US4740483A
Expired / Lapsed
US
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Selective LPCVD tungsten deposition by nitridation of a dielectric
Assignee: Motorola Solutions Inc
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Filing: 1987-03-02
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Granted: 1988-04-26
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Expires: 2007-03-02
Abstract
Abstract A process for selective deposition of a refractory metal such as tungsten at high temperatures and low pressure via chemical vapor deposition during semiconductor device manufacturing is provided. A dielectric layer is nitrided by chemical deposition of a nitrogen bearing gas prior to LPCVD deposition of tungsten for purposes such as contact metallization of current conducting electrodes and current controlling electrodes of transistors. Since nitridation of the dielectric is a surface chemical reaction and not an addition of material to the dielectric, no additional complexity is introduced into the LPCVD process. The refractory metal does not substantially deposit on the nitrided dielectric thereby providing selective metal deposition.
Inventors
- 👤 Philip J. Tobin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:58
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/60; H10P14/65; H10P14/6516; H10P14/6529; H10P14/6532; H10P14/6518; H10P14/6524; H10P14/6526; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/056; H10W20/057; H10P14/69; H10P14/692; H10P14/6921; H10P14/6922; H10P14/6923; Y; Y10; Y10S; Y10S148/00; Y10S148/112; Y10S148/133
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
144 words
A process for selectively forming a refractory metal on silicon and polysilicon surfaces via low pressure chemical vapor deposition (LPCVD) comprising the steps of: forming a transistor having first and second current electrode regions in a semiconductor substrate and a current control region separated from the substrate by an insulator; providing a dielectric material having a top surface and a bottom surface which covers the transistor; nitriding the top surface of the dielectric material by reacting a nitrogen bearing gas with the dielectric material; forming a contact region with the first and second current electrode regions and the current control region of the transistor; and selectively depositing the refractory metal on the first and second current electrode regions and the current control region of the transistor by chemical vapor deposition substantially without depositing the refractory metal on the top surface of the dielectric material.
Claim 2
Dependent Claim
144 words
A process for selectively forming a refractory metal on silicon and polysilicon surfaces via low pressure chemical vapor deposition (LPCVD) comprising the steps of: forming a transistor having first and second current electrode regions in a semiconductor substrate and a current control region separated from the substrate by an insulator; providing a dielectric material having a top surface and a bottom surface which covers the transistor; nitriding the top surface of the dielectric material by reacting a nitrogen bearing gas with the dielectric material; forming a contact region with the first and second current electrode regions and the current control region of the transistor; and selectively depositing the refractory metal on the first and second current electrode regions and the current control region of the transistor by chemical vapor deposition substantially without depositing the refractory metal on the top surface of the dielectric material.
Claim 3
Dependent Claim
11 words
The process of claim 1 wherein the refractory metal is tungsten.
Claim 4
Dependent Claim
13 words
The process of claim 1 wherein the dielectric material is a flowable material.
Claim 5
Dependent Claim
12 words
The process of claim 3 wherein the flowable material is borophosphosilicate glass.
Claim 6
Dependent Claim
24 words
The process of claim 1 wherein the nitridation of the dielectric is at a temperature substantially in the range of 800° to 1300° C.
Claim 7
Dependent Claim
18 words
The process of claim 1 wherein the nitridation of the flowed dielectric is acheived with a plasma discharge.
Claim 8
Dependent Claim
12 words
The process of claim 1 wherein the nitrogen bearing gas is ammonia.
Claim 9
Dependent Claim
14 words
The process of claim 1 wherein the dielectric is a nonflowable low temperature oxide.
Claim 10
Dependent Claim
100 words
A process for selectively forming tungsten on silicon and polysilicon surfaces via low pressure chemical vapor deposition (LPCVD) comprising the steps of: forming an electrode region in a semiconductor substrate; providing a dielectric material having a top surface and a bottom surface which covers the electrode region; nitriding the top surface of the dielectric material by reacting a nitrogen bearing gas with the dielectric material; forming a contact region with the electrode region; and selectively depositing the tungsten on the current electrode region by chemical vapor deposition substantially without depositing the tungsten on the top surface of the dielectric material.
Claim 11
Dependent Claim
100 words
A process for selectively forming tungsten on silicon and polysilicon surfaces via low pressure chemical vapor deposition (LPCVD) comprising the steps of: forming an electrode region in a semiconductor substrate; providing a dielectric material having a top surface and a bottom surface which covers the electrode region; nitriding the top surface of the dielectric material by reacting a nitrogen bearing gas with the dielectric material; forming a contact region with the electrode region; and selectively depositing the tungsten on the current electrode region by chemical vapor deposition substantially without depositing the tungsten on the top surface of the dielectric material.
Claim 12
Dependent Claim
13 words
The process of claim 9 wherein the dielectric material is a flowable material.
Claim 13
Dependent Claim
12 words
The process of claim 10 wherein the flowable material is borophosphosilicate glass.
Claim 14
Dependent Claim
24 words
The process of claim 9 wherein the nitridation of the dielectric is at a temperature substantially in the range of 800° to 1300° C.
Claim 15
Dependent Claim
18 words
The process of claim 9 wherein the nitridation of the flowed dielectric is acheived with a plasma discharge.
Claim 16
Dependent Claim
12 words
The process of claim 9 wherein the nitrogen bearing gas is ammonia.
Claim 17
Dependent Claim
14 words
The process of claim 9 wherein the dielectric is a nonflowable low temperature oxide.
Claim 18
Dependent Claim
125 words
A process for selectively forming a refractory metal on silicon and polysilicon surfaces via low pressure chemical vapor deposition (LPCVD) comprising the steps of: forming at least one current electrode region in a semiconductor substrate; providing a nonflowable dielectric material having a top surface and a bottom surface which covers the current electrode region; etching the nonflowable dielectric material to substantially planarize the top surface of the dielectric material; nitriding the top surface of the dielectric material by reacting a nitrogen bearing gas with the dielectric material; forming a contact region with the current electrode region; and selectively depositing the refractory metal on the current electrode region by chemical vapor deposition substantially without depositing the refractory metal on the top surface of the dielectric material.
Claim 19
Dependent Claim
125 words
A process for selectively forming a refractory metal on silicon and polysilicon surfaces via low pressure chemical vapor deposition (LPCVD) comprising the steps of: forming at least one current electrode region in a semiconductor substrate; providing a nonflowable dielectric material having a top surface and a bottom surface which covers the current electrode region; etching the nonflowable dielectric material to substantially planarize the top surface of the dielectric material; nitriding the top surface of the dielectric material by reacting a nitrogen bearing gas with the dielectric material; forming a contact region with the current electrode region; and selectively depositing the refractory metal on the current electrode region by chemical vapor deposition substantially without depositing the refractory metal on the top surface of the dielectric material.
Claim 20
Dependent Claim
15 words
The process of claim 16 wherein the nonflowable dielectric material is a low temperature oxide.
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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) | 1991-04-26 | 1991-10-26 | 1992-04-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-04-26 | 1995-10-26 | 1996-04-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-04-26 | 1999-10-26 | 2000-04-26 | $7700.00 | Window Closed / Lapsed |