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Chandler, AZ, United States

Garg A.,Nanyang Technological University | Vijayaraghavan V.,Nanyang Technological University | Vijayaraghavan V.,Technology Development Center | Wong C.H.,Nanyang Technological University | And 2 more authors.
Simulation Modelling Practice and Theory | Year: 2014

The thermal property of single layer graphene sheet is investigated in this work by using an embedded approach of molecular dynamics (MD) and soft computing method. The effect of temperature and Stone-Thrower-Wales (STW) defects on the thermal conductivity of graphene sheet is first analyzed using MD simulation. The data obtained using the MD simulation is then fed into the paradigm of soft computing approach, multi-gene genetic programming (MGGP), which was specifically designed to model the response of thermal conductivity of graphene sheet with changes in system temperature and STW defect concentration. We find that our proposed MGGP model is able to model the thermal conductivity of graphene sheet very well which can be used to complement the analytical solution developed by MD simulation. Additionally, we also conducted sensitivity and parametric analysis to find out specific influence and variation of each of the input system parameters on the thermal conductivity of graphene sheet. It was found that the STW defects has the most dominating influence on the thermal conductivity of graphene sheet. © 2014 Elsevier B.V. All rights reserved. Source

Kuttner R.,Technology Development Center
Proceedings of the International Conference of DAAAM Baltic "Industrial Engineering" | Year: 2012

A firm must plan its manufacturing activities at a variety of levels and operate these as a system. Manufacturing planning and scheduling has attracted an increasing amount of attention from both the academia and the industry in the past decade. This study aims to develop a better understanding of the production planning problems for lowvolume and make-to-order production for engineering industry. The proposed models based on mathematical programming. The time horizon splitting approach is proposed, where the whole planning task is decomposed into hierarchy of sub-problems. Source

Arnold W.H.,Technology Development Center
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2011

EUVL lithography using high resolution step and scan systems operating at 13.5nm is being inserted in leading edge production lines for memory and logic devices. These tools use mirror optics and either laser produced plasma (LPP) or discharge produced plasma (DPP) sources along with reflective reduction masks to image circuit features. These tools show their capability to meet the challenging device requirements for imaging and overlay. Next generation scanners with resolution and overlay capability to produce 1X nm (10 nm class) memory and logic devices are in preparation. Challenges remain for EUVL, the principal of which are increasing source power enabling high productivity, building a volume mask business encouraging rapid learning cycles, and improving resist performance so it is capable of sub 20nm resolution. © 2011 SPIE. Source

Seetharaman S.,National University of Singapore | Subramanian J.,National University of Singapore | Tun K.S.,Technology Development Center | Hamouda A.S.,Qatar University | Gupta M.,National University of Singapore
Materials | Year: 2013

In this study, magnesium composites with nano-size boron nitride (BN) particulates of varying contents were synthesized using the powder metallurgy (PM) technique incorporating microwave-assisted two-directional sintering followed by hot extrusion. The effect of nano-BN addition on the microstructural and the mechanical behavior of the developed Mg/BN composites were studied in comparison with pure Mg using the structure-property correlation. Microstructural characterization revealed uniform distribution of nano-BN particulates and marginal grain refinement. The coefficient of thermal expansion (CTE) value of the magnesium matrix was improved with the addition of nano-sized BN particulates. The results of XRD studies indicate basal texture weakening with an increase in nano-BN addition. The composites showed improved mechanical properties measured under micro-indentation, tension and compression loading. While the tensile yield strength improvement was marginal, a significant increase in compressive yield strength was observed. This resulted in the reduction of tension-compression yield asymmetry and can be attributed to the weakening of the strong basal texture. © 2013 by the authors; licensee MDPI, Basel, Switzerland. Source

Hansen S.G.,Technology Development Center
Journal of Micro/Nanolithography, MEMS, and MOEMS | Year: 2011

This work examines aspects of source mask polarization optimization (SMPO). Cases are described where unusual polarization conditions, beyond the familiar and expected XY or TE, are beneficial. These results are best understood by examining the diffraction patterns and noticing that image formation is influenced by interference between higher diffraction orders when the zeroth order is relatively weak. Examples include hole patterns with attenuated phase shift masks and also dark field illumination. Further analysis shows, however, that for some problems, perhaps most, aggressive mask optimization can transform the imaging problem in such away that zeroth order light again dominates. Under these conditions familiar two beam imaging can be obtained with off-axis illumination, and then TE polarization will probably provide the best solution. From a computational point-of-view SMPO procedures are hampered by the fact that polarization affects the required optical proximity correction (OPC), the OPC affects the diffraction pattern, and the diffraction pattern and polarized source light interact to determine lithographic performance. This makes co-optimization of source, mask, and polarization conditions difficult, and a useful intermediate approach was found to be source mask optimization with a scalar imaging calculation. © 2011 Society of Photo-Optical Instrumentation Engineers (SPIE). Source

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