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Gereige I.,King Abdullah University of Science and Technology | Robert S.,Jean Monnet University | Robert S.,CNRS Telecom Laboratory of Claude Chappe | Eid J.,King Abdullah University of Science and Technology
Microelectronic Engineering | Year: 2012

Photolithography is a fundamental process in the semiconductor industry and it is considered as the key element towards extreme nanoscale integration. In this technique, a polymer photo sensitive mask with the desired patterns is created on the substrate to be etched. Roughly speaking, the areas to be etched are not covered with polymer. Thus, no residual layer should remain on these areas in order to insure an optimal transfer of the patterns on the substrate. In this paper, we propose a nondestructive method based on a classification approach achieved by artificial neural network for automatic residual layer detection from an ellipsometric signature. Only the case of regular defect, i.e. homogenous residual layer, will be considered. The limitation of the method will be discussed. Then, an experimental result on a 400 nm period grating manufactured with nanoimprint lithography is analyzed with our method. © 2012 Elsevier B.V. All rights reserved.

Godinho V.,University of Seville | Caballero-Hernandez J.,University of Seville | Jamon D.,Jean Monnet University | Jamon D.,CNRS Telecom Laboratory of Claude Chappe | And 3 more authors.
Nanotechnology | Year: 2013

A new approach is presented to produce amorphous porous silicon coatings (a-pSi) with closed porosity by magnetron sputtering of a silicon target. It is shown how the use of He as the process gas at moderated power (50-150 W RF) promotes the formation of closed nanometric pores during the growth of the silicon films. The use of oblique-angle deposition demonstrates the possibility of aligning and orientating the pores in one direction. The control of the deposition power allows the control of the pore size distribution. The films have been characterized by a variety of techniques, including scanning and transmission electron microscopy, electron energy loss spectroscopy, Rutherford back scattering and x-ray photoelectron spectroscopy, showing the incorporation of He into the films (most probably inside the closed pores) and limited surface oxidation of the silicon coating. The ellipsometry measurements show a significant decrease in the refractive index of porous coatings (n500 nm = 3.75) in comparison to dense coatings (n500 nm = 4.75). The capability of the method to prepare coatings with a tailored refractive index is therefore demonstrated. The versatility of the methodology is shown in this paper by preparing intrinsic or doped silicon and also depositing (under DC or RF discharge) a-pSi films on a variety of substrates, including flexible materials, with good chemical and mechanical stability. The fabrication of multilayers of silicon films of controlled refractive index in a simple (one-target chamber) deposition methodology is also presented. © 2013 IOP Publishing Ltd.

Battie Y.,CNRS Hubert Curien Laboratory | Destouches N.,CNRS Hubert Curien Laboratory | Chassagneux F.,University Claude Bernard Lyon 1 | Jamon D.,CNRS Telecom Laboratory of Claude Chappe | And 4 more authors.
Optical Materials Express | Year: 2011

The composition, the structure and the optical properties of mesostructured hybrid silica films elaborated by sol-gel routine are studied versus the temperature of the post treatment by comparing ellipsometric measurements, atomic force microscopy and electronic microscopy characterizations, X-ray diffraction and thermal analysis. This paper shows that the refractive index variation is a combination between the structure contraction, the solvent evaporation, the silica wall condensation and the pyrolysis of the copolymer. We also investigate the optical properties of thermally grown silver nanoparticles in the mesotructured films and we demonstrate that these properties depend on the optical properties of the host matrix and on the silver concentration profile in the film. © 2011 Optical Society of America.

Lebbal M.R.,University of Mentouri Constantine | Boumaza T.,University of Mentouri Constantine | Bouchemat M.,University of Mentouri Constantine | Royer F.,CNRS Telecom Laboratory of Claude Chappe | Rousseau J.J.,CNRS Telecom Laboratory of Claude Chappe
International Review on Modelling and Simulations | Year: 2012

Magneto-optical waveguides isolators are indispensable devices for stable operation of telecommunication. However, minimizing the phase mismatch between fundamental TE and TM propagation modes is an essential condition to ameliorate the isolation[1]-[3]. This condition can be satisfied depending to the substrate and the material with thickness of the guiding thin layer. The simulation carried out by MATLAB allowed deducing the conditions to decrease the phase mismatch and increase the conversion ration of modes. This last can be satisfied in an optimized waveguides made by SiO2/ZrO2 doped with ferrite of cobalt and deposited in a glass substrate, with a selected thickness of the guiding thin film. © 2012 Praise Worthy Prize S.r.l. - All Rigthts Reserved.

Battie Y.,University of Lorraine | Jamon D.,CNRS Telecom Laboratory of Claude Chappe | Lauret J.-S.,CNRS Quantum and Molecular Photonics Laboratory | En Naciri A.,University of Lorraine | And 2 more authors.
Carbon | Year: 2012

The optical properties of single walled carbon nanotube (SWCNT) films, produced by vacuum filtration, are correlated with their diameter and their in plane preferred orientation by coupling transmission and scanning electron microscopy to conventional ellipsometry. We focused on the optical anisotropy of this material and we demonstrated that it was originated from a breakdown in the selection rules. © 2012 Elsevier Ltd. All rights reserved.

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