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Patent History
  • Application
    US 09/336445 1999-06-21
  • Granted
    US 6327033 2001-12-04
 
Supplementary

Granted Patent: Detection Of Phase Defects On Photomasks By Differential Imaging
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TitleDetection Of Phase Defects On Photomasks By Differential Imaging
 
Granted PatentUS 6327033
 
Granted Date2001-12-04
 
Priority Date1999-06-21 US 09/336445
 
InventorsFerguson, RA
Wong, AKK
 
Issue Date2001
 
CitationUS Patent 6327033. Washington, DC: US Patent and Trademark Office (USPTO), 2001 [How to Cite?]
 
AbstractA Method For Detecting Phase Features Or Phase Defects On Photomasks For Optical Lithography Is Described. The Asymmetric Imaging Behavior Through Focus Of Defects Or Features With A Phase Other Than 0 Deg Or 180 Deg Is Used To Distinguish Them From Other Features On The Mask. The Mask Is Inspected At Equally Spaced Positions About An Optimum Focus In Both Positive And Negative Directions. The Images Are Subtracted From One Another To Produce A Differential Image Of The Mask. While Opaque Features As Well As Transmitting Features At 0 Deg And 180 Deg Behave Identically At Positive And Negative Defocus, Thus Leading To A Zero-Valued Differential Image, The Focus Asymmetry Of Phase Defects And Features Produces A Non-Zero Differential Image From Which These Phase Defects And Features Can Be Located. By Comparing The Locations On The Mask For Which A Non-Zero Differential Image Is Obtained With The Designed Data For The Mask, The Phase Defects Can Be Sorted From The Phase Features And The Absence Of Phase Features Can Be Detected. Additional Image Processing Can Be Applied To Verify The Integrity Of The Phase Features. The Differential Image Inspection Technique Can Be Implemented On Existing Optical Inspection Tools By Employing A Two-Pass Inspection Performed At Positive And Negative Defocus In Sequence. In Addition, A New Apparatus With Parallel Inspection Optics Is Described For Inspecting The Mask At Positive And Negative Focus Simultaneously.
 
ReferencesUS 5270796 (A) 1993-12-14

US 5353116 (A) 1994-10-04

US 5786112 (A) 1998-07-28
 
DC FieldValue
dc.contributor.inventorFerguson, RA
 
dc.contributor.inventorWong, AKK
 
dc.date.accessioned2007-10-30T06:52:13Z
 
patents.date.application1999-06-21
 
dc.date.available2007-10-30T06:52:13Z
 
patents.date.granted2001-12-04
 
dc.date.issued2001
 
patents.date.priority1999-06-21 US 09/336445
 
dc.description.abstractA Method For Detecting Phase Features Or Phase Defects On Photomasks For Optical Lithography Is Described. The Asymmetric Imaging Behavior Through Focus Of Defects Or Features With A Phase Other Than 0 Deg Or 180 Deg Is Used To Distinguish Them From Other Features On The Mask. The Mask Is Inspected At Equally Spaced Positions About An Optimum Focus In Both Positive And Negative Directions. The Images Are Subtracted From One Another To Produce A Differential Image Of The Mask. While Opaque Features As Well As Transmitting Features At 0 Deg And 180 Deg Behave Identically At Positive And Negative Defocus, Thus Leading To A Zero-Valued Differential Image, The Focus Asymmetry Of Phase Defects And Features Produces A Non-Zero Differential Image From Which These Phase Defects And Features Can Be Located. By Comparing The Locations On The Mask For Which A Non-Zero Differential Image Is Obtained With The Designed Data For The Mask, The Phase Defects Can Be Sorted From The Phase Features And The Absence Of Phase Features Can Be Detected. Additional Image Processing Can Be Applied To Verify The Integrity Of The Phase Features. The Differential Image Inspection Technique Can Be Implemented On Existing Optical Inspection Tools By Employing A Two-Pass Inspection Performed At Positive And Negative Defocus In Sequence. In Addition, A New Apparatus With Parallel Inspection Optics Is Described For Inspecting The Mask At Positive And Negative Focus Simultaneously.
 
patents.description.assigneeIbm [Us]
 
patents.description.ccUS
 
patents.description.countryUnited States of America
 
patents.description.kindB1
 
dc.description.naturepublished_or_final_version
 
dc.format.extent2095326 bytes
 
dc.format.extent5278 bytes
 
dc.format.mimetypeapplication/pdf
 
dc.format.mimetypetext/plain
 
patents.identifier.applicationUS 09/336445
 
dc.identifier.citationUS Patent 6327033. Washington, DC: US Patent and Trademark Office (USPTO), 2001 [How to Cite?]
 
patents.identifier.grantedUS 6327033
 
dc.identifier.urihttp://hdl.handle.net/10722/46533
 
dc.languageeng
 
patents.relation.familyUS 6327033 (B1) 2001-12-04
 
dc.relation.isreferencedbyUS 2010226562 (A1) 2010-09-09
 
dc.relation.isreferencedbyUS 8111900 (B2) 2012-02-07
 
dc.relation.isreferencedbyWO 2005026706 (A1) 2005-03-24
 
dc.relation.isreferencedbyUS 6879406 (B1) 2005-04-12
 
dc.relation.isreferencedbyWO 2004027830 (A2) 2004-04-01
 
dc.relation.isreferencedbyWO 2004027830 (A3) 2004-05-06
 
dc.relation.isreferencedbyUS 2004223145 (A1) 2004-11-11
 
dc.relation.isreferencedbyUS 7016027 (B2) 2006-03-21
 
dc.relation.isreferencedbyWO 03058681 (A2) 2003-07-17
 
dc.relation.isreferencedbyWO 03058681 (A3) 2003-08-28
 
dc.relation.isreferencedbyUS 2004105577 (A1) 2004-06-03
 
dc.relation.isreferencedbyUS 7171034 (B2) 2007-01-30
 
dc.relation.isreferencedbyUS 6994939 (B1) 2006-02-07
 
dc.relation.isreferencedbyUS 7027635 (B1) 2006-04-11
 
dc.relation.isreferencedbyUS 2002186879 (A1) 2002-12-12
 
dc.relation.isreferencedbyUS 7072502 (B2) 2006-07-04
 
dc.relation.isreferencedbyUS 2001019625 (A1) 2001-09-06
 
dc.relation.isreferencedbyUS 7133548 (B2) 2006-11-07
 
dc.relation.isreferencedbyUS 6704695 (B1) 2004-03-09
 
dc.relation.referencesUS 5270796 (A) 1993-12-14
 
dc.relation.referencesUS 5353116 (A) 1994-10-04
 
dc.relation.referencesUS 5786112 (A) 1998-07-28
 
dc.rightsCreative Commons: Attribution 3.0 Hong Kong License For Public Patent Documents
 
dc.titleDetection Of Phase Defects On Photomasks By Differential Imaging
 
dc.typePatent
 
patents.typePatent_granted
 
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