GA optimisation of crossed dipole FSS array geometry

Scatterometry is a novel optical metrology that has received considerable attention in the silicon industry in the past few years. Based on the analysis of light scattered from a periodic sample, scatterometry technology can be thought of as consisting of two parts known as the forward problem and the inverse problem. In the forward problem, a scatterometer "signature" is measured. The signature is simply the measured optical response of the scattering features to some incident illumination, like laser light. In the inverse problem, the signature is analyzed in order to determine the parameters (such as linewidth, thickness, profile, etc) of the scattering features. Typically a rigorous electrodynamic model is used in the solution to the inverse problem, but due to the complexity of the model there is no direct analytic solution. Instead, a variety of numerical methods to solve the inverse problem have been proposed and utilized.The earliest widely used method of solution to the inverse problem involved the generation of a "library" of scatter signatures corresponding to discrete parameter combinations of the structure being measured. Once the library was generated, it was then searched in order to determine the best match to the measured signature. The parameters of the best match were then reported as the parameters of the measured signature. As the technology matured, other methods such as model optimization techniques also emerged. In fact, a variety of alternate techniques have been explored and reported, but a general study comparing the results (and hence the strengths and weaknesses) of the various techniques has yet to be performed.In this research, we shall report results from using several different solutions to the inverse problem on two applications (patterned resist and etched poly). The solution methods shall include the classic library search method as well as three common optimization methods. The results will show that each technique has strengths and weaknesses. For example, the library search methods are generally the most robust but also the most time consuming, and the optimization methods, while fast, are prone to reporting a local but not global minima.

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“…A good introductory book has been written by Goldberg 18 . Chuprin has used GA for the design of finite element antennas [19][20] .…”

Section: Genetic Algorithmmentioning

confidence: 99%

Comparison of solutions to the scatterometry inverse problem

Raymond

Littau

Chuprin³

et al. 2004

Metrology, Inspection, and Process Control for Microlithography XVIII

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“…These surfaces have near identical reflection and transmission coefficient magnitudes for TE and TM polarized waves. Several FSS geometries with such properties have been presented including crossed dipoles [7], Jerusalem cross apertures [8], conducting rings [9], double square loop arrays and gridded double square loop arrays [10]. FSS consisting of an array of nested slots have recently been developed for the detection of dual-polarized radiation in passive remote sensing space science instruments [11]- [12].…”

mentioning

confidence: 99%

“…1. While the designs in [7]- [12] focus on ensuring that reflection and transmission magnitude are equal for obliquely incident TE and TM polarized waves, their phase properties are not considered and therefore the conservation of CP upon reflection and transmission cannot be guaranteed.…”

mentioning

confidence: 99%

Circular Polarization Frequency Selective Surface Operating in Ku and Ka Band

Orr

Fusco

Zelenchuk

et al. 2015

IEEE Trans. Antennas Propagat.

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“…In the cross-dipole case, it has been studied the reflectivity response when the electric field of the exciting plane is polarized along the x or y axis. The cross-dipole scatterers are sensitive to both polarizations since they have long metallization along both the x and y directions, and therefore, they are used as dual polarized elements in frequency selective surfaces [Parker 2001]. As it can be inferred from the previous analysis with simple metallic dipoles, the total reflection peaks found at 48.5 GHz in the H-plane and 34 GHz in the E-plane in Fig. 2.4.18(a) are mainly related to the dimensions ax and ay, respectively.…”

Section: Modeling Other Scatterersmentioning

confidence: 99%

Analysis and design of hybrid leaky-wave antennas loaded with frequency selective surfaces

Garcia-Vigueras¹

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vii "Cuando creíamos que teníamos todas las respuestas, de pronto, cambiaron todas las preguntas." Mario Benedetti IX AcknowledgementsLa realización de esta tesis ha significado para mí uno de los periodos de mayor crecimiento personal y profesional. Durante este proceso de evolución y cambios, he contado con el cariño, la ayuda y el apoyo de grandes personas, lo que me hace sentir profundamente afortunada.Sin lugar a dudas quiero comenzar por José Luis; tu intuición y criterio han sido fundamentales en este proyecto. Gracias por haber confiado en mí, compartiendo desde el primer día tanta ilusión, tiempo y esfuerzo. Espero poder seguir aprendiendo contigo, dire.También ha sido inestimable la ayuda de los profesores

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GA optimisation of crossed dipole FSS array geometry

Abstract: The version in the Kent Academic Repository may differ from the final published version. Users are advised to check http://kar.kent.ac.uk for the status of the paper. Users should always cite the published version of record.

Cited by 19 publications

References 3 publications

Comparison of solutions to the scatterometry inverse problem

Comparison of solutions to the scatterometry inverse problem

Circular Polarization Frequency Selective Surface Operating in Ku and Ka Band

Analysis and design of hybrid leaky-wave antennas loaded with frequency selective surfaces

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