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Year
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Day
Investigation of Electron Transfer-Based Photonic and Electro-Optic Materials and Devices
Montanaâs state program began its sixth year in 2006. The projectâs research cluster focused on physical, chemical, and biological materials that exhibit unique electron-transfer properties. Our investigators have filed several patents and have also have established five spin-off businesses (3 MSU, 2 UM) and a research center (MT Tech). In addition, this project involved faculty and students at three campuses (MSU, UM, MT Tech) and has a number of under-represented students, including 10 women and 5 Native Americans. In 2006, there was an added emphasis on exporting seminars and speakers via the Internet from UM to Chief Dull Knife Community College, as well as work with the MT Department of Commerce to better educate our faculty regarding establishing small businesses, licensing and patent issues, and SBIR program opportunities.
Date:
March 28, 2008
Creator:
Bromenshenk, Jerry J; Abbott, Edwin H; Dickensheets, David; Donovan, Richard P; Hobbs, J D; Spangler, Lee et al.
Object Type:
Report
System:
The UNT Digital Library
PINCH WELD TESTING TO SUPPORT CHANGE IN MANUFACTURING OIL AT THE KCP
This task supports the change from an oil mixture termed 50:50 oil (an equal parts mixture of Milpro 634 and Pennex N47) to a new oil mixture (Castrol Illocut 334). This change was necessitated by a KCP vendor no longer supplying the Pennex N47 component of the 50-50. In order to continue production of machined parts, a detailed process was followed to ensure that high quality parts could be manufactured and that the cutting oil selected would provide acceptable human performance characteristics, e.g., skin irritability, smell, etc. A prime consideration in changing the oil was that no apparent change in the pinch weldability of the fill stems fabricated using the new oil and process parameters, if any, be observed. A two part approach, as detailed in the plan shown in Appendix B, was used to qualify the effect of the process on pinch weld characteristics. In the first phase, ref. 1., the weld parameter window was defined using fill stems made from 304L, 21-6-9, and 316 stainless steel. These weld conditions were then subsequently used for the Castrol Illocut 334 machined fill stems. The results of this activity are reported in this document. A follow-on task of welding in the …
Date:
February 28, 2008
Creator:
Korinko, P & David Maxwell, D
Object Type:
Report
System:
The UNT Digital Library
Proactive Management of Materials Degradation - A Review of Principles and Programs
The U.S. Nuclear Regulatory Commission (NRC) has undertaken a program to lay the technical foundation for defining proactive actions so that future degradation of materials in light water reactors (LWRs) is limited and, thereby, does not diminish either the integrity of important LWR components or the safety of operating plants. This technical letter report was prepared by staff at Pacific Northwest National Laboratory in support of the NRC Proactive Management of Materials Degradation (PMMD) program and relies heavily on work that was completed by Dr. Joseph Muscara and documented in NUREG/CR-6923. This report concisely explains the basic principles of PMMD and its relationship to prognostics, provides a review of programs related to PMMD being conducted worldwide, and provides an assessment of the technical gaps in PMMD and prognostics that need to be addressed. This technical letter report is timely because the majority of the U.S. reactor fleet is applying for license renewal, and many plants are also applying for increases in power rating. Both of these changes could increase the likelihood of materials degradation and underline, therefore, the interest in proactive management in the future.
Date:
August 28, 2008
Creator:
Bond, Leonard J.; Doctor, Steven R. & Taylor, Theodore T.
Object Type:
Report
System:
The UNT Digital Library
Analysis of the structure of complex networks at different resolution levels
Modular structure is ubiquitous in real-world complex networks, and its detection is important because it gives insights in the structure-functionality relationship. The standard approach is based on the optimization of a quality function, modularity, which is a relative quality measure for a partition of a network into modules. Recently some authors have pointed out that the optimization of modularity has a fundamental drawback: the existence of a resolution limit beyond which no modular structure can be detected even though these modules might have own entity. The reason is that several topological descriptions of the network coexist at different scales, which is, in general, a fingerprint of complex systems. Here we propose a method that allows for multiple resolution screening of the modular structure. The method has been validated using synthetic networks, discovering the predefined structures at all scales. Its application to two real social networks allows to find the exact splits reported in the literature, as well as the substructure beyond the actual split.
Date:
February 28, 2008
Creator:
Arenas, A.; Fernandez, A. & Gomez, S.
Object Type:
Article
System:
The UNT Digital Library
Three-body breakup in dissociative electron attachment to the water molecule
We report the results of {\em ab initio} calculations on dissociative electron attachment (DEA) to water that demonstrate the importance of including three-body breakup in the dissociation dynamics. While three-body breakup is ubiquitous in the analogous process of dissociative recombination, its importance in low-energy dissociative electron attachment to a polyatomic target has not previously been quantified. Our calculations, along with our earlier studies of DEA into two-body channels, indicate that three-body breakup is a major component of the observed O- cross section. The local complex potential model provides a generally accurate picture of the experimentallyobserved features in this system, reproducing some quantitatively, others qualitatively, and one not at all.
Date:
August 28, 2008
Creator:
Haxton, Daniel J.; Rescigno, Thomas N. & McCurdy, C. William
Object Type:
Article
System:
The UNT Digital Library
Dissolved gas and isotopic tracers of denitrification
We present results from field studies in California (USA) where tritium-helium age dating is used in conjunction with major gases (N{sub 2}, O{sub 2}, CH{sub 4}, CO{sub 2}), noble gases (He, Ne, Ar, Kr, Xe), and stable isotopes ({sup 15}N/{sup 14}N, {sup 18}O/{sup 16}O) in order to document nitrate loading and denitrification associated with confined animal agricultural operations and septic systems. Preliminary results show that in-field extraction of the full suite of dissolved gases will be possible using a new Gas Extraction System under development to augment the current Noble Gas Mass Spectrometry and Membrane Inlet Mass Spectrometry techniques. Ascribing observed groundwater nitrate levels to specific current and past land use practices is often complicated by uncertainty in groundwater age and the degree and locus of dentrification. Groundwater age dating at dairy field sites using the {sup 3}H-{sup 3}He method indicates that the highest nitrate concentrations (150-260 mg/L-NO3) occur in waters with apparent ages of <5 yrs, whereas older waters contain excess N{sub 2} from saturated zone denitrification [1]. At a residential septic system site in Livermore, CA, waters with young apparent ages (<1 yr) proximal to leach line drainage have lower nitrate concentrations and elevated nitrate {delta}{sup 15}N and …
Date:
February 28, 2008
Creator:
Singleton, M. J.; Moran, J. E.; Esser, B. K.; McNab, W. W.; Carle, S. F. & Cey, B. D.
Object Type:
Article
System:
The UNT Digital Library
Photoemission Study of Cs-NF3 Activated GaAs(100) Negative Electron Affinity Photocathodes
GaAs based negative electron affinity photocathodes activated with Cs and NF{sub 3} are used as polarized electron sources for linear accelerators. It is generally believed that the activation layer consists of CsF. The activation layers of Cs-NF{sub 3} on GaAs photocathodes are herein investigated using synchrotron radiation photoelectron spectroscopy (SR-PES). F1s, N1s and other core levels are recorded at photon energies ranging from 70eV to 820eV. Surprisingly, a significant amount of nitrogen is observed in the activation layers. Two distinct species of nitrogen are observed, one of which decreases along with the Fluorine signal as the yield of the photocathode decays with time.
Date:
May 28, 2008
Creator:
Liu, Z.; Sun, Y.; Peterson, S. & Pianetta, P.
Object Type:
Article
System:
The UNT Digital Library
Compound Nucleus Contributions to the Optical Potential
An ab-initio calculation of the optical potential for neutron-nucleus scattering has been performed by explicitly coupling the elastic channel to all the particle-hole (p-h) excitation states in the target. These p-h states may be regarded as doorway states through which the flux flows to more complicated configurations, and (in the end) to long-lived compound nucleus resonances. The random-phase approximation (RPA) provides the linear combinations of p-h states that include the residual interactions within the target, and we show preliminary results for elastic flux loss using both p-h and RPA descriptions of target excitations.
Date:
January 28, 2008
Creator:
Thompson, I J; Dietrich, F S; Escher, J E & Dupuis, M
Object Type:
Article
System:
The UNT Digital Library
WaterSense Program: Methodology for National Water Savings Analysis Model Indoor Residential Water Use
The U.S. Environmental Protection Agency (EPA) influences the market for plumbing fixtures and fittings by encouraging consumers to purchase products that carry the WaterSense label, which certifies those products as performing at low flow rates compared to unlabeled fixtures and fittings. As consumers decide to purchase water-efficient products, water consumption will decline nationwide. Decreased water consumption should prolong the operating life of water and wastewater treatment facilities.This report describes the method used to calculate national water savings attributable to EPA?s WaterSense program. A Microsoft Excel spreadsheet model, the National Water Savings (NWS) analysis model, accompanies this methodology report. Version 1.0 of the NWS model evaluates indoor residential water consumption. Two additional documents, a Users? Guide to the spreadsheet model and an Impacts Report, accompany the NWS model and this methodology document. Altogether, these four documents represent Phase One of this project. The Users? Guide leads policy makers through the spreadsheet options available for projecting the water savings that result from various policy scenarios. The Impacts Report shows national water savings that will result from differing degrees of market saturation of high-efficiency water-using products.This detailed methodology report describes the NWS analysis model, which examines the effects of WaterSense by tracking the …
Date:
February 28, 2008
Creator:
Whitehead, Camilla Dunham; McNeil, Michael; Dunham_Whitehead, Camilla; Letschert, Virginie & della_Cava, Mirka
Object Type:
Article
System:
The UNT Digital Library
STAR Vertex Detector Upgrade Development
We report on the development and prototyping efforts undertaken with the goal of producing a micro-vertex detector for the STAR experiment at the RHIC accelerator at BNL. We present the basic detector requirements and show a sensor development path, conceptual mechanical design candidates and readout architecture. Prototyping and beam test results with current generation MimoSTAR-2 sensors and a readout system featuring FPGA based on-the-fly hit finding and data sparsification are also presented.
Date:
January 28, 2008
Creator:
Greiner, Leo C.; Matis, Howard S.; Stezelberger, Thorsten; Vu,Chinh Q.; Wieman, Howard; Szelezniak, Michal et al.
Object Type:
Article
System:
The UNT Digital Library
Zambia: Long-Term Generation Expansion Study - Executive Summary.
The objective of this study is to analyze possible long-term development options of the Zambian electric power system in the period up to 2015. The analysis involved the hydro operations studies of the Zambezi river basin and the systems planning studies for the least-cost generation expansion planning. Two well-known and widely accepted computer models were used in the analysis: PC-VALORAGUA model for the hydro operations and optimization studies and the WASP-III Plus model for the optimization of long-term system development. The WASP-III Plus model is a part of the Argonne National Laboratory's Energy and Power Evaluation Model (ENPEP). The analysis was conducted in close collaboration with the Zambia Electricity Supply Corporation (ZESCO). On the initiative from The World Bank, the sponsor of the study, ZESCO formed a team of experts that participated in the analysis and were trained in the use of computer models. Both models were transferred to ZESCO free of charge and installed on several computers in the ZESCO corporate offices in Lusaka. In September-October 1995, two members of the ZESCO National Team participated in a 4-week training course at Argonne National Laboratory near Chicago, U.S.A., focusing on the long-term system expansion planning using the WASP and VALORAGUA …
Date:
February 28, 2008
Creator:
Conzelmann, G.; Koritarov, V.; Buehring, W.; Veselka, T. & Sciences, Decision and Information
Object Type:
Report
System:
The UNT Digital Library
Quantitive DNA Fiber Mapping
Several hybridization-based methods used to delineate single copy or repeated DNA sequences in larger genomic intervals take advantage of the increased resolution and sensitivity of free chromatin, i.e., chromatin released from interphase cell nuclei. Quantitative DNA fiber mapping (QDFM) differs from the majority of these methods in that it applies FISH to purified, clonal DNA molecules which have been bound with at least one end to a solid substrate. The DNA molecules are then stretched by the action of a receding meniscus at the water-air interface resulting in DNA molecules stretched homogeneously to about 2.3 kb/{micro}m. When non-isotopically, multicolor-labeled probes are hybridized to these stretched DNA fibers, their respective binding sites are visualized in the fluorescence microscope, their relative distance can be measured and converted into kilobase pairs (kb). The QDFM technique has found useful applications ranging from the detection and delineation of deletions or overlap between linked clones to the construction of high-resolution physical maps to studies of stalled DNA replication and transcription.
Date:
January 28, 2008
Creator:
Lu, Chun-Mei; Wang, Mei; Greulich-Bode, Karin M.; Weier, Jingly F. & Weier, Heinz-Ulli G.
Object Type:
Book
System:
The UNT Digital Library
A discontinuous Galerkin front tracking method for two-phase flows with surface tension
A Discontinuous Galerkin method for solving hyperbolic systems of conservation laws involving interfaces is presented. The interfaces are represented by a collection of element boundaries and their position is updated using an arbitrary Lagrangian-Eulerian method. The motion of the interfaces and the numerical fluxes are obtained by solving a Riemann problem. As the interface is propagated, a simple and effective remeshing technique based on distance functions regenerates the grid to preserve its quality. Compared to other interface capturing techniques, the proposed approach avoids smearing of the jumps across the interface which leads to an improvement in accuracy. Numerical results are presented for several typical two-dimensional interface problems, including flows with surface tension.
Date:
December 28, 2008
Creator:
Nguyen, V. T.; Peraire, J.; Cheong, K. B. & Persson, P. O.
Object Type:
Article
System:
The UNT Digital Library
Remaining Sites Verification Package for the 600-111, P-11 Critical Mass Laboratory Crib, and UPR-600-16, Fire and Contamination Spread Waste Sites, Waste Site Reclassification Form 2008-045
The UPR-600-16, Fire and Contamination Spread waste site is an unplanned release that occurred on December 4, 1951, when plutonium contamination was spread by a fire that ignited inside the 120 Experimental Building. The 120 Experimental Building was a laboratory building that was constructed in 1949 and used for plutonium criticality studies as part of the P-11 Project. In November 1951, a criticality occurred in the 120 Experimental Building that resulted in extensive plutonium contamination inside the building. The confirmatory evaluation supports a reclassification of this site to Interim Closed Out. The current site conditions achieve the remedial action objectives and the corresponding remedial action goals established in the Remaining Sites ROD. The results of the extensive radiological survey of the surface soil and the confirmatory and verification sampling show that residual contaminant concentrations do not preclude any future uses and allow for unrestricted use of shallow zone soils. The results also demonstrate that residual contaminant concentrations are protective of groundwater and the Columbia River.
Date:
October 28, 2008
Creator:
Capron, J. M.
Object Type:
Report
System:
The UNT Digital Library
SODIUM ALUMINOSILICATE FOULING AND CLEANING OF DECONTAMINATED SALT SOLUTION COALESCERS
During initial non-radioactive operations at the Modular Caustic Side Solvent Extraction Unit (MCU), the pressure drop across the decontaminated salt solution coalescer reached {approx}10 psi while processing {approx}1250 gallons of salt solution, indicating possible fouling or plugging of the coalescer. An analysis of the feed solution and the 'plugged coalescer' concluded that the plugging was due to sodium aluminosilicate solids. MCU personnel requested Savannah River National Laboratory (SRNL) to investigate the formation of the sodium aluminosilicate solids (NAS) and the impact of the solids on the decontaminated salt solution coalescer. Researchers performed developmental testing of the cleaning protocols with a bench-scale coalescer container 1-inch long segments of a new coalescer element fouled using simulant solution. In addition, the authors obtained a 'plugged' Decontaminated Salt Solution coalescer from non-radioactive testing in the MCU and cleaned it according to the proposed cleaning procedure. Conclusions from this testing include the following: (1) Testing with the bench-scale coalescer showed an increase in pressure drop from solid particles, but the increase was not as large as observed at MCU. (2) Cleaning the bench-scale coalescer with nitric acid reduced the pressure drop and removed a large amount of solid particles (11 g of bayerite if all …
Date:
October 28, 2008
Creator:
Poirier, M; Thomas Peters, T; Fernando Fondeur, F & Samuel Fink, S
Object Type:
Report
System:
The UNT Digital Library
SEQUESTRATION AND TREATMENT OF VADOSE ZONE SOLVENTS USING EDIBLE OILS
Edible oils have emerged as an effective treatment amendment for a variety of contaminants. When applied to chlorinated volatile organic compounds (cVOCs) in the saturated zone, edible oils have been shown to enhance anaerobic bioremediation and sequester the contaminants. However, edible oils have not been applied to the vadose zone for contaminant treatment. Soybean oil was injected into the vadose zone in M-Area at the Department of Energy's (DOE) Savannah River Site (SRS) as a research study to evaluate the effectiveness of edible oils for solvent sequestration and the ability to change a vadose system from aerobic to anaerobic to initiate reductive dechlorination. The proposed use of this technique would be an enhanced attenuation/transition step after active remediation. The goals of the research were to evaluate oil emplacement methods and monitoring techniques to measure oil placement, partitioning and degradation. Gas sampling was the cornerstone for this evaluation. Analyses for cVOCs and biotransformation products were performed. Overall, the cVOC concentration/flux reduction was 75-85% in this vadose zone setting. Destruction of the cVOCs by biotic or abiotic process has not yet been verified at this site. No reductive dechlorination products have been measured. The deployment has resulted in a substantial generation of …
Date:
March 28, 2008
Creator:
Riha, B; Brian02 Looney, B & Richard Hall (NOEMAIL), R
Object Type:
Article
System:
The UNT Digital Library
Enhanced Functionality for Materials Analysis in the DTEM
The recent explosion in the use of pump–probe studies on the picosecond timescale to investigate structural and electronic phase transitions and the dynamics of chemical reactions has been based largely on laser–induced reactions coupled with laser interrogation techniques, or on laser induced reactions coupled with synchrotron radiation interrogation techniques. Much less attention has been given to approaches based on laser–induced (or electron–beam–induced) reactions coupled with electron interrogation methods, despite the fact that electron sources are brighter, and their interactions with matter stronger (thereby giving higher signal levels). The use of electrons as probes has great potential to study complex transient events not only because of the possible high temporal resolution using ultrafast electron diffraction (UED) but also the potential for high spatial resolution using dynamic transmission electron microscopy (DTEM). Taking this potential of electron interrogation methods and turning it into a routine nanoscale characterization technique requires several key aspects of the instrumentation used for electron microscopy/diffraction to be optimized. In this proposal, several approaches to instrument optimization for DTEM and UED (to be performed in the same instrument) will be addressed. The new instrumentation developments will be used to study the dynamics of strongly driven materials, aging and corrosion in …
Date:
April 28, 2008
Creator:
Browning, Nigel D.
Object Type:
Report
System:
The UNT Digital Library
Final Report : Results of the 2006-2007 Investigation of Potential Contamination at the Former CCC/Usda Facility in Barnes, Kansas.
The 2006-2007 investigation of carbon tetrachloride and chloroform contamination at Barnes, Kansas, was conducted at the request of the Kansas Department of Health and Environment (KDHE). The Environmental Science Division of Argonne National Laboratory implemented the investigation on behalf of the Commodity Credit Corporation of the U.S. Department of Agriculture (CCC/USDA). The overall goal of the investigation was to establish criteria for monitoring leading to potential site reclassification. The investigation objectives were to (1) determine the hydraulic gradient near the former CCC/USDA facility, (2) delineate the downgradient carbon tetrachloride plume, and (3) design and implement an expanded monitoring network at Barnes (Argonne 2006a).
Date:
August 28, 2008
Creator:
LaFreniere, L. M.
Object Type:
Report
System:
The UNT Digital Library
Comparison of Meteorological Measurements from Sparse and Dense Surface Observation Networks in the U.S. Southern Great Plains
The primary objective of this study was to analyze the spatial variability of temperature and relative humidity across Kansas (KS) and Oklahoma (OK) for sparse and dense networks by comparing data from (1) the Surface Meteorological Observing System (SMOS) installations at the Atmospheric Radiation Measurement (ARM; Peppler et al. 2008) Program’s Southern Great Plains site and (2) the Oklahoma Mesonet (OKM; McPherson et al. 2007). Given the wealth of observations available from these networks, this study provided the unique opportunity to determine, within a quantifiable statistical limit, an optimal distance between stations deployed for observation of the climatological values of temperature and relative humidity. Average distances between a given station and its closest neighboring station for the ARM SMOS (~ 70 km) and the OKM (~ 30 km; Brotzge and Richardson 2003) networks provided an excellent framework for comparisons of sparse and dense observations (Figure 1). This study further lays groundwork for a future investigation to determine the necessary spacing between observations for initialization of gridded numerical models.
Date:
February 28, 2008
Creator:
Monroe, J. W.; Ritsche, M. T.; Franklin, M. & Kehoe, K. E.
Object Type:
Report
System:
The UNT Digital Library
SUSY at the ILC and Solving the LHC Inverse Problem
Recently a large scale study of points in the MSSM parameter space which are problematic at the Large Hadron Collider (LHC) has been performed. This work was carried out in part to determine whether the proposed International Linear Collider (ILC) could be used to solve the LHC inverse problem. The results suggest that while the ILC will be a valuable tool, an energy upgrade may be crucial to its success, and that, in general, precision studies of the MSSM are more difficult at the ILC than has generally been believed.
Date:
May 28, 2008
Creator:
Gainer, James S.
Object Type:
Article
System:
The UNT Digital Library
Argonne's Laboratory Computing Center - 2007 Annual Report.
Argonne National Laboratory founded the Laboratory Computing Resource Center (LCRC) in the spring of 2002 to help meet pressing program needs for computational modeling, simulation, and analysis. The guiding mission is to provide critical computing resources that accelerate the development of high-performance computing expertise, applications, and computations to meet the Laboratory's challenging science and engineering missions. In September 2002 the LCRC deployed a 350-node computing cluster from Linux NetworX to address Laboratory needs for mid-range supercomputing. This cluster, named 'Jazz', achieved over a teraflop of computing power (1012 floating-point calculations per second) on standard tests, making it the Laboratory's first terascale computing system and one of the 50 fastest computers in the world at the time. Jazz was made available to early users in November 2002 while the system was undergoing development and configuration. In April 2003, Jazz was officially made available for production operation. Since then, the Jazz user community has grown steadily. By the end of fiscal year 2007, there were over 60 active projects representing a wide cross-section of Laboratory expertise, including work in biosciences, chemistry, climate, computer science, engineering applications, environmental science, geoscience, information science, materials science, mathematics, nanoscience, nuclear engineering, and physics. Most important, many …
Date:
May 28, 2008
Creator:
Bair, R. & Pieper, G. W.
Object Type:
Report
System:
The UNT Digital Library
Hydrogen Optical Fiber Sensors
Optically-based hydrogen sensors promise to deliver an added level of safety as hydrogen and fuel cell technologies enter the mainstream. More importantly, they offer reduced power consumption and lower cost, which are desirable for mass production applications such as automobiles and consumer appliances. This program addressed two of the major challenges previously identified in porous optrode-based optical hydrogen sensors: sensitivity to moisture (ambient humidity), and interference from the oxygen in air. Polymer coatings to inhibit moisture and oxygen were developed in conjunction with newer and novel hydrogen sensing chemistries. The results showed that it is possible to achieve sensitive hydrogen detection and rapid response with minimal interference from oxygen and humidity. As a result of this work, a new and more exciting avenue of investigation was developed: the elimination of the porous optrode and deposition of the sensor chemistry directly into the polymer film. Initial results have been promising, and open up a wider range of potential applications from extended optical fiber sensing networks, to simple plastic "stickers" for use around the home and office.
Date:
July 28, 2008
Creator:
Lieberman, Robert A.; Beshay, Manal & Cordero, Steven R.
Object Type:
Report
System:
The UNT Digital Library
Factorization and resummation for collinear poles in QCD amplitudes
We study the origin of subleading soft and collinear poles of form factors and amplitudes in dimensionally-regulated massless gauge theories. In the case of form factors of fundamental fields, these poles originate from a single function of the coupling, denoted G({alpha}{sub s}), depending on both the spin and gauge quantum numbers of the field. We relate G({alpha}{sub s}) to gauge-theory matrix elements involving the gluon field strength. We then show that G({alpha}{sub s}) is the sum of three terms: a universal eikonal anomalous dimension, a universal non-eikonal contribution, given by the coefficient B{sub {delta}}({alpha}{sub s}) of {delta}(1-z) in the collinear evolution kernel, and a process-dependent short-distance coefficient function, which does not contribute to infrared poles. Using general results on the factorization of soft and collinear singularities in fixed-angle massless gauge theory amplitudes, we conclude that all such singularities are captured by the eikonal approximation, supplemented only by the knowledge of B{sub {delta}}({alpha}{sub s}). We explore the consequences of our results for conformal gauge theories, where in particular we find a simple exact relation between the form factor and the cusp anomalous dimension.
Date:
May 28, 2008
Creator:
Dixon, Lance J.; Magnea, Lorenzo & Sterman, George
Object Type:
Article
System:
The UNT Digital Library
Determining the Critcial Size of EUV Mask Substrate Defects
Determining the printability of substrate defects beneath the extreme ultraviolet (EUV) reflecting multilayer stack is an important issue in EUVL lithography. Several simulation studies have been performed in the past to determine the tolerable defect size on EUV mask blank substrates but the industry still has no exact specification based on real printability tests. Therefore, it is imperative to experimentally determine the printability of small defects on a mask blanks that are caused by substrate defects using direct printing of programmed substrate defect in an EUV exposure tool. SEMATECH fabricated bump type program defect masks using standard electron beam lithography and performed printing tests with the masks using an EUV exposure tool. Defect images were also captured using SEMATECH's Berkeley Actinic Imaging Tool in order to compare aerial defect images with secondary electron microscope images from exposed wafers. In this paper, a comprehensive understanding of substrate defect printability will be presented and printability specifications of EUV mask substrate defects will be discussed.
Date:
February 28, 2008
Creator:
Mccall, Monnikue M.; Han, Hakseung; Cho, Wonil; Goldberg, Kenneth; Gullikson, Eric; Jeon, Chan-Uk et al.
Object Type:
Article
System:
The UNT Digital Library