441 research outputs found

    Reduced basis method for source mask optimization

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    Image modeling and simulation are critical to extending the limits of leading edge lithography technologies used for IC making. Simultaneous source mask optimization (SMO) has become an important objective in the field of computational lithography. SMO is considered essential to extending immersion lithography beyond the 45nm node. However, SMO is computationally extremely challenging and time-consuming. The key challenges are due to run time vs. accuracy tradeoffs of the imaging models used for the computational lithography. We present a new technique to be incorporated in the SMO flow. This new approach is based on the reduced basis method (RBM) applied to the simulation of light transmission through the lithography masks. It provides a rigorous approximation to the exact lithographical problem, based on fully vectorial Maxwell's equations. Using the reduced basis method, the optimization process is divided into an offline and an online steps. In the offline step, a RBM model with variable geometrical parameters is built self-adaptively and using a Finite Element (FEM) based solver. In the online step, the RBM model can be solved very fast for arbitrary illumination and geometrical parameters, such as dimensions of OPC features, line widths, etc. This approach dramatically reduces computational costs of the optimization procedure while providing accuracy superior to the approaches involving simplified mask models. RBM furthermore provides rigorous error estimators, which assure the quality and reliability of the reduced basis solutions. We apply the reduced basis method to a 3D SMO example. We quantify performance, computational costs and accuracy of our method.Comment: BACUS Photomask Technology 201

    Critical dimension control influencing factors and measurement

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    Best practice guide for the assessment of EMF exposure from vehicle Wireless Power Transfer systems

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    open11sì(Editors: Roberta Guilizzoni, Stuart Harmon, Mauro Zucca)This document is based on the experience gained by the partners involved in the EMPIR Project 16ENG08 "Metrology for inductive charging of electric vehicles (MICEV)" (www.micev.eu). The project addressed the electromagnetic metrology and human exposure problems related to inductive charging of electric vehicles, both from a modelling and a measurement point of view. The guidelines reported here are designed for people who approach the assessment of human exposure in vehicles and around inductive charging stations. These guidelines are intended to complement the published standards in use and those currently being developed by international technical organisations and bodies. This document concerns the charging of electric vehicles, for transmitted power up to 200 kW. The frequency range of interest is related to resonant coils that produce significant electromagnetic field (EMF) emissions from the charging station. Resonant coils operate in the frequency range between 20 kHz and 85 kHz. Their electric current, and thus the magnetic field and harmonic distortion, is very low and not significant in relation to human exposure guidelines. Consequently, the frequency range of interest for human exposure does not exceed 100 kHz. This guide seeks to assemble the experience gained in the field of human exposure assessment and to provide information for the assessment of exposure through experimental measurements and validated calculations. The calculation of the induced quantities, in particular the induced electric field and electric currents in the tissues, is of fundamental importance for the determination of human exposure. From the point of view of dosimetry, for obvious reasons of feasibility, the calculation replaces the measurement. Therefore, a whole chapter of this guide covers the choice of instruments and the description of the correct settings for both the magnetic field calculations and the dosimetric calculations. The document particularly focuses on the following challenges: • the testing framework, including the common layout of charging stations, with reference to the normative and EU Directive on magnetic field exposure (Sections 4 to 6); • means and methods to perform: o measurements of the magnetic flux density in and around a vehicle; o measurements of limb currents (Section 7); • means and methods to perform: o analytical calculation of magnetic flux density levels for EMF exposure assessment; o computation of the induced electric fields in human beings (Section 8). The guidelines contain some appendices, which include the following: a real example of a charging station; some tables with the exposure limits referred to in this guide; a brief comparison between two existing standards; a test case of a numerical code to calculate the sources; some results on the sensitivity of simulated exposure metrics to the variations in tissue properties and, finally, the measurement capabilities of European national metrological institutes concerning AC magnetic fields at the frequency range of interest for Wireless Power Transfer systems (WPTs). These guidelines do not intend to discuss the implementation of wireless charging systems, the design of their components or the optimisation of their performance, as they do not discuss the interoperability or the techniques for building the systems, or their classification. Risk analysis and mitigation measures are beyond the scope of this guideopenAnkarson, Peter; Bottauscio, Oriano; Clarke, Bob; Freschi, Fabio; Guilizzoni, Roberta; Harmon, Stuart; Laporta, Erika; Pichon, Lionel; Bruna Romero, Jorge; Zilberti, Luca; Zucca, MauroAnkarson, Peter; Bottauscio, Oriano; Clarke, Bob; Freschi, Fabio; Guilizzoni, Roberta; Harmon, Stuart; Laporta, Erika; Pichon, Lionel; Bruna Romero, Jorge; Zilberti, Luca; Zucca, Maur

    Small Molecule Organic Optoelectronic Devices

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    abstract: Organic optoelectronics include a class of devices synthesized from carbon containing ‘small molecule’ thin films without long range order crystalline or polymer structure. Novel properties such as low modulus and flexibility as well as excellent device performance such as photon emission approaching 100% internal quantum efficiency have accelerated research in this area substantially. While optoelectronic organic light emitting devices have already realized commercial application, challenges to obtain extended lifetime for the high energy visible spectrum and the ability to reproduce natural white light with a simple architecture have limited the value of this technology for some display and lighting applications. In this research, novel materials discovered from a systematic analysis of empirical device data are shown to produce high quality white light through combination of monomer and excimer emission from a single molecule: platinum(II) bis(methyl-imidazolyl)toluene chloride (Pt-17). Illumination quality achieved Commission Internationale de L’Éclairage (CIE) chromaticity coordinates (x = 0.31, y = 0.38) and color rendering index (CRI) > 75. Further optimization of a device containing Pt-17 resulted in a maximum forward viewing power efficiency of 37.8 lm/W on a plain glass substrate. In addition, accelerated aging tests suggest high energy blue emission from a halogen-free cyclometalated platinum complex could demonstrate degradation rates comparable to known stable emitters. Finally, a buckling based metrology is applied to characterize the mechanical properties of small molecule organic thin films towards understanding the deposition kinetics responsible for an elastic modulus that is both temperature and thickness dependent. These results could contribute to the viability of organic electronic technology in potentially flexible display and lighting applications. The results also provide insight to organic film growth kinetics responsible for optical, mechanical, and water uptake properties relevant to engineering the next generation of optoelectronic devices.Dissertation/ThesisDoctoral Dissertation Chemical Engineering 201

    Advanced photomask characterisation for microlithography

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    System Analysis and Design for the Resonant Inductive Near-field Generation System (RINGS)

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    The Resonant Inductive Near-field Generation System (RINGS) is a technology demonstrator experiment which will allow for the first ever testing of electromagnetic formation flight (EMFF) algorithms in a full six degree of freedom environment on board the International Space Station (ISS). RINGS is a hybrid design, which, in addition to providing EMFF capabilities, also allows for wireless power transfer (WPT) via resonant inductive coupling. This thesis presents an overview of the mechanical and electrical design of the RINGS experiment, as well as simulation techniques used to model various system parameters in both EMFF and WPT operational modes. Also presented is an analytical and experimental investigation of the influence of the proximity effect on a multi-layer flat spiral coil made from ribbon wire

    Advanced finite-element methods for design and analysis of nanooptical structures: Applications

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    An overview on recent applications of the finite-element method Maxwell-solver JCMsuite to simulation tasks in nanooptics is given. Numerical achievements in the fields of optical metamaterials, plasmonics, photonic crystal fibers, light emitting devices, solar cells, optical lithography, optical metrology, integrated optics, and photonic crystals are summarized

    Development of Quantum Unit of Temperature Standard in Thermoelectric Research

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    The quantum standard of temperature based on the revealed quantum unit of the mentioned quantity is studied. It is recommended first to apply as an intrinsic standard. Such a standard does not need permanently recurring measurements against the realization of the SI unit to validate its accuracy. It may be considered as the intrinsic standard of temperature that could be embedded into cyber-physical systems (CPSs) ensuring their precision operation. The methodological base of involvement of the developed standard in the formation of the thermoelectric power of thermoelectric transducers as well as the generator is considered. The feasibility of a unified consideration of the nature of thermoelectric power within macro- and nanothermodynamics is shown. This approach is driven by the increasing use of nano elements based on 1D-, 2D- nanomaterials (nanowires and nanosheets, respectively) and nanostructured materials in technology, in particular, to improve the key parameters of thermoelectric generators and thermometers. In the first case, this is thermoelectric efficiency, and in the second case, the accuracy of thermometers, which is determined by the stability in a time of thermoelectric power

    Accuracy Assessment of Numerical Dosimetry for the Evaluation of Human Exposure to Electric Vehicle Inductive Charging Systems

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    In this article, we discuss numerical aspects related to the accuracy and the computational efficiency of numerical dosimetric simulations, performed in the context of human exposure to static inductive charging systems of electric vehicles. Two alternative numerical methods based on electric vector potential and electric scalar potential formulations, respectively, are here considered for the electric field computation in highly detailed anatomical human models. The results obtained by the numerical implementation of both approaches are discussed in terms of compliance assessment with ICNIRP guidelines limits for human exposure to electromagnetic fields. In particular, different strategies for smoothing localized unphysical outliers are compared, including novel techniques based on statistical considerations. The outlier removal is particularly relevant when comparison with basic restrictions is required to define the safety of electromagnetic fields exposure. The analysis demonstrates that it is not possible to derive general conclusions about the most robust method for dosimetric solutions. Nevertheless, the combined use of both formulations, together with the use of an algorithm for outliers removal based on a statistical approach, allows to determine final results to be compared with reference limits with a significant level of reliability
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