Patent US5624874A successfully refreshed from Google Patents.
US5624874A
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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 01:51
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.
References Cited (Backward Citations)
US4373050A
Cited
US4104424A
Cited
US4176206A
Cited
US4199624A
Cited
JPS5669723A
Cited
JPS5728952A
Cited
JPS57143479A
Cited
JPS5855573A
Cited
US4744858A
Cited
US5073408A
Cited
JPS6256581A
Cited
JPS62166505A
Cited
US4696098A
Cited
US4814293A
Cited
US4787958A
Cited
JPH01127681A
Cited
US4990997A
Cited
US5093710A
Cited
US5019234A
Cited
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 |