US5082755A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Liquid crystal programmable photoresist exposure method for making a set of masks
Assignee: General Electric Co
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Filing: 1990-12-17
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Granted: 1992-01-21
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Expires: 2010-12-17
Abstract
Abstract Photoresist layers are rapidly exposed in a pattern determined by electronically stored data by exposure of the photoresist through a high resolution liquid crystal shutter array.
Inventors
- 👤 Yung S. Liu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 19:49
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/70; G03F7/70216; G03F7/70283; G03F7/70291; H; H05; H05K; H05K3/00; H05K3/0073; H05K3/0082
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
173 words
A method for making a set of masks which includes a plurality of isolated mask regions intended for sequential exposure of a surface of a block of material, said method comprising: (a) providing a mask blank comprising a transmissive substrate, an opaque coating and a layer of photoresist over said coating; (b) aligning said mask blank with respect to a liquid crystal shutter array with one of said plurality of mask regions aligned with said liquid crystal shutter array; (c) rendering said liquid crystal shutter array optically transmissive in a pattern corresponding to the desired pattern for the particular mask region; (d) exposing said photoresist layer to activating illumination through said liquid crystal shutter array; (e) repeating steps b-d for each of the rest of said plurality of mask regions, with the desired pattern being different for at least some of said mask regions; and (f) developing said photoresist and removing unprotected portions of said opaque coating from said substrate to provide said set of masks comprising a plurality of isolated mask regions.
Claim 2
Independent Claim
173 words
A method for making a set of masks which includes a plurality of isolated mask regions intended for sequential exposure of a surface of a block of material, said method comprising: (a) providing a mask blank comprising a transmissive substrate, an opaque coating and a layer of photoresist over said coating; (b) aligning said mask blank with respect to a liquid crystal shutter array with one of said plurality of mask regions aligned with said liquid crystal shutter array; (c) rendering said liquid crystal shutter array optically transmissive in a pattern corresponding to the desired pattern for the particular mask region; (d) exposing said photoresist layer to activating illumination through said liquid crystal shutter array; (e) repeating steps b-d for each of the rest of said plurality of mask regions, with the desired pattern being different for at least some of said mask regions; and (f) developing said photoresist and removing unprotected portions of said opaque coating from said substrate to provide said set of masks comprising a plurality of isolated mask regions.
Claim 3
Dependent Claim
34 words
The method recited in claim 1 wherein said photoresist is a positive photoresist and said liquid crystal display is rendered transmissive in the pattern in which transmissive areas are desired in said final mask.
Claim 4
Dependent Claim
36 words
The method recited in claim 1 wherein said photoresist is a negative photoresist and said liquid crystal display is rendered transmissive in the complement of the pattern in which transmissive areas are desired in said mask.
Claim 5
Dependent Claim
14 words
The method recited in claim 1 wherein: said substrate is transmissive to ultraviolet light.
Claim 6
Dependent Claim
23 words
The method recited in claim 1 wherein: said substrate is transmissive to ultraviolet light having a wavelength in the vicinity of 193 nanometers.
Claim 7
Independent Claim
197 words
A method of making a mask comprising: (a) providing a mask blank comprising a transmissive substrate, an opaque coating and a layer of photoresist over said coating; (b) aligning said mask blank with respect to a liquid crystal shutter array consisting of a single line of shutter cells; (c) rendering said liquid crystal shutter array optically transmissive in a pattern corresponding to the desired mask pattern for one line of said mask; (d) exposing said photoresist layer to activating illumination through said liquid crystal shutter array; (e) shifting said mask blank relative to said liquid crystal shutter array to align the next line of said mask blank with said liquid crystal shutter array in a manner to produce a continuous mask pattern; (f) rendering said liquid crystal shutter array optically transmissive in a pattern corresponding to the desired mask pattern for the aligned line of said mask blank; (g) exposing said photoresist layer to activating illumination through said liquid crystal shutter array; (h) repeating steps e-g until the mask blank has been exposed in a manner to produce the desired mask; and (i) developing said photoresist and removing unprotected portions of said opaque coating from said substrate.
Claim 8
Independent Claim
197 words
A method of making a mask comprising: (a) providing a mask blank comprising a transmissive substrate, an opaque coating and a layer of photoresist over said coating; (b) aligning said mask blank with respect to a liquid crystal shutter array consisting of a single line of shutter cells; (c) rendering said liquid crystal shutter array optically transmissive in a pattern corresponding to the desired mask pattern for one line of said mask; (d) exposing said photoresist layer to activating illumination through said liquid crystal shutter array; (e) shifting said mask blank relative to said liquid crystal shutter array to align the next line of said mask blank with said liquid crystal shutter array in a manner to produce a continuous mask pattern; (f) rendering said liquid crystal shutter array optically transmissive in a pattern corresponding to the desired mask pattern for the aligned line of said mask blank; (g) exposing said photoresist layer to activating illumination through said liquid crystal shutter array; (h) repeating steps e-g until the mask blank has been exposed in a manner to produce the desired mask; and (i) developing said photoresist and removing unprotected portions of said opaque coating from said substrate.
Claim 9
Dependent Claim
34 words
The method recited in claim 6 wherein said photoresist is a positive photoresist and said liquid crystal display is rendered transmissive in the pattern in which transmissive areas are desired in said final mask.
Claim 10
Dependent Claim
36 words
The method recited in claim 6 wherein said photoresist is a negative photoresist and said liquid crystal display is rendered transmissive in the complement of the pattern in which transmissive areas are desired in said mask.
Claim 11
Dependent Claim
14 words
The method recited in claim 6 wherein: said substrate is transmissive to ultraviolet light.
Claim 12
Dependent Claim
23 words
The method recited in claim 6 wherein: said substrate is transmissive to ultraviolet light having a wavelength in the vicinity of 193 nanometers.
References Cited (Backward Citations)
US4610940A
Cited
JPS63212843A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-01-20 | 1995-07-22 | 1996-01-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-01-20 | 1999-07-22 | 2000-01-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-01-20 | 2003-07-22 | 2004-01-21 | $7700.00 | Window Closed / Lapsed |