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EUV mask reflectivity measurements with micron-scale spatial resolution (open access)

EUV mask reflectivity measurements with micron-scale spatial resolution

The effort to produce defect-free mask blanks for EUV lithography relies on increasing the detection sensitivity of advanced mask inspection tools, operating at several wavelengths. We describe the unique measurement capabilities of a prototype actinic (EUV wavelength) microscope that is capable of detecting small defects and reflectivity changes that occur on the scale of microns to nanometers. Types of defects: (a) Buried Substrate Defects: particles & pits (causes amplitude and/or phase variations); (b) Surface Contamination (reduces reflectivity and (possibly) contrast); (c) Damage from Inspection and Use (reduces the reflectivity of the multilayer coating). This paper presents an overview of several topics where scanning actinic inspection makes a unique contribution to EUVL research. We describe the role of actinic scanning inspection in four cases: defect repair studies; observations of laser damage; after scanning electron microscopy; and native and programmed defects.
Date: May 26, 2008
Creator: Goldberg, Kenneth A.; Rekawa, S. B.; Kemp, C. D.; Barty, A.; Anderson, E. H.; Kearney, Patrick et al.
Object Type: Article
System: The UNT Digital Library
Visualization of Excitonic Structure in the Fenna-Matthews-OlsonPhotosynthetic Complex by Polarization-Dependent Two-DimensionalElectronic Spectroscopy (open access)

Visualization of Excitonic Structure in the Fenna-Matthews-OlsonPhotosynthetic Complex by Polarization-Dependent Two-DimensionalElectronic Spectroscopy

Photosynthetic light-harvesting proceeds by the collection and highly efficient transfer of energy through a network of pigment-protein complexes. Inter-chromophore electronic couplings and interactions between pigments and the surrounding protein determine energy levels of excitonic states and dictate the mechanism of energy flow. The excitonic structure (orientation of excitonic transition dipoles) of pigment-protein complexes is generally deduced indirectly from x-ray crystallography in combination with predictions of transition energies and couplings in the chromophore site basis. Here, we demonstrate that coarse-grained excitonic structural information in the form of projection angles between transition dipole moments can be obtained from polarization-dependent two-dimensional electronic spectroscopy of an isotropic sample, particularly when the nonrephasing or free polarization decay signal rather than the photon echo signal is considered. The method provides an experimental link between atomic and electronic structure and accesses dynamical information with femtosecond time resolution. In an investigation of the Fenna-Matthews-Olson complex from green sulfur bacteria, energy transfer connecting two particular exciton states in the protein is isolated as being the primary contributor to a cross peak in the nonrephasing 2D spectrum at 400 fs under a specific sequence of polarized excitation pulses. The results suggest the possibility of designing experiments using combinations of tailored …
Date: May 26, 2008
Creator: Department of Chemistry, The University of Chicago; Department of Biology, Department of Chemistry, Washington University; Fleming, Graham; Read, Elizabeth L.; Schlau-Cohen, Gabriela S.; Engel, Gregory S. et al.
Object Type: Article
System: The UNT Digital Library
Determining the critical size of EUV mask substrate defects (open access)

Determining the critical 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 tools. 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: May 26, 2008
Creator: Goldberg, Kenneth A.; Gullikson, Eric M.; Han, Hakseung; Cho, Wonil; Jeon, Chan-Uk & Wurm, Stefan
Object Type: Article
System: The UNT Digital Library
[News Clip: Memorial day ceremony] captions transcript

[News Clip: Memorial day ceremony]

Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.
Date: May 26, 2008
Creator: KXAS-TV (Television station : Fort Worth, Tex.)
Object Type: Video
System: The UNT Digital Library
[News Clip: Racism] captions transcript

[News Clip: Racism]

Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.
Date: May 26, 2008
Creator: KXAS-TV (Television station : Fort Worth, Tex.)
Object Type: Video
System: The UNT Digital Library
[News Clip: Bees] captions transcript

[News Clip: Bees]

Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.
Date: May 26, 2008
Creator: KXAS-TV (Television station : Fort Worth, Tex.)
Object Type: Video
System: The UNT Digital Library
[News Clip: Car accidents] captions transcript

[News Clip: Car accidents]

Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.
Date: May 26, 2008
Creator: KXAS-TV (Television station : Fort Worth, Tex.)
Object Type: Video
System: The UNT Digital Library
[News Clip: Election primaries] captions transcript

[News Clip: Election primaries]

Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.
Date: May 26, 2008
Creator: KXAS-TV (Television station : Fort Worth, Tex.)
Object Type: Video
System: The UNT Digital Library
[News Clip: Mars lander] captions transcript

[News Clip: Mars lander]

Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.
Date: May 26, 2008
Creator: KXAS-TV (Television station : Fort Worth, Tex.)
Object Type: Video
System: The UNT Digital Library
[News Clip: Tornado b-roll] captions transcript

[News Clip: Tornado b-roll]

Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.
Date: May 26, 2008
Creator: KXAS-TV (Television station : Fort Worth, Tex.)
Object Type: Video
System: The UNT Digital Library
[News Clip: Sheriff] captions transcript

[News Clip: Sheriff]

Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.
Date: May 26, 2008
Creator: KXAS-TV (Television station : Fort Worth, Tex.)
Object Type: Video
System: The UNT Digital Library
[News Clip: Apartments] captions transcript

[News Clip: Apartments]

Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.
Date: May 26, 2008
Creator: KXAS-TV (Television station : Fort Worth, Tex.)
Object Type: Video
System: The UNT Digital Library
[News Clip: Fish release] captions transcript

[News Clip: Fish release]

Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.
Date: May 26, 2008
Creator: KXAS-TV (Television station : Fort Worth, Tex.)
Object Type: Video
System: The UNT Digital Library
[News Clip: Traffic] captions transcript

[News Clip: Traffic]

Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.
Date: May 26, 2008
Creator: KXAS-TV (Television station : Fort Worth, Tex.)
Object Type: Video
System: The UNT Digital Library
[News Clip: Marathon] captions transcript

[News Clip: Marathon]

Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.
Date: May 26, 2008
Creator: KXAS-TV (Television station : Fort Worth, Tex.)
Object Type: Video
System: The UNT Digital Library
[News Clip: Veterans memorial] captions transcript

[News Clip: Veterans memorial]

Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.
Date: May 26, 2008
Creator: KXAS-TV (Television station : Fort Worth, Tex.)
Object Type: Video
System: The UNT Digital Library
[News Clip: Bus emissions] captions transcript

[News Clip: Bus emissions]

Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.
Date: May 26, 2008
Creator: KXAS-TV (Television station : Fort Worth, Tex.)
Object Type: Video
System: The UNT Digital Library
[News Clip: Veteran ceremonies] captions transcript

[News Clip: Veteran ceremonies]

Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.
Date: May 26, 2008
Creator: KXAS-TV (Television station : Fort Worth, Tex.)
Object Type: Video
System: The UNT Digital Library
[News Clip: Veterans memorial ceremony] captions transcript

[News Clip: Veterans memorial ceremony]

Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.
Date: May 26, 2008
Creator: KXAS-TV (Television station : Fort Worth, Tex.)
Object Type: Video
System: The UNT Digital Library
[News Clip: Home invasion] captions transcript

[News Clip: Home invasion]

Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.
Date: May 26, 2008
Creator: KXAS-TV (Television station : Fort Worth, Tex.)
Object Type: Video
System: The UNT Digital Library
[News Clip: Traffic accidents] captions transcript

[News Clip: Traffic accidents]

Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.
Date: May 26, 2008
Creator: KXAS-TV (Television station : Fort Worth, Tex.)
Object Type: Video
System: The UNT Digital Library
[News Clip: Gas prices] captions transcript

[News Clip: Gas prices]

Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.
Date: May 26, 2008
Creator: KXAS-TV (Television station : Fort Worth, Tex.)
Object Type: Video
System: The UNT Digital Library
[News Clip: Emergency response] captions transcript

[News Clip: Emergency response]

Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.
Date: May 26, 2008
Creator: KXAS-TV (Television station : Fort Worth, Tex.)
Object Type: Video
System: The UNT Digital Library
[News Clip: Fishing reservoir] captions transcript

[News Clip: Fishing reservoir]

Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.
Date: May 26, 2008
Creator: KXAS-TV (Television station : Fort Worth, Tex.)
Object Type: Video
System: The UNT Digital Library