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Vacuum deposited polymer films: Past, present, and future applications

Description: Two extremely high rate processes have been developed for the vacuum deposition of polymer thin films. Dubbed the PML (for Polymer Multi-Layer) and LML (for Liquid Multi-Layer) processes, the PML technique was originally developed for the manufacture of polymer/aluminum surface mount capacitors while the LML method arose from a need to fabricate lithium polymer batteries. These processes have since been found to be compatible with most other vacuum deposition techniques in, integrated, in-line coating processes. Battelle has developed an extensive program, and a great deal of hardware, to pursue a wide variety of PML and LML applications which integrate these two process technologies with other, conventional, vacuum deposition methods. The historical development of the technologies is reviewed and the Battelle PML/LML facilities are described. Current Battelle work involving solar thermal control films, PML QWOTs, and polymer/metal high reflectors are also discussed. Battelle PML work that is just starting, involving non-linear optical materials/devices, lithium polymer battery fabrication, electrochromic devices, and polymer/oxide multilayers, is discussed as well.
Date: November 1, 1994
Creator: Affinito, J.; Martin, P.; Gross, M. & Bennett, W.
Partner: UNT Libraries Government Documents Department

Deposition of field emissions cathodes over large areas

Description: Field emission cathodes (FECs) with characteristics of cold emission, low voltage operation, high current density and microscopic size meet the requirements for an electron source for use in vacuum microelectronics. Deposition efforts have focused on evaporation techniques, as electron beam, to produce the size and shape of cathode required for efficient operation. After two decades of development, the convention for FEC synthesis involves coating with very high tolerances for thickness uniformity using a planetary substrate fixture and a long source-to-substrate distance. A further reduction in the operating voltage results by increasing the density of emitters through a reduction of cathode size and spacing. In addition, the objective of scaling the substrate size from small to large areas has compounded the manufacturing requirements to a point beyond that which is obtainable through modifications to the conventional FEC deposition process. We have been successful in a new alternative approach to design, assemble and operate a system that enables FEC synthesis over large areas through the control of deposition source divergence and step-and-repeat substrate handling.
Date: April 3, 1997
Creator: Jankowski, A.F. & Hayes, J.P.
Partner: UNT Libraries Government Documents Department

HYDROGEN SEPARATION MEMBRANES

Description: A likely membrane for future testing of high-temperature hydrogen separation from a gasification product stream was targeted as an inorganic analog of a dense-metal membrane, where the hydrogen would dissolve into and diffuse through the membrane structure. An amorphous membrane such as zinc sulfide appeared to be promising. Previously, ZnS film coating tests had been performed using an electron-beam vacuum coating instrument, with zinc films successfully applied to glass substrates. The coatings appeared relatively stable in air and in a simple simulated gasification atmosphere at elevated temperature. Because the electron-beam coating instrument suffered irreparable breakdown, several alternative methods were tested in an effort to produce a nitrogen-impermeable, hydrogen-permeable membrane on porous sintered steel substrates. None of the preparation methods proved successful in sealing the porous substrate against nitrogen gas. To provide a nitrogen-impermeable ZnS material to test for hydrogen permeability, two ZnS infrared sample windows were purchased. These relatively thick ''membranes'' did not show measurable permeation of hydrogen, either due to lack of absorption or a negligible permeation rate due to their thickness. To determine if hydrogen was indeed adsorbed, thermogravimetric and differential thermal analyses tests were performed on samples of ZnS powder. A significant uptake of hydrogen gas occurred, corresponding to a maximum of 1 mole H{sub 2} per 1 mole ZnS at a temperature of 175 C. The hydrogen remained in the material at ambient temperature in a hydrogen atmosphere, but approximately 50% would be removed in argon. Reheating in a hydrogen atmosphere resulted in no additional hydrogen uptake. Differential scanning calorimetry indicated that the hydrogen uptake was probably due to the formation of a zinc-sulfur-hydrogen species resulting in the formation of hydrogen sulfide. The zinc sulfide was found to be unstable above approximately 200 C, probably with the reduction to metallic zinc with the evolution of hydrogen ...
Date: August 1, 1999
Creator: McCollor, Donald P. & Kay, John P.
Partner: UNT Libraries Government Documents Department

Energetic Deposition in Vacuum

Description: In hoping to improve Niobium deposition on Copper cavity, a vacuum deposition system has been built to test the idea of Nb energetic condensation on copper substrate. The system directly uses microwave power to create the pure Nb plasma, which can be used to extract energetic Nb ion flux to do direct deposition on copper substrate. In this paper, we briefly describe the system, discuss the potential benefit of this technique and report the initial result of Nb plasma creation and Niobium thin film deposition.
Date: September 1, 2001
Creator: Wu, G.; Phillips, L.; Sundelin, R. & Goodman, T.
Partner: UNT Libraries Government Documents Department

Ba{sub 1{minus}x}Sr{sub x}TiO{sub 3} thin film sputter-growth processes and electrical property relationships for high frequency devices

Description: Precise control of Ba{sub 1{minus}x}Sr{sub x}Ti0{sub 3} (BST) film composition is critical for the production of high-quality BST thin films. Specifically, it is known that nonstoichiometry greatly affects the electrical properties of BST film capacitors. The authors are investigating the composition-microstructure-electrical property relationships of polycrystalline BST films produced by magnetron sputter-deposition using a single target with a Ba/Sr ratio of 50/50 and a (Ba+Sr)/Ti ratio of 1.0. It was determined that the (Ba+Sr)/Ti ratios of these BST films could be adjusted from 0.73 to 0.98 by changing the total (Ar+O{sub 2}) process pressure, while the O{sub 2}/Ar ratio did not strongly affect the metal ion composition. The crystalline quality as well as the measured dielectric constant, dielectric tunability, and electrical breakdown voltage of BST films have been found to be strongly dependent on the composition of the BST films, especially the (Ba+Sr)/Ti ratio. The authors discuss the impact of BST film composition control, through film deposition and process parameters, on the electrical properties of BST capacitors for high frequency devices.
Date: December 21, 1999
Creator: Im, J.; Auciello, O.; Streiffer, S. K.; Baumann, P. K.; Eastman, J. A.; Kaufman, D. Y. et al.
Partner: UNT Libraries Government Documents Department

High rate PLD of diamond-like-carbon utilizing copper vapor lasers

Description: Thin film formation by pulsed laser deposition (PLD) has been routinely demonstrated at the laboratory scale for many elements and compounds. In order for processes based on PLD to progress from bench top experiments to commercialization, a number of key issues must be resolved. The principal limitations of current PLD technology are low deposition rate, inclusion of macro particles in the film that are ejected from the target, and difficulty in producing uniform coatings over large areas. Only thin films of very high value are considered economic at present deposition rates, of order 10 {micro}m-cm{sup 2}/h. Recently, a significant increase in PLD rate has been achieved in the laboratory, over 2,000 {micro} {center_dot} cm{sup 2}/h. These rates were accompanied by good surface characteristics by utilizing a copper vapor laser, operating at 100 W to 200 W average power and 4.3 kHz pulse repetition rate. The initial system demonstrations were performed by depositing high quality diamond-like-carbon (DLC) films with a remarkably low level of macro particle inclusions. The experiments and material characterizations performed on the deposited material are reviewed here.
Date: August 15, 1994
Creator: McLean, W. II; Fehring, E.; Dragon, E. & Warner, B.
Partner: UNT Libraries Government Documents Department

Direct current sputtering of boron from boron/carbon mixtures

Description: A method for coating a substrate with boron by sputtering includes lowering the electrical resistance of a boron-containing rod to allow electrical conduction in the rod; placing the boron-containing rod inside a vacuum chamber containing substrate material to be coated; applying an electrical potential between the boron target material and the vacuum chamber; countering a current avalanche that commences when the conduction heating rate exceeds the cooling rate, and until a steady equilibrium heating current is reached and coating the substrate material with boron by sputtering from the boron-containing rod.
Date: December 31, 1993
Creator: Timberlake, J.R.; Manos, D. & Nartowitz, E.
Partner: UNT Libraries Government Documents Department

Improving the figure of very good mirrors by deposition

Description: Mid-spatial frequency errors of near perfect mirrors can be reduced by deposition through a computer generated mask without degrading the superpolish. Experimental results are presented.
Date: June 1996
Creator: Sweatt, W. C.; Weed, J. W.; Farnsworth, A. V.; Warren, M. E.; Neumann, C. C.; Goeke, R. S. et al.
Partner: UNT Libraries Government Documents Department

Research on the electronic and optical properties of polymer and other organic molecular thin films

Description: The main goal of the work is to find materials and methods of optimization of organic layered electroluminescent cells and to study such properties of polymers and other organic materials that can be used in various opto-electronic devices. The summary of results obtained during the first year of work is presented. They are: (1) the possibility to produce electroluminescent cells using a vacuum deposition photoresist technology for commercial photoresists has been demonstrated; (2) the idea to replace the polyaryl polymers by other polymers with weaker hole conductivity for optimization of electroluminescent cells with ITO-Al electrodes has been suggested. The goal is to obtain amorphous processable thin films of radiative recombination layers in electroluminescent devices; (3) procedures of preparation of high-quality vacuum-deposited poly (p-phenylene) (PPP) films on various substrates have been developed; (4) it was found for the first time that the fluorescence intensity of PPP films depends on the degree of polymerization; (5) the role of interfaces between organic compounds, on one side, and metals or semiconductors, on the other side, has been studied and quenching of the fluorescence caused by semiconductor layer in thin sandwiches has been observed; (6) studies of the dynamics of photoexcitations revealed the exciton self-trapping in quasi-one-dimensional aggregates; and (7) conditions for preparation of highly crystalline fullerene C{sub 60} films by vacuum deposition have been found. Composites of C{sub 60} with conjugated polymers have been prepared.
Date: February 1, 1997
Partner: UNT Libraries Government Documents Department

Continuous processing of YBCO/IBAD coated conductors on flexible substrates

Description: A continuous coating system has been developed for depositing YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} (YBCO) on 1 cm wide flexible tapes up to 113 cm long. The authors best result to date is a 12 cm long tape with a critical current (I{sub c}) of 70 A at 75 K. Variations along the length of the tape limited the overall current, but indicated the potential for long length critical currents in excess of 100 A.
Date: October 1, 1997
Creator: Foltyn, S.R.; Arendt, P.N. & Dowden, P.C.
Partner: UNT Libraries Government Documents Department

Process for fabrication of metal oxide films

Description: This invention is comprised of a method of fabricating metal oxide films from a plurality of reactants by inducing a reaction by plasma deposition among the reactants. The plasma reaction is effective for consolidating the reactants and producing thin films of metal oxides, e.g. electro-optically active transition metal oxides, at a high deposition rate. The presence of hydrogen during the plasma reaction enhances the deposition rate of the metal oxide. Various types of metal oxide films can be produced.
Date: July 17, 1990
Creator: Tracy, C. E.; Benson, D. & Svensson, S.
Partner: UNT Libraries Government Documents Department

Extremely high rate deposition of polymer multilayer optical thin film materials

Description: This paper highlights a new technique for extremely high rate deposition of optical dielectric films (vacuum deposition of polymer multilayer thin films). This is a way to produce multilayer optical filters comprised of thousands of layers of either linear or nonlinear optical materials. The technique involves the flash evaporation of an acrylic monomer onto a moving substrate; the monomer is then cured. Acrylic polymers deposited to date are very clear for wavelengths between 0.35 and 2.5 {mu}m; they have extinction coefficients of k{approx}10{sup {minus}7}. Application of electric field during cross linking can polarize (``pole``) the film to greatly enhance the nonlinear optical properties. ``Poling`` films with the polymer multilayer technique offers advantages over conventional approaches, in that the polarization should not decay over time. Battelle`s Pacific Northwest Laboratory is well suited for bringing linear and nonlinear polymer multilayer optical filter technology to manufacturing production status for batch and wide area web applications. 10 figs.
Date: March 1, 1993
Creator: Affinito, J. D.
Partner: UNT Libraries Government Documents Department

Isothermal and cyclic oxidation of an air plasma-sprayed thermal barrier coating system

Description: Thermogravimetric methods for evaluating bond coat oxidation in plasma-sprayed thermal barrier coating (TBC) systems were assessed by high-temperature testing of TBC systems with air plasma-sprayed (APS) Ni-22Cr-10Al-1Y bond coatings and yttria-stabilized zirconia top coatings. High-mass thermogravimetric analysis (at 1150{sup degrees}C) was used to measure bond coat oxidation kinetics. Furnace cycling was used to evaluate APS TBC durability. This paper describes the experimental methods and relative oxidation kinetics of the various specimen types. Characterization of the APS TBCs and their reaction products is discussed.
Date: August 1, 1996
Creator: Haynes, J.A.; Ferber, M.K.; Porter, W.D. & Rigney, E.D.
Partner: UNT Libraries Government Documents Department

Effect of periodic chemical variation on the mechanical properties of Ta foils

Description: Acetylene gas was admitted to the chamber over approx. two orders of magnitude of pressure during Ta deposition. Residual gas analysis was used to verify that a reaction between the Ta film and the gas occurred. Subsequent Auger analysis showed that the carbon in the films could be predicted using a simple pressure vs rate equation. The pulse gas process (PGP) has been applied to the electron beam gun deposition of Ta. Tensile test specimens a few micro-meters thick have been produced to show fracture strengths varying from approx. 170 MPa to approx. 860 MPa for pure to highly pulsed runs. The fracture strength loosely follows a Hall--Petch relation fracture strength to the time between pulses. Although diffusion of the carbon smoothes out the chemical period, it is thought that the remaining structure accounts for the strength enhancement.
Date: January 1, 1978
Creator: Springer, R.W.; Ott, N.L. & Catlett, D.S.
Partner: UNT Libraries Government Documents Department

Deposition and characterization of vacuum deposited aluminum films on Kapton laminates

Description: A process has been developed for the vacuum deposition by electron beam evaporation of high quality aluminum films 10 ..mu..m thick on domed three-layer laminated substrates consisting of Kapton/Pyralux/Kapton/Pyralux/Aluminum (Du Pont Corporation). Thermogravimetric analysis and mass spectrometry of the substrate materials and in-process residual gas analysis were used to determine the outgassing characteristics of the substrate laminate and to aid in the development of suitable thermal processing. The laminated substrates required bakeouts both at atmosphere and in high vacuum prior to deposition to permit evaporation at a pressure of 0.1 mPa (1 x 10/sup -6/ torr). Film properties that were obtained were a thickness uniformity across a 200 mm diameter part in the 1 percent range, a resistivity near that of bulk pure aluminum, a smooth and shiny film surface, and adequate film adhesion.
Date: July 1, 1978
Creator: Sherman, D.M.
Partner: UNT Libraries Government Documents Department

Proceedings of the sixth annual conference of the International Nuclear Target Development Society

Description: The Sixth Annual Conference of the International Nuclear Target Development Society was held at the Lawrence Berkeley Laboratory, University of California, Berkeley, California, on October 19--21, 1977. The discussion covered nuclear target preparation by evaporation, reduction of oxides, electrodeposition, reactive sputtering, rolling, gas jets, and related techniques. Abstracts were prepared for eighteen of the papers presented at the conference and are included in the data base. (GHT)
Date: August 1, 1978
Creator: Steers, G. (comp.)
Partner: UNT Libraries Government Documents Department

Evaluation of target purity using various vacuum systems

Description: Gold targets were prepared under various conditions using both a cryopump and a conventional diffusion pump evaporator system. Measurements were made at the Argonne Tandem Accelerator system to determine the purity of these targets.
Date: January 1, 1984
Creator: Thomas, G.E.; Rehm, K.E. & Klimczak, G.W.
Partner: UNT Libraries Government Documents Department

Characterization of Plasma Sprayed Beryllium ITER First Wall Mockups

Description: ITER first wall beryllium mockups, which were fabricated by vacuum plasma spraying the beryllium armor, have survived 3000 thermal fatigue cycles at 1 MW/sq m without damage during high heat flux testing at the Plasma Materials Test Facility at Sandia National Laboratory in New Mexico. The thermal and mechanical properties of the plasma sprayed beryllium armor have been characterized. Results are reported on the chemical composition of the beryllium armor in the as-deposited condition, the through thickness and normal to the through thickness thermal conductivity and thermal expansion, the four-point bend flexure strength and edge-notch fracture toughness of the beryllium armor, the bond strength between the beryllium armor and the underlying heat sink material, and ultrasonic C-scans of the Be/heat sink interface.
Date: December 31, 1997
Creator: Castro, Richard G.; Vaidya, Rajendra U. & Hollis, Kendall J.
Partner: UNT Libraries Government Documents Department

Development of plating thickness standards. Milestone report

Description: Standards which are unavailable from the National Bureau of Standards were developed to support the nondestructive measurement of plating thickness. Their fabrication, measurement, certification, and calibration-recall schedule are discussed. Reference standards that have been put into service include aluminum/Kapton, silver/copper, tin/steel, gold/silver, cadmium/Kovar, silver/iron, rhodium/copper, and gold/ceramic. 6 figures, 3 tables.
Date: January 1, 1978
Creator: Russell, R.J.
Partner: UNT Libraries Government Documents Department

Vacuum deposition system

Description: The Physics Section vacuum deposition system is available for several types of thin film techniques. This vacuum evaporation system operates in the high vacuum range. The evaporation source is a resistive heating element, either a boat or a filament design. Coating is then line of sight from the source. Substrates to be coated can have a maximum diameter of 17 inches. At this time the variations in the thickness of the coatings can be controlled, by monitor, to within about 100 angstroms. The system diagrams follow the Operation Procedures and the Sample Coating Procedures provided in this document. 3 figs.
Date: May 31, 1990
Creator: Austin, S. & Bark, D.
Partner: UNT Libraries Government Documents Department

Layered Ultrathin Coherent Structures (LUCS)

Description: A new class of superconducting materials, Layered Ultrathin Coherent Structures (LUCS) are described. These materials are produced by sequentially depositing ultrathin layers of materials using high rate magnetron sputtering or thermal evaporation. Strong evidence is presented that layers as thin as 10 A can be prepared in this fashion. Resistivity data indicates that the mean free path is layer thickness limited. A strong disagreement is found between the experimentally measured transition temperatures T/sub c/ and the T/sub c/'s calculated using the Cooper limit approximation. This is interpreted as a change in the band structure or the phonon structure of the material due to layering or to surfaces.
Date: January 1, 1979
Creator: Schuller, I.K. & Falco, C.M.
Partner: UNT Libraries Government Documents Department