US5880026A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for air gap formation by plasma treatment of aluminum interconnects
Assignee: Texas Instruments Inc
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Filing: 1997-12-16
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Granted: 1999-03-09
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Expires: 2017-12-16
Abstract
Abstract An ultimate low k (k=1) gap structure for high speed logic devices in which the sidewalls fully or partially cover the gaps between the interconnects by dry etching the already formed aluminum interconnects after the photoresist has been stripped. This method is particularly useful for the subsequent deposition of silicon dioxide and for forming air gaps.
Inventors
- 👤 Guoqiang Xing
- 👤 Kenneth D. Brennan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 20:41
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/063; H10W20/0633; H10W20/071; H10W20/072; H10W20/40; H10W20/45; H10W20/46; H10W20/495
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
115 words
An integrated circuit metallization fabrication method, comprising the steps of: (a.) depositing a sacrificial metal layer atop a metal layer; (b.) etching through said sacrificial layer and said metal layer in a common pattern to form metal lines, while forming a sidewall coating on said sacrificial layer; (c.) at least partially removing said sacrificial layer, and causing said sidewall coating to curl laterally outward from the sides of said metal layer to form a partial or complete arch between adjacent ones of said metal lines; and (d.) depositing a dielectric layer overall to form air gaps between adjacent ones of said metal lines; whereby capacitive coupling between adjacent ones of said metal lines is reduced.
Claim 2
Dependent Claim
115 words
An integrated circuit metallization fabrication method, comprising the steps of: (a.) depositing a sacrificial metal layer atop a metal layer; (b.) etching through said sacrificial layer and said metal layer in a common pattern to form metal lines, while forming a sidewall coating on said sacrificial layer; (c.) at least partially removing said sacrificial layer, and causing said sidewall coating to curl laterally outward from the sides of said metal layer to form a partial or complete arch between adjacent ones of said metal lines; and (d.) depositing a dielectric layer overall to form air gaps between adjacent ones of said metal lines; whereby capacitive coupling between adjacent ones of said metal lines is reduced.
Claim 3
Dependent Claim
12 words
The method of claim 1, wherein said sidewall coating is an insulator.
Claim 4
Dependent Claim
26 words
The method of claim 1, wherein said metal is aluminum, and said step of etching is performed using a source gas containing boron, nitrogen and chlorine.
Claim 5
Dependent Claim
29 words
The method of claim 1, wherein said step of removing said sacrificial layer and causing said sidewall coating to curl is performed using a plasma etch and rinse processes.
Claim 6
Independent Claim
170 words
A method of forming air gaps within an integrated circuit structure, comprising the steps of: (a.) providing a partially fabricated integrated circuit structure, and depositing a metal layer thereon; (b.) depositing a sacrificial metal layer atop said metal layer, said sacrificial layer being composed of the same material as said metal layer, said sacrificial layer and said metal layer being separated by an etch stop; (c.) etching through said sacrificial layer and said metal layer in selected locations to form metal lines, while forming an insulating sidewall coating on said sacrificial layer and said metal layer; (d.) at least partially removing said sacrificial layer, and causing said sidewall coating to curl laterally outward from the sides of said metal layer to form a partial or complete arch between adjacent ones of said metal lines; and (e.) depositing a dielectric layer overall to form a capping layer; whereby air gaps laterally separate adjacent ones of said metal lines to reduce the capacitive coupling between said adjacent ones of said metal lines.
Claim 7
Independent Claim
170 words
A method of forming air gaps within an integrated circuit structure, comprising the steps of: (a.) providing a partially fabricated integrated circuit structure, and depositing a metal layer thereon; (b.) depositing a sacrificial metal layer atop said metal layer, said sacrificial layer being composed of the same material as said metal layer, said sacrificial layer and said metal layer being separated by an etch stop; (c.) etching through said sacrificial layer and said metal layer in selected locations to form metal lines, while forming an insulating sidewall coating on said sacrificial layer and said metal layer; (d.) at least partially removing said sacrificial layer, and causing said sidewall coating to curl laterally outward from the sides of said metal layer to form a partial or complete arch between adjacent ones of said metal lines; and (e.) depositing a dielectric layer overall to form a capping layer; whereby air gaps laterally separate adjacent ones of said metal lines to reduce the capacitive coupling between said adjacent ones of said metal lines.
Claim 8
Dependent Claim
26 words
The method of claim 5, wherein said metal is aluminum, and said step of etching is performed using a source gas containing boron, nitrogen and chlorine.
Claim 9
Dependent Claim
29 words
The method of claim 5, wherein said step of removing said sacrificial layer and causing said sidewall coating to curl is performed using a plasma etch and rinse process.
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) | 2002-03-08 | 2002-09-07 | 2003-03-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-03-08 | 2006-09-07 | 2007-03-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-03-08 | 2010-09-07 | 2011-03-09 | $7700.00 | Window Closed / Lapsed |