US5731245A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High aspect ratio low resistivity lines/vias with a tungsten-germanium alloy hard cap
Assignee: GlobalFoundries Inc
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Filing: 1996-10-28
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Granted: 1998-03-24
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Expires: 2016-10-28
Abstract
Abstract A structure and method for fabricating circuits which use field effect transistors (FETs), bipolar transistors, or BiCMOS (combined Bipolar/Complementary Metal Oxide Silicon structures), uses low temperature germanium gas flow to affect metals and alloys deposited in high aspect ratio structures including lines and vias. By using a germanium gas flow, germanium (Ge) will be introduced in a surface reaction which prevents voids and side seams and which also provides a passivating layer of CuGe. If a hard cap is needed for surface passivation or a wear-resistance application, the GeH4 gas followed by WF6 can be used to produce an in-situ hard cap and polish stop of WxGey, a tungsten-germanium alloy. Further, high aspect ratio vias/lines (aspect ratio of 3 or more) can be filled by utilizing low pressures and high temperatures (i.e., below 450 DEG C.) without degrading the underlying metals.
Inventors
- 👤 Rajiv Vasant Joshi
- 👤 Manu Jamnadas Tejwani
- 👤 Kris Venkatraman Srikrishnan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 13:55
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/01; H10W20/031; H10W20/032; H10W20/033; H10W20/037; H10P; H10P52/00; H10P52/40; H10P52/403; H10P95/00; H10W20/055; H10W20/056; H10W20/064; H10W20/071; H10W20/081; H10W20/084; H10W20/40; H10W20/41; H10W20/42; H10W20/44; H10W20/4403; H10W20/4405; H10W20/4407; H10W20/4432; H10W20/4435; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12486; Y10T428/12493; Y10T428/12528; Y10T428/12674; Y10T428/12736; Y10T428/12771; Y10T428/12806; Y10T428/12826; Y10T428/1284; Y10T428/12861; Y10T428/12889; Y10T428/12896
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
102 words
A method of creating one of a dual damascene and a damascene structure in combination with reactive ion etching, on a substrate on which a stack is fabricated, said stack including a low resistivity metal layer including one of Al, Cu, Al--Cu, Al--Cu--Ge, and Al--Ge having a hardness, said method comprising the steps of: removing said low resistivity metal layer having said hardness, by chemical and mechanical polishing using slurries having a hardness at least twice that of said low resistivity metal layer to be removed wherein said low resistivity metal layer has a hard cap comprising a tungsten and germanium alloy.
Claim 2
Independent Claim
102 words
A method of creating one of a dual damascene and a damascene structure in combination with reactive ion etching, on a substrate on which a stack is fabricated, said stack including a low resistivity metal layer including one of Al, Cu, Al--Cu, Al--Cu--Ge, and Al--Ge having a hardness, said method comprising the steps of: removing said low resistivity metal layer having said hardness, by chemical and mechanical polishing using slurries having a hardness at least twice that of said low resistivity metal layer to be removed wherein said low resistivity metal layer has a hard cap comprising a tungsten and germanium alloy.
Claim 3
Dependent Claim
26 words
A method according to claim 1, wherein said slurry hardness is two to three times as hard as said low resistivity metal layer to be removed.
Claim 4
Independent Claim
98 words
A method of creating one of a dual damascene and a damascene structure in combination with reactive ion etching, on a substrate on which a stack is fabricated, said stack including a metal layer having a hardness, said method comprising the steps of: removing said metal layer having said hardness, by chemical and mechanical polishing using slurries having a hardness at least twice that of said metal layer to be removed, wherein said metal layer has a hard cap comprising a tungsten-germanium alloy and said step of removing including chemical and mechanical polishing employing a slurry including alumina.
Claim 5
Independent Claim
98 words
A method of creating one of a dual damascene and a damascene structure in combination with reactive ion etching, on a substrate on which a stack is fabricated, said stack including a metal layer having a hardness, said method comprising the steps of: removing said metal layer having said hardness, by chemical and mechanical polishing using slurries having a hardness at least twice that of said metal layer to be removed, wherein said metal layer has a hard cap comprising a tungsten-germanium alloy and said step of removing including chemical and mechanical polishing employing a slurry including alumina.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-03-23 | 2001-09-22 | 2002-03-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-03-23 | 2005-09-22 | 2006-03-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-03-23 | 2009-09-22 | 2010-03-24 | $7700.00 | Window Closed / Lapsed |