Patent US5795688A successfully refreshed from Google Patents.
US5795688A
Expired / Lapsed
US
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Process for detecting defects in photomasks through aerial image comparisons
Assignee: Micron Technology Inc
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Filing: 1996-08-14
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Granted: 1998-08-18
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Expires: 2016-08-14
Abstract
Abstract The present invention provides a process for performing automatic inspection of advanced design photomasks. In a preferred embodiment, an aerial image of a portion of a photomask is generated. A simulated image corresponding to original pattern data is also generated. The aerial image and simulated image are then compared and discrepancies are detected as possible defects.
Inventors
- 👤 James Burdorf
- 👤 Christophe Pierrat
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 21:38
CPC Classifications
G; G03; G03F; G03F1/00; G03F1/36; G01; G01N; G01N21/00; G01N21/84; G01N21/88; G01N21/95; G01N21/956; G01N21/95607; G03F1/68; G03F1/82; G03F1/84; G03F7/00; G03F7/70; G03F7/70483; G03F7/70605; G03F7/70616; G03F7/7065; G03F7/70653; G03F7/70666
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
53 words
A process for detecting defects in masks comprising: generating an aerial image of a portion of a mask; generating a simulated image corresponding to original pattern data used to create said mask taking into account expected distortions and corner rounding due to image processing; and comparing said aerial image to said simulated image.
Claim 2
Dependent Claim
53 words
A process for detecting defects in masks comprising: generating an aerial image of a portion of a mask; generating a simulated image corresponding to original pattern data used to create said mask taking into account expected distortions and corner rounding due to image processing; and comparing said aerial image to said simulated image.
Claim 3
Dependent Claim
41 words
A process for detecting defects in masks as defined in claim 1 wherein said simulated image is obtained by generating a simulated aerial image of a mask design used to generate a portion of the mask with which it is compared.
Claim 4
Dependent Claim
22 words
A process for detecting defects in masks as defined in claim 1 wherein said mask is generated using proximity effect correction techniques.
Claim 5
Dependent Claim
23 words
A process for detecting defects in masks as defined in claim 3 wherein said mask is generated using optical proximity effect correction techniques.
Claim 6
Dependent Claim
23 words
A process for detecting defects in masks as defined in claim 3 wherein said mask is generated using x-ray proximity effect correction techniques.
Claim 7
Dependent Claim
24 words
A process for detecting defects in masks as defined in claim 3 wherein said mask is generated using ion beam proximity effect correction techniques.
Claim 8
Dependent Claim
23 words
A process for detecting defects in masks as defined in claim 3 wherein said mask is generated using e-beam proximity effect correction techniques.
Claim 9
Dependent Claim
19 words
A process for detecting defects in masks as defined in claim 1 wherein said mask includes phase shifting techniques.
Claim 10
Dependent Claim
24 words
A process for detecting defects in masks as defined in claim 1 wherein said mask includes proximity effect correction techniques and phase shifting techniques.
Claim 11
Dependent Claim
23 words
A process for detecting defects in masks as defined in claim 1 wherein said masks are used in the manufacture of integrated circuits.
Claim 12
Dependent Claim
19 words
A process for detecting defects in masks as defined in claim 1 wherein said mask comprises an x-ray mask.
Claim 13
Dependent Claim
23 words
A process for detecting defects in masks as defined in claim 1 wherein said mask comprises a stencil mask for ion projection lithography.
Claim 14
Dependent Claim
23 words
A process for detecting defects in masks as defined in claim 1 wherein said mask comprises a mask for electron beam projection lithography.
Claim 15
Dependent Claim
25 words
A process for detecting defects in masks as defined in claim 1 wherein said aerial image and said simulated image are generated out of focus.
Claim 16
Dependent Claim
53 words
A process for detecting defects in photomasks comprising: generating an aerial image of a portion of a photomask; generating a simulated image corresponding to original pattern data used to create said photomask taking into account expected distortions and corner rounding due to image processing; and comparing said aerial image to said simulated image.
Claim 17
Dependent Claim
53 words
A process for detecting defects in photomasks comprising: generating an aerial image of a portion of a photomask; generating a simulated image corresponding to original pattern data used to create said photomask taking into account expected distortions and corner rounding due to image processing; and comparing said aerial image to said simulated image.
Claim 18
Dependent Claim
41 words
A process for detecting defects in photomasks as defined in claim 15 wherein said simulated image is obtained by generating a simulated aerial image of a mask design used to generate the portion of the photomask with which it is compared.
Claim 19
Dependent Claim
23 words
A process for detecting defects in photomasks as defined in claim 15 wherein said photomask is generated using optical proximity effect correction techniques.
Claim 20
Dependent Claim
19 words
A process for detecting defects in photomasks as defined in claim 15 wherein said photomask includes phase shifting techniques.
Claim 21
Dependent Claim
24 words
A process for detecting defects in photomasks as defined in claim 15 wherein said photomask includes proximity effect correction techniques and phase shifting techniques.
Claim 22
Dependent Claim
25 words
A process for detecting defects in photomasks as defined in claim 15 wherein said aerial image and said simulated image are generated out of focus.
Claim 23
Dependent Claim
45 words
A process for detecting defects in masks comprising: generating an aerial image of a portion of a mask; generating a simulated aerial image of a mask design used to generate said portion of said mask; and comparing said aerial image to said simulated aerial image.
Claim 24
Dependent Claim
45 words
A process for detecting defects in masks comprising: generating an aerial image of a portion of a mask; generating a simulated aerial image of a mask design used to generate said portion of said mask; and comparing said aerial image to said simulated aerial image.
Claim 25
Dependent Claim
22 words
A process for detecting defects in masks as defined in claim 21 wherein said mask is generated using proximity effect correction techniques.
Claim 26
Dependent Claim
19 words
A process for detecting defects in masks as defined in claim 21 wherein said mask includes phase shifting techniques.
Claim 27
Dependent Claim
24 words
A process for detecting defects in masks as defined in claim 21 wherein said mask includes proximity effect correction techniques and phase shifting techniques.
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) | 2001-08-17 | 2002-02-16 | 2002-08-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-08-17 | 2006-02-16 | 2006-08-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-08-17 | 2010-02-16 | 2010-08-18 | $7700.00 | Window Closed / Lapsed |