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Contribution des réseaux de neurones dans le domaine de l'ellipsométrie: Application à la scatterométrie

Abstract : Nowadays, miniaturization is the most explored research topic in various domains of science and technology. Manufacturing processes, such as lithography, have been prodigiously developed during these last years and allow high scale integration of devices. This technological progress has created systematically the need of reliable, efficient and if possible low cost characterization techniques. The aim of this PhD is to study and implement an original mathematical tool, namely neural networks, within the framework of optical and dimensional metrology achieved by ellipsometry. In the first part of this work, we have shown that the neural network can be effectively employed for the determination of the optical and geometrical properties (refractive index and thickness) of thin films. For instance, neural classification has been proposed in order to estimate the thickness range of films without any prior information about the structure. This technique can be coupled with any other optimization algorithm requiring a prior knowledge about the solution. In the second part, we have clearly shown the contribution of the neural network in scatterometry for the characterization of diffraction gratings with different geometrical profiles. The neural method can also be employed to determine the grating pitch when it is required. Neural classification has been applied for structural identification of the geometrical model, giving thus a direct application in lithography for automatic detection of the residual layer undesirable for the etching step.
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Contributor : Issam Gereige <>
Submitted on : Thursday, November 26, 2009 - 1:32:04 AM
Last modification on : Wednesday, November 20, 2019 - 3:18:33 AM
Long-term archiving on: : Thursday, September 23, 2010 - 11:01:50 AM


  • HAL Id : tel-00365631, version 2



Issam Gereige. Contribution des réseaux de neurones dans le domaine de l'ellipsométrie: Application à la scatterométrie. Sciences de l'ingénieur [physics]. Université Jean Monnet - Saint-Etienne, 2008. Français. ⟨tel-00365631v2⟩



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