EP0545602A1
Expired / Lapsed
EP
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Method for forming barrier metal layers
Assignee: STMicroelectronics lnc USA
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Filing: 1992-11-24
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Granted: —
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Expires: 2012-11-24
Abstract
Abstract A method for forming interlevel contacts in integrated circuits includes the formation of a titanium nitride layer (26) prior to formation of an overlying conductive layer of a material such as polycrystalline silicon or a metal. In one approach, CVD titanium nitride (26) is deposited over a partially formed integrated circuit device and in a contact opening (20). The titanium nitride layer (26) is then exposed to an atmosphere containing oxygen, so that oxygen atoms diffuse into the titanium nitride layer (26). This may be done in conjunction with an annealing step. In another embodiment, layers of titanium (28) and titanium nitride (30) are sequentially sputtered onto the device. The nitride layer may then be exposed to an oxygen ambient, or the oxygen may be incorporated into the titanium nitride layer during the sputter deposition.
Inventors
- 👤 Girish A. Dixit
- 👤 Fu-Tai Liou
- 👤 Che-Chia Wei
- 👤 Fusen Chen
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 04:35
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/032; H10W20/047; H10W20/048; H10W20/033; H10W20/056
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
76 words
A method for forming a barrier layer on an integrated circuit device, comprising the steps of: forming an insulating layer over the device; forming an opening through the insulating layer to expose a portion of an underlying conducting layer; forming a layer of titanium nitride over the insulating layer and in the opening; and exposing the titanium nitride layer to an ambient atmosphere containing oxygen to cause oxygen molecules to diffuse into the titanium nitride layer.
Claim 2
Dependent Claim
14 words
The method of Claim 1, wherein the underlying conductive layer comprises a semiconductor substrate.
Claim 3
Dependent Claim
30 words
The method of Claim 1, wherein said step of forming a layer of titanium nitride comprises the step of: depositing a layer of substantially stoichiometric titanium nitride over the device.
Claim 4
Dependent Claim
16 words
The method of Claim 3, wherein the titanium nitride layer is formed by chemical vapor deposition.
Claim 5
Dependent Claim
40 words
The method of Claim 3, wherein said depositing step comprises the steps of: depositing a layer of titanium in a nonreactive ambient atmosphere; introducing nitrogen into the ambient atmosphere; and depositing titanium reacted with the nitrogen to form titanium nitride.
Claim 6
Dependent Claim
16 words
The method of Claim 5, wherein the titanium layer is deposited in an atmosphere containing argon.
Claim 7
Dependent Claim
17 words
The method of Claim 5, wherein said introducing step further includes introducing oxygen into the ambient atmosphere.
Claim 8
Dependent Claim
33 words
The method of Claim 5, further comprising the step of: thermally annealing the device after depositing the titanium nitride, wherein titanium silicide is formed in the exposed portion of the underlying conducting layer.
Claim 9
Dependent Claim
22 words
The method of Claim 1, wherein said exposing step comprises the step of: exposing the titanium nitride layer to an oxygen plasma.
Claim 10
Dependent Claim
35 words
The method of Claim 1, wherein said exposing step comprises the step of: exposing the titanium nitride layer to an atmosphere containing oxygen and argon at a temperature of between 100 and 500 degrees C.
Claim 11
Dependent Claim
42 words
The method of Claim 1, wherein said step of forming the titanium nitride layer comprises the step of: providing an ambient atmosphere containing oxygen; and depositing the titanium nitride over the device, wherein oxygen atoms are included in the titanium nitride layer.
Claim 12
Dependent Claim
54 words
A barrier layer structure for an integrated circuit device, comprising: an insulating layer overlying a conductive structure; an opening through said insulating layer which exposes a portion of the underlying conductive structure; a barrier metal layer overlying a portion of the insulating layer and said opening, said barrier metal layer containing oxygen atoms therein.
Claim 13
Dependent Claim
13 words
The structure of Claim 12, wherein said barrier metal layer comprises titanium nitride.
Claim 14
Dependent Claim
18 words
The structure of Claim 13, wherein said barrier metal layer comprises substantially stoichiometric titanium nitride throughout its thickness.
Claim 15
Dependent Claim
46 words
The structure of Claim 12, wherein said barrier metal layer comprises: a layer of titanium in contact with said insulating layer and the underlying conductive layer; and a layer of substantially stoichiometric titanium nitride overlying said titanium layer, said titanium nitride containing oxygen atoms diffused thereinto.
Claim 16
Dependent Claim
29 words
The structure of Claim 15, wherein said titanium nitride layer comprises a layer of material formed by sputtering titanium nitride over said titanium layer in an atmosphere containing oxygen.
Claim 17
Dependent Claim
44 words
The structure of Claim 15, wherein said titanium nitride layer comprises a layer of material formed by sputtering titanium nitride over said titanium layer in an atmosphere not containing oxygen, followed by diffusing oxygen into said titanium nitride layer from an upper surface thereof.
References Cited (Backward Citations)
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