EP0430403A2
Expired / Lapsed
EP
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Method for fabricating interlevel contacts
Assignee: STMicroelectronics lnc USA
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Filing: 1990-08-30
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Granted: —
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Expires: 2010-08-30
Abstract
Abstract A method for fabricating interlevel contacts in semiconductor integrated circuits provides for formation of a contact opening through an insulating layer. A layer of refractory metal, or refractory metal alloy, is deposited over the surface of the integrated circuit chip. An aluminum layer is then deposited at a significantly elevated temperature, so that an aluminum/refractory metal alloy is formed at the interface between the aluminum layer and the refractory metal layer. Formation of such an alloy causes an expansion of the metal within the contact opening, thereby filling the contact opening and providing a smooth upper contour to the deposited aluminum layer.
Inventors
- 👤 Fusen E. Chen
- 👤 Fu-Tai Liou
- 👤 Timothy Edward Turner
- 👤 Che-Chia Wei
- 👤 Yih-Shung Lin
- 👤 Girish Anant Dixit
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 10:45
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/40; H10W20/41; H10W20/42; H10W20/01; H10W20/031; H10W20/032; H10W20/047; H10W20/049; H10D; H10D64/00; H10D64/01; H10D64/011; H10D64/0111; H10W20/033; H10W20/035; H10W20/056; H10W20/063; H10W20/0633; H10W20/071; H10W20/081; H10W20/425; H10W20/44; H10W20/4403; H10W20/4405; H10W20/4437; H10W20/4441; H10W20/4446
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
70 words
A method for fabricating interlevel contacts in integrated circuits, comprising the steps of: forming a contact opening in an insulating layer to expose a conducting region beneath; depositing a conducting layer containing a refractory metal over the insulating layer and in the contact opening; and depositing an aluminum layer at a temperature exceeding approximately 150°C, wherein an alloy of aluminum and the refractory metal is formed in the contact opening.
Claim 2
Dependent Claim
21 words
The method of Claim 1, wherein the aluminum layer is deposited at a temperature in the range of 350°C to 500°C.
Claim 3
Dependent Claim
18 words
The method of Claim 2, wherein the aluminum layer is deposited at a rate of approximately 20-200 A/sec.
Claim 4
Dependent Claim
26 words
The method of Claim 1, wherein the alloy formed in the contact opening has a volume greater than that of unalloyed aluminum and the refractory metal.
Claim 5
Dependent Claim
17 words
The method of Claim 1, wherein the conducting layer containing refractory metal comprises a refractory metal compound.
Claim 6
Dependent Claim
57 words
The method of Claim 1, wherein said deposition of a conformal layer containing refractory metal step comprises the steps of: forming a refractory metal layer over the insulating layer and within the contact opening; reacting the refractory metal layer to form a refractory metal compound; and forming a second refractory metal layer over the reacted compound layer.
Claim 7
Dependent Claim
20 words
The method of Claim 6, wherein said reacting step comprises reacting the refractory metal to form a refractory metal nitride.
Claim 8
Dependent Claim
21 words
The method of Claim 6, wherein said reacting step comprising reacting the refractory metal layer to form a refractory metal silicide.
Claim 9
Dependent Claim
22 words
The method of Claim 1, wherein the contact opening is formed over a previously fabricated contact to a lower level conducting structure.
Claim 10
Independent Claim
63 words
A method for fabricating interlevel contacts in an integrated circuit, comprising the steps of: forming an opening in an insulating layer to expose a conductive region beneath; depositing a conducting layer containing refractory metal over the insulating layer and within the opening; and depositing aluminum at a temperature sufficient to cause the aluminum to alloy with the refractory metal at an interface thereof.
Claim 11
Dependent Claim
57 words
The method of Claim 10, wherein said deposition of a conducting layer containing refractory metal step comprises the steps of: forming a refractory metal layer over the insulating layer and within the contact opening; reacting the refractory metal layer to form a refractory metal compound; and forming a second refractory metal layer over the reacted compound layer.
Claim 12
Dependent Claim
20 words
The method of Claim 11, wherein said reacting step comprises reacting the refractory metal to form a refractory metal nitride.
Claim 13
Dependent Claim
21 words
The method of Claim 11, wherein said reacting step comprises reacting the refractory metal layer to form a refractory metal silicide.
Claim 14
Dependent Claim
76 words
A semiconductor structure comprising: an insulating layer overlying a conductive region; an opening formed in said insulating layer and exposing a portion of the conducting region; a layer containing refractory metal overlying said insulating layer, and covering sidewalls of the opening and the exposed portion of the conducting region; a layer containing an alloy of aluminum and the refractory metal overlying said layer containing refractory metal; and a layer of aluminum overlying said alloy containing layer.
Claim 15
Dependent Claim
30 words
The semiconductor structure of Claim 14, wherein said layer containing refractory metal comprises: a layer of refractory metal silicide; and a layer of refractory metal overlying said metal silicide layer.
Claim 16
Dependent Claim
30 words
The semiconductor structure of Claim 14, wherein said layer containing refractory metal comprises: a layer of refractory metal nitride; and a layer of refractory metal overlying said metal nitride layer.
Claim 17
Dependent Claim
98 words
A semiconductor structure according to Claim 14, further comprising: a second insulating layer covering said aluminum layer and said first insulating layer; a second opening in said second insulating layer, wherein said second opening exposes a portion of said aluminum layer; a second layer containing refractory metal overlying said second insulating layer, and covering sidewalls of said second opening and the exposed portion of said aluminum layer; a second layer containing an alloy of aluminum and the refractory metal overlying said second layer containing refractory metal; and a second layer of aluminum overlying said second alloy containing layer.
References Cited (Backward Citations)
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