Inspection of lithographic mask blanks for defects

Patent · Mon Jan 01 00:00:00 EST 2001

OSTI ID:873511

Sommargren, Gary E ^[1]

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1. Santa Cruz, CA

A visible light method for detecting sub-100 nm size defects on mask blanks used for lithography. By using optical heterodyne techniques, detection of the scattered light can be significantly enhanced as compared to standard intensity detection methods. The invention is useful in the inspection of super-polished surfaces for isolated surface defects or particulate contamination and in the inspection of lithographic mask or reticle blanks for surface defects or bulk defects or for surface particulate contamination.

• Research Organization: Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
• DOE Contract Number: W-7405-ENG-48
• Assignee: Regents of University of California (Oakland, CA)
• Patent Number(s): US 6177993
• OSTI ID: 873511
• Country of Publication: United States
• Language: English

Related Subjects

inspection
lithographic
mask
blanks
defects
visible
light
method
detecting
sub-100
nm
size
lithography
optical
heterodyne
techniques
detection
scattered
significantly
enhanced
compared
standard
intensity
methods
useful
super-polished
surfaces
isolated
surface
particulate
contamination
reticle
bulk
surface defects
significantly enhanced
detection methods
detection method
scattered light
visible light
particulate contamination
optical heterodyne
heterodyne techniques
standard intensity
heterodyne technique
lithographic mask
mask blanks
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