US5644221A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Endpoint detection for chemical mechanical polishing using frequency or amplitude mode
Assignee: Ebara Corp
•
Filing: 1996-03-19
•
Granted: 1997-07-01
•
Expires: 2016-03-19
Abstract
Abstract A method and apparatus for endpoint detection in removal of a film from a semiconductor wafer is provided, with a sensor for creating a signal responsive to the film removal process, a positive feedback amplifier coupled to the sensor, the positive feedback amplifier having a mode selector, and an analyzer coupled to the positive feedback amplifier.
Inventors
- 👤 Leping Li
- 👤 Steven George Barbee
- 👤 Arnold Halperin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 18:26
CPC Classifications
G; G01; G01B; G01B7/00; G01B7/02; G01B7/06; G01B7/10; G01B7/105
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
52 words
An apparatus for endpoint detection in removal of a film from a semiconductor wafer, comprising: a sensor for creating a signal responsive to the film removal process; a positive feedback amplifier coupled to the sensor, the positive feedback amplifier having a mode selector; and an analyzer coupled to the positive feedback amplifier.
Claim 2
Independent Claim
52 words
An apparatus for endpoint detection in removal of a film from a semiconductor wafer, comprising: a sensor for creating a signal responsive to the film removal process; a positive feedback amplifier coupled to the sensor, the positive feedback amplifier having a mode selector; and an analyzer coupled to the positive feedback amplifier.
Claim 3
Dependent Claim
14 words
The apparatus of claim 1 wherein the sensor comprises a capacitor and an inductor.
Claim 4
Dependent Claim
17 words
The apparatus of claim 1 wherein the mode selector comprises means for selecting operation in frequency mode.
Claim 5
Dependent Claim
19 words
The apparatus of claim 3 further comprising a filter means coupled between the positive feedback amplifier and the analyzer.
Claim 6
Dependent Claim
13 words
The apparatus of claim 4 wherein the filter means comprises a multi-order filter.
Claim 7
Dependent Claim
13 words
The apparatus of claim 5 wherein the analyzer means comprises a frequency counter.
Claim 8
Dependent Claim
18 words
The apparatus of claim 1 wherein the mode selector comprises means for selecting operation in automatic amplitude mode.
Claim 9
Dependent Claim
37 words
The apparatus of claim 7 wherein the mode selector comprises means for automatically selecting the gain of the positive feedback amplifier and sensor so that an oscillation is produced when the film is removed from the wafer.
Claim 10
Dependent Claim
22 words
The apparatus of claim 8 wherein the means for selecting the gain comprises means for automatically setting a voltage on a varactor.
Claim 11
Dependent Claim
13 words
The apparatus of claim 1 wherein the film is removed by chemical-mechanical polishing.
Claim 12
Independent Claim
63 words
A method for in-situ monitoring of removal of a film from a semiconductor wafer, comprising the steps of: creating a signal responsive to removal of the film from the wafer; amplifying the signal with a positive feedback amplifier coupled to the sensor, the positive feedback amplifier having a mode selector; and analyzing the signal with an analyzer coupled to the positive feedback amplifier.
Claim 13
Independent Claim
63 words
A method for in-situ monitoring of removal of a film from a semiconductor wafer, comprising the steps of: creating a signal responsive to removal of the film from the wafer; amplifying the signal with a positive feedback amplifier coupled to the sensor, the positive feedback amplifier having a mode selector; and analyzing the signal with an analyzer coupled to the positive feedback amplifier.
Claim 14
Dependent Claim
15 words
The method of claim 11 further comprising the step of selecting operation in frequency mode.
Claim 15
Dependent Claim
21 words
The method of claim 12 further comprising the step of filtering the signal between the positive feedback amplifier and the analyzer.
Claim 16
Dependent Claim
15 words
The method of claim 13 wherein the filtered signal is analyzed with a frequency counter.
Claim 17
Dependent Claim
16 words
The method of claim 11 further comprising the step of selecting operation in automatic amplitude mode.
Claim 18
Dependent Claim
31 words
The method of claim 15 further comprising selecting the gain of the positive feedback amplifier and sensor so that an oscillation is produced when the film is removed from the wafer.
Claim 19
Dependent Claim
18 words
The method of claim 16 wherein the gain is set by automatically setting a voltage on a varactor.
Claim 20
Dependent Claim
13 words
The method of claim 11 wherein the film is removed by chemical-mechanical polishing.
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) | 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 |