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Particle transport in plasma reactors

Description: SEMATECH and the Department of Energy have established a Contamination Free Manufacturing Research Center (CFMRC) located at Sandia National Laboratories. One of the programs underway at the CFMRC is directed towards defect reduction in semiconductor process reactors by the application of computational modeling. The goal is to use fluid, thermal, plasma, and particle transport models to identify process conditions and tool designs that reduce the deposition rate of particles on wafers. The prog… more
Date: January 1, 1995
Creator: Rader, D. J.; Geller, A. S.; Choi, Seung J. & Kushner, M. J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

A Conceptual Design Methodology for Enhanced Conformance Quality

Description: Traditional manufacturing practice has depended upon Statistical Process Control (SPC) to eliminate defects. However, our research demonstrates that these sampling based methods significantly underestimate the tails of a distribution. As a consequence of the limitations of SPC, mistakes require different methods of control to achieve defect rates in the tens of parts per million range. Furthermore, product complexity contributes to defects resulting from both mistakes and excess variation. Corr… more
Date: December 31, 1995
Creator: Hinckley, C. M. & Barkan, Phillip
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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High resolution transmission electron microscopy study of diamond films grown from fullerene precursors

Description: High-resolution transmission electron microscopy (HRTEM) has been used to investigate the microstructure of diamond films grown by plasma-assisted chemical vapor deposition using fullerene precursors. HRTEM observations of as-grown films revealed an array of larger crystals (>200 nm) within a polycrystalline matrix of much smaller crystallites (<20 nm). The randomly oriented small crystallites were nearly free of structural imperfections such as stacking faults or twins, while the larger ones h… more
Date: July 1995
Creator: Luo, J. S.; Gruen, D. M. & Krauss, A. R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Research on the stability, electronic properties, and structure of a-Si:H and its alloys. Final subcontract report, 1 June 1991--31 May 1994

Description: The authors research has focused on defect metastability and a-Si:C:H alloys. A new aspect of the metastability is the growing interest in the defect recovery process. They have continued to explore the role of hydrogen in the metastability and other properties of a-Si:H. This has led them to perform first principles calculations of Si-H bonding configurations. Another new feature of the metastability work is the study of the effects in hydrogenated poly-silicon. They have grown and studied the… more
Date: July 1, 1995
Creator: Jackson, W.B.; Johnson, N.; Nickel, N.; Schumm, G.; Street, R.A.; Thompson, R. et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Branches on the family tree: Superconductivity in epitaxial films of {open_quotes}first-in-line{close_quotes} descendants of the parent compound SrCuO{sub 2}

Description: The defect-induced carrier doping in epitaxial films of the parent compound SrCuO{sub 2} is reviewed. Two superconducting descendants were synthesized by expanding the role of natural defects in the parent SuCuO{sub 2} films, namely, the Ruddlesheim-Popper phases Sr{sub n+1}Cu{sub n}O{sub 2n+1} and a nonstoichiometric variant of the oxycarbonate Sr{sub 2}CuO{sub 2}(CO{sub 3}). The synthesis and structures are described.
Date: April 1, 1995
Creator: Feenstra, R.; Budai, J. D. & Norton, D. P.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Heavy-Section Steel Technology Program Semiannual progress report, April--September 1993. Volume 10, No. 2

Description: The Heavy-Section Steel Technology (HSST) Program is conducted for the Nuclear Regulatory Commission by Oak Ridge National Laboratory (ORNL). The program focuses on the development and validation of technology for the assessment of fracture-prevention margins in commercial nuclear reactor pressure vessels. The HSST Program is organized in 12 tasks: Program management, fracture methodology and analysis, material characterizations and properties, special technical assistance, fracture analysis co… more
Date: May 1, 1995
Creator: Pennell, W.E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Critical parameters of superconducting materials and structures

Description: We report here the completion of a one year project to investigate the synthesis, electronic structure, defect structure, and physical transport properties of high temperature superconducting oxide materials. During the course of this project we produced some of the finest samples of single crystal detwinned YBa{sub 2}Cu{sub 3}O{sub 7}, and stoichiometrically perfect (Ba,K)BiO{sub 3}. We deduced the Fermi surface of YBa{sub 2}Cu{sub 3}O{sub 7}, (La,Sr){sub 2}CuO{sub 4}, and (Ba,K)BiO{sub 3} thr… more
Date: February 1, 1995
Creator: Fluss, M.J.; Howell, R.H.; Sterne, P.A.; Dykes, J.W.; Mosley, W.D.; Chaiken, A. et al.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Expansion on reduction of calcium doped lanthanum chromite

Description: Doped lanthanum chromites have been considered as interconnect materials for the solid oxide fuel cell (SOFC) because of their favorable chemical and electrical properties under both oxidizing and reducing environments. Several investigators have studied the materials properties of the doped lanthanum chromites to optimize their overall performance as an interconnect material. These properties include electrical conductivity, thermal expansion, sinterability, and chemical compatibility with oth… more
Date: July 1995
Creator: Carter, J. D.; Hendriksen, P. V. & Mogensen, M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Automated laser scatter detection of surface and subsurface defects in Si{sub 3}N{sub 4} components

Description: Silicon Nitride (Si{sub 3}N{sub 4}) ceramics are currently a primary material of choice to replace conventional materials in many structural applications because of their oxidation resistance and desirable mechanical and thermal properties at elevated temperatures. However, surface or near-subsurface defects, such as cracks, voids, or inclusions, significantly affect component lifetimes. These defects are currently difficult to detect, so a technique is desired for the rapid automated detection… more
Date: June 1995
Creator: Steckenrider, J. S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Development of radiation detectors based on hydrogenated amorphous silicon and its alloys

Description: Hydrogenated amorphous silicon and related materials have been applied to radiation detectors, utilizing their good radiation resistance and the feasibility of making deposits over a large area at low cost. Effects of deposition parameters on various material properties of a-Si:H have been studied to produce a material satisfying the requirements for specific detection application. Thick(-{approximately}50 {mu}m), device quality a-Si:H p-i-n diodes for direct detection of minimum ionizing parti… more
Date: April 1, 1995
Creator: Hong, Wan-Shick
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
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Optical scatter as a diagnostic tool for studying bulk defects which cause laser damage in conventional and rapid growth KP and DKDP

Description: Single crystals of KH{sub 2}PO{sub 4} (KDP) and (D{sub x}H{sub 1-x}){sub 2}PO{sub 4} (DKDP) will be used for frequency conversion and as part of a large aperture optical switch in the proposed National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory (LLNL). These crystals must have good optical properties and high laser damage thresholds. Currently these crystals have a lower laser damage threshold than other optical materials in the laser chain which has forced designers … more
Date: July 10, 1995
Creator: Woods, B.; Runkel, M. & Yan, M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Electrical biasing and voltage contrast imaging in a focused ion beam system

Description: We present two new techniques that enhance conventional focused ion beam (FIB) system capabilities for integrated circuit (IC) analysis: in situ electrical biasing and voltage contrast imaging. We have used in situ electrical biasing to enable a number of advanced failure analysis applications including (1) real time evaluation of device electrical behavior during milling and deposition, (2) verification of IC functional modifications without removal from the FIB system, and (3) ultraprecision … more
Date: September 1, 1995
Creator: Campbell, A. N.; Soden, J. M.; Rife, J. L. & Lee, R. G.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Fast and slow border traps in MOS devices

Description: Convergent lines of evidence are reviewed which show that near-interfacial oxide traps (border traps) that exchange charge with the Si can strongly affect the performance, radiation response, and long-term reliability of MOS devices. Observable effects of border traps include capacitance-voltage (C-V) hysteresis, enhanced 1/f noise, compensation of trapped holes, and increased thermally stimulated current in MOS capacitors. Effects of fast (switching times between {approximately} 10{sup {minus}… more
Date: September 1, 1995
Creator: Fleetwood, D.M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Defect studies with isotopically designed semiconductors

Description: Most semiconductors consist of elements which are made up of a number of stable isotopes. Access to highly enriched isotopes in macroscopic quantities opens up new and unique possibilities for semiconductor defect research. The use of isotope mass sensitive effects including the frequencies of local vibrational modes, nuclear spin, as well as nuclear cross sections for thermal neutron capture for the study of native and impurity defects will be reviewed and illustrated with relevant examples. F… more
Date: July 1, 1995
Creator: Haller, E.E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Characterization of silicon implanted SiO{sub 2} layers using positron annihilation spectroscopy

Description: Silicon implanted thermal SiO{sub 2} layers were studied using depth-resolved positron annihilation spectroscopy (PAS) and transmission electron microscopy (TEM). TEM observations show the presence of silicon nanocrystals (Si{sub nc}) in the region between 200 nm and 200 nm. The defect annealing behavior is studied by means of PAS. For 1000{degrees}C annealed samples at a depth for which Si{sub nc} are observed, a distinctive PAS signal is detected and ascribed to the Si{sub nc}/SiO{sub 2} inte… more
Date: August 1, 1995
Creator: Ghislotti, G.; Nielsen, B.; Asoka-Kumar, P.; Lynn, K. G.; Szeles, C.; Bottani, C. E. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Active fiber optic technologies used as tamper-indicating devices

Description: The Sandia National Laboratories (SNL) Safeguards and Seals Evaluation Program is evaluating new fiber optic active seal technologies for use at Department of Energy (DOE) facilities. The goal of the program is to investigate active seal technologies that can monitor secured containers storing special nuclear materials (SNM) within DOE vaults. Specifically investigated were active seal technologies that can be used as tamper-indicating devices to monitor secured containers within vaults while p… more
Date: November 1, 1995
Creator: Horton, P.R.V. & Waddoups, I.G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Muonium quantum diffusion and localization in cryocrystals

Description: The authors review their recent study of atomic muonium ({mu}{sup +}e{sup {minus}} or Mu, a light isotope of the hydrogen atom) diffusion in the simplest solids--Van der Walls cryocrystals. They give experimental evidence of the quantum-mechanical nature of the Mu diffusion in these solids. The results are compared with the current theories of quantum diffusion in insulators. The predicted T{sup {+-}7} power-law temperature dependence of the Mu hop rate is observed directly for the first time i… more
Date: August 1, 1995
Creator: Storchak, V.; Brewer, J.H. & Morris, G.D.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Activation of shallow dopants in II-VI compounds

Description: The amphoteric native defect model is applied to the understanding of the variations in the dopant activation efficiency in II-VI compounds. It is shown that the location of the common energy reference, the Fermi level stabilization energy, relative to the band edges can be used to determine the doping induced reduction of the formation energy and the enhancement of the concentration of compensating native defects. The model is applied to the most extensively studied compound semiconductors as … more
Date: August 1, 1995
Creator: Walukiewicz, W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Microdefects in nitrogen doped FZ silicon revealed by Li+ drifting

Description: ULSI technology requires ultra-thin device oxides with excellent breakdown integrity. Recent studies have unveiled degraded dielectric breakdown voltage (DBV) performance of the ultra-thin oxides. These findings suggest that one source for poor oxide integrity is the incorporation of native defects from the Si substrate during oxide growth. Primary defect candidates are D defects which exist mostly in the central region of floating zone (FZ) grown Si crystals. Nitrogen (N) doping eliminates D d… more
Date: July 1, 1995
Creator: Knowlton, W. B.; Walton, J. T. & Lee, J. S.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Defects and morphological concerns in electroluminescent polymers

Description: The degradation of luminescence in phenylenevinylene polymers is due to exciton diffusion to quenching defects. The microscopic structure of these defects is identified by in-situ vibrational spectroscopy. The authors present evidence that the defect quenching is due to charge transfer by studies on model phenylenevinylene oligomer. In the absence of defect quenchers, the authors have achieved nearly exponential photoluminescence decay with observed lifetimes > 1 ns and a fourfold increase in e… more
Date: July 24, 1995
Creator: Yan, M.; Rothberg, L. & Galvin, M.E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Atomistic studies in grain boundaries in NiAl

Description: This paper presents the results of atomistic studies of grain boundaries in NiAl B2 alloy. The interatomic forces are described by Finnis-Sinclair type N-body potentials, and are fitted to properties of NiAl. The results show that the structure, energy and cohesive strength of a grain boundary depend strongly on its chemical configurations, and a grain boundary with surplus of Al is the weakest. Energies of antisite defects at the grain boundary {Sigma}5 (210) are also calculated, and the resul… more
Date: January 1, 1995
Creator: Yan, M.; Chen, S. P. & Vitek, V.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Positron microscopy

Description: The negative work function property that some materials have for positrons make possible the development of positron reemission microscopy (PRM). Because of the low energies with which the positrons are emitted, some unique applications, such as the imaging of defects, can be made. The history of the concept of PRM, and its present state of development will be reviewed. The potential of positron microprobe techniques will be discussed also.
Date: February 1, 1995
Creator: Hulett, L. D. Jr. & Xu, J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

An interim report on shallow-flaw fracture technology development

Description: Shallow-flaw fracture technology is being developed for application to the safety assessment of radiation-embrittled nuclear reactor pressure vessels (RPVS) containing flaws. Fracture mechanics tests on RPV steel, coupled with detailed elastic-plastic finite-element analyses of the crack-tip stress fields, have shown that (1) constraint relaxation at the crack tip of shallow surface flaws results in increased data scatter but no increase in the lower-bound fracture toughness, (2) the nil ductil… more
Date: June 1, 1995
Creator: Pennell, William E.; Bass, B. Richard; Bryson, John W. & McAfee, Wallace J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Energy changes in transforming solids. Final report, January 31, 1991--January 31, 1995

Description: The following topics are discussed: A new thermodynamical theory of continuum damage mechanics capable of incorporating non-isothermal processes and of providing explicit expressions for the thermal dissipation during damage evolution; the advancement of the methodology of heterogenization to analyze elastic bodies with defects; and investigations of bonded dissimilar piezoelectric half-spaces.
Date: April 3, 1995
Creator: Herrmann, G. & Barnett, D.M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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