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in creator/contributor: "Picraux, S.T."

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Hydrogen recycling: fundamental processes

The recycling of hydrogen at the interior surfaces of plasma devices is an important and largely uncontrolled process at present. There remain important questions concerning the fundamental processes involved in recycling phenomena and the material dependence of these pocesses. A primary aim of the fundamental studies should be to develop sufficient understanding of the influence of materials properties on hydrogen recycling so that the materials and machine operating conditions can be selected… more

Date: January 1, 1979

Creator: Picraux, S.T.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Ion channeling studies of hydrogen lattice location

The application of ion channeling to study the lattice site location of hydrogen in solids is briefly reviewed. The technique has been applied to both metals and semiconductors and is particularly valuable when combined with ion implantation for the introduction of hydrogen in the study of hydrogen trapping by defects.

Date: January 1, 1979

Creator: Picraux, S.T.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Application of Ion Channeling to Radiation Damage Studies

A brief summary of the ion channeling technique is presented as it applies to the study of radiation damage. Primary emphasis is given to recent advances which allow quantitative depth profiling studies of intrinsic defects in metals.

Date: 1979~

Creator: Picraux, S. T.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Release of H and He from TiC, stainless steel and graphite by pulsed electron and furnace heating

The release of implanted D and /sup 3/He from TiC coatings, SS 304 and graphite by pulsed electron beam (e-beam) heating and furnace heating has been investigated. Low fluence implants of D or /sup 3/He and saturation fluence D implants have been studied for 0.5 - 1.5 keV D and 3 keV /sup 3/He. The retained D or /sup 3/He was monitored by ion beam analysis. The 50 ns e-beam pulsing resulted in the release of D in all materials and was compared with release during isochronal annealing in a furna… more

Date: January 1, 1980

Creator: Picraux, S.T. & Wampler, W.R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Statistical equilibrium spatial density in planar channeling

The calculation of the particle spatial probability density for planar channeling is carried out as a function of incident angle for statistical equilibrium using the continuum model. A computer code is given for the numerical computation of the spatial density. In addition, the channeled particle trajectory wavelength vs. amplitude is also obtained. An approximation is found which results in a simple analytic expression for the spatial density and gives reasonable agreement with numerical calc… more

Date: May 1, 1977

Creator: Ellison, J. A. & Picraux, S. T.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Impurity gettering

Transition metal impurities are well known to cause detrimental effects when present in the active regions of Si devices. Their presence degrades minority carrier lifetime, provides recombination-generation centers, increases junction leakage current and reduces gate oxide integrity. Thus, gettering processes are used to reduce the available metal impurities from the active region of microelectronic circuits. Gettering processes are usually divided into intrinsic (or internal) and extrinsic (or… more

Date: June 1, 1995

Creator: Picraux, S.T.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Amorphous surface layers in Ti-implanted Fe

Implanting Ti into high-purity Fe results in an amorphous surface layer which is composed of not only Fe and Ti, but also C. Implantations were carried out at room temperature over the energy range 90 to 190 keV and fluence range 1 to 2 x 10/sup 16/ at/cm/sup 2/. The Ti-implanted Fe system has been characterized using transmission electron microscopy (TEM), ion backscattering and channeling analysis, and (d,p) nuclear reaction analysis. The amorphous layer was observed to form at the surface an… more

Date: January 1, 1979

Creator: Knapp, J.A.; Follstaedt, D.M. & Picraux, S.T.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Ion implantation applied to fusion research

Ion implantation and microanalysis have been used to investigate plasma-surface interactions relevant to fusion applications. Previous results for pure metals are reviewed and current results are presented for TiB/sub 2/ and B/sub 4/C coatings for tokamak surfaces. Enhanced trapping of implanted, low-energy hydrogen has been shown to occur at room temperature in W, Au, Pd, Mo, Nb, TiB/sub 2/, and B/sub 4/C for He or other ion predamage. Hydrogen depth profiles obtained using /sup 1/H(/sup 19/F,… more

Date: January 1, 1979

Creator: Vook, F.L.; Doyle, B.L. & Picraux, S.T.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Precipitation in ion-implanted Al during electron beam pulsed annealing

TEM and ion channeling were used to examine the microstructure of Al implanted with Zn or Sb following pulsed electron beam annealing with deposited energies of 0.7 to 1.6 J/cm/sup 2/. The Zn-implanted samples show a high density of dislocations in the near surface region. Zn precipitation is not seen in the electron diffraction patterns. For Sb, randomly oriented AlSb precipitates are observed, and precipitation is inferred to have occurred in molten Al. This is accounted for with the Al-Sb bi… more

Date: January 1, 1979

Creator: Follstaedt, D.M.; Picraux, S.T. & Wampler, W.R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Sandia programs relevant to microelectronics fabrication

This report was prepared for the Semiconductor Industry and the National Laboratories Workshop held at the National Academy of Sciences, Washington, DC, February 24, 1987. It details the current Sandia program activities relevant to microelectronics fabrication.

Date: April 1, 1987

Creator: Picraux, S. T.; Vook, F. L. & Gregory, B. L.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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National Needs Drivers for Nanotechnology

Societal needs related to demographics, resources, and human behavior will drive technological advances over the next 20 years. Nanotechnology is anticipated to be an important enabler of these advances, and thus maybe anticipated to have significant influence on new systems approaches to solving societal problems as well as on extending current science and technology-based applications. To examine the potential implications of nanotechnology a societal needs-driven approach is taken. Thus the … more

Date: October 9, 2000

Creator: Yonas, G. & Picraux, S.T.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Saturation and isotopic replacement of deuterium in low-Z material

The saturation and replacement of hydrogen isotopes implanted into TiC, TiB/sub 2/, VB/sub 2/, B/sub 4/C, B, Si, and C has been examined experimentally and modeled theoretically. The deuterium saturation concentrations for these materials varied from .16 to .57. A new isotopic replacement model is presented which predicts isotopic trapping and exchange on the basis of the depth dependence of the implanted ions and the experimentally determined hydrogen saturation concentration. Our results indi… more

Date: January 1, 1980

Creator: Doyle, B.L.; Wampler, W.R.; Brice, D.K. & Picraux, S.T.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Retention, isotope exchange, and thermal release of hydrogen in candidate materials for TFTR

The materials studied included TiC, TiB/sub 2/, VB/sub 2/, B/sub 4/C, B, Si, graphite, and the metals Ti, V, and 304L stainless steel. The TiC and TiB/sub 2/ were formed by chemical vapor deposition on a graphite substrate. The C/Ti ratio of the TiC was measured to be 1.0 +- .05 by ion backscattering analysis. The Ti and V were explosively bonded to copper substrates, and the VB/sub 2/ was made by borodizing vanadium. Carbon (compression annealed pyrolytic graphite from Union Carbide and Papyex… more

Date: August 1, 1980

Creator: Wampler, W. R.; Doyle, B. L.; Brice, D. K. & Picraux, S. T.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Energetic ion beams in semiconductor processing: Summary of a DOE panel study

The trend toward smaller dimensions in integrated circuit technology presents severe physical and engineering challenges for ion implantation. These challenges, together with the need for physically-based models at exceedingly small dimensions, are leading to a new level of understanding of fundamental defect science in silicon. Recently the DOE Council on Materials requested that our panel examine the current status and future research opportunities in the area of ion beams in semiconductor pr… more

Date: December 31, 1995

Creator: Picraux, S.T.; Cchason, E. & Poate, J.M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Probe measurements of impurities in the plasma boundary of PLT

Carbon probes were exposed to the plasma edge in PLT at various distances from the plasma and to different numbers (1, 2, 3, 6, 12) of overlayed discharges. The type and areal density of impurities retained were determined using ion backscattering. The principal impurities with Z > 6 were found to be O, Fe, Cr, Ti, and Cu in decreasing order of abundance. Fluxes for these impurities at a position close to the wall were found to be respectively 14, 2.8, 0.8, 0.6 and 0.2 x 10/sup 15//cm/sup 2/ (+… more

Date: January 1, 1980

Creator: Wampler, W.R.; Picraux, S.T.; Cohen, S.A.; Dylla, H.F.; Rossnagel, S.M. & McCracken, G.M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Trapping, detrapping, and replacement of keV hydrogen implanted into graphite

Trapping and detrapping of low energy hydrogen isotopes in graphite is relevant to the collection of fuel particles in graphite probes for diagnostics of particle fluxes and energies in the plasma boundary layer, and to the recycling of fuel particles. The measurement of saturation concentrations by ..cap alpha.. profiling of D may be influenced by detrapping of deuterium by the analyzing /sup 3/He-beam.

Date: January 1, 1980

Creator: Roth, J.; Scherzer, B. M.U.; Blewer, R. S.; Brice, D. K.; Picraux, S. T. & Wampler, W. R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Long-term changes in the surface conditions of PLT

Long-term changes in the surface conditions of the PLT vacuum vessel wall have been monitoried by the periodic analysis of a variety of sample substrates (stainless steel, alumina, silicon), exposed to PLT discharges for periods of up to several months and subsequently removed for analysis by Auger electron spectroscopy (AES), photoelectron spectroscopy (ESCA), ion backscattering, nuclear reaction analysis, secondary ion mass spectrometry (SIMS), and scanning electron microscopy. Samples expose… more

Date: June 1, 1978

Creator: Cohen, S.A.; Dylla, H.F.; Rossnagel, S.M.; Picraux, S.T.; Borders, J.A. & Magee, C.W.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Flux and energy of deuterium incident on a limiter-like probe in PLT

The radial dependence of the flux and energy of deuterium incident on a probe in PLT has been determined from analysis of deuterium retained in the probe. From this data and the assumption of a poloidal symmetry it is concluded that deuterium ion impacts on the limiters can account for an impurity generation rate via sputtering of .5 - 3 x 10/sup 19/ s/sup -1/ and a power flow onto the limiters of 11 to 18% of the ohmic heating.

Date: January 1, 1979

Creator: McCracken, G.M.; Cohen, S.A.; Dylla, H.F.; Rossnagel, S.M.; Magee, C.W.; Picraux, S.T. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Hydrogen isotope trapping in materials exposed in PLT

Samples exposed at various minor radii in PLT to small numbers of high power discharges have been analyzed for the amount and depth distribution of implanted hydrogen isotopes and higher Z impurities. Comparisons of the measured H,D concentrations and depth profiles with laboratory implantations and calculated depth profiles give the energy and fluence of the hydrogen implanted in the PLT samples. For a Maxwellian distribution, characteristic temperatures of 500 to 600 eV due to plasma charge e… more

Date: April 1, 1979

Creator: Wampler, W.R.; Picraux, S.T.; Cohen, S.A.; Dylla, H.F.; McCracken, G.M.; Rossnagel, S.M. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Intra-cascade surface recombination of point defects during ion bombardment of Ge (001)

Low energy Ar and Xe ion bombardment of Ge (001) produces large numbers of point defects on the Ge surface and in the near-surface regions. Defect concentrations on the surface are detected and quantified in real time during bombardment using in situ Reflection High Energy Electron Diffraction (RHEED). We report the energy dependence of the defect yield for 70--500 eV Ar and Xe ion bombardment, and the temperature dependence of the defect yield (defects/ion) during 200 eV ion bombardment. The d… more

Date: December 31, 1993

Creator: Floro, J. A.; Kellerman, B. K.; Chason, E.; Picraux, S. T.; Brice, D. K. & Horn, K. M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Defect production and recombination during low-energy ion processing

Low-energy ion processing produces damaged, microroughened semiconductor surfaces due to the production of point defects. The authors present a study of point defect production and annealing on the Ge(001)-2x1 surface during low-energy inert ion bombardment as a function of ion energy, ion mass and substrate temperature. Ion-induced surface point defect production was quantified experimentally in real time using in situ Reflection High Energy Electron Diffraction. The observed surface defect yi… more

Date: October 1, 1994

Creator: Kellerman, B. K.; Floro, J. A.; Chason, E.; Brice, D. K.; Picraux, S. T. & White, J. M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Stability and precipitation kinetics in Si{sub 1{minus}y}C{sub y}/Si and Si{sub 1{minus}x{minus}y}Ge{sub x}C{sub y}/Si heterostructures prepared by solid phase epitaxy

This study investigates the stability of metastable Si{sub 1{minus}y}C{sub y}/Si heterostructures during rapid thermal annealing (RTA) over a temperature range of 1,000--1,150 C. Heterostructures of Si{sub 1{minus}y}C{sub y}/Si and Si{sub 1{minus}x{minus}y}Ge{sub x}C{sub y}/Si (x {equals} 0.77, Y {<=} .0014) were formed by solid phase epitaxy from C implanted, preamorphized substrates using a 30 minute 700 C anneal in N{sub 2}. The occupancy of C in substitution lattice sites was monitored by F… more

Date: December 31, 1993

Creator: Strane, J. W.; Picraux, S. T.; Stein, H. J.; Lee, S. R.; Candelaria, J.; Theodore, D. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Anisotropic displacement threshold energies in silicon by molecular dynamics simulations

A combination of molecular dynamics simulations and theoretical modeling was used to examine the orientation dependent threshold energies for displacement of silicon atoms from their lattice site due to energetic particle collisions. These results are important for a detailed understanding of both radiation effects in silicon devices and beam-enhanced stimulation of molecular beam epitaxial growth. The molecular dynamics code developed for this study, which employs a Tersoff interaction potenti… more

Date: January 1, 1990

Creator: Miller, L.A.; Brice, D.K.; Picraux, S.T. (Sandia National Labs., Albuquerque, NM (USA)) & Prinja, A.K. (New Mexico Univ., Albuquerque, NM (USA). Dept. of Chemical and Nuclear Engineering)

Item Type: Article

Partner: UNT Libraries Government Documents Department