9nm node wafer defect inspection using visible light

Renjie Zhou, Chris Edwards, Gabriel Popescu, Lynford L Goddard

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Over the past 2 years, we have developed a common optical-path, 532 nm laser epi-illumination diffraction phase microscope (epi-DPM) and successfully applied it to detect different types of defects down to 20 by 100 nm in a 22nm node intentional defect array (IDA) wafer. An image post-processing method called 2DISC, using image frame 2nd order differential, image stitching, and convolution, was used to significantly improve sensitivity of the measured images. To address 9nm node IDA wafer inspection, we updated our system with a highly stable 405 nm diode laser. By using the 2DISC method, we detected parallel bridge defects in the 9nm node wafer. To further enhance detectability, we are exploring 3D wafer scanning, white-light illumination, and dark-field inspection.

Original languageEnglish (US)
Title of host publicationMetrology, Inspection, and Process Control for Microlithography XXVIII
ISBN (Print)9780819499738
StatePublished - 2014
EventMetrology, Inspection, and Process Control for Microlithography XXVIII - San Jose, CA, United States
Duration: Feb 24 2014Feb 27 2014

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X


OtherMetrology, Inspection, and Process Control for Microlithography XXVIII
Country/TerritoryUnited States
CitySan Jose, CA


  • 9nm node wafer
  • dark-field imaging
  • image processing
  • phase imaging
  • signal to noise ratio
  • wafer defect inspection

ASJC Scopus subject areas

  • Applied Mathematics
  • Computer Science Applications
  • Electrical and Electronic Engineering
  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics


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