US5643044A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic chemical and mechanical polishing system for semiconductor wafers
Assignee: Individual
•
Filing: 1994-11-01
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Granted: 1997-07-01
•
Expires: 2014-11-01
Abstract
Abstract A system and method for chemically and mechanically polishing a semiconductor wafer having a substrate and a surface film. A wafer mounting device, which may include a vacuum chuck, holds the semiconductor wafer without requiring that the wafer have a central aperture. The mounting device and wafer are moved with an orbit-within-an-orbit motion while a tape transport mechanism applies an abrasive polishing tape to the surface film of the moving wafer to polish one surface of the wafer to a flatness of less than two microns. The system determines the thickness of the wafer surface film during the polishing process with a real time measurement device such as an ellipsometer, or by determining a work-performed factor and calculating an estimated film thickness from the work-performed factor. Finally, the system automatically controls the polishing process to stop polishing the semiconductor wafer when the wafer surface film achieves a predefined planarization.
Inventors
- 👤 Douglas E. Lund
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 02:28
CPC Classifications
B; B24; B24B; B24B37/00; B24B37/04; B24B37/07; B24B37/10; B24B37/105; B24B21/00; B24B37/005; B24B37/013; B24B49/00; B24B49/12
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
114 words
A method of polishing a semiconductor wafer having a substrate and a surface film, said method comprising the steps of: holding said semiconductor wafer without requiring that said wafer have a central aperture; polishing one surface of said wafer to a microscopically smooth surface; determining the thickness of said surface film, in real time, while polishing said wafer; and automatically controlling said polishing step with a control computer, said automatic controlling step including the steps of: providing measurements of said surface film thickness to said control computer in real time; and stopping said polishing step when the thickness of said surface film, averaged over the entire surface of said wafer, achieves a predefined value.
Claim 2
Independent Claim
114 words
A method of polishing a semiconductor wafer having a substrate and a surface film, said method comprising the steps of: holding said semiconductor wafer without requiring that said wafer have a central aperture; polishing one surface of said wafer to a microscopically smooth surface; determining the thickness of said surface film, in real time, while polishing said wafer; and automatically controlling said polishing step with a control computer, said automatic controlling step including the steps of: providing measurements of said surface film thickness to said control computer in real time; and stopping said polishing step when the thickness of said surface film, averaged over the entire surface of said wafer, achieves a predefined value.
Claim 3
Dependent Claim
35 words
The method of polishing a semiconductor wafer of claim 1 wherein said step of holding said semiconductor wafer without requiring that said wafer have a central aperture includes holding said wafer with a vacuum chuck.
Claim 4
Dependent Claim
60 words
The method of polishing a semiconductor wafer of claim 2 wherein said step of polishing one surface of said wafer to a microscopically smooth surface includes: mounting said wafer on a mounting mechanism; moving said mounting mechanism in an orbit-within-an-orbit motion; and applying an abrasive polishing tape to the surface film of the moving wafer with a tape transport mechanism.
Claim 5
Dependent Claim
39 words
The method of polishing a semiconductor wafer of claim 3 wherein said step of mounting said wafer on a mounting mechanism includes supplying a negative pressure of approximately 10 Torr to said vacuum chuck with a rotary vacuum mechanism.
Claim 6
Dependent Claim
35 words
The method of polishing a semiconductor wafer of claim 4 wherein said step of determining the thickness of said surface film, in real time, includes measuring the thickness of said surface film with an ellipsometer.
Claim 7
Dependent Claim
60 words
The method of polishing a semiconductor wafer of claim 1 wherein said step of polishing one surface of said wafer to a microscopically smooth surface includes: mounting said wafer on a mounting mechanism; moving said mounting mechanism in an orbit-within-an-orbit motion; and applying an abrasive polishing tape to the surface film of the moving wafer with a tape transport mechanism.
Claim 8
Dependent Claim
39 words
The method of polishing a semiconductor wafer of claim 1 wherein said step of mounting said wafer on a mounting mechanism includes supplying a negative pressure of approximately 10 Torr to said vacuum chuck with a rotary vacuum mechanism.
Claim 9
Dependent Claim
35 words
The method of polishing a semiconductor wafer of claim 1 wherein said step of determining the thickness of said surface film, in real time, includes measuring the thickness of said surface film with an ellipsometer.
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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) | 2000-06-30 | 2000-12-30 | 2001-07-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-06-30 | 2004-12-30 | 2005-07-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-06-30 | 2008-12-30 | 2009-07-01 | $7700.00 | Window Closed / Lapsed |