barrier layer and the remaining conformal layer.
Claim 7
Dependent Claim
47 words
The method of claim 4, further comprising the steps of: partially etching the second conductive layer wherein the second conductive layer remains only on the conformal layer in the contact opening, and forming a third conductive layer over the barrier layer and the remaining second conductive layer.
Claim 8
Dependent Claim
17 words
The method of claim 4, wherein the first conductive structure is a source/drain region of a transistor.
Claim 9
Dependent Claim
12 words
The method of claim 4, wherein the first dielectric layer comprises BPSG.
Claim 10
Dependent Claim
26 words
The method of claim 7, further comprising the steps of: reflowing the BPSG layer before the contact opening is formed to substantially planarize the BPSG layer.
Claim 11
Dependent Claim
22 words
The method of claim 4, wherein the forming the contact opening step is formed by anisotropically dry etching the first dielectric layer.
Claim 12
Dependent Claim
50 words
The method of claim 4, wherein the forming the barrier layer step comprises the steps of: forming a refractory metal nitride layer over the first dielectric layer and in the contact opening; and annealing the refractory metal nitride layer to form a silicide in the bottom of the contact opening.
Claim 13
Dependent Claim
14 words
The method of claim 10, wherein the refractory metal nitride layer comprises titanium nitride.
Claim 14
Dependent Claim
34 words
The method of claim 10, further comprising the step of: forming a refractory metal layer over said first dielectric layer and in the contact opening before the forming a refractory metal nitride layer step.
Claim 15
Dependent Claim
12 words
The method of claim 12, wherein the refractory metal layer comprises titanium.
Claim 16
Dependent Claim
12 words
The method of claim 12, wherein the refractory metal layer comprises tungsten.
Claim 17
Dependent Claim
22 words
The method of claim 11, further comprising the step of: annealing the refractory metal layer before forming the refractory metal nitride layer.
Claim 18
Dependent Claim
17 words
The method of claim 10, wherein the refractory metal nitride layer is formed by chemical vapor deposition.
Claim 19
Dependent Claim
64 words
The method of claim 10, further comprising the steps of: forming a polysilicon layer over the integrated circuit and in the contact opening before the forming a barrier layer step; etching the polysilicon layer wherein polysilicon spacers remain on the sidewalls of the contact opening and wherein the annealing step forms a silicide on the sidewalls and in the bottom of the contact opening.
Claim 20
Dependent Claim
11 words
The method of claim 4, wherein the conformal layer comprises oxide.
Claim 21
Dependent Claim
11 words
The method of claim 4, wherein the conformal layer comprises polysilicon.
Claim 22
Dependent Claim
24 words
The method of claim 1, further comprising the step of forming a conductive plug on top of said dielectric plug in the contact opening.
Claim 23
Dependent Claim
32 words
The method of claim 1, wherein said first dielectric layer has a thickness of approximately 5000 to 10000 Ångstroms and said dielectric plug has a thickness of between 1000 and 4000 Ångstroms.
Claim 24
Dependent Claim
13 words
The method of claim 1, wherein said dielectric plug consists essentially of polysilicon.
Claim 25
Dependent Claim
14 words
The method of claim 4, wherein said conformal dielectic layer consists essentially of polysilicon.
Claim 26
Dependent Claim
30 words
The method of claim 4, further comprising the step of etching said second conductive layer to form a conductive plug on top of said dielectric plug within the contact opening.
Claim 27
Dependent Claim
19 words
The method of claim 4, wherein said first dielectric layer has a thickness of approximately 5000 to 10000 Ångstroms.
Claim 28
Independent Claim
73 words
A method of forming submicron contacts of an integrated circuit, comprising the steps of: forming a contact opening in a first dielectric layer exposing a portion of an underlying first conductive layer; forming a barrier layer over the integrated circuit and in the contact opening; forming a dielectric plug in only the bottom part of the contact opening; and forming a conductive plug on top of said dielectric plug within the contact opening.
Claim 29
Independent Claim
73 words
A method of forming submicron contacts of an integrated circuit, comprising the steps of: forming a contact opening in a first dielectric layer exposing a portion of an underlying first conductive layer; forming a barrier layer over the integrated circuit and in the contact opening; forming a dielectric plug in only the bottom part of the contact opening; and forming a conductive plug on top of said dielectric plug within the contact opening.
Claim 30
Dependent Claim
32 words
The method of claim 26, wherein said first dielectric layer has a thickness of approximately 5000 to 10000 Ångstroms and said dielectric plug has a thickness of between 1000 and 4000 Ångstroms.
Claim 31
Dependent Claim
19 words
The method of claim 26, wherein said first dielectric layer has a thickness of approximately 5000 to 10000 Ångstroms.
Claim 32
Dependent Claim
12 words
The method of claim 26, wherein said first dielectric layer comprises BPSG.
Claim 33
Dependent Claim
17 words
The method of claim 26, wherein said dielectric plug has thickness of between 1000 and 4000 Ångstroms.
Claim 34
Dependent Claim
12 words
The method of claim 26, wherein said dielectic plug consists of polysilicon.
Claim 35
Dependent Claim
25 words
The method of claim 26, further comprising the subsequent step of forming a second conductive layer over the barrier layer and in the contact opening.
Claim 36
Independent Claim
133 words
A method of forming submicron contacts of an integrated circuit, comprising the steps of: forming a first conductive structure on the integrated circuit; forming a first dielectric layer over the integrated circuit; forming a contact opening in the dielectric layer exposing a portion of the underlying first conductive structure; forming a barrier layer on the dielectric layer and in the contact opening; forming a substantially conformal dielectric layer over the barrier layer and in the contact opening; partially etching the conformal layer wherein the conformal layer remains only in a bottom portion of the contact opening; forming a second conductive layer over the barrier layer and the remainder of said conformal layer; and etching said second conductive layer to form a conductive plug on top of said dielectric plug within the contact opening.
Claim 37
Independent Claim
133 words
A method of forming submicron contacts of an integrated circuit, comprising the steps of: forming a first conductive structure on the integrated circuit; forming a first dielectric layer over the integrated circuit; forming a contact opening in the dielectric layer exposing a portion of the underlying first conductive structure; forming a barrier layer on the dielectric layer and in the contact opening; forming a substantially conformal dielectric layer over the barrier layer and in the contact opening; partially etching the conformal layer wherein the conformal layer remains only in a bottom portion of the contact opening; forming a second conductive layer over the barrier layer and the remainder of said conformal layer; and etching said second conductive layer to form a conductive plug on top of said dielectric plug within the contact opening.
Claim 38
Dependent Claim
19 words
The method of claim 33, wherein said first dielectric layer has a thickness of approximately 5000 to 10000 Ångstroms.
Claim 39
Dependent Claim
12 words
The method of claim 33, wherein said first dielectric layer comprises BPSG.
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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) | 1999-12-10 | 2000-06-10 | 2000-12-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-12-10 | 2004-06-10 | 2004-12-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-12-10 | 2008-06-10 | 2008-12-10 | $7700.00 | Window Closed / Lapsed |