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Hard carbon field emitters for flat panel displays

Description: Goal was to determine the field emission of laser-ablated hard carbon coatings. The coatings, deposited on Mo tip arrays, were found (with ion field emission microscope) to have excellent Fowler-Nordheim behavior: plots of the logarithm of emission current divided by voltage squared vs inverse of voltage are linear. This indicates the tips are operating as field emitters. Field emission current of as-coated tip arrays was lower than uncoated tips; this disagrees with observations in literature. Hydrogen plasma cleaning was studied. Cleaned, laser-ablated carbon coatings of field emission tips have two benefits: the emission current increases at fixed voltage, and stability of the emission increases. These results would be advantageous for field emission flat panel displays.
Date: March 20, 1996
Creator: Kania, D.R.
Partner: UNT Libraries Government Documents Department

Diamond radiation detectors I. Detector properties for IIa diamond

Description: The detector properties and carrier dynamics of type IIa diamonds are reasonably well understood. The trends in the electron and hole mobilities have been characterized as a function of temperature, impurity content, electric field and carrier density. The carrier lifetimes are coupled through the nitrogen impurity. This leaves us with typical samples with collection distances of 20 to 50 micrometers. The detailed dynamics of the carriers can be modeled using a rate equation analysis. Much progress has been made in understanding the detector properties of diamond, but continued progress has been limited by the geologic processes used to make the material, for example sample size and no synthesis control. CVD diamond promises to eliminate these restrictions.
Date: May 16, 1997
Creator: Kania, D. R.
Partner: UNT Libraries Government Documents Department

Diamond radiation detectors II. CVD diamond development for radiation detectors

Description: Interest in radiation detectors has supplied some of the impetus for improving the electronic properties of CVD diamond. In the present discussion, we will restrict our attention to polycrystalhne CVD material. We will focus on the evolution of these materials over the past decade and the correlation of detector performance with other properties of the material.
Date: May 16, 1997
Creator: Kania, D.R.
Partner: UNT Libraries Government Documents Department

The application of photoconductive detectors to the measurement of x-ray production in laser produced plasmas

Description: Photoconductive detectors (PCDs) offer an attractive alternative for the measurement of pulsed x-rays from laser produced plasmas. These devices are fast (FWHM approx.100 ps), sensitive and simple to use. We have used InP, GaAs, and Type IIa diamond as PCDs to measure x-rays emission from 100 eV to 100 keV. Specifically, we have used these detectors to measure total radiation yields, corona temperatures, and hot electron generated x-rays from laser produced plasmas. 5 refs., 4 figs.
Date: August 1, 1987
Creator: Kania, D.R.; Bell, P. & Trebes, J.
Partner: UNT Libraries Government Documents Department

Synchrotron based measurements of the soft x-ray performance of thin film multilayer structures

Description: Using synchrotron radiation, measuring system has been developed to test the performance of layered synthetic microstructures (LSMs) from 50 to 500 eV. The measurement techniques are reviewed, and results are compared to theoretical predictions of LSM performance. (LEW)
Date: January 1, 1985
Creator: Kania, D.R.; Bartlett, R.J. & Trela, W.J.
Partner: UNT Libraries Government Documents Department

Preliminary investigation of an additive approach to the fabrication of precision aspheres

Description: We report progress in the aspherization of precision optical substrates via deposition of graded period Mo/Si multilayer coatings using a masking technique. These preliminary results show good agreement between the measured and desired thickness profiles over 85% of the sample, however, thickness deviations of up to 7 % are observed in the central area. The errors are attributed to misalignments of the mask relative to the substrate during deposition.
Date: May 24, 1996
Creator: Weber, F.W.; Montcalm, C.; Vernon, S.P. & Kania, D.R.
Partner: UNT Libraries Government Documents Department

Characterization of SAL605 negative resist at {lambda}=13 nm

Description: We have characterized the response of the negative resist SAL605 in the extreme ultraviolet ({lambda}=13 nm). The sensitivity was found to be {approx}1 mJ/cm{sup 3} for all conditions studied. We have identified processing conditions leading to high ({gamma}{gt}4) contrast. The resist response was modeled using Prolith/2 and the development parameters were obtained from the exposure curves.
Date: May 24, 1996
Creator: La Fontaine, B.; Ciarlo, D.; Gaines, D.P. & Kania, D.R.
Partner: UNT Libraries Government Documents Department

Coating strategy for enhancing illumination uniformity in a lithographic condenser

Description: A three-element Koehler condenser system has been fabricated, characterized, and integrated into an EUV lithographic system. The multilayer coatings deposited on the optics were designed to provide optimal radiation transport efficiency and illumination uniformity. Extensive EUV characterization measurements performed on the individual optics and follow-on system measurements indicated that the condenser was operating close to design goals. Multilayer d-spacings were within 0.05 nm of specifications, and reflectances were approximately 60%. Illumination uniformity was better than {plus_minus}10%. The broadband transport efficiency was 11%.
Date: January 26, 1995
Creator: Gaines, D.P.; Vernon, S.P.; Sommargren, G.E. & Kania, D.R.
Partner: UNT Libraries Government Documents Department

High speed detection of thermonuclear neutrons with solid state detectors

Description: Inertial confinement fusion experiments generate thermonuclear neutrons on subnanosecond time scales. To understand the burning of DT fuel, we have developed a 14 MeV neutron detector with subnanosecond time response. The detectors are made of neutron damaged, bulk GaAs with electron-hole recombination times of 60 ps. The conductivity of the detector is modulated by the energy deposited by the neutrons interacting in the detector that create free carriers. The fast electron hole recombination time of this material quickly removes these radiation generated carriers from the conduction process resulting in extremely fast response times. The measurements and calculations of the sensitivity of these detectors to 14 MeV neutrons are in good agreement. 3 refs., 1 fig.
Date: October 1, 1987
Creator: Kania, D.R.; Lane, S.; Jones, B.; Bennett, C.; Prussin, S. & Detzon, M.S.
Partner: UNT Libraries Government Documents Department

Performance of multilayer dispersion elements from 80 to 500 eV

Description: We have measured the reflectivity of several multilayer dispersion elements between 80 and 500 eV. Two samples of ReW-C and one of Ni-C with 2d spacing of approximately 70 A and 150 A were tested at angles of incidence between 10/sup 0/ to 80/sup 0/. Measurements were made by fixing the incident and reflected angles (Bragg) and scanning the photon energy. Theoretical analyses of these multilayers have also been made and the results are compared with the experimental measurements.
Date: January 1, 1983
Creator: Bartlett, R.J.; Kania, D.R.; Trela, W.J.; Kaellne, E.; Lee, P. & Spiller, E.
Partner: UNT Libraries Government Documents Department

Performance of transition metal-carbon multilayer mirrors from 80 to 350 eV

Description: We report measurements and theoretical calculations of the reflectivity and resolving power of multilayer mirrors made of alternate layers of a transition metal (Co, Fe, V, and Cr) and carbon (2d approx. = 140 A) from 80 to 350 eV.
Date: March 1, 1984
Creator: Kania, D.R.; Bartlett, R.J.; Trela, W.J.; Spiller, E. & Golub, L.
Partner: UNT Libraries Government Documents Department

Magnetic force microscopy of single-domain cobalt dots patterned using interference lithography

Description: We have fabricated arrays of Co dots of diameters 100 and 70 nm using interference lithography. Density of these arrays is 7.2x10{sup 9}/in{sup 2}. Magnetic force microscopy indicate that the Co dots are single domain with moments that can be controlled to point either in-plane or out-of-plane. Interference lithography is a process that is easily scaled to large areas and is potentially capable of high throughput. Large, uniform arrays of single-domain structures are potentially useful for high-density, low-noise data storage.
Date: March 20, 1996
Creator: Fernandez, A.; Bedrossian, P.J.; Baker, S.L.; Vernon, S.P. & Kania, D.R.
Partner: UNT Libraries Government Documents Department

Large GMR values of sputtered Co/Cu multilayer structures with Co-Cu buffer layers

Description: We demonstrate large giant magnetoresistance (GMR) values of Co/Cu multilayers (MLs) sputtered on combined Co18{angstrom}/Cu48{angstrom} buffer layer. GMR values at room temperature reach 62% at the first antiferromagnetically (AF) coupling peak and 33% at the 2nd AF coupled peak, which are very close to those found in Co/Cu MLs sputtered on a Fe buffer layer. The large GMR effect is attributed to the superior superlattice structure of these samples, as evidenced by the x-ray reflectivity data as well as the TEM micrographs. In particular, the role of thin Co initial layer deposited beneath the Cu buffer layer on improved ML structure has been clarified from cross-sectional micrographs of high-resolution TEM.
Date: February 29, 1996
Creator: Huai, Y.; Vernon, S.P.; Stearns, D.G.; Cerjan, C. & Kania, D.R.
Partner: UNT Libraries Government Documents Department

EUV reticle pattern repair experiments using 10 KeV neon ions

Description: Any potential lithography must demonstrate an industrially-compatable reticle pattern repair process before the lithographic process can be seriously considered for production. Repair of clear defects on ELTV reticles (i.e., regions on the mask which are reflective and should be non-reflective) requires the deposition of a thin layer of absorbing material. This process has been demonstrated in commercially available tools which were originally developed to repair proximity-print x-ray lithography masks. However, the repair of opaque defects (i.e., the recovery of reflectivity from regions on the reticle covered with an absorber) is more difficult. Opaque defect repair requires the removal of the absorber layer without damaging the underlying multilayer, a process which could degrade the mirror reflectivity. While opaque defect repair processes have been demonstrated in a research environment these processes may not be commercially suitable. We are developing reticle repair processes that will be consistent with a commercially available repair tool. In this paper, we report on our first results.
Date: January 19, 1995
Creator: Hawryluk, A.M.; Kania, D.R.; Celliers, P.; DaSilva, L.; Stith, A.; Stewart, D. et al.
Partner: UNT Libraries Government Documents Department

Non-thermal effects in a hot dense plasma

Description: A hollow gas shell Z-pinch device is described, and some initial observations are shown to lead to the conclusion that there is an energetic electron beam produced along the axis of the collapsing gas shell. An experiment is summarized that directly measured some of the characteristics of this runaway electron beam. Finally, the results of an experiment which observed a new affect are presented along with a model that uses a runaway electron beam to explain this new effect. 9 refs., 17 figs.
Date: January 1, 1985
Creator: Jones, L.A.; Kania, D.R.; Hammel, B.A.; Kallne, E.; Maestas, M.D.; McGurn, J. et al.
Partner: UNT Libraries Government Documents Department

Single-mode fiber-optic sensor for high currents

Description: We are developing a pulsed current sensor that will be less intrusive than present sensors and that we hope will remain linear to much higher current levels. Polarized laser light is transmited by a low-birefringence, single mode optical fiber that encircles the current carrier. We observe the Faraday rotation of the polarization plane in the current-induced magnetic field. We have measured a Verdet constant of about 260/sup 0//MA for 633 nm light in Lightwave Technologies, Inc., Model F1506C fiber, and we have detected currents of up to 12 MA in pulses 0.5 to 40 ..mu..s long. Our major problems have involved signal noise from stray plasma light getting into the fiber and shock-induced birefringence that rotates the polarization slightly. Future plans are to try to Sagnac interferometer to reduce the sensitivity to shock waves.
Date: January 1, 1983
Creator: Veeser, L.R.; Caird, R.S.; Freeman, B.L.; Kania, D.R.; Kruse, P.J.; Trainor, R.J. et al.
Partner: UNT Libraries Government Documents Department

Reticle blanks for extreme ultraviolet lithography: Ion beam sputter deposition of low defect density Mo/Si multilayers

Description: We report on growth of low defect density Mo/Si multilayer (ML) coatings. The coatings were grown in a deposition system designed for EUVL reticle blank fabrication. Complete, 81 layer, high reflectance Mo/Si ML coatings were deposited on 150 mm dia (100) oriented Si wafer substrates using ion beam sputter deposition. Added defects, measured by optical scattering, correspond to defect densities of 2x10{sup -2}/cm{sup 2}. This represents a reduction in defect density of Mo/Si ML coatings by a factor of 10{sup 5}.
Date: June 24, 1996
Creator: Vernon, S.P.; Kania, D.R.; Kearney, P.A.; Levesque, R.A.; Hayes, A.V.; Druz, B. et al.
Partner: UNT Libraries Government Documents Department

Performance of a two-mirror, four-reflection, ring-field optical system at {lambda}=13 nm

Description: Performance of an Extreme Ultraviolet Lithography (EUVL) imaging optic was characterized by printing resolution test images in resist. While features as small as 0.137 {mu}m were successfully printed, a resolution of 0.175 {mu}m better represents the performance of the system over the full 0.9 mm{sup 2} image field. The contrast of the aerial image was estimated to be about 40% or less for the fine features printed. This low contrast value is attributed to a degradation of the modulation transfer function due to presence of scattered light in the image.
Date: May 24, 1996
Creator: La Fontaine, B.; Gaines, D.P.; Kania, D.R.; Sommargren, G.E.; Baker, S.L. & Ciarlo, D.
Partner: UNT Libraries Government Documents Department

Measuring the effect of scatter on the performance of a lithography system

Description: The distribution of scattered light at the image plane of an extreme ultraviolet lithography (EUVL) system was measured, in situ. These measurements revealed a significant degradation of the modulation transfer function of the imaging optic, relative to its value in the absence of scattering.
Date: May 24, 1996
Creator: La Fontaine, B.; Daly, T.P.; Chapman, H.N.; Gaines, D.P.; Stearns, D.G.; Sweeney, D.W. et al.
Partner: UNT Libraries Government Documents Department

Quartz substrates for EUVL reticles

Description: A EUVL reticle blank was fabricated on a specially polished quartz blank. The stress-induced distortion of the multilayer coating was unacceptably large. The distortion can be effectively eliminated by coating the backside of the reticle blank with an identical coating. This strategy has the potential to eliminate multilayer induced stress distortion for the reticle blank in a manner which is compatible with the existing reticle fabrication infrastructure.
Date: February 10, 1995
Creator: Kania, D.R.; Weber, F.J.; Vernon, S.P.; Hawryluk, A.; Baker, S.L.; Golub, A.M. et al.
Partner: UNT Libraries Government Documents Department

High average power laser for EUV lithography

Description: We have demonstrated the operation of a high average power, all solid state laser and target system for EUV lithography. The laser operates at 1.06 {mu}m with a pulse repetition rate of 200 Hz. Each pulse contains up to 400 mJ of energy and is less than 10 ns in duration. The ELTV conversion efficiency measured with the laser is independent of the laser repetition rate. Operating at 200 Hz, the laser has been used for lithography using a 3 bounce Kohler illuminator.
Date: January 19, 1995
Creator: Kania, D.R.; Gaines, D.P.; Hermann, M.; Honig, J.; Hostetler, R.; Levesque, R. et al.
Partner: UNT Libraries Government Documents Department

High Z interaction physics on Nova

Description: A detailed understanding of the interaction of laser light with high Z materials is important for the development of indirect drive inertial confinement fusion. To improve our understanding of the interaction of 0.35 ..mu..m light at intensities between 10/sup 14/ and 10/sup 15/ W/cm/sup 2/ with high Z materials, we have performed a variety of experiments to address important physics issues. Hydrodynamics and ablation, transport processes, and x-ray conversion have been studied with thin Au dot targets and Au and Be mixture targets. 2 refs., 5 figs.
Date: August 1, 1987
Creator: Kania, D.R.; Albritton, J.; Hatcher, B.; Kauffman, R.; Kornblum, H.; Langer, S. et al.
Partner: UNT Libraries Government Documents Department

Precision optical aspheres for extreme ultraviolet lithography

Description: We have demonstrated significant advances in the production of aspheric optics for extreme ultraviolet lithography. An optic has been fabricated with an aspheric departure of 1.5 {mu}m, a figure error of 0.7 nm rms and a nanoroughness of 0.25 nm rms. Further improvements are required in the figure and nanoroughness to reach high throughput and near diffraction limited performance in an EUVL system. 8 refs., 2 figs.
Date: May 1, 1996
Creator: Kania, D.R.; Gaines, D.P.; Sweeney, D.S.; Sommargren, G.E.; La Fontaine, B.; Vernon, S.P. et al.
Partner: UNT Libraries Government Documents Department