Patent US3840440A successfully refreshed from Google Patents.
US4886728A
Expired / Lapsed
US
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Use of particular mixtures of ethyl lactate and methyl ethyl ketone to remove undesirable peripheral material (e.g. edge beads) from photoresist-coated substrates
Assignee: Olin Microelectronic Chemicals Inc
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Filing: 1988-01-06
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Granted: 1989-12-12
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Expires: 2008-01-06
Abstract
Abstract A process for removing unwanted photoresist material from the peripheral areas of a photoresist substrate comprising the steps of: (a) spin coating a photoresist solution onto a surface of a substrate, thereby applying a photoresist coating which comprises a uniform film over substantially all of said substrate surface except for unwanted photoresist material deposits at the peripheral areas of said surface; (b) contacting said peripheral area of the coated substrate with a sufficient amount of a solvent mixture comprising a mixture of ethyl lactate and methyl ethyl ketone present in a volume ratio of about 65:35 to about 25:75, respectively, to selectively dissolve said unwanted deposits without adversely affecting said uniform film; and (c) separating said dissolved deposits from said coated substrate.
Inventors
- 👤 Thomas E. Salamy
- 👤 Marvin L. Love, Jr.
- 👤 Mark E. Towner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 18:44
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/76; G03F; G03F7/00; G03F7/16; G03F7/162
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
123 words
A process for removing unwanted photoresist material from the peripheral areas of a photoresist substrate comprising the steps of: (a) spin coating a photoresist solution onto a surface of a substrate, thereby applying a photoresist coating which comprises a uniform film over substantially all of said substrate surface except for unwanted photoresist material deposits at the peripheral areas of said surface; (b) contacting said peripheral areas of the coated substrate with a sufficient amount of a solvent mixture comprising a mixture of ethyl lactate and methyl ethyl ketone present in a volume ratio of about 65:35 to about 25:75, respectively, to selectively dissolve said unwanted deposits without adversely affecting said uniform film; and 1 (c) separating said dissolved deposits from said coated substrate.
Claim 2
Dependent Claim
123 words
A process for removing unwanted photoresist material from the peripheral areas of a photoresist substrate comprising the steps of: (a) spin coating a photoresist solution onto a surface of a substrate, thereby applying a photoresist coating which comprises a uniform film over substantially all of said substrate surface except for unwanted photoresist material deposits at the peripheral areas of said surface; (b) contacting said peripheral areas of the coated substrate with a sufficient amount of a solvent mixture comprising a mixture of ethyl lactate and methyl ethyl ketone present in a volume ratio of about 65:35 to about 25:75, respectively, to selectively dissolve said unwanted deposits without adversely affecting said uniform film; and 1 (c) separating said dissolved deposits from said coated substrate.
Claim 3
Dependent Claim
12 words
The process of claim 1 wherein said substrate is silicon oxide/silicon wafer.
Claim 4
Dependent Claim
23 words
The process of claim 1, wherein said photoresist solutions comprise a solution of a novolak resin and a naphthoquinone diazide photosensitizer in a
Claim 5
Dependent Claim
24 words
The process of claim 1 wherein said volume ratio of ethyl lactate to methyl ethyl ketone is from about 60:40 to about 40:60, respectively.
Claim 6
Dependent Claim
11 words
The process of claim 4 wherein said volume ratio is 50:50.
Claim 7
Dependent Claim
46 words
The process of claim 1 wherein said solvent contacting step (b) is carried out by directing said solvent mixture against the backside surface of said substrate periphery by means of a nozzle and allowing said solvent mixture to migrate over the peripheral edge of said substrate.
Claim 8
Dependent Claim
133 words
A process for removing unwanted photoresist material from the peripheral areas of a silicon oxide/silicon wafer comprising: (a) spin coating a photoresist solution comprising a novolak resin and a naphthoquinone diazide photosensitizer in a solvent onto the top surface of said wafer, thereby applying a photoresist coating which comprises a uniform film over substantially all of said wafer surface except for unwanted photoresist material deposits at the periperal areas of said wafer; (b) contacting said peripheral areas of the coated wafer with a sufficient amount of a solvent mixture comprising a mixture of ethyl lactate and methyl ethyl ketone present in a volume ratio of about 65:35 to about 25:75, respectively, to selectively dissolve said unwanted deposits without adversely affecting said uniform film; and (c) separating said dissolved deposits from said coated wafer.
Claim 9
Dependent Claim
133 words
A process for removing unwanted photoresist material from the peripheral areas of a silicon oxide/silicon wafer comprising: (a) spin coating a photoresist solution comprising a novolak resin and a naphthoquinone diazide photosensitizer in a solvent onto the top surface of said wafer, thereby applying a photoresist coating which comprises a uniform film over substantially all of said wafer surface except for unwanted photoresist material deposits at the periperal areas of said wafer; (b) contacting said peripheral areas of the coated wafer with a sufficient amount of a solvent mixture comprising a mixture of ethyl lactate and methyl ethyl ketone present in a volume ratio of about 65:35 to about 25:75, respectively, to selectively dissolve said unwanted deposits without adversely affecting said uniform film; and (c) separating said dissolved deposits from said coated wafer.
Claim 10
Dependent Claim
24 words
The process of claim 7 wherein said volume ratio of ethyl lactate to methyl ethyl ketone is from about 60:40 to about 40:60, respectively.
Claim 11
Dependent Claim
11 words
The process of claim 8 wherein said volume ratio is 50:50.
Claim 12
Dependent Claim
43 words
The process of claim 7 wherein said solvent contacting step (b) is carried out by directing said solvent mixture against the backside of said wafer by means of a nozzle and allowing the solvent mixture to migrate over the edge of the wafer.
Claim 13
Dependent Claim
16 words
The process of claim 7 wherein said novolak resin is a mixed isomer cresol/formaldehyde novolak resin.
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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) | 1992-12-11 | 1993-06-12 | 1993-12-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-12-11 | 1997-06-12 | 1997-12-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-12-11 | 2001-06-12 | 2001-12-12 | $7700.00 | Window Closed / Lapsed |