US5624874A
Expired / Lapsed
US
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Barrier layer enhancement in metallization scheme for semiconductor device fabrication
Assignee: Philips North America LLC
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Filing: 1995-10-18
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Granted: 1997-04-29
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Expires: 2015-10-18
Abstract
Abstract The properties of a diffusion barrier material layer over a semiconductor substrate are enhanced in a simple and time-effective manner by immersing the substrate in an oxidizing liquid. For a titanium-tungsten barrier metal, a dip in nitric acid for 1-60 minutes provides the metal with an oxide layer of the right thickness of 10-20 Å.
Inventors
- 👤 Sheldon C. P. Lim
- 👤 Stanley C. Chu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 01:35
CPC Classifications
H; H10; H10D; H10D48/00; H10D48/30; H10D48/32; H10D48/36; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/032; H10W20/047; H10D64/00; H10D64/01; H10D64/011; H10W20/033; H10W20/035; H10W72/00; H10W72/01; H10W72/012; H10W72/20; H10W72/251
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
96 words
A method of fabricating a semiconductor device in a portion of a semiconductor substrate, the method comprising the step of forming an oxide layer on top of a barrier material layer of titanium-tungsten prior to depositing a further material layer over the oxide layer, wherein the oxide layer is formed by oxidizing a surface of the barrier material layer with a liquid oxidizing agent at a temperature between room temperature and 100° C. for a time sufficient to produce an oxide layer of titanium and tungsten oxides having a thickness on the order of 10-20 angstroms.
Claim 2
Independent Claim
96 words
A method of fabricating a semiconductor device in a portion of a semiconductor substrate, the method comprising the step of forming an oxide layer on top of a barrier material layer of titanium-tungsten prior to depositing a further material layer over the oxide layer, wherein the oxide layer is formed by oxidizing a surface of the barrier material layer with a liquid oxidizing agent at a temperature between room temperature and 100° C. for a time sufficient to produce an oxide layer of titanium and tungsten oxides having a thickness on the order of 10-20 angstroms.
Claim 3
Dependent Claim
19 words
A method as in claim 1 wherein the oxidizing is performed by immersing the portion in the oxidizing agent.
Claim 4
Dependent Claim
14 words
A method as in claim 2 wherein the immersion is performed at room temperature.
Claim 5
Dependent Claim
30 words
A method as in claim 1 wherein the portion is made inaccessible to the oxidizing agent by means of a blanket deposition of the barrier material layer over the portion.
Claim 6
Dependent Claim
13 words
A method as in claim 1 wherein the oxidizing agent includes an acid.
Claim 7
Dependent Claim
15 words
A method as in claim 5 wherein the acid includes nitric acid or sulfuric acid.
Claim 8
Dependent Claim
25 words
A method as in claim 6 wherein the barrier material layer is immersed in the nitric acid for 1 to 60 minutes at room temperature.
Claim 9
Dependent Claim
25 words
A method as in claim 6 wherein the barrier material layer is immersed in the nitric acid for 5 to 15 minutes at room temperature.
Claim 10
Dependent Claim
109 words
In a method of fabricating a semiconductor device in a portion of a semiconductor substrate, wherein the method includes the step of forming a barrier layer prior to depositing a further material layer over the barrier layer, the barrier layer comprising a material layer of titanium-tungsten and an oxide layer on the material layer of titanium-tungsten, the improvement comprising forming the oxide layer by oxidizing a surface of the titanium-tungsten material layer by immersion thereof into an oxidizing liquid for a time sufficient thereby to produce on the material layer of titanium-tungsten an oxide layer of titanium and tungsten oxides having a thickness on the order of 10-20 angstroms.
Claim 11
Dependent Claim
109 words
In a method of fabricating a semiconductor device in a portion of a semiconductor substrate, wherein the method includes the step of forming a barrier layer prior to depositing a further material layer over the barrier layer, the barrier layer comprising a material layer of titanium-tungsten and an oxide layer on the material layer of titanium-tungsten, the improvement comprising forming the oxide layer by oxidizing a surface of the titanium-tungsten material layer by immersion thereof into an oxidizing liquid for a time sufficient thereby to produce on the material layer of titanium-tungsten an oxide layer of titanium and tungsten oxides having a thickness on the order of 10-20 angstroms.
Claim 12
Dependent Claim
22 words
A method as defined in claim 9 wherein the oxide layer is formed at a temperature between room temperature and 100° C.
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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) | 2000-04-28 | 2000-10-28 | 2001-04-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-04-28 | 2004-10-28 | 2005-04-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-04-28 | 2008-10-28 | 2009-04-29 | $7700.00 | Window Closed / Lapsed |