US5836805A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of forming planarized layers in an integrated circuit
Assignee: Nokia of America Corp
•
Filing: 1996-12-18
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Granted: 1998-11-17
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Expires: 2016-12-18
Abstract
Abstract A method of chemical mechanical polishing (CMP) useful in the manufacture of integrated circuits is disclosed. Waste slurry is examined and its conductivity, luminescence, or particulate mass evaluated to determine an endpoint for the CMP operation.
Inventors
- 👤 Yaw Samuel Obeng
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 17:14
CPC Classifications
B; B24; B24B; B24B37/00; B24B37/005; B24B37/013; H; H10; H10D; H10D62/00; H10D62/50; B24B49/00; B24B49/02; B24B49/10; B24B49/12
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
45 words
A method of polishing an integrated circuit comprising: polishing a wafer having an overlying layer of metal with a polishing slurry, said polishing producing a waste slurry; measuring the conductivity of said waste slurry; and terminating said polishing operation after said conductivity begins to decrease.
Claim 2
Independent Claim
45 words
A method of polishing an integrated circuit comprising: polishing a wafer having an overlying layer of metal with a polishing slurry, said polishing producing a waste slurry; measuring the conductivity of said waste slurry; and terminating said polishing operation after said conductivity begins to decrease.
Claim 3
Dependent Claim
47 words
The method of claim 1 in which said conductivity of said waste slurry has a decreasing slope as a function of time and in which at least a portion of said decreasing slope is extrapolated to determine the time at which said polishing is to be terminated.
Claim 4
Dependent Claim
26 words
The method of claim 1 in which said metal is chosen from the group consisting of tungsten, tungsten alloys; aluminum, aluminum-silicon; aluminum-silicon-copper, copper, and transition metals.
Claim 5
Dependent Claim
61 words
The method of claim 1 in which said metal layer has been formed in contact with a dielectric layer; said dielectric layer having vias therein, said metal covering said dielectric and filling said vias; and further in which said polishing operation is terminated where substantially all of said metal covering said dielectric has been removed; said metal still filling said vias.
References Cited (Backward Citations)
US5722875A
Cited
US5664990A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-11-16 | 2002-05-18 | 2002-11-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-11-16 | 2006-05-18 | 2006-11-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-11-16 | 2010-05-18 | 2010-11-17 | $7700.00 | Window Closed / Lapsed |