US5420072A
Expired / Lapsed
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Method for forming a conductive interconnect in an integrated circuit
Assignee: Motorola Solutions Inc
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Filing: 1994-02-04
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Granted: 1995-05-30
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Expires: 2014-02-04
Abstract
Abstract A conformal titanium nitride film having a preferred <111> crystal orientation is formed by chemically vapor depositing the film in two separate steps. In the first deposition step a titanium nitride layer (22) having poor step coverage and a preferred <111> crystal orientation is formed. In the second deposition step a second conformal layer of titanium nitride (24) is insitu deposited onto the first titanium nitride layer (22), wherein during the deposition the first titanium nitride layer (22) acts as a crystallographic seed layer for the second titanium nitride layer (24). As a result, a titanium nitride layer exhibiting a preferred <111> crystal orientation and good step coverage is achieved.
Inventors
- 👤 Robert W. Fiordalice
- 👤 Johnson O. Olowolafe
- 👤 Hisao Kawasaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 07:38
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/032; H10W20/042; H10W20/045; H10W20/033; H10W20/0425
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
115 words
A method for forming a conductive interconnect comprising the steps of: providing an integrated circuit structure; chemically vapor depositing a first layer of titanium nitride with a first deposition process, wherein the first layer of titanium nitride overlies the integrated circuit structure and has a preferred <111> crystal orientation; and chemically vapor depositing a second layer of titanium nitride overlying the first layer of titanium nitride with a second deposition process, wherein the second deposition process differs from the first deposition process and the first layer of titanium nitride serves as a crystallographic seed layer for the second layer of titanium nitride and the second layer of titanium nitride has a preferred <111> crystal orientation.
Claim 2
Independent Claim
115 words
A method for forming a conductive interconnect comprising the steps of: providing an integrated circuit structure; chemically vapor depositing a first layer of titanium nitride with a first deposition process, wherein the first layer of titanium nitride overlies the integrated circuit structure and has a preferred <111> crystal orientation; and chemically vapor depositing a second layer of titanium nitride overlying the first layer of titanium nitride with a second deposition process, wherein the second deposition process differs from the first deposition process and the first layer of titanium nitride serves as a crystallographic seed layer for the second layer of titanium nitride and the second layer of titanium nitride has a preferred <111> crystal orientation.
Claim 3
Dependent Claim
23 words
The method of claim 1, further comprising the step of depositing a conductive layer of material overlying the second layer of titanium nitride.
Claim 4
Dependent Claim
24 words
The method of claim 2, wherein the step of depositing the conductive layer of material is further characterized as depositing a layer comprising aluminum.
Claim 5
Dependent Claim
30 words
The method of claim 3, wherein the step of depositing the layer comprising aluminum is further characterized as depositing the layer comprising aluminum to have a preferred <111> crystal orientation.
Claim 6
Dependent Claim
24 words
The method of claim 2, wherein the step of depositing the conductive layer of material is further characterized as depositing a layer of tungsten.
Claim 7
Dependent Claim
52 words
The method of claim 1, wherein the step of chemical vapor depositing the first layer of titanium nitride with the first deposition process is further characterized as depositing the first layer of titanium nitride with a deposition ambient comprising titanium tetrachloride and ammonia, wherein the titanium tetrachloride has a first partial pressure.
Claim 8
Dependent Claim
52 words
The method of claim 6, wherein the step of chemical vapor depositing the second layer of titanium nitride with the second deposition process is further characterized as depositing the second layer of titanium nitride with a deposition ambient comprising titanium tetrachloride and ammonia, wherein the titanium tetrachloride has a second partial pressure.
Claim 9
Dependent Claim
17 words
The method of claim 7, wherein the second partial pressure is greater than the first partial pressure.
Claim 10
Dependent Claim
37 words
The method of claim 1, wherein the step of chemical vapor depositing the second layer of titanium nitride is further characterized as depositing the second layer of titanium nitride insitu with the first layer of titanium nitride.
Claim 11
Independent Claim
153 words
A method for forming a conductive interconnect comprising the steps of: providing an integrated circuit structure; chemically vapor depositing a first layer of titanium nitride with a first deposition ambient comprising titanium tetrachloride and ammonia, wherein: the first layer of titanium nitride overlies the integrated circuit structure and has a preferred <111> crystal orientation and the first deposition ambient has a first titanium tetrachloride partial pressure; and chemically vapor depositing a second layer of titanium nitride overlying the first layer of titanium nitride with a second deposition ambient comprising titanium tetrachloride and ammonia, the second deposition ambient having a second titanium tetrachloride partial pressure, wherein the second titanium tetrachloride partial pressure is greater than the first titanium tetrachloride partial pressure and the first layer of titanium nitride serves as a crystallographic seed layer for the second layer of titanium nitride and the second layer of titanium nitride has a preferred <111> crystal orientation.
Claim 12
Independent Claim
153 words
A method for forming a conductive interconnect comprising the steps of: providing an integrated circuit structure; chemically vapor depositing a first layer of titanium nitride with a first deposition ambient comprising titanium tetrachloride and ammonia, wherein: the first layer of titanium nitride overlies the integrated circuit structure and has a preferred <111> crystal orientation and the first deposition ambient has a first titanium tetrachloride partial pressure; and chemically vapor depositing a second layer of titanium nitride overlying the first layer of titanium nitride with a second deposition ambient comprising titanium tetrachloride and ammonia, the second deposition ambient having a second titanium tetrachloride partial pressure, wherein the second titanium tetrachloride partial pressure is greater than the first titanium tetrachloride partial pressure and the first layer of titanium nitride serves as a crystallographic seed layer for the second layer of titanium nitride and the second layer of titanium nitride has a preferred <111> crystal orientation.
Claim 13
Dependent Claim
23 words
The method of claim 10, further comprising the step of depositing a conductive layer of material overlying the second layer of titanium nitride.
Claim 14
Dependent Claim
24 words
The method of claim 11, wherein the step of depositing the conductive layer of material is further characterized as depositing a layer comprising aluminum.
Claim 15
Dependent Claim
29 words
The method of claim 12, wherein the step of depositing the layer comprising aluminum is further characterized as depositing the layer comprising aluminum with a preferred <111> crystal orientation.
Claim 16
Dependent Claim
24 words
The method of claim 11, wherein the step of depositing the conductive layer of material is further characterized as depositing a layer of tungsten.
Claim 17
Independent Claim
184 words
A method for forming a conductive interconnect in an integrated circuit comprising the steps of: providing an integrated circuit structure, the integrated circuit structure comprising a dielectric layer overlying a conductive region; patterning the dielectric layer to form an opening and to form an exposed portion of the conductive region; chemically vapor depositing a first layer of titanium nitride within the opening using a first deposition ambient comprising titanium tetrachloride and ammonia, wherein the first layer of titanium nitride has a preferred <111> crystal orientation and the first deposition ambient has a first titanium tetrachloride partial pressure; and chemically vapor depositing a second layer of titanium nitride overlying the first layer of titanium nitride using a second deposition ambient comprising titanium tetrachloride and ammonia, the second deposition ambient having a second titanium tetrachloride partial pressure, wherein the second titanium tetrachloride partial pressure is greater than the first titanium tetrachloride partial pressure and the first layer of titanium nitride serves as a crystallographic seed layer for the second layer of titanium nitride and the second layer of titanium nitride has a preferred <111> crystal orientation.
Claim 18
Independent Claim
184 words
A method for forming a conductive interconnect in an integrated circuit comprising the steps of: providing an integrated circuit structure, the integrated circuit structure comprising a dielectric layer overlying a conductive region; patterning the dielectric layer to form an opening and to form an exposed portion of the conductive region; chemically vapor depositing a first layer of titanium nitride within the opening using a first deposition ambient comprising titanium tetrachloride and ammonia, wherein the first layer of titanium nitride has a preferred <111> crystal orientation and the first deposition ambient has a first titanium tetrachloride partial pressure; and chemically vapor depositing a second layer of titanium nitride overlying the first layer of titanium nitride using a second deposition ambient comprising titanium tetrachloride and ammonia, the second deposition ambient having a second titanium tetrachloride partial pressure, wherein the second titanium tetrachloride partial pressure is greater than the first titanium tetrachloride partial pressure and the first layer of titanium nitride serves as a crystallographic seed layer for the second layer of titanium nitride and the second layer of titanium nitride has a preferred <111> crystal orientation.
Claim 19
Dependent Claim
24 words
The method of claim 15, further comprising the step of depositing a first conductive layer of material overlying the second layer of titanium nitride.
Claim 20
Dependent Claim
25 words
The method of claim 16, wherein the step of depositing the first conductive layer of material is further characterized as depositing a layer comprising aluminum.
Claim 21
Dependent Claim
25 words
The method of claim 16, wherein the step of depositing the first conductive layer of material is further characterized as depositing a layer of tungsten.
Claim 22
Dependent Claim
17 words
The method of claim 18, further comprising the step of forming a tungsten plug within the opening.
Claim 23
Dependent Claim
21 words
The method of claim 19, further comprising the step of depositing a second conductive layer of material overlying the tungsten plug.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-05-29 | 1998-11-28 | 1999-05-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-05-29 | 2002-11-28 | 2003-05-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-05-29 | 2006-11-28 | 2007-05-30 | $7700.00 | Window Closed / Lapsed |