Patent US5049200A successfully refreshed from Google Patents.
US5049200A
Expired / Lapsed
US
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Process for the hydrophilizing and/or cement-residue-removing surface treatment of silicon wafers
Assignee: Siltronic AG
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Filing: 1988-10-05
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Granted: 1991-09-17
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Expires: 2008-10-05
Abstract
Abstract Silicon wafers can be provided with a hydrophilic surface and/or freed of adhering cement residues originating from the polishing operation with the aid of solutions adjusted to a pH of 8 to 14 with the aid of alkali-metal or alkaline-earth-metal compounds and containing hydrogen peroxide. These processes can even be carried out at room temperature and are remarkable for their low chemical consumption and easy manageability.
Inventors
- 👤 Roland Brunner
- 👤 Susanne Bauer-Mayer
- 👤 Rudolf Griesshammer
- 👤 Helmut Kirschner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 16:07
CPC Classifications
H; H10; H10P; H10P70/00; H10P70/10; H10P70/15
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
102 words
A process for the surface treatment of silicon wafers by utilizing alkaline aqueous solutions containing hydrogen peroxide, wherein the treatment effects a result which is selected from the group consisting of hydrophilizing by means of surface oxidation, cement-residue-removal, and a combination thereof, which process comprises the step of: contacting said wafer with at least one aqueous solution having a minimum content of 0.1% by weight of hydrogen peroxide and adjusted to a pH of 8-14 with the aid of at least one salt of the alkali metals or alkaline-earth metals formed with weak acids, to produce said treatment on the wafer surface.
Claim 2
Dependent Claim
102 words
A process for the surface treatment of silicon wafers by utilizing alkaline aqueous solutions containing hydrogen peroxide, wherein the treatment effects a result which is selected from the group consisting of hydrophilizing by means of surface oxidation, cement-residue-removal, and a combination thereof, which process comprises the step of: contacting said wafer with at least one aqueous solution having a minimum content of 0.1% by weight of hydrogen peroxide and adjusted to a pH of 8-14 with the aid of at least one salt of the alkali metals or alkaline-earth metals formed with weak acids, to produce said treatment on the wafer surface.
Claim 3
Dependent Claim
18 words
The process as claimed in claim 1, wherein the pH of the aqueous solution is adjusted to 9-12.
Claim 4
Dependent Claim
19 words
The process as claimed in claim 1, wherein alkali-metal salts of carbon-containing acids are used to adjust the pH.
Claim 5
Dependent Claim
56 words
The process as claimed in claim 3, wherein a member selected from the group consisting of potassium salts of carbonic acid, sodium salts of carbonic acid, potassium salts of acetic acid, sodium salts of acetic acid, potassium salts of citric acid, sodium salts of citric acid, and a combination thereof is used to adjust the pH.
Claim 6
Dependent Claim
20 words
The process as claimed in claim 1, wherein the solution is held at a temperature of 15 to 40° C.
Claim 7
Dependent Claim
30 words
The process as claimed in claim 1, wherein the concentration of the compounds of the alkali or alkaline-earth metals in the solution is adjusted to 0.1 to 10% by weight.
Claim 8
Dependent Claim
31 words
The process as claimed in claim 1, wherein the silicon wafers are contacted with a solution containing hydrofluoric acid before contacting the wafer surface with said at least one aqueous solution.
Claim 9
Dependent Claim
46 words
The process as claimed in claim 1, wherein the hydrophilizing is carried out in a first step by contacting the wafer surface with aqueous solution and the cement-residue removing is carried out in a second step by contacting the wafer surface with said alkaline aqueous solution.
Claim 10
Dependent Claim
118 words
A process for the surface treatment of silicon wafers by utilizing alkaline aqueous solutions containing hydrogen peroxide, wherein the treatment effects a result which is selected from the group consisting of hydrophilizing by means of surface oxidation, cement-residue-removal, and a combination thereof, which process consists essentially of the steps of: contacting said wafer with at least one aqueous solution consisting essentially of a minimum content of 0.1% by weight of hydrogen peroxide and adjusted to a pH of 8-14 with the aid of at least one salt of the alkaline metals or alkaline-earth metals formed with weak acids, to produce said treatment on the wafer surface; and holding the solution at a temperature of 15 to 40° C.
Claim 11
Dependent Claim
118 words
A process for the surface treatment of silicon wafers by utilizing alkaline aqueous solutions containing hydrogen peroxide, wherein the treatment effects a result which is selected from the group consisting of hydrophilizing by means of surface oxidation, cement-residue-removal, and a combination thereof, which process consists essentially of the steps of: contacting said wafer with at least one aqueous solution consisting essentially of a minimum content of 0.1% by weight of hydrogen peroxide and adjusted to a pH of 8-14 with the aid of at least one salt of the alkaline metals or alkaline-earth metals formed with weak acids, to produce said treatment on the wafer surface; and holding the solution at a temperature of 15 to 40° C.
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) | 1994-09-16 | 1995-03-18 | 1995-09-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-09-16 | 1999-03-18 | 1999-09-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-09-16 | 2003-03-18 | 2003-09-17 | $7700.00 | Window Closed / Lapsed |