US5614990A
Expired / Lapsed
US
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Illumination tailoring system using photochromic filter
Assignee: International Business Machines Corp
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Filing: 1994-08-31
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Granted: 1997-03-25
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Expires: 2014-08-31
Abstract
Abstract Photochromic glass is situated between a light source for exposing resist coated on a wafer and the wafer. The photochromic glass is activated by a wavelength different from that which activates the resist. An array of individual light sources, each of varying intensity, provide activation light to the photochromic glass. A CCD array temporarily in the imaging plane measures light intensity distribution. A controller varies the individual light source array intensities to activate the photochromic glass to varying degrees to produce a desired effect at the imaging plane.
Inventors
- 👤 James A. Bruce
- 👤 Joseph Gortych
- 👤 Michael S. Hibbs
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 08:25
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/0126; G03; G03F; G03F7/00; G03F7/70; G03F7/70058; G02F2203/00; G02F2203/52
Claims Analysis
Total Claims: 37
Claim 1
Independent Claim
69 words
Apparatus for providing light to a light-sensitive material at an imaging plane, comprising: a photochromic filter activated by light of a first wavelength; a first light source for activating said photochromic filter with light of said first wavelength; and a second light source for providing, at said imaging plane, light of a second wavelength different from said first wavelength passed through said activated photochromic filter to said light-sensitive material.
Claim 2
Dependent Claim
69 words
Apparatus for providing light to a light-sensitive material at an imaging plane, comprising: a photochromic filter activated by light of a first wavelength; a first light source for activating said photochromic filter with light of said first wavelength; and a second light source for providing, at said imaging plane, light of a second wavelength different from said first wavelength passed through said activated photochromic filter to said light-sensitive material.
Claim 3
Dependent Claim
18 words
The apparatus of claim 1 wherein said photochromic filter darkens upon exposure to light of said first wavelength.
Claim 4
Dependent Claim
18 words
The apparatus of claim 1 wherein said photochromic filter lightens upon exposure to light of said first wavelength.
Claim 5
Dependent Claim
15 words
The apparatus of claim 1 wherein said first light source selectively activates said photochromic filter.
Claim 6
Dependent Claim
16 words
The apparatus of claim 1 wherein said first light source comprises a variable intensity light source.
Claim 7
Dependent Claim
18 words
The apparatus of claim 5 further comprising a detector situated in said imaging plane for measuring light intensity.
Claim 8
Dependent Claim
22 words
The apparatus of claim 6 further comprising a controller for controlling said variable intensity light source based on said measured light intensity.
Claim 9
Dependent Claim
66 words
Apparatus for exposing a light-sensitive material situated in an imaging plane, comprising: a photochromic filter activated by light of a first wavelength; a first light source for selectively activating said photochromic filter with light of said first wavelength; and a second light source for exposing said light-sensitive material with light of a second wavelength different from said first wavelength passed through said selectively activated photochromic filter.
Claim 10
Dependent Claim
66 words
Apparatus for exposing a light-sensitive material situated in an imaging plane, comprising: a photochromic filter activated by light of a first wavelength; a first light source for selectively activating said photochromic filter with light of said first wavelength; and a second light source for exposing said light-sensitive material with light of a second wavelength different from said first wavelength passed through said selectively activated photochromic filter.
Claim 11
Dependent Claim
27 words
The apparatus of claim 8, wherein said first light source comprises a plurality of light sources, each of said plurality of light sources having a variable intensity.
Claim 12
Dependent Claim
17 words
The apparatus of claim 8, wherein said first light source comprises a diffuser for varying light intensity.
Claim 13
Dependent Claim
16 words
The apparatus of claim 8, wherein said first light source comprises a variable intensity raster scanner.
Claim 14
Dependent Claim
32 words
The apparatus of claim 8 further comprising a detector situated in said imaging plane for measuring intensity distribution of said light of said second wavelength in selected portions of said imaging plane.
Claim 15
Dependent Claim
21 words
The apparatus of claim 12 further comprising a controller for controlling said first light source based on said measured intensity distribution.
Claim 16
Dependent Claim
11 words
The apparatus of claim 13 wherein said controller comprises a computer.
Claim 17
Dependent Claim
15 words
The apparatus of claim 12 wherein said detector comprises an array of charge coupled devices.
Claim 18
Dependent Claim
123 words
Apparatus for imaging features on a semiconductor wafer situated in an imaging plane coated with a light-sensitive material, comprising: a photochromic filter activated by light of a first wavelength; a first variable-intensity light source for selectively activating said photochromic filter with light of said first wavelength; a second light source for exposing said light-sensitive material with light of a second wavelength different from said first wavelength passed through said photochromic filter; a mask for imaging said features in said light-sensitive material; a plurality of detectors temporarily situated in said imaging plane for measuring light intensity distribution in selected portions of said imaging plane; and a controller for controlling light intensity of said first variable-intensity light source based on said measured light intensity distribution.
Claim 19
Dependent Claim
123 words
Apparatus for imaging features on a semiconductor wafer situated in an imaging plane coated with a light-sensitive material, comprising: a photochromic filter activated by light of a first wavelength; a first variable-intensity light source for selectively activating said photochromic filter with light of said first wavelength; a second light source for exposing said light-sensitive material with light of a second wavelength different from said first wavelength passed through said photochromic filter; a mask for imaging said features in said light-sensitive material; a plurality of detectors temporarily situated in said imaging plane for measuring light intensity distribution in selected portions of said imaging plane; and a controller for controlling light intensity of said first variable-intensity light source based on said measured light intensity distribution.
Claim 20
Dependent Claim
18 words
The apparatus of claim 16, wherein said first variable-intensity light source comprises a plurality of variable-intensity light sources.
Claim 21
Dependent Claim
22 words
The apparatus of claim 16 further comprising a beam splitter for directing light from said first light source to said photochromic filter.
Claim 22
Dependent Claim
19 words
The apparatus of claim 18 wherein said beam splitter lies in a light path of said second light source.
Claim 23
Dependent Claim
24 words
The apparatus of claim 19 wherein said beam splitter reflects said light of said first wavelength and transmits said light of said second wavelength.
Claim 24
Independent Claim
60 words
A method for exposing a light-sensitive material in an imaging plane, comprising steps of: activating a photochromic filter with light of a first wavelength, said photochromic filter being situated in a light path for exposing said light-sensitive material; and exposing said light-sensitive material with light of a second wavelength different from said first wavelength passed through said activated photochromic filter.
Claim 25
Independent Claim
60 words
A method for exposing a light-sensitive material in an imaging plane, comprising steps of: activating a photochromic filter with light of a first wavelength, said photochromic filter being situated in a light path for exposing said light-sensitive material; and exposing said light-sensitive material with light of a second wavelength different from said first wavelength passed through said activated photochromic filter.
Claim 26
Dependent Claim
23 words
The method of claim 21 wherein said step of activating comprises exposing said photochromic filter to varying intensity light of said first wavelength.
Claim 27
Dependent Claim
32 words
The method of claim 21 further comprising steps of: measuring light intensity at said imaging plane; and altering intensity of said light of said first wavelength based on said measured light intensity.
Claim 28
Dependent Claim
73 words
The method of claim 23, wherein said photochromic filter darkens upon exposure to said light of said first wavelength and wherein said step of altering comprises: reducing said intensity for a corresponding location on said photochromic filter if said measured light intensity is greater than a predetermined light intensity; and increasing said intensity for a corresponding location on said photochromic filter if said measured light intensity is less than said predetermined light intensity.
Claim 29
Independent Claim
58 words
A method for exposing a light-sensitive material in an imaging plane, comprising steps of: selectively activating a photochromic filter with light of a first wavelength situated in a light path for exposing said light-sensitive material; and exposing said light-sensitive material with light of a second wavelength different from said first wavelength passed through said selectively activated photochromic filter.
Claim 30
Independent Claim
58 words
A method for exposing a light-sensitive material in an imaging plane, comprising steps of: selectively activating a photochromic filter with light of a first wavelength situated in a light path for exposing said light-sensitive material; and exposing said light-sensitive material with light of a second wavelength different from said first wavelength passed through said selectively activated photochromic filter.
Claim 31
Dependent Claim
20 words
The method of claim 25 wherein said step of selectively activating comprises creating a blocking pattern in said photochromic filter.
Claim 32
Dependent Claim
27 words
The method of claim 25 wherein said step of selectively activating comprises exposing selected portions of said photochromic filter to varying intensity light of said first wavelength.
Claim 33
Dependent Claim
38 words
The method of claim 25 further comprising steps of: measuring light intensity distribution in selected portions of said imaging plane; and altering intensity distribution of said light of said first wavelength based on said measured light intensity distribution.
Claim 34
Dependent Claim
24 words
The method of claim 28 wherein said step of measuring comprises sampling light intensity at a plurality of predetermined locations across said imaging plane.
Claim 35
Dependent Claim
122 words
The method of claim 29, wherein said photochromic filter darkens upon exposure to said light of said first wavelength and wherein said step of altering comprises: determining for each of said plurality of predetermined locations, a variation of said sampled light intensity from an average light intensity for all of said plurality of predetermined locations; reducing light intensity for a corresponding location on said photochromic filter if said measured light intensity at a given one of said plurality of predetermined locations is greater than said average light intensity; and increasing light intensity for a corresponding location on said photochromic filter if said measured light intensity at a given one of said plurality of predetermined locations is less than said average light intensity.
Claim 36
Independent Claim
87 words
A method for imaging a uniform feature type on a semiconductor wafer coated with a light-sensitive material in an imaging plane, comprising steps of: selectively activating a photochromic filter with variable intensity light of a first wavelength; exposing said light-sensitive material with light of a second wavelength different from said first wavelength passed through said selectively activated photochromic filter; measuring light intensity distribution across said imaging plane; and automatically altering intensity of said variable intensity light based on said measured light intensity distribution to maintain feature-type uniformity.
Claim 37
Independent Claim
87 words
A method for imaging a uniform feature type on a semiconductor wafer coated with a light-sensitive material in an imaging plane, comprising steps of: selectively activating a photochromic filter with variable intensity light of a first wavelength; exposing said light-sensitive material with light of a second wavelength different from said first wavelength passed through said selectively activated photochromic filter; measuring light intensity distribution across said imaging plane; and automatically altering intensity of said variable intensity light based on said measured light intensity distribution to maintain feature-type uniformity.
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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) | 2000-03-24 | 2000-09-23 | 2001-03-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-03-24 | 2004-09-23 | 2005-03-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-03-24 | 2008-09-23 | 2009-03-25 | $7700.00 | Window Closed / Lapsed |