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US5595526A
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Method and apparatus for endpoint detection in a chemical/mechanical process for polishing a substrate
Assignee: Micron Technology Inc
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Filing: 1994-11-30
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Granted: 1997-01-21
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Expires: 2014-11-30
Abstract
Abstract A method for polishing the surface of a substrate that overcomes the problems inherent in the prior art. During the polishing of a substrate, a quantity is calculated which is approximately proportional to a share of the total energy the polisher is consuming. Once this calculated quantity reaches a predetermined amount, it is detected.
Inventors
- 👤 Leopoldo D. Yau
- 👤 Paul B. Fischer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 18:30
CPC Classifications
B; B24; B24B; B24B37/00; B24B37/005; B24B37/013; B24B37/04; B24B37/042
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
99 words
In a chemical/mechanical process for polishing a substrate, a method of endpoint detection comprising the steps of: (a) determining a target amount of energy needed by a polishing apparatus to produce a desired polishing result on the substrate; (b) providing an energy source to the polishing apparatus to commence the chemical/mechanical process; (c) calculating a total energy consumption by integrating over time an electrical parameter of the polishing apparatus that is approximately proportional to an instantaneous power consumed by the polishing apparatus; and (d) stopping the chemical/mechanical process when the total energy consumption equal the target amount of energy.
Claim 2
Dependent Claim
99 words
In a chemical/mechanical process for polishing a substrate, a method of endpoint detection comprising the steps of: (a) determining a target amount of energy needed by a polishing apparatus to produce a desired polishing result on the substrate; (b) providing an energy source to the polishing apparatus to commence the chemical/mechanical process; (c) calculating a total energy consumption by integrating over time an electrical parameter of the polishing apparatus that is approximately proportional to an instantaneous power consumed by the polishing apparatus; and (d) stopping the chemical/mechanical process when the total energy consumption equal the target amount of energy.
Claim 3
Dependent Claim
20 words
The method of claim 1 wherein the electrical parameter comprises a current supplied to a motor of the polishing apparatus.
Claim 4
Dependent Claim
26 words
The method of claim 1 wherein the electrical parameter comprises a voltage supplied to a motor of the polishing apparatus that utilizes a constant current source.
Claim 5
Dependent Claim
51 words
The method of claim 1 wherein step (c) comprises the steps of: performing measurements of the electrical parameter in a time period; integrating the measurements over the time period to produce a first energy quantity; subtracting an overhead energy contribution from the first energy quantity, resulting in the total energy consumption.
Claim 6
Dependent Claim
15 words
The method of claim 4 wherein the overhead energy contribution includes a chemical etch component.
Claim 7
Dependent Claim
24 words
The method of claim 1 wherein the desired polishing result is a planarized surface of a dielectric film disposed over a layer of interconnects.
Claim 8
Dependent Claim
96 words
In a chemical/mechanical process for polishing a semiconductor substrate, a method of endpoint detection comprising the steps of: (a) determining a target amount of energy needed by a polishing apparatus to produce a desired polishing result on the semiconductor substrate; (b) energizing a plurality of motors in the polishing apparatus to begin the chemical/mechanical process; (c) repeatedly performing parametric measurements to calculate a total energy consumed by the motors over a time period; (d) stopping the chemical/mechanical process when the total energy consumed by the motors over the time period equals the target amount of energy.
Claim 9
Dependent Claim
96 words
In a chemical/mechanical process for polishing a semiconductor substrate, a method of endpoint detection comprising the steps of: (a) determining a target amount of energy needed by a polishing apparatus to produce a desired polishing result on the semiconductor substrate; (b) energizing a plurality of motors in the polishing apparatus to begin the chemical/mechanical process; (c) repeatedly performing parametric measurements to calculate a total energy consumed by the motors over a time period; (d) stopping the chemical/mechanical process when the total energy consumed by the motors over the time period equals the target amount of energy.
Claim 10
Dependent Claim
32 words
The method of claim 7 wherein the plurality of motors includes a first motor that rotates a polishing surface, and a second motor that rotates the semiconductor substrate against the polishing surface.
Claim 11
Dependent Claim
21 words
The method of claim 8 wherein step (c) includes the step of: measuring a first current supplied to the first motor.
Claim 12
Dependent Claim
22 words
The method of claim 9 wherein step (c) further includes the step of: measuring a second current supplied to the second motor.
Claim 13
Dependent Claim
23 words
The method of claim 10 wherein step (c) further includes the step of: integrating the first and second currents over the time period.
Claim 14
Dependent Claim
23 words
The method of claim 10 wherein step (c) further includes the step of: subtracting an overhead energy contribution to the total energy consumed.
Claim 15
Dependent Claim
15 words
The method of claim 12 wherein the overhead energy contribution includes a chemical etch component.
Claim 16
Dependent Claim
24 words
The method of claim 7 wherein the desired polishing result is a planarized surface of a dielectric film disposed over a layer of interconnects.
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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) | 2000-01-21 | 2000-07-22 | 2001-01-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-01-21 | 2004-07-22 | 2005-01-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-01-21 | 2008-07-22 | 2009-01-21 | $7700.00 | Window Closed / Lapsed |