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Journal of the Optical Society of America A

Journal of the Optical Society of America A


  • Editor: Stephen A. Burns
  • Vol. 25, Iss. 7 — Jul. 1, 2008
  • pp: 1661–1667

Recognition of diffraction-grating profile using a neural network classifier in optical scatterometry

Issam Gereige, Stéphane Robert, Sylvie Thiria, Fouad Badran, Gérard Granet, and Jean Jacques Rousseau  »View Author Affiliations

JOSA A, Vol. 25, Issue 7, pp. 1661-1667 (2008)

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Optical scatterometry has been given much credit during the past few years in the semiconductor industry. The geometry of an optical diffracted structure is deduced from the scattered intensity by solving an inverse problem. This step always requires a previously defined geometrical model. We develop an artificial neural network classifier whose purpose is to identify the structural geometry of a diffraction grating from its measured ellipsometric signature. This will take place before the characterization stage. Two types of geometry will be treated: sinusoidal and symmetric trapezoidal. Experimental results are performed on two manufactured samples: a sinusoidal photoresist grating deposited on a glass substrate and a trapezoidal grating etched on a SiO 2 substrate with periods of 2 μ m and 0.565 μ m , respectively.

© 2008 Optical Society of America

OCIS Codes
(050.1950) Diffraction and gratings : Diffraction gratings
(120.2130) Instrumentation, measurement, and metrology : Ellipsometry and polarimetry
(120.4290) Instrumentation, measurement, and metrology : Nondestructive testing
(100.4996) Image processing : Pattern recognition, neural networks

ToC Category:
Instrumentation, Measurement, and Metrology

Original Manuscript: April 8, 2008
Manuscript Accepted: May 10, 2008
Published: June 24, 2008

Issam Gereige, Stéphane Robert, Sylvie Thiria, Fouad Badran, Gérard Granet, and Jean Jacques Rousseau, "Recognition of diffraction-grating profile using a neural network classifier in optical scatterometry," J. Opt. Soc. Am. A 25, 1661-1667 (2008)

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