US5525191A
Expired / Lapsed
US
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Process for polishing a semiconductor substrate
Assignee: NXP USA Inc
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Filing: 1994-07-25
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Granted: 1996-06-11
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Expires: 2014-07-25
Abstract
Abstract The selection of pH, the polishing slurry, and types of polishing particles within a polishing slurry are chosen, so that polishing product is capable of coating onto the polishing particles. More specifically, the pH of the polishing slurry is selected to be between the iso-electric points of the polishing product and the particles within the polishing slurry. More than one type of material may be used within a polishing slurry. Particles of one material may do most of the polishing, while the particles of the other material become coated with polishing product and aid in transporting it away from the substrate.
Inventors
- 👤 Papu D. Maniar
- 👤 Chris C. Yu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 00:48
CPC Classifications
C; C09; C09G; C09G1/00; C09G1/02; B; B24; B24B; B24B37/00; B24B37/04; B24B37/042; B24B37/044
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
85 words
A process for polishing a layer over a semiconductor substrate comprising the steps of: forming the layer over the substrate; and polishing the layer with a slurry including first particles and second particles, wherein: the first particles include magnesium oxide; the second particles are selected from a group consisting of silica, alumina, cerium dioxide, cerium trioxide, and zirconium dioxide; each of the first particles is smaller than each of the second particles; and the step of polishing forms a polishing product that includes silicon dioxide.
Claim 2
Dependent Claim
85 words
A process for polishing a layer over a semiconductor substrate comprising the steps of: forming the layer over the substrate; and polishing the layer with a slurry including first particles and second particles, wherein: the first particles include magnesium oxide; the second particles are selected from a group consisting of silica, alumina, cerium dioxide, cerium trioxide, and zirconium dioxide; each of the first particles is smaller than each of the second particles; and the step of polishing forms a polishing product that includes silicon dioxide.
Claim 3
Dependent Claim
17 words
The process of claim 1, wherein each of the first particles are softer than the second particles.
Claim 4
Dependent Claim
18 words
The process of claim 1, wherein the slurry has a pH higher than 2.2 and lower than 12.4.
Claim 5
Dependent Claim
153 words
A process for polishing a semiconductor substrate comprising the steps of: placing the substrate into a polisher; and polishing the substrate with a slurry including first particles and second particles, wherein: the substrate includes a semiconductor material; the polishing step has a beginning, and at the beginning, the semiconductor material contacts the slurry; the first particles include a material having a first iso-electric point; the second particles include a material having a second iso-electric point that is different from the first iso-electric point; each of the first particles is smaller than each of the second particles; the step of polishing forms a polishing product having a third iso-electric point that is different from the first iso-electric point; the slurry has a pH that is between the first and third iso-electric points; and the first iso-electric point is higher than the second iso-electric point, the third iso-electric point, and the pH of the slurry.
Claim 6
Dependent Claim
153 words
A process for polishing a semiconductor substrate comprising the steps of: placing the substrate into a polisher; and polishing the substrate with a slurry including first particles and second particles, wherein: the substrate includes a semiconductor material; the polishing step has a beginning, and at the beginning, the semiconductor material contacts the slurry; the first particles include a material having a first iso-electric point; the second particles include a material having a second iso-electric point that is different from the first iso-electric point; each of the first particles is smaller than each of the second particles; the step of polishing forms a polishing product having a third iso-electric point that is different from the first iso-electric point; the slurry has a pH that is between the first and third iso-electric points; and the first iso-electric point is higher than the second iso-electric point, the third iso-electric point, and the pH of the slurry.
Claim 7
Dependent Claim
19 words
The process of claim 4, wherein the semiconductor material is selected from a group consisting of silicon and germanium.
Claim 8
Dependent Claim
45 words
The process of claim 4, wherein: the second particles include a material selected from a group consisting of magnesium oxide, cerium trioxide, and zirconium monoxide; the polishing product includes silicon dioxide; and the slurry has a pH higher than 2.2 and no higher than 10.0.
Claim 9
Dependent Claim
63 words
A process for polishing a layer over a semiconductor substrate comprising the steps of: forming the layer over the substrate; and polishing the layer with a slurry including first particles and second particles, wherein: the first particles includes a first material; the second particles include a nitride; and each of the first particles is smaller and softer than each of the second particles.
Claim 10
Dependent Claim
63 words
A process for polishing a layer over a semiconductor substrate comprising the steps of: forming the layer over the substrate; and polishing the layer with a slurry including first particles and second particles, wherein: the first particles includes a first material; the second particles include a nitride; and each of the first particles is smaller and softer than each of the second particles.
Claim 11
Dependent Claim
25 words
The process of claim 7, wherein: the first particles include magnesium oxide; and the step of polishing forms a polishing product that includes silicon dioxide.
Claim 12
Dependent Claim
18 words
The process of claim 8, wherein the slurry has a pH higher than 2.2 and lower than 12.4.
Claim 13
Dependent Claim
135 words
A process for polishing a layer over a semiconductor substrate comprising the steps of: forming the layer over the substrate; and polishing the layer with a slurry including first particles and second particles wherein: the first particles include magnesium oxide and has an iso-electric point; the second particles include silica and has an iso-electric point; each of the first particles is smaller and softer than each of the second particles; the step of polishing forms a polishing product that includes silicon dioxide and has an iso-electric point that is different from the iso-electric point of the magnesium oxide; the iso-electric point of the silica is a same as the iso-electric point of the polishing product; and the slurry has a pH that is between the iso-electric points of the magnesium oxide and the polishing product.
Claim 14
Dependent Claim
135 words
A process for polishing a layer over a semiconductor substrate comprising the steps of: forming the layer over the substrate; and polishing the layer with a slurry including first particles and second particles wherein: the first particles include magnesium oxide and has an iso-electric point; the second particles include silica and has an iso-electric point; each of the first particles is smaller and softer than each of the second particles; the step of polishing forms a polishing product that includes silicon dioxide and has an iso-electric point that is different from the iso-electric point of the magnesium oxide; the iso-electric point of the silica is a same as the iso-electric point of the polishing product; and the slurry has a pH that is between the iso-electric points of the magnesium oxide and the polishing product.
Claim 15
Dependent Claim
18 words
The process of claim 10, wherein the slurry has a pH higher than 2.2 and lower than 12.4.
Claim 16
Dependent Claim
44 words
The process of claim 1, wherein the step of polishing forms a polishing product, and wherein first particles have an iso-electric point higher than an iso-electric point of the second particles, an iso-electric point of the polishing product, and a pH of the slurry.
Claim 17
Dependent Claim
17 words
The process of claim 4, wherein each of the first particles is softer than the second particles.
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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) | 1999-06-11 | 1999-12-11 | 2000-06-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-06-11 | 2003-12-11 | 2004-06-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-06-11 | 2007-12-11 | 2008-06-11 | $7700.00 | Window Closed / Lapsed |