Line width measurement below 60nm using an optical interferometer and artificial neural network

Chung W. See, Richard J. Smith, Michael Geoffrey Somekh, Andrew Yacoot

Research output: Chapter in book / Conference proceedingConference article published in proceeding or bookAcademic researchpeer-review

1 Citation (Scopus)


We have recently described a technique for optical line-width measurements. The system currently is capable of measuring line-width down to 60 nm with a precision of 2 nm, and potentially should be able to measure down to 10nm. The system consists of an ultra-stable interferometer and artificial neural networks (ANNs). The former is used to generate optical profiles which are input to the ANNs. The outputs of the ANNs are the desired sample parameters. Different types of samples have been tested with equally impressive results. In this paper we will discuss the factors that are essential to extend the application of the technique. Two of the factors are signal conditioning and sample classification. Methods, including principal component analysis, that are capable of performing these tasks will be considered.
Original languageEnglish
Title of host publicationMetrology, Inspection, and Process Control for Microlithography XXI
EditionPART 1
Publication statusPublished - 15 Oct 2007
Externally publishedYes
EventMetrology, Inspection, and Process Control for Microlithography XXI - San Jose, CA, United States
Duration: 26 Feb 20071 Mar 2007


ConferenceMetrology, Inspection, and Process Control for Microlithography XXI
Country/TerritoryUnited States
CitySan Jose, CA


  • Artificial neural network
  • Interferometer
  • Line-width measurement
  • Principal component analysis

ASJC Scopus subject areas

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

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