Abstract

The accurate determination of critical dimensions and roughness is necessary to ensure the quality of photoresist masks that are crucial for the operational reliability of electronic components. Scatterometry provides a fast indirect optical nondestructive method for the determination of profile parameters that are obtained from scattered light intensities using inverse methods. We illustrate the effect of line roughness on the reconstruction of grating parameters employing a maximum likelihood scheme. Neglecting line roughness introduces a strong bias in the parameter estimations. Therefore, such roughness has to be included in the mathematical model of the measurement in order to obtain accurate reconstruction results. In addition, the method allows to determine line roughness from scatterometry. The approach is demonstrated for simulated scattering intensities as well as for experimental data of extreme ultraviolet light scatterometry measurements. The results obtained from the experimental data are in agreement with independent atomic force microscopy measurements.

© 2012 Optical Society of America

Modeling of line roughness and its impact on the diffraction intensities and the reconstructed critical dimensions in scatterometry

H. Gross, M.-A. Henn, S. Heidenreich, A. Rathsfeld, and M. Bär
Appl. Opt. 51(30) 7384-7394 (2012)

A maximum likelihood approach to the inverse problem of scatterometry

Mark-Alexander Henn, Hermann Gross, Frank Scholze, Matthias Wurm, Clemens Elster, and Markus Bär
Opt. Express 20(12) 12771-12786 (2012)

Effect of line roughness on the diffraction intensities in angular resolved scatterometry

Akiko Kato and Frank Scholze
Appl. Opt. 49(31) 6102-6110 (2010)

Analytical modeling and three-dimensional finite element simulation of line edge roughness in scatterometry

Akiko Kato, Sven Burger, and Frank Scholze
Appl. Opt. 51(27) 6457-6464 (2012)

Improved deep-etched multilayer grating reconstruction by considering etching anisotropy and abnormal errors in optical scatterometry

Jinlong Zhu, Shiyuan Liu, Hao Jiang, Chuanwei Zhang, and Xiuguo Chen
Opt. Lett. 40(4) 471-474 (2015)