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Title: Tantalum Tube for Diffusion Barriers

 [1];  [1];  [2]
  1. Shear Form, Inc., Bryan, TX (United States)
  2. Texas A & M Univ., College Station, TX (United States)
Publication Date:
Research Org.:
Shear Form, Inc., Bryan, TX (United States)
Sponsoring Org.:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
OSTI Identifier:
Report Number(s):
Final Technical Report on DOE SBIR Grant DE-SC0006441
DOE Contract Number:
Type / Phase:
Resource Type:
Technical Report
Country of Publication:
United States
36 MATERIALS SCIENCE; 42 ENGINEERING; 43 PARTICLE ACCELERATORS; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; tantalum; diffusion barrier; Nb3Sn; severe plastic deformation; superconductor wire

Citation Formats

Barber, Robert E., Foley, David C., and Hartwig, Karl T. Tantalum Tube for Diffusion Barriers. United States: N. p., 2017. Web.
Barber, Robert E., Foley, David C., & Hartwig, Karl T. Tantalum Tube for Diffusion Barriers. United States.
Barber, Robert E., Foley, David C., and Hartwig, Karl T. 2017. "Tantalum Tube for Diffusion Barriers". United States. doi:.
title = {Tantalum Tube for Diffusion Barriers},
author = {Barber, Robert E. and Foley, David C. and Hartwig, Karl T.},
abstractNote = {},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = 2017,
month = 6

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  • The characteristics of barriers suitable for isotopic separation by gaseous diffusion are described mathematically. It is shown how the results given by the experimental methods on structure control of barriers (A/Conf.15/P/ 1265) can lead to a representation of barriers and will permit the elimination of non-usable industrial barriers by detecting too numerous large pores or microfissures and the existence of leaks at the joints. The discussion is limited to the use of information given by the specific permeability and the separation efficiency. Some examples of routine measurements are given to show how imperfect barriers are detected. (J.S.R.)
  • Westinghouse Hanford Company and Pacific Northwest Laboratory are jointly developing earthen protective barriers for the near-surface disposal of radioactive and hazardous waste at the Hanford Site. The proposed barrier design consists of a blanket of fine-textured soil overlying a sequence of layers, varying from sand to basalt riprap. This project is part of a research program to assesses the long-term performance of the barrier in inhibiting plants, animals, and water from contacting buried waste and potentially transporting contaminants to the groundwater or to the land surface. The purpose of this report is to describe the work performed in fiscal yearsmore » 1988--1989 on construction and operation of the Small-Tube Lysimeter Test Facility (SLTF) located adjacent to the Hanford Meteorological Station. The experiments discussed in this report were designed to measure the influence of erosion control practices and alternate barrier-layer configurations on water movement within the barrier, and extraction of water from the barrier. Included in the report are descriptions of the experimental design, fill specifications. Baseline data, weight change data through August 1989. 31 refs., 17 figs., 4 tabs.« less
  • Cosputtered W70Zr30 and W40Zr60 films are investigated as diffusion barriers between Aq and Si. W-Zr alloys of both compositions were determined by x-ray diffraction to crystallize at 900/sup 0/C on A1/sub 2/O/sub 3/ substrates. On <111>Si the W-Zr alloy reacts with the substrate above 700/sup 0/C, forming a uniform, polycrystalline layer of W and Zr silicides. Despite the high crystallization temperatures, an A1 overlayer interacts with W-Zr and the Si substrate at approx. 500/sup 0/C. MeV He-backscattering spectrometry, SEM, and EDAX indicate that this reaction is laterally nonuniform with the formation of deep pits penetrating into the Si substrate. Themore » authors believe this to be a consequence of fractures in the W-Zr layer induced by reaction with A1. Electrical measurements on shallow junction diodes with /W-Zr/Al contacts show that the device junctions were thermally stable after a 30 min annealing at 450/sup 0/C but were all shorted after heat treatments at 500/sup 0/C or above.« less
  • As device dimensions in integrated circuits are continuously scaled, it becomes essential for device reliability to incorporate diffusion barriers in contact structures to semiconductors. With the advent of low-pressure chemical vapor deposition processes, tungsten-based barrier materials are expected to play increasing roles in contact metallurgy. Reactively sputtered tungsten nitride (W(x)N(1-X) layers are investigated as diffusion barriers between Al overlayers and Si shallow n(+)-p junctions. Both amorphous W(80)N(20) and polycrystalline W (60)N(40) films were found to be very effective in preserving the integrity of the n(+)-p diodes for 30-min vacuum annealing up to 575 C. Diode failure at higher temperatures ismore » caused by localized penetration of Al into (Si) through the W(x)N(1-x) barriers. The effectiveness of the barrier decreases for polycrystalline W(90)N(10) and is worse for pure W.« less