US5736458A
Expired / Lapsed
US
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Method for improved aluminium-copper deposition and robust via contact resistance
Assignee: Taiwan Semiconductor Manufacturing Co TSMC Ltd
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Filing: 1997-04-14
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Granted: 1998-04-07
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Expires: 2017-04-14
Abstract
Abstract A method for improving the electrical resistance of contacting surfaces in via holes in semiconductor substrates is disclosed. The via holes are formed and later filled with metal to interconnect metal layers in the substrate. The method involves the introduction of a post-treatment process in the filling of vias with metal. Specifically, the nitrogen treatment step followed by a vacuum break is introduced right after the deposition of a titanium layer over the exposed first upper metal layer when the via holes are first opened. The treatment is accomplished in situ, that is, without breaking vacuum, and at room temperature. The remaining steps of filling the vias follow the conventional methods. It is shown that the contact resistances are reduced and that a further reduction in the contact resistance is achieved if the nitrogen treatment is performed along with vacuum break.
Inventors
- 👤 Ming-Chang Teng
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 13:05
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/032; H10W20/033; H10P; H10P14/00; H10P14/40; H10P14/42; H10P14/44; H10W20/056
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
102 words
A method of post-treatment in a via metal deposition process on a semiconductor substrate comprising the steps of: providing a silicon substrate over which via holes are formed through an insulating layer onto a first upper metal layer; performing a pre-sputter-clean etch of said via holes; sputter depositing in vacuum a barrier layer in said via holes; performing said post-treatment of said barrier layer in nitrogen gas followed by a vacuum break whereby said barrier layer is exposed to atmospheric pressure; depositing second upper metal layer over said barrier layer; and depositing an anti-reflective coating (ARC) onto said second upper metal layer.
Claim 2
Independent Claim
102 words
A method of post-treatment in a via metal deposition process on a semiconductor substrate comprising the steps of: providing a silicon substrate over which via holes are formed through an insulating layer onto a first upper metal layer; performing a pre-sputter-clean etch of said via holes; sputter depositing in vacuum a barrier layer in said via holes; performing said post-treatment of said barrier layer in nitrogen gas followed by a vacuum break whereby said barrier layer is exposed to atmospheric pressure; depositing second upper metal layer over said barrier layer; and depositing an anti-reflective coating (ARC) onto said second upper metal layer.
Claim 3
Dependent Claim
15 words
The method of claim 1, wherein the first upper metal layer is aluminum copper alloy.
Claim 4
Dependent Claim
12 words
The method of claim 1, wherein the insulating layer is planarized oxide.
Claim 5
Dependent Claim
15 words
The method of claim 1, wherein said insulating layer is dry-etched to form via holes.
Claim 6
Dependent Claim
18 words
The method of claim 1, wherein said pre-sputter-clean etch is performed with an etchant aided by argon ions.
Claim 7
Dependent Claim
12 words
The method of claim 1, wherein said barrier layer is titanium (Ti).
Claim 8
Dependent Claim
17 words
The method of claim 6, wherein the Ti thickness is in between about 1,000 to 2,000 Angstroms.
Claim 9
Dependent Claim
21 words
The method of claim 1, wherein said post-treatment temperature is performed between about 20° C. to 30° C. at atmospheric conditions.
Claim 10
Dependent Claim
29 words
The method of claim 1, wherein said vacuum break to atmospheric pressure is performed air at a temperature in between about 20° C. to 30° C. at atmospheric conditions.
Claim 11
Dependent Claim
15 words
The method of claim 1, wherein the second upper metal layer is aluminum copper alloy.
Claim 12
Dependent Claim
19 words
The method of claim 10, wherein the aluminum copper alloy thickness is in between about 5,500 to 6,500 Angstroms.
Claim 13
Dependent Claim
12 words
The method of claim 9, wherein said ARC is titanium nitride (TiN).
Claim 14
Dependent Claim
16 words
The method of claim 12, wherein said TiN thickness is between about 200 to 300 Angstroms.
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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) | 2001-04-06 | 2001-10-06 | 2002-04-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-04-06 | 2005-10-06 | 2006-04-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-04-06 | 2009-10-06 | 2010-04-07 | $7700.00 | Window Closed / Lapsed |