US5677238A
Expired / Lapsed
US
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Semiconductor contact metallization
Assignee: GlobalFoundries Singapore Pte Ltd
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Filing: 1996-04-29
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Granted: 1997-10-14
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Expires: 2016-04-29
Abstract
Abstract A method for fabricating an improved connection between active device regions in silicon, to an overlying metallization level, has been developed. The method produces contacts with superior and improved barrier integrity, which permits silicon device exposure to extended thermal process times and/or higher temperature processes without metal penetration into the silicon contact junction regions. The critical element is the addition of a conformal CVD tungsten layer in the multilayer barrier structure.
Inventors
- 👤 Fang Hong Gn
- 👤 Sekar Ramamoorthy
- 👤 Lap Chan
- 👤 Che-Chia Wei
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 23:39
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/032; H10W20/033; H10W20/035; H10P; H10P14/00; H10P14/40; H10P14/42; H10P14/43; H10P14/44; H10W20/056; H10W20/063; H10W20/0633; H10W20/40; H10W20/41; H10W20/425
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
151 words
A method for fabricating a MOSFET device on a semiconductor substrate, wherein contact to the active device element comprises the steps of: providing said active device element in said semiconductor substrate; depositing an interlevel dielectric layer on said semiconductor substrate, that includes said active device element; providing a contact opening, etched through said interlevel dielectric layer, to said active device element; depositing a first titanium layer over the surface of said interlevel dielectric layer and into said contact opening; depositing a titanium nitride layer over said first titanium layer; depositing a conformal CVD tungsten layer over said titanium nitride layer; depositing a second titanium layer over said conformal CVD tungsten layer; cold sputtering an aluminum layer over said second titanium layer at a temperature of less than about 100° C.; and hot sputtering an aluminum layer over said cold sputtered aluminum layer at a temperature of more than about 430° C.
Claim 2
Independent Claim
151 words
A method for fabricating a MOSFET device on a semiconductor substrate, wherein contact to the active device element comprises the steps of: providing said active device element in said semiconductor substrate; depositing an interlevel dielectric layer on said semiconductor substrate, that includes said active device element; providing a contact opening, etched through said interlevel dielectric layer, to said active device element; depositing a first titanium layer over the surface of said interlevel dielectric layer and into said contact opening; depositing a titanium nitride layer over said first titanium layer; depositing a conformal CVD tungsten layer over said titanium nitride layer; depositing a second titanium layer over said conformal CVD tungsten layer; cold sputtering an aluminum layer over said second titanium layer at a temperature of less than about 100° C.; and hot sputtering an aluminum layer over said cold sputtered aluminum layer at a temperature of more than about 430° C.
Claim 3
Dependent Claim
19 words
The method of claim 1, wherein said active device element in said semiconductor substrate, is an N-type doped region.
Claim 4
Dependent Claim
38 words
The method of claim 1, wherein said interlevel dielectric layer is silicon oxide, deposited using LPCVD, APCVD or PECVD processes, at a temperature between about 400° to 850° C., to a thickness between about 5,000 to 15,000 Angstroms.
Claim 5
Dependent Claim
36 words
The method of claim 1, wherein said contact opening is created using anisotropic RIE removal of said interlevel dielectric, in O 2 , CHF 3 , CF 4 , CO or C 4 F 8 chemistry.
Claim 6
Dependent Claim
23 words
The method of claim 1, wherein said first titanium layer, having a thickness between about 400 to 800 Angstroms, is deposited by sputtering.
Claim 7
Dependent Claim
23 words
The method of claim 1, wherein said titanium nitride layer, having a thickness between about 800 to 1,500 Angstroms, is deposited by sputtering.
Claim 8
Dependent Claim
49 words
The method of claim 1, wherein said conformal CVD tungsten layer is deposited at a temperature between about 350° to 480° C., to a thickness between about 800 to 2,500 Angstroms, using WF 6 , SiH 4 and H 2 at a pressure between about 60 to 120 Torr.
Claim 9
Dependent Claim
23 words
The method of claim 1, wherein said second titanium layer, having a thickness between about 400 to 800 Angstroms, is deposited by sputtering.
Claim 10
Dependent Claim
24 words
The method of claim 1, wherein said cold sputtering of said aluminum layer is performed at a temperature between about 25° to 150° C.
Claim 11
Dependent Claim
24 words
The method of claim 1, wherein said hot sputtering of said aluminum layer is performed at a temperature between about 400° to 580° C.
Claim 12
Dependent Claim
22 words
The method of claim 9, wherein said cold sputtered aluminum layer is deposited to a thickness between about 1,500 to 3,500 Angstroms.
Claim 13
Dependent Claim
22 words
The method of claim 10, wherein said hot sputtered aluminum layer is deposited to a thickness between about 2,500 to 7,500 Angstroms.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-10-13 | 2001-04-14 | 2001-10-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-10-13 | 2005-04-14 | 2005-10-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-10-13 | 2009-04-14 | 2009-10-14 | $7700.00 | Window Closed / Lapsed |