US5562530A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pulsed-force chemical mechanical polishing
Assignee: State University of New York Polytechnic Institute
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Filing: 1994-08-02
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Granted: 1996-10-08
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Expires: 2014-08-02
Abstract
Abstract A pulsed-force CMP scheme allows for the down force holding a wafer onto a pad to cycle periodically between minimum and maximum values. When the force is near its minimum value, slurry flows into the space between the wafer and the pad. When the force is near its maximum value, slurry is squeezed out allowing for the abrasive action of the pad surface to erode wafer surface features.
Inventors
- 👤 Scott Runnels
- 👤 L. Michael Eyman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 08:57
CPC Classifications
B; B24; B24B; B24B37/00; B24B37/04; B24B37/07; B24B37/10; B24B37/102; B24B1/00; B24B1/04
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
235 words
A method of polishing a surface by exerting a pulsed force directed substantially normal to said surface in combination with an abrasive motion directed across said surface to erode material from said surface, comprising the steps of: placing said surface adjacent to an abrasive pad; flowing a hydrodynamic layer of chemical slurry between said surface and said abrasive pad; moving said surface relative to said abrasive pad in order to provide a mechanical motion between said surface and said abrasive pad for exertion of said abrasive motion across said surface; providing a force directed substantially normal to said surface in order to press said surface against said abrasive pad; pulsing said force at a set rate in order to vary said force being exerted on said surface by said abrasive pad; wherein during periods of maximal force, said slurry is squeezed out from between said surface and said pad in order for said pad to abrasively remove said material; and during periods of minimal force, said slurry is replenished between said surface and said pad, but in order to permit said slurry to flow between said surface and said pad during periods of minimal force, said set rate must be of sufficiently low frequency so that ample time is available for slurry flow onto said surface before slurry is squeezed out from between said surface and said pad again during subsequent period of maximal force.
Claim 2
Independent Claim
235 words
A method of polishing a surface by exerting a pulsed force directed substantially normal to said surface in combination with an abrasive motion directed across said surface to erode material from said surface, comprising the steps of: placing said surface adjacent to an abrasive pad; flowing a hydrodynamic layer of chemical slurry between said surface and said abrasive pad; moving said surface relative to said abrasive pad in order to provide a mechanical motion between said surface and said abrasive pad for exertion of said abrasive motion across said surface; providing a force directed substantially normal to said surface in order to press said surface against said abrasive pad; pulsing said force at a set rate in order to vary said force being exerted on said surface by said abrasive pad; wherein during periods of maximal force, said slurry is squeezed out from between said surface and said pad in order for said pad to abrasively remove said material; and during periods of minimal force, said slurry is replenished between said surface and said pad, but in order to permit said slurry to flow between said surface and said pad during periods of minimal force, said set rate must be of sufficiently low frequency so that ample time is available for slurry flow onto said surface before slurry is squeezed out from between said surface and said pad again during subsequent period of maximal force.
Claim 3
Dependent Claim
32 words
The method of claim 1 wherein said force has a time-averaged value approximately equal to a constant force value which would be utilized, if said polishing is achieved without pulsing said force.
Claim 4
Dependent Claim
17 words
The method of claim 2 wherein said force is pulsed at a frequency of approximately 0.5-4 Hz.
Claim 5
Independent Claim
245 words
A method of polishing a surface of a semiconductor wafer by exerting a pulsed force directed substantially normal to said surface in combination with an abrasive motion directed across said surface to perform chemical-mechanical polishing for removing material from said surface, comprising the steps of: placing said surface adjacent to an abrasive pad; flowing a hydrodynamic layer of chemical slurry between said surface and said abrasive pad; moving said surface relative to said abrasive pad in order to provide a mechanical motion between said wafer surface and said abrasive pad for exertion of said abrasive motion across said surface; providing a force directed substantially normal to said surface in order to press said surface against said abrasive pad; pulsing said force at a set rate in order to vary said force being exerted on said surface by said abrasive pad; wherein during periods of maximal force, said slurry is squeezed out from between said surface and said pad in order for said pad to abrasively remove said material; and during periods of minimal force, said slurry is replenished between said wafer surface and said pad, but in order to permit said slurry to flow between said surface and said pad during periods of minimal force, said set rate must be of sufficiently low frequency so that ample time is available for slurry flow onto said surface before slurry is squeezed out from between said surface and said pad again during subsequent period of maximal force.
Claim 6
Independent Claim
245 words
A method of polishing a surface of a semiconductor wafer by exerting a pulsed force directed substantially normal to said surface in combination with an abrasive motion directed across said surface to perform chemical-mechanical polishing for removing material from said surface, comprising the steps of: placing said surface adjacent to an abrasive pad; flowing a hydrodynamic layer of chemical slurry between said surface and said abrasive pad; moving said surface relative to said abrasive pad in order to provide a mechanical motion between said wafer surface and said abrasive pad for exertion of said abrasive motion across said surface; providing a force directed substantially normal to said surface in order to press said surface against said abrasive pad; pulsing said force at a set rate in order to vary said force being exerted on said surface by said abrasive pad; wherein during periods of maximal force, said slurry is squeezed out from between said surface and said pad in order for said pad to abrasively remove said material; and during periods of minimal force, said slurry is replenished between said wafer surface and said pad, but in order to permit said slurry to flow between said surface and said pad during periods of minimal force, said set rate must be of sufficiently low frequency so that ample time is available for slurry flow onto said surface before slurry is squeezed out from between said surface and said pad again during subsequent period of maximal force.
Claim 7
Dependent Claim
17 words
The method of claim 4 wherein said force is pulsed at a frequency of approximately 0.5-4 Hz.
Claim 8
Dependent Claim
25 words
The method of claim 5 wherein said maximal force is approximately 9-12 pounds per square inch (p.s.i.), while said minimal force is approximately 2-3 p.s.i.
Claim 9
Independent Claim
278 words
An apparatus for polishing a surface of a semiconductor wafer by exerting a pulsed force directed substantially normal to said surface in combination with an abrasive directed across said surface to perform chemical-mechanical polishing for removing material from said surface comprising: a wafer carrier for retaining said wafer and in which said wafer surface to be polished is exposed; an abrasive pad disposed adjacent to said carrier and said wafer surface; a hydrodynamic layer of chemical slurry disposed between said wafer surface and said abrasive pad; said carrier being moved horizontally relative to said abrasive pad in order to provide a mechanical motion between said wafer surface and said abrasive pad for exertion of said abrasive motion across said wafer surface; said carrier being forced against said pad by a force exerted substantially normal to said wafer surface in order to press said wafer surface against said abrasive pad; said force being pulsed at a set rate in order to vary said force being exerted on said surface by said abrasive pad; wherein during periods of maximal force, said slurry is squeezed out from between said wafer surface and said pad in order for said pad to abrasively remove said material; and during periods of minimal force, said slurry is replenished between said wafer surface and said pad, but in order to permit said slurry to flow between said surface and said pad during periods of minimal force, said set rate must be of sufficiently low frequency so that ample time is available for slurry flow onto said surface before slurry is squeezed out from between said surface and said pad again during subsequent period of maximal force.
Claim 10
Independent Claim
278 words
An apparatus for polishing a surface of a semiconductor wafer by exerting a pulsed force directed substantially normal to said surface in combination with an abrasive directed across said surface to perform chemical-mechanical polishing for removing material from said surface comprising: a wafer carrier for retaining said wafer and in which said wafer surface to be polished is exposed; an abrasive pad disposed adjacent to said carrier and said wafer surface; a hydrodynamic layer of chemical slurry disposed between said wafer surface and said abrasive pad; said carrier being moved horizontally relative to said abrasive pad in order to provide a mechanical motion between said wafer surface and said abrasive pad for exertion of said abrasive motion across said wafer surface; said carrier being forced against said pad by a force exerted substantially normal to said wafer surface in order to press said wafer surface against said abrasive pad; said force being pulsed at a set rate in order to vary said force being exerted on said surface by said abrasive pad; wherein during periods of maximal force, said slurry is squeezed out from between said wafer surface and said pad in order for said pad to abrasively remove said material; and during periods of minimal force, said slurry is replenished between said wafer surface and said pad, but in order to permit said slurry to flow between said surface and said pad during periods of minimal force, said set rate must be of sufficiently low frequency so that ample time is available for slurry flow onto said surface before slurry is squeezed out from between said surface and said pad again during subsequent period of maximal force.
Claim 11
Dependent Claim
32 words
The apparatus of claim 7 wherein said force has a time-averaged value approximately equal to a constant force value which would be utilized, if said polishing is achieved without pulsing said force.
Claim 12
Dependent Claim
17 words
The apparatus of claim 7 wherein said force is pulsed at a frequency of approximately 0.5-4 Hz.
Claim 13
Dependent Claim
25 words
The apparatus of claim 9 wherein said maximal force is approximately 9-12 pounds per square inch (p.s.i.), while said minimal force is approximately 2-3 p.s.i.
References Cited (Backward Citations)
US2922264A
Cited
US3436286A
Cited
US3629023A
Cited
US3748790A
Cited
GB1437934A
Cited
GB1443299A
Cited
US3979239A
Cited
US4141180A
Cited
US4193226A
Cited
US4240231A
Cited
US4244775A
Cited
US4270314A
Cited
US4519168A
Cited
US4256535A
Cited
US4319432A
Cited
US4373991A
Cited
US4448634A
Cited
US4435247A
Cited
US4600469A
Cited
US4805348A
Cited
US4645561A
Cited
US5040336A
Cited
US4927432A
Cited
US4720938A
Cited
US5099614A
Cited
JPS6362657A
Cited
JPS6362658A
Cited
JPS6362660A
Cited
JPS6362659A
Cited
US4842678A
Cited
US4841680A
Cited
US4916868A
Cited
US5097630A
Cited
US5032203A
Cited
US4954141A
Cited
US4826563A
Cited
US5096854A
Cited
US4860498A
Cited
US4879258A
Cited
US4910155A
Cited
US4974370A
Cited
US4959113A
Cited
US4959113C1
Cited
US5094037A
Cited
US4940507A
Cited
US5177908A
Cited
US5123218A
Cited
US5104828A
Cited
US5257478A
Cited
US5157876A
Cited
US5137544A
Cited
US5246525A
Cited
US5212910A
Cited
US5240552A
Cited
US5205082A
Cited
US5196353A
Cited
US5245790A
Cited
US5245796A
Cited
US5234867A
Cited
US5267418A
Cited
US5225034A
Cited
US5209816A
Cited
US5230182A
Cited
US5216843A
Cited
US5232875A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-10-08 | 2000-04-08 | 2000-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-10-08 | 2004-04-08 | 2004-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-10-08 | 2008-04-08 | 2008-10-08 | $7700.00 | Window Closed / Lapsed |