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US5259888A
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Process for cleaning quartz and silicon surfaces
Assignee: Sachem Inc
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Filing: 1992-02-03
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Granted: 1993-11-09
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Expires: 2012-02-03
Abstract
Abstract A process for cleaning quartz and silicon surfaces by removing inorganic substances from said surfaces which comprises contacting the surface to be cleaned with a liquid at a temperature and for a period of time effective to remove said substances from the surface, said liquid comprising a solution in a solvent of at least one quaternary ammonium hydroxide characterized by the formula ##STR1## wherein R 1 , R 2 , R 3 and R 4 are each independently alkyl groups containing from 1 to about 10 carbon atoms, aryl groups, or R 1 and R 2 are alkylene groups which together with the nitrogen atom may form an aromatic or non-aromatic heterocyclic ring provided that if the heterocyclic group contains a --C═N-- bond, R 3 is the second bond.
Inventors
- 👤 Scott I. McCoy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:46
CPC Classifications
H; H10; H10P; H10P72/00; H10P72/04; H10P72/0402; H10P72/0406; H10P72/0411; H10P72/0416; C; C11; C11D; C11D3/00; C11D3/16; C11D3/26; C11D3/30; H10P72/0414
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
129 words
A process for cleaning quartz and silicon surfaces by removing inorganic substances from said surfaces which comprises contacting the surface to be cleaned with a liquid at a temperature and for a period of time effective to remove the substances from the surface, said liquid comprising a solution in a solvent of at least one quaternary ammonium hydroxide characterized by the formula ##STR7## wherein R 1 , R 2 , R 3 and R 4 are each independently alkyl groups containing from 1 to about 10 carbon atoms, aryl groups, or R 1 and R 2 are alkylene groups which together with the nitrogen atom may form an aromatic or non-aromatic heterocyclic ring provided that if the heterocyclic group contains a --C═N-- bond, R 3 is the second bond.
Claim 2
Dependent Claim
129 words
A process for cleaning quartz and silicon surfaces by removing inorganic substances from said surfaces which comprises contacting the surface to be cleaned with a liquid at a temperature and for a period of time effective to remove the substances from the surface, said liquid comprising a solution in a solvent of at least one quaternary ammonium hydroxide characterized by the formula ##STR7## wherein R 1 , R 2 , R 3 and R 4 are each independently alkyl groups containing from 1 to about 10 carbon atoms, aryl groups, or R 1 and R 2 are alkylene groups which together with the nitrogen atom may form an aromatic or non-aromatic heterocyclic ring provided that if the heterocyclic group contains a --C═N-- bond, R 3 is the second bond.
Claim 3
Dependent Claim
26 words
The process of claim 1 wherein the surface to be cleaned is contacted with the solution at a temperature of from at least about 50° C.
Claim 4
Dependent Claim
27 words
The process of claim 1 wherein the surface to be cleaned is contacted with the solution at a temperature of from about 50° to about 95° C.
Claim 5
Dependent Claim
27 words
The process of claim 1 wherein the surface to be cleaned is contacted with the solution at a temperature of from about 70° to about 95° C.
Claim 6
Dependent Claim
28 words
The process of claim 1 wherein R 1 , R 2 , R 3 and R 4 are alkyl groups containing from 1 to about 10 carbon atoms.
Claim 7
Dependent Claim
27 words
The process of claim 1 wherein R 1 , R 2 , R 3 and R 4 are alkyl groups containing from 1 to 4 carbon atoms.
Claim 8
Dependent Claim
22 words
The process of claim 1 wherein R 1 , R 2 , R 3 and R 4 are methyl or ethyl groups.
Claim 9
Dependent Claim
24 words
The process of claim 1 wherein the solution comprises water and from about 0.1% to about 60% by weight of the quaternary ammonium hydroxide.
Claim 10
Dependent Claim
24 words
The process of claim 1 wherein the solution comprises water and from about 5% to about 40% by weight of the quaternary ammonium hydroxide.
Claim 11
Dependent Claim
24 words
The process of claim 1 wherein the solution comprises water and from about 10% to about 15% by weight of the quaternary ammonium hydroxide.
Claim 12
Dependent Claim
15 words
The process of claim 1 wherein the solution also contains at least one supplemental surfactant.
Claim 13
Dependent Claim
25 words
The process of claim 1 wherein the solution comprises an alcohol and from about 0.1 to about 60% by weight of the quaternary ammonium hydroxide.
Claim 14
Dependent Claim
11 words
The process of claim 1 wherein the inorganic substance is polysilicon.
Claim 15
Dependent Claim
95 words
A process for cleaning quartz and silicon surfaces by removing inorganic substances from said surface which comprises contacting the surface to be cleaned with an aqueous solution at a temperature and for a period of time effective to remove said substances from the surface, said aqueous solution comprising water and from about 5 to about 40% by weight of at least one quaternary ammonium hydroxide characterized by the formula ##STR8## wherein R 1 , R 2 , R 3 and R 4 are each independently alkyl groups containing from 1 to about 10 carbon atoms.
Claim 16
Dependent Claim
95 words
A process for cleaning quartz and silicon surfaces by removing inorganic substances from said surface which comprises contacting the surface to be cleaned with an aqueous solution at a temperature and for a period of time effective to remove said substances from the surface, said aqueous solution comprising water and from about 5 to about 40% by weight of at least one quaternary ammonium hydroxide characterized by the formula ##STR8## wherein R 1 , R 2 , R 3 and R 4 are each independently alkyl groups containing from 1 to about 10 carbon atoms.
Claim 17
Dependent Claim
24 words
The process of claim 14 wherein R 1 , R 2 , R 3 and R 4 are each independently methyl or ethyl groups.
Claim 18
Dependent Claim
20 words
The process of claim 14 wherein R 1 , R 2 , R 3 and R 4 are methyl groups.
Claim 19
Dependent Claim
21 words
The process of claim 14 wherein the surface to be cleaned is contacted with the aqueous solution by spraying or immersion.
Claim 20
Dependent Claim
12 words
The process of claim 14 wherein the inorganic substance is a polysilicon.
Claim 21
Dependent Claim
59 words
The process of claim 14 wherein the inorganic substances comprises poly-silicon and silica and the surfaces containing said substances are precleaned by contacting the surfaces with a dilute aqueous mineral acid containing from about 0.1 to 5% of the mineral acid to remove silica, and thereafter contacted with the aqueous solution comprising the quaternary ammonium hydroxide to remove polysilicon.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1996-11-08 | 1997-05-10 | 1997-11-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-11-08 | 2001-05-10 | 2001-11-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-11-08 | 2005-05-10 | 2005-11-09 | $7700.00 | Window Closed / Lapsed |