Patent US6077782A successfully refreshed from Google Patents.
US6077782A
Expired / Lapsed
US
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Method to improve the texture of aluminum metallization
Assignee: Texas Instruments Inc
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Filing: 1998-02-13
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Granted: 2000-06-20
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Expires: 2018-02-13
Abstract
Abstract A method to improve the texture of titanium and aluminum to reduce electromigration by controlling the deposition conditions and the texture of the substrates. Aluminum films can develop strong <111> texture, when titanium is used underneath aluminum. However, to prevent the interaction between aluminum and titanium, a layer of TiN or other barrier is necessary. Fortunately, TiN has a similar atom arrangement on the <111> plane as that of aluminum <111> and titanium <002>. Therefore, by controlling the orientation of titanium using a pre-sputter argon etch and low titanium deposition temperature, the texture of titanium can be transferred to TiN, and subsequently to aluminum.
Inventors
- 👤 Wei-Yung Hsu
- 👤 Qi-Zhong Hong
- 👤 Robert H. Havemann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 16:33
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/071; H10W20/081; H10W20/031; H10W20/032; H10W20/033; H10W20/052; H10W20/0523; H10W20/056; H10W20/059; H10W20/40; H10W20/41; H10W20/425
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
154 words
A fabrication method, comprising: (a.) performing degas and sputter etch operations on a partially fabricated integrated circuit structure having openings in a dielectric layer which expose portions of underlying structures; (b.) depositing a first metal layer on a surface of said dielectric layer and within said openings to coat sides of said openings and said exposed portions of said underlying structures, said first metal layer having a texture; (c.) forming a conductive diffusion barrier layer over at least part of said first metal layer, with a texture which is substantially aligned to the texture of said first metal layer; (d.) depositing a second metal layer over said barrier layer, with a texture which is substantially aligned to the texture of said barrier layer; and wherein a cool down step is performed after performing said degas operation and prior to said sputter etch operation and whereby the texture of said second metal layer is improved.
Claim 2
Dependent Claim
154 words
A fabrication method, comprising: (a.) performing degas and sputter etch operations on a partially fabricated integrated circuit structure having openings in a dielectric layer which expose portions of underlying structures; (b.) depositing a first metal layer on a surface of said dielectric layer and within said openings to coat sides of said openings and said exposed portions of said underlying structures, said first metal layer having a texture; (c.) forming a conductive diffusion barrier layer over at least part of said first metal layer, with a texture which is substantially aligned to the texture of said first metal layer; (d.) depositing a second metal layer over said barrier layer, with a texture which is substantially aligned to the texture of said barrier layer; and wherein a cool down step is performed after performing said degas operation and prior to said sputter etch operation and whereby the texture of said second metal layer is improved.
Claim 3
Dependent Claim
36 words
The method of claim 1, wherein said depositing a first metal layer and said forming a conductive diffusion barrier layer is performed at a temperature in the range of 200 degrees C to 350 degrees C.
Claim 4
Dependent Claim
13 words
The method of claim 1, wherein said first metal layer predominantly comprises aluminum.
Claim 5
Dependent Claim
11 words
The method of claim 1, wherein said barrier layer comprises TiN.
Claim 6
Dependent Claim
13 words
The method of claim 1, wherein said second metal layer predominantly comprises aluminum.
Claim 7
Dependent Claim
14 words
The method of claim 1, wherein said second metal layer has a <111> texture.
Claim 8
Dependent Claim
12 words
The method of claim 1, wherein said second metal layer comprises copper.
Claim 9
Dependent Claim
20 words
The method of claim 1, wherein said sputter etch is performed at a peak temperature less than 410 degrees C.
Claim 10
Independent Claim
159 words
A method of improving texture of an aluminum surface, comprising: (a.) performing degas, sputter etch, and cool down operations on a partially fabricated integrated circuit structure having openings in a dielectric layer which expose portions of underlying structures; (b.) depositing a first metal layer on [the] a surface of said dielectric layer and within said openings to coat [the] sides of said openings and said exposed portions of said underlying structures, said first metal layer having a texture; (c.) forming a barrier layer over at least part of said first metal layer, with a texture which is substantially aligned to the texture of said first metal layer; (d.) depositing a second metal layer predominantly comprising aluminum over said barrier layer, with a texture which is substantially aligned to the texture of said barrier layer; and wherein said cool down operation is performed prior to said sputter etch operation and whereby the texture of said second metal layer is improved.
Claim 11
Independent Claim
159 words
A method of improving texture of an aluminum surface, comprising: (a.) performing degas, sputter etch, and cool down operations on a partially fabricated integrated circuit structure having openings in a dielectric layer which expose portions of underlying structures; (b.) depositing a first metal layer on [the] a surface of said dielectric layer and within said openings to coat [the] sides of said openings and said exposed portions of said underlying structures, said first metal layer having a texture; (c.) forming a barrier layer over at least part of said first metal layer, with a texture which is substantially aligned to the texture of said first metal layer; (d.) depositing a second metal layer predominantly comprising aluminum over said barrier layer, with a texture which is substantially aligned to the texture of said barrier layer; and wherein said cool down operation is performed prior to said sputter etch operation and whereby the texture of said second metal layer is improved.
Claim 12
Dependent Claim
15 words
The method of claim 9, wherein said sputter etch operation uses a reactive ion etch.
Claim 13
Dependent Claim
14 words
The method of claim 9, wherein said second metal layer has a <111> texture.
Claim 14
Independent Claim
156 words
A method of improving texture of an aluminum surface, comprising: (a.) performing degas, sputter etch, and cool down operations on a partially fabricated integrated circuit structure having openings in a dielectric layer which expose portions of underlying structures; (b.) depositing a first metal layer, which predominantly comprises titanium with a <002> texture, on a surface of said dielectric layer and within said openings to coat sides of said openings and said exposed portions of said underlying structures; (c.) forming a diffusion barrier layer, which predominantly comprises titanium nitride, with a <111> texture, over at least part of said first metal layer; (d.) depositing a second metal layer, which predominantly comprises aluminum, with a <111> texture, over said barrier layer, said second metal layer having a surface with a texture; and wherein said cool down operation is performed prior to said sputter etch and whereby the texture of the surface of said second metal layer is improved.
Claim 15
Independent Claim
156 words
A method of improving texture of an aluminum surface, comprising: (a.) performing degas, sputter etch, and cool down operations on a partially fabricated integrated circuit structure having openings in a dielectric layer which expose portions of underlying structures; (b.) depositing a first metal layer, which predominantly comprises titanium with a <002> texture, on a surface of said dielectric layer and within said openings to coat sides of said openings and said exposed portions of said underlying structures; (c.) forming a diffusion barrier layer, which predominantly comprises titanium nitride, with a <111> texture, over at least part of said first metal layer; (d.) depositing a second metal layer, which predominantly comprises aluminum, with a <111> texture, over said barrier layer, said second metal layer having a surface with a texture; and wherein said cool down operation is performed prior to said sputter etch and whereby the texture of the surface of said second metal layer is improved.
Claim 16
Dependent Claim
17 words
The method of claim 12, wherein said sputter etch process uses a combination of argon and hydrogen.
Claim 17
Dependent Claim
17 words
The method of claim 12, wherein said sputter etch is performed with Ar sputtering at room temperature.
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) | 2003-06-20 | 2003-12-20 | 2004-06-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-06-20 | 2007-12-20 | 2008-06-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-06-20 | 2011-12-20 | 2012-06-20 | $7700.00 | Window Closed / Lapsed |