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  • 101.
    Lundin, Daniel
    et al.
    University of Paris 11, France .
    Jensen, Jens
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, The Institute of Technology.
    Pedersen, Henrik
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, The Institute of Technology.
    Influence of pulse power amplitude on plasma properties and film deposition in high power pulsed plasma enhanced chemical vapor deposition2014In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 32, no 3Article in journal (Refereed)
    Abstract [en]

    The discharge characteristics in high power pulsed plasma enhanced chemical vapor deposition is studied with the aim to characterize the impact of high power pulses (HiPP). Using a power scheme of combined HiPP and direct current (DC) to ignite the plasma discharge, and adjusting the HiPP/DC time-averaged power ratio while keeping the total power constant, the effect of the high power pulses was isolated from the total power. By monitoring the discharge current along with the optical emission from the plasma, it is found that the amount of available ions increased with increasing HiPP/DC ratio, which indicates a higher plasma density. Using carbon films deposited from acetylene in an argon plasma as model system, a strong increase in deposition rate with higher HiPP/DC is observed. The increased deposition rate is ascribed to a more efficient plasma chemistry generated by the denser plasma.

  • 102. Macak, K.
    et al.
    Kouznetsov, V.
    Schneider, Jochen
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology.
    Helmersson, Ulf
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Plasma and Coating Physics .
    Petrov, I.
    Materials Science Department, Materials Research Laboratory, University of Illinois, Urbana, IL 61801, United States.
    Ionized sputter deposition using an extremely high plasma density pulsed magnetron discharge2000In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 18, no 4 II, p. 1533-1537Article in journal (Refereed)
    Abstract [en]

    A high power density pulsed plasma discharge for ionized sputter deposition is studied. The temporal evolution of the plasma ion composition in high power pulsed magnetron sputtering is investigated and shows that Ar ions dominated the beginning of the pulse. As time elapsed, metal ions are detected and finally dominated the ion composition.

  • 103.
    Magnus, Fridrik
    et al.
    Univ Iceland, Inst Sci, IS-107 Reykjavik, Iceland..
    Tryggvason, Tryggvi K.
    Univ Iceland, Inst Sci, IS-107 Reykjavik, Iceland..
    Olafsson, Sveinn
    Univ Iceland, Inst Sci, IS-107 Reykjavik, Iceland..
    Gudmundsson, Jon T.
    Univ Iceland, Inst Sci, IS-107 Reykjavik, Iceland.;Shanghai Jiao Tong Univ, Univ Michigan Shanghai Jiao Tong Univ Joint Inst, Shanghai 200240, Peoples R China..
    Current-voltage-time characteristics of the reactive Ar/O-2 high power impulse magnetron sputtering discharge2012In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 30, no 5, article id 050601Article in journal (Refereed)
    Abstract [en]

    The discharge current-voltage-time waveforms are studied in the reactive Ar/O-2 high power impulse magnetron sputtering discharge with a titanium target for 400 mu s long pulses. The discharge current waveform is highly dependent on both the pulse repetition frequency and discharge voltage and the current increases with decreasing frequency or voltage. The authors attribute this to an increase in the secondary electron emission yield during the self-sputtering phase of the pulse, as an oxide forms on the target. (C) 2012 American Vacuum Society. [http://dx.doi.org/10.1116/1.4732735]

  • 104.
    Magnuson, Martin
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Tengdelius, Lina
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Greczynski, Grzegorz
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Eriksson, Fredrik
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Jensen, Jens
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Lu, Jun
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Samuelsson, Mattias
    Linköping University, Department of Physics, Chemistry and Biology, Nanoscale engineering. Linköping University, Faculty of Science & Engineering.
    Eklund, Per
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Hultman, Lars
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Högberg, Hans
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Compositional dependence of epitaxial Tin+1SiCn MAX-phase thin films grown from a Ti3SiC2 compound target2019In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 37, no 2, article id 021506Article in journal (Refereed)
    Abstract [en]

    The authors investigate sputtering of a Ti3SiC2 compound target at temperatures ranging from RT (no applied external heating) to 970 °C as well as the influence of the sputtering power at 850 °C for the deposition of Ti3SiC2 films on Al2O3(0001) substrates. Elemental composition obtained from time-of-flight energy elastic recoil detection analysis shows an excess of carbon in all films, which is explained by differences in the angular distribution between C, Si, and Ti, where C scatters the least during sputtering. The oxygen content is 2.6 at. % in the film deposited at RT and decreases with increasing deposition temperature, showing that higher temperatures favor high purity films. Chemical bonding analysis by x-ray photoelectron spectroscopy shows C–Ti and Si–C bonding in the Ti3SiC2 films and Si–Si bonding in the Ti3SiC2 compound target. X-ray diffraction reveals that the phases Ti3SiC2, Ti4SiC3, and Ti7Si2C5 can be deposited from a Ti3SiC2 compound target at substrate temperatures above 850 °C and with the growth of TiC and the Nowotny phase Ti5Si3Cx at lower temperatures. High-resolution scanning transmission electron microscopy shows epitaxial growth of Ti3SiC2, Ti4SiC3, and Ti7Si2C5 on TiC at 970 °C. Four-point probe resistivity measurements give values in the range ∼120 to ∼450 μΩ cm and with the lowest values obtained for films containing Ti3SiC2, Ti4SiC3, and Ti7Si2C5.

  • 105.
    Malinovskis, Paulius
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Persson, Per O. Å. (Contributor)
    Linköping university.
    Lewin, Erik (Contributor)
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Jansson, Ulf (Contributor)
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Synthesis and characterization of MoB2−x thin films grown by nonreactive DC magnetron sputtering2016In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559Article in journal (Refereed)
  • 106.
    Malinovskis, Paulius
    et al.
    Uppsala University, Sweden.
    Palisaitis, Justinas
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, The Institute of Technology.
    Persson, Per
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, The Institute of Technology.
    Lewin, Erik
    Uppsala University, Sweden.
    Jansson, Ulf
    Uppsala University, Sweden.
    Synthesis and characterization of MoB2-x thin films grown by nonreactive DC magnetron sputtering2016In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 34, p. 031511-1-031511-8Article in journal (Refereed)
    Abstract [en]

    DC magnetron sputtering was used to depositmolybdenumboridethin films for potential low-friction applications. The films exhibit a nanocomposite structure with ∼10 nm large MoB2−x (x > 0.4) grains surrounded by a boron-rich tissue phase. The preferred formation of the metastable and substoichiometric hP3-MoB2structure (AlB2-type) is explained with kinetic constraints to form the thermodynamically stable hR18-MoB2 phase with a very complex crystal structure. Nanoindentation revealed a relatively high hardness of (29 ± 2) GPa, which is higher than bulk samples. The high hardness can be explained by a hardening effect associated with the nanocomposite microstructure where the surrounding tissue phase restricts dislocation movement. A tribological study confirmed a significant formation of a tribofilm consisting of molybdenum oxide and boron oxide, however, without any lubricating effects at room temperature.

  • 107.
    Malinovskis, Paulius
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Palisaitis, Justinas
    Linkoping Univ, Dept Phys Chem & Biol IFM, Thin Film Phys Div, SE-58183 Linkoping, Sweden..
    Persson, Per O. A.
    Linkoping Univ, Dept Phys Chem & Biol IFM, Thin Film Phys Div, SE-58183 Linkoping, Sweden..
    Lewin, Erik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Jansson, Ulf
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Synthesis and characterization of MoB2-x thin films grown by nonreactive DC magnetron sputtering2016In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 34, no 3, article id 031511Article in journal (Refereed)
    Abstract [en]

    DC magnetron sputtering was used to deposit molybdenum boride thin films for potential low-friction applications. The films exhibit a nanocomposite structure with similar to 10 nm large MoB2-x (x > 0.4) grains surrounded by a boron-rich tissue phase. The preferred formation of the metastable and substoichiometric hP3-MoB2 structure (AlB2-type) is explained with kinetic constraints to form the thermodynamically stable hR18-MoB2 phase with a very complex crystal structure. Nanoindentation revealed a relatively high hardness of (29 +/- 2) GPa, which is higher than bulk samples. The high hardness can be explained by a hardening effect associated with the nanocomposite microstructure where the surrounding tissue phase restricts dislocation movement. A tribological study confirmed a significant formation of a tribofilm consisting of molybdenum oxide and boron oxide, however, without any lubricating effects at room temperature.

  • 108. Marchack, Nathan
    et al.
    Kim, Taeseung
    Blom, Hans-Olof
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Chang, Jane P.
    In-situ etch rate study of HfxLayOz in Cl-2/BCl3 plasmas using the quartz crystal microbalance2015In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 33, no 3, article id 031305Article in journal (Refereed)
    Abstract [en]

    The etch rate of HfxLayOz films in Cl-2/BCl3 plasmas was measured in-situ in an inductively coupled plasma reactor using a quartz crystal microbalance and corroborated by cross-sectional SEM measurements. The etch rate depended on the ion energy as well as the plasma chemistry. In contrast to other Hf-based ternary oxides, the etch rate of HfxLayOz films was higher in Cl-2 than in BCl3. In the etching of Hf0.25La0.12O0.63, Hf appeared to be preferentially removed in Cl-2 plasmas, per surface compositional analysis by x-ray photoelectron spectroscopy and the detection of HfCl3 generation in mass spectroscopy. These findings were consistent with the higher etch rate of Hf0.25La0.12O0.63 than that of La2O3.

  • 109. Martin, Ryan M.
    et al.
    Blom, Hans-Olof
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Chang, Jane P.
    Plasma Etching of Hf-based High-k Thin Films. Part II, Ion Enhanced Surface Reaction Mechanisms2009In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 27, no 2, p. 217-223Article in journal (Refereed)
    Abstract [en]

    The mechanism for ion-enhanced chemical etching of hafnium aluminate thin films in Cl-2/BCl3 plasmas was investigated in this work, specifically how the film composition, ion energy, and plasma chemistry determine their etch rates. Several compositions of Hf1-xAlxOy thin films ranging from pure HfO2 to pure Al2O3 were etched in BCl3/Cl-2 plasmas and their etch rates were found to scale with E-ion in both Cl-2 and BCl3 plasmas. In Cl-2 plasmas, a transition point was observed around 50 eV, where the etch rate was significantly enhanced while the linear dependence toE(ion) was maintained, corresponding to a change in the removal of fully chlorinated to less chlorinated reaction products. In BCl3 plasma, deposition dominates at ion energies below 50 eV, while etching occurs above that energy with an etch rate of three to seven times that in Cl-2. The faster etch rate in BCl3 was attributed to a   change in the dominant ion from Cl-2+ in Cl-2 plasma to BCl2+ in BCl3, which facilitated the formation of more volatile etch products and their removal. The surface chlorination (0-3 at. %) was enhanced with increasing ion energy while the amount of boron on the surface   increases with decreasing ion energy, highlighting the effect of different plasma chemistries on the etch rates, etch product formation, and surface termination.

  • 110.
    Mattsson, Andreas
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Hu, Shuanglin
    Hermansson, Kersti
    Österlund, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Adsorbtion and photodecomposition of formic acid on stoichiometric and defective rutile TiO2 (110) surfaces2014In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 32, no 061402-1Article in journal (Refereed)
  • 111.
    Mattsson, Andreas
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Hu, Shuang-Lin
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Hermansson, Kersti
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Österlund, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Infrared spectroscopy study of adsorption and photodecomposition of formic acid on reduced and defective rutile TiO2 (110) surfaces2014In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 32, no 6, article id 061402Article in journal (Refereed)
    Abstract [en]

    Adsorption and photodecomposition of formic acid on rutile TiO2 (110) have been investigated with infrared reflection–absorption spectroscopy (IRRAS) employing p- and s-polarized light along the [001] and [ 11⎯⎯0 ] crystal directions. The single crystal surfaces were prepared either by sputtering and annealing in ultrahigh vacuum (UHV) to obtain a reduced surface (r-TiO2), or by sputtering without annealing to create a rough, highly defective surface (sp-TiO2). Results are compared with corresponding measurements on rutile nanocrystals performed in synthetic air. IRRAS spectra obtained on r-TiO2 and rutile nanocrystals are very similar, and show that in both cases formic acid dissociates and is predominately adsorbed as a bridging bidentate formate species, and that the formate adsorption structure on the nanocrystals is dominated by interactions with majority (110) surfaces. In contrast, the IRRAS spectra on sp-TiO2 are different, with only minor spectral features associated with (110) surfaces and lost azimuthal symmetry, both of which imply changed adsorption geometry due to bonding to low-coordinated Ti atoms with lower valences. The UV-induced rate of formate photodecomposition is about 30 times higher on rutile nanocrystals in synthetic air compared with sp-TiO2 under UHV conditions, and even larger than on r-TiO2. These differences are explained by the lack of oxygen and limited hydroxyl coverage under UHV conditions. The difference in reactivity between the r-TiO2 and sp-TiO2 surfaces is attributed to a high concentration of strongly bonded bridging bidentate formate species on the (110) surface, which lowers its reactivity. The results point to a pressure gap where the availability of molecular oxygen and the hydroxyl concentration limit the photoreactivity in UHV leading to an almost 20-fold decrease of the formate degradation rate in UHV. In contrast, the structure represented by the single crystal (110) surface is shown to capture the essential structural properties, which dictates the formic acid adsorption and adsorption structure of rutile nanocrystals.

  • 112.
    Mei, A B
    et al.
    University of Illinois, IL 61801 USA .
    Howe, B M
    Air Force Research Lab, OH 45433 USA .
    Zhang, C
    University of Illinois, IL 61801 USA .
    Sardela, M
    University of Illinois, IL 61801 USA .
    Eckstein, J N
    University of Illinois, IL 61801 USA .
    Hultman, Lars
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, The Institute of Technology.
    Rockett, A
    University of Illinois, IL 61801 USA .
    Petrov, I
    University of Illinois, IL 61801 USA .
    Greene, J E
    University of Illinois, IL 61801 USA .
    Physical properties of epitaxial ZrN/MgO(001) layers grown by reactive magnetron sputtering2013In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 31, no 6, p. 061516-Article in journal (Refereed)
    Abstract [en]

    Single-crystal ZrN films, 830 nm thick, are grown on MgO(001) at 450 degrees C by magnetically unbalanced reactive magnetron sputtering. The combination of high-resolution x-ray diffraction reciprocal lattice maps, high-resolution cross-sectional transmission electron microscopy, and selected-area electron diffraction shows that ZrN grows epitaxially on MgO(001) with a cube-on-cube orientational relationship, (001)(ZrN)parallel to(001)(MgO) and [100](ZrN)parallel to[100](MgO). The layers are essentially fully relaxed with a lattice parameter of 0.4575 nm, in good agreement with reported results for bulk ZrN crystals. X-ray reflectivity results reveal that the films are completely dense with smooth surfaces (roughness = 1.3 nm, consistent with atomic-force microscopy analyses). Based on temperature-dependent electronic transport measurements, epitaxial ZrN/MgO(001) layers have a room-temperature resistivity rho(300K) of 12.0 mu Omega-cm, a temperature coefficient of resistivity between 100 and 300K of 5.6 x 10(-8) Omega-cm K-1, a residual resistivity rho(o) below 30K of 0.78 mu Omega-cm (corresponding to a residual resistivity ratio rho(300K)/rho(15K) = 15), and the layers exhibit a superconducting transition temperature of 10.4 K. The relatively high residual resistivity ratio, combined with long in-plane and out-of-plane x-ray coherence lengths, xi(parallel to) = 18 nm and xi(perpendicular to) = 161 nm, indicates high crystalline quality with low mosaicity. The reflectance of ZrN(001), as determined by variable-angle spectroscopic ellipsometry, decreases slowly from 95% at 1 eV to 90% at 2 eV with a reflectance edge at 3.04 eV. Interband transitions dominate the dielectric response above 2 eV. The ZrN(001) nanoindentation hardness and modulus are 22.7 +/- 1.7 and 450 +/- 25 GPa.

  • 113.
    Mikula, Marian
    et al.
    Comenius University, Slovakia; Slovak Academic Science, Slovakia.
    Truchly, Martin
    Comenius University, Slovakia.
    Sangiovanni, Davide
    Linköping University, Department of Physics, Chemistry and Biology, Theoretical Physics. Linköping University, Faculty of Science & Engineering. Ruhr University of Bochum, Germany.
    Plasienka, Dusan
    Comenius University, Slovakia.
    Roch, Tomas
    Comenius University, Slovakia.
    Gregor, Maros
    Comenius University, Slovakia.
    Durina, Pavol
    Comenius University, Slovakia.
    Janik, Marian
    Comenius University, Slovakia.
    Kus, Peter
    Comenius University, Slovakia.
    Experimental and computational studies on toughness enhancement in Ti-Al-Ta-N quaternaries2017In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 35, no 6, article id 060602Article in journal (Refereed)
    Abstract [en]

    Design of hard ceramic material coatings with enhanced toughness, which prevents crack formation/propagation leading to brittle failure during application, is a primary industrial requirement. In this work, experimental methods supported by ab initio density functional theory (DFT) calculations and electronic structure analyses are used to investigate the mechanical behavior of magnetron sputtered Ti-Al-Ta-N hard coatings. The as-deposited Ti1-x-yAlxTayN (y = 0-0.60) films exhibit a single phase cubic sodium chloride (B1) structure identified as TiAl(Ta)N solid solutions. While the hardness H of Ti0.46Al0.54N (32.5 +/- 2 GPa) is not significantly affected by alloying with TaN (H of the quaternary nitrides varies between 26 +/- 2 and 35 +/- 4 GPa), the elastic stiffness monotonically decreases from 442 to 354 GPa with increasing Ta contents, which indicates improved toughness in TiAlTaN. Consistent with the experimental findings, the DFT results show that Ta substitutions in TiAlN reduce the shear resistance due to the enhanced occupation of metal-metal bonding states while preserving strong metal-N bonds. The metal-N bonding character, however, is progressively modified from prevalently ionic (TiAlN) toward more covalent (TiAlTaN). (C) 2017 American Vacuum Society.

  • 114. Miniotas, A
    et al.
    Karlsson, Ulf O
    KTH, School of Information and Communication Technology (ICT).
    Brazdeikis, A
    Chu, C W
    Large magnetoresistance effect in as-grown epitaxial LaxCa1-xMnO3 films prepared by a molecular beam epitaxy coevaporation technique1998In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 16, no 3, p. 1268-1271Article in journal (Refereed)
    Abstract [en]

    Thin films of LaxCa1-xMnO3 (0.64 less than or equal to x less than or equal to 0.68) have been grown by NO2-assisted molecular beam epitaxy on single crystal SrTiO3(100) and LaAlO3(100) substrates. As-grown films are found to be grown epitaxially, b-axis oriented on both SrTiO3 and LaAlO3 substrates, and exhibit a large magnetoresistance effect {[R(O)-R(H)]/R(H)X100} of about 1500% at 214 K. The magnetoresistance effect values obtained are similar to those reported for as-grown LaxCa1-xMnO3 (0.60 less than or equal to x less than or equal to 0.7) films synthesized either by so-called "block-by-block" or "layer-by-layer" molecular beam epitaxy techniques, but the effect appears at significantly higher temperatures. For epitaxial La0.68Ca0.32MnO3 films grown on SrTiO3 a relatively large resistance suppression of 200% at 1.0 T is observed. (C) 1998 American Vacuum Society.

  • 115. Moradi, M
    et al.
    Nender, C
    Berg, Sören
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Blom, Hans-Olof
    Belkind, A
    Orban, Z
    Modeling of multicomponent reactive sputtering1991In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559Article in journal (Refereed)
  • 116.
    Moreira, Milena A.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Törndahl, Tobias
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Katardjiev, Ilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Kubart, Tomas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Deposition of highly textured AlN thin films by reactive high power impulse magnetron sputtering2015In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 33, no 2, article id 021518Article in journal (Refereed)
    Abstract [en]

    Aluminum nitride thin films were deposited by reactive high power impulse magnetron sputtering (HiPIMS) and pulsed direct-current on Si (100) and textured Mo substrates, where the same deposition conditions were used for both techniques. The films were characterized by x-ray diffraction and atomic force microscopy. The results show a pronounced improvement in the AlN crystalline texture for all films deposited by HiPIMS on Si. Already at room temperature, the HiPIMS films exhibited a strong preferred (002) orientation and at 400 degrees C, no contributions from other orientations were detected. Despite the low film thickness of only 200 nm, an x-scan full width at half maximum value of 5.1 degrees was achieved on Si. The results are attributed to the high ionization of sputtered material achieved in HiPIMS. On textured Mo, there was no significant difference between the deposition techniques.

  • 117. Mullings, Marja N.
    et al.
    Hägglund, Carl
    Department of Chemical Engineering, Stanford University, Stanford, California.
    Bent, Stacey F.
    Tin oxide atomic layer deposition from tetrakis(dimethylamino)tin and water2013In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 31Article in journal (Refereed)
  • 118.
    Music, Denis
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, The Institute of Technology.
    Kugler, Veronika Mozhdeh
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, The Institute of Technology.
    Czigany, Zolt
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, The Institute of Technology.
    Flink, Axel
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, The Institute of Technology.
    Werner, Oskar
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, The Institute of Technology.
    Schneider, J.M.
    Materials Chemistry, RWTH Aachen.
    Hultman, Lars
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, The Institute of Technology.
    Helmersson, Ulf
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, The Institute of Technology.
    Role of carbon in boron suboxide thin films2003In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 21, no 4, p. 1355-1358Article in journal (Refereed)
    Abstract [en]

    X-ray amorphous BO0.02 thin films with the C content from 0 to 0.6 at. % were grown by reactive dual magnetron sputtering in an UHV system. It was shown that the elastic and dielectric properties of the as-deposited films are affected by the amount of the incorporated C and the film density.

  • 119.
    Music, Denis
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics.
    Schneider, Jochen
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology.
    Kugler, Veronika Mozhdeh
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology.
    Nakao, S.
    National Industrial Research Institute of Nagoya, Nagoya 462-8510, Japan.
    Jin, P.
    National Industrial Research Institute of Nagoya, Nagoya 462-8510, Japan.
    Östblom, Mattias
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Sensor Science and Molecular Physics .
    Hultman, Lars
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics.
    Helmersson, Ulf
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Plasma and Coating Physics .
    Synthesis and mechanical properties of boron suboxide thin films2002In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 20, no 2, p. 335-337Article in journal (Refereed)
    Abstract [en]

    The synthesis and mechanical properties of boron suboxide thin films deposited on silicon and graphite substrates was discussed. The deposition was performed using reactive magnetron sputtering technique, and amorphous films were obtained. The affect of varying O2 partial pressure on film composition and microstructure was studied using spectroscopic techniques. It was found that variation of partial pressure from 0.02 to 0.21 resulted in a decrease in elastic modulus from 272 to 109 GPa.

  • 120.
    Nedfors, Nils
    et al.
    Uppsala University, Sweden .
    Tengstrand, Olof
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, The Institute of Technology.
    Eklund, Per
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, The Institute of Technology.
    Hultman, Lars
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, The Institute of Technology.
    Jansson, Ulf
    Uppsala University, Sweden .
    Nb-B-C thin films for electrical contact applications deposited by magnetron sputtering2014In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 32, no 4, p. 041503-Article in journal (Refereed)
    Abstract [en]

    The high wear resistance, high chemical inertness, and high electrical conductivity of magnetron-sputtered transition metal diborides make them a candidate material for sliding electrical contacts. However, their high hardness makes it difficult to penetrate surface oxides, resulting in a high electrical contact resistance. In this study, the authors have investigated how the contact resistance can be improved by the formation of softer Nb-B-C films. The Nb-B-C films were deposited by magnetron sputtering and shown to exhibit a nanocomposite microstructure consisting of nanocrystalline NbB2-x grains with a solid solution of C separated by an amorphous BCx phase. The formation of the BCx phase reduces the hardness from 41 GPa for the NbB2-x film to 19 GPa at 36 at. % C. As a consequence the contact resistance is drastically reduced and the lowest contact resistance of 35 m Omega (contact force 5N) is achieved for a film containing 30 at. % C. However, crack formation and subsequent delamination and fragmentation is observed for the C-containing Nb-B-C films in tribology tests resulting in high friction values for these films.

  • 121.
    Nedfors, Nils
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Tengstrand, Olof
    Eklund, Per
    Hultman, Lars
    Jansson, Ulf
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Nb-B-C thin films for electrical contact applications deposited by magnetron sputtering2014In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 32, no 4, p. 041503-Article in journal (Refereed)
    Abstract [en]

    The high wear resistance, high chemical inertness, and high electrical conductivity of magnetron-sputtered transition metal diborides (MeB2) make them a candidate material for sliding electrical contacts. However, their high hardness makes it difficult to penetrate surface oxides, resulting in a high electrical contact resistance. We have in this study investigated how the contact resistance can be improved by the formation of softer Nb-B-C films. The Nb-B-C films were deposited by magnetron sputtering and shown to exhibit a nanocomposite microstructure consisting of nanocrystalline NbB2-x grains with a solid solution of C separated by an amorphous BCx phase. The formation of the BCx phase reduces the hardness from 41 GPa for the NbB2-x film to 19 GPa at 36 at.% C. As a consequence the contact resistance is drastically reduced and the lowest contact resistance of 35 mΩ (contact force 5 N) is achieved for a film containing 30 at.% C. However, crack formation and subsequent delamination and fragmentation is observed for the C-containing Nb-B-C films in tribology tests resulting in high friction values for these films.

  • 122.
    Nedfors, Nils
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Vozniy, Oleksiy
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Rosén, Johanna
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Effect of synchronized bias in the deposition of TiB2 thin films using high power impulse magnetron sputtering2018In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 36, no 3, article id 031510Article in journal (Refereed)
    Abstract [en]

    Titanium diboride thin films have been deposited from a compound TiB2 target on Si(001) substrates at a temperature of 500 degrees C using high power impulse magnetron sputtering (HiPIMS) at a frequency of 1000 Hz and pulse lengths of 20 and 40 mu s. A -60V bias pulse of different pulse length was applied at different time delay relative to the HiPIMS pulse. The average energy per deposited species, amp;lt; E-D amp;gt; = E-i(J(i)/J(t)), where E-i is the average ion energy and J(i)/J(t) is the ratio of the ion bombarding flux to the total flux of deposited species, is strongly dependent on bias mode. A change in preferred orientation from (101) to (001) is observed when amp;lt; E-D amp;gt; increase above 50 eV. The limited adatom mobility at amp;lt; E-D amp;gt; below 50 eV promote growth of fast growing planes resulting in a (101) texture, while amp;lt; E-D amp;gt; above 50 eV supply sufficient energy for development of the thermodynamically more favorable (001) texture. A linear increase in compressive residual stress with the increase in amp;lt; E-D amp;gt; is also found, due to more intensive Ar+ ion bombardment. Analysis of charge-state-resolved plasma chemistry and ion energy shows that the total flux of bombarding ions contains a higher fraction of B+ when the bias is applied in synchronous with the HiPIMS pulse instead of after, resulting in a lower residual stress at similar values of amp;lt; E-D amp;gt; (cf. -2.0 +/- 0.2 and -2.6 +/- 0.1 GPa). This study shows that use of a bias synchronized in different modes relative to the HiPIMS pulse, can be used as a tool to control amp;lt; E-D amp;gt; and to some extent the type of bombarding species, and hence the microstructure of TiB2 thin films. Published by the AVS.

  • 123.
    Neidhardt, Jörg
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics.
    Hultman, Lars
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics.
    Beyond ?- C3 N4 -Fullerene-like carbon nitride: A promising coating material2007In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 25, no 4, p. 633-644Article in journal (Refereed)
    Abstract [en]

    Even though the synthesis of super-hard-crystalline ?- C3 N4 remains elusive, noncrystalline C Nx compounds are of increasing importance owing to their competitive properties. Especially the fullerene-like allotrope of C Nx exhibits outstanding elasticity in combination with low work of indentation. This new class of thin solid film materials is characterized by a microstructure of bent and intersecting basal planes. Substitutional incorporation of nitrogen into the predominantly s p2 hybridized graphitic layer triggers the formation of curvature-inducing pentagons and interplanar cross-links at a much lower energy cost as compared to carbon-only materials. The term "fullerene- like" was coined to reflect the nanometer scale of curved structural units. Thus, fullerene-like C Nx deforms by bond angle deflection and compression of the graphitic interplanar lattice spacing, whereas the superior strength of the s p2 bonds inhibits plastic deformation giving the material an extremely resilient character. The orientation, radius of curvature of basal planes, and density of cross-linking can be adjusted by the synthesis conditions. Here, the existence of significant numbers of precursor molecules is a determining factor. The inherent resiliency of the material in combination with the carbon-based beneficial friction promises to give rise to numerous tribological applications. © 2007 American Vacuum Society.

  • 124. Nender, C
    et al.
    Berg, Sören
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Buchta, R
    Norström, H
    Dry etching of n- and p-type polysilicon - a rate control study1987In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 5, no 4, p. 1600-Article in journal (Refereed)
  • 125. Nender, C
    et al.
    Berg, Sören
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Gelin, B
    Stridh, B
    Selective deposition of Ti - an interface study1987In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 5, no 4, p. 1073-Article in journal (Refereed)
  • 126.
    Nguyen, Hugo
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Bejhed, Johan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Köhler, Johan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Thornell, Greger
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Microsystems Technology.
    Thermally regulated valve for minute flows2007In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 25, no 4, p. 686-691Article in journal (Refereed)
    Abstract [en]

    In this work, a gas valve using a microstructured silicon valve lid and a stainless steel valve seat clamped axially together in an aluminum cylinder is investigated. The difference in coefficient of thermal expansion of these components makes the valve open and close on a temperature change. A simple model accounting for elastic deformation of the system’s components is proposed to facilitate design of the valve. By means of a helium leak detector, a typical increase in flow rate from 1.0×10−8 to 1.0×10−4 sccs gaseous helium under a pressure of up to 10 bars was observed upon the increase of temperature from 12 to around 98 °C, after a single breaking-in. Plastic deformation of the valve seat as a consequence of an imprint of the microstructured valve lid and contaminating particles was studied. Microscopy confirmed a tolerance for particles of up to a few micrometers in diameter. Larger particles were found to be a possible cause of failure.

  • 127.
    Nordin, M.
    et al.
    AB Sandvik Coromant, Stockholm, Sweden .
    Larsson, M.
    Materials Science Division, The Ångström Laboratory, Uppsala University, Uppsala, Sweden .
    Joelsson, Torbjörn
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, The Institute of Technology.
    Birch, Jens
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, The Institute of Technology.
    Hultman, Lars
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, The Institute of Technology.
    Residual stress formation in multilayered TiN/TaNx coatings during reactive magnetron sputter deposition2000In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 18, no 6, p. 2884-2889Article in journal (Refereed)
    Abstract [en]

    Multilayered physical vapor deposited TiN/TaNx coatings were deposited on cemented carbide substrates using a dual target magnetron sputtering system. The coatings were investigated with respect to the influence of nitrogen partial pressure during deposition on the residual stress developed in the coatings. Furthermore, the fracture strength of the material, i.e., the magnitude of the tensile stress that the coating can support without cracking, was evaluated. It was found that, by increasing the nitrogen partial pressure, it is possible to change the stress from compressive to tensile. The highest tensile stress was about 3.6 GPa. Despite this high stress, the coating displayed no cracking. This implies that it is possible to grow TiN/TaNx multilayered coatings with high tensile fracture strength using dual magnetron sputtering and a high deposition temperature (about 680 °C). 

  • 128.
    Norström, H
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Runovic, F
    Buchta, R
    Wiklund, P
    Östling, M
    Petersson, CS
    Redistribution of dopants in TiSi2-polycrystalline bilayers during heat treatment1983In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 1, no 2, p. 463-Article in journal (Refereed)
  • 129. Paul, Jan
    Alkali overlayers on aluminum, alumina, and aluminum carbide1987In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 5, no 4, p. 664-670Article in journal (Refereed)
    Abstract [en]

    Adsorption data for potassium and sodium atoms on the surfaces of aluminum metal, aluminum oxide, and aluminum carbide are presented. Low coverage adsorption of K(Na) on Al(100) is characterized by a 4.6(3.2) D surface dipole and desorption around 620(590) K. Increasing the alkali coverage lowers the desorption temperature as well as the effective surface dipole per alkali atom. Clustering on aluminum metal is activated by annealing to around room temperature. The adsorption of K and Na monomers on dehydrogenated Al2O3 is characterized by desorption around 350 K and, for sodium, by cluster formation even at submonolayer coverage. Finally, potassium but not sodium atoms bind strongly to Al4C3 (Id>700 K). This explains a previous observation of potassium at a promoted aluminum surface after exposure to carbon monoxide and annealing to 700 K.

  • 130.
    Pedersen, Henrik
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Alling, Björn
    Linköping University, Department of Physics, Chemistry and Biology, Theoretical Physics. Linköping University, Faculty of Science & Engineering.
    Högberg, Hans
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Ektarawong, Annop
    Linköping University, Department of Physics, Chemistry and Biology, Theoretical Physics. Linköping University, Faculty of Science & Engineering. Chulalongkorn Univ, Thailand; Commiss Higher Educ, Thailand.
    Thermodynamic stability of hexagonal and rhombohedral boron nitride under chemical vapor deposition conditions from van der Waals corrected first principles calculations2019In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 37, no 4, article id 040603Article in journal (Refereed)
    Abstract [en]

    Thin films of boron nitride (BN), particularly the sp(2)-hybridized polytypes hexagonal BN (h-BN) and rhombohedral BN (r-BN), are interesting for several electronic applications, given the bandgaps in the UV. They are typically deposited close to thermal equilibrium by chemical vapor deposition (CVD) at temperatures and pressures in the regions 1400-1800K and 1000-10000Pa, respectively. In this letter, the authors use the van der Waals corrected density functional theory and thermodynamic stability calculations to determine the stability of r-BN and compare it to that of h-BN as well as to cubic BN and wurtzitic BN. The authors find that r-BN is the stable sp(2)-hybridized phase at CVD conditions, while h-BN is metastable. Thus, their calculations suggest that thin films of h-BN must be deposited far from thermal equilibrium.

  • 131.
    Pedersen, Henrik
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Semiconductor Materials. Linköping University, The Institute of Technology.
    Lin, Ching-Chi
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Ojamäe, Lars
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    On the change of preferential growth orientation in chemical vapor deposition of titanium carbide by aromatic hydrocarbon precursors2013In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 31, no 2Article in journal (Refereed)
    Abstract [en]

    Thin films of titanium carbide grown by chemical vapor deposition exhibit a strong preferential (111) growth direction if aromatic hydrocarbons, such as benzene, are used as a carbon precursor. If aliphatic hydrocarbons such as methane are used, growth on the (100) surface is preferred. In this study, quantum chemical computations are used to study the adsorption of benzene and methane on the (100) and (111) surfaces to provide an explanation for the changed growth behavior. The adsorption energy of benzene is found to be approximately twice as high on the (111) surface as compared to the (100) surface, and adsorption studies further suggest that benzene chemisorbs on the (111) surface, while it physisorbs on the (100) surface. The studies reveal no significant differences in adsorption energy or behavior for methane on the two surfaces. The authors propose that the higher benzene adsorption energy and different adsorption behavior on the (111) surface are the explanations for the preferential growth orientation.

  • 132.
    Petrov, I.
    et al.
    Frederick Seitz Materials Research Laboratory and Department of Materials Science, University of Illinois, Urbana, Illinois.
    Barna, P.B.
    Research Institute for Technical Physics and Materials Science, Hungarian Academy of Sciences, Budapest, Hungary .
    Hultman, Lars
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, The Institute of Technology.
    Greene, J.E.
    Frederick Seitz Materials Research Laboratory and Department of Materials Science, University of Illinois, Urbana, Illinois.
    Microstructural evolution during film growth2003In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 21, no 5, p. 117-Article in journal (Refereed)
    Abstract [en]

    Atomic-scale control and manipulation of the microstructure of polycrystalline thin films during kinetically limited low-temperature deposition, crucial for a broad range of industrial applications, has been a leading goal of materials science during the past decades. Here, we review the present understanding of film growth processes—nucleation, coalescence, competitive grain growth, and recrystallization—and their role in microstructural evolution as a function of deposition variables including temperature, the presence of reactive species, and the use of low-energy ion irradiation during growth.

  • 133.
    Petrov, Ivan
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering. University of Illinois, IL 61801 USA.
    Hall, Allen
    University of Illinois, IL 61801 USA; University of Illinois, IL 61801 USA.
    Mei, Antonio B.
    University of Illinois, IL 61801 USA.
    Nedfors, Nils
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Zhirkov, Igor
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Rosén, Johanna
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Reed, Amber
    Mat and Mfg Directorate, OH 45431 USA.
    Howe, Brandon
    Mat and Mfg Directorate, OH 45431 USA.
    Greczynski, Grzegorz
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Birch, Jens
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Hultman, Lars
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Greene, Joseph E
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering. University of Illinois, IL 61801 USA; University of Illinois, IL 61801 USA; University of Illinois, IL 61801 USA.
    Controlling the boron-to-titanium ratio in magnetron-sputter-deposited TiBx thin films2017In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 35, no 5, article id 050601Article in journal (Refereed)
    Abstract [en]

    Magnetron sputter-deposited TiBx films grown from TiB2 targets are typically highly overstoichiometric with x ranging from 3.5 to 2.4 due to differences in Ti and B preferential ejection angles and gasphase scattering during transport between the target and the substrate. The authors show that the use of highly magnetically unbalanced magnetron sputtering leads to selective ionization of sputter-ejected Ti atoms which are steered via an external magnetic field to the film, thus establishing control of the B/Ti ratio with the ability to obtain stoichiometric TiB2 films over a wide range in Ar sputtering pressures. (C) 2017 American Vacuum Society.

  • 134.
    Piao, Yinghua
    et al.
    State Key Laboratory of ASIC and System, School of Microelectronics, Fudan University, Shanghai, Kina.
    Zhu, Zhiwei
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Gao, Xindong
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Karabko, Aleksandra
    Dept of Electronic Techniques and Technologies, Belarusian State University of Informatics and Radioelectronics, Minsk, Vitryssland.
    Hu, C
    State Key Laboratory of ASIC and System, School of Microelectronics, Fudan University, Shanghai, Kina.
    Qiu, Z.-J
    State Key Laboratory of ASIC and System, School of Microelectronics, Fudan University, Shanghai, Kina.
    Luo, Jun
    Institute of Microelectronics, Chinese Academy of Sciences, Beijing, Kina.
    Zhang, Zhi-Bin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Zhang, Shi-Li
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Wu, Donping
    State Key Laboratory of ASIC and System, School of Microelectronics, Fudan University, Shanghai, Kina.
    An extensive Raman spectroscopic investigation of ultrathin Co1-xNixSi2 films grown on Si(100)2012In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 30, no 4, p. 041511-041518Article in journal (Refereed)
    Abstract [en]

    Ultrathin silicide films were formed by starting from 1-8 nm thick Co1-xNix (x = 0, 0.25, 0.5, 0.75, and 1) at 350 degrees C-900 degrees C. For each composition x, there exists a critical thickness above which the transition temperature from monosilicides CoSi and NiSi to a disilicide-like phase increases with increasing film thickness. Below this thickness, the disilicide phase seems to form without exhibiting the monosilicides within the detection resolution limits of transmission electron microscopy and Raman spectroscopy. Raman spectroscopic analysis seems to indicate that Ni could be dissolved in the CoSi lattice to a certain fraction despite the fact that CoSi and NiSi are distinct with different crystallographic structures. Moreover, the disorder-induced Raman scattering in NiSi2 is found to be enhanced by Co incorporation. The observed annealing behaviors are attributed to variations in free energy change for phase transition caused by differences in metal thickness.

  • 135. Rao, D. S.
    et al.
    Valleti, K.
    Joshi, S. V.
    Janardhan, G. R.
    Processing-structure-property relationships in electron beam physical vapor deposited yttria stabilized zirconia coatings2011In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 29, no 3, article id 031501Article in journal (Refereed)
    Abstract [en]

    The physical and mechanical properties of yttria stabilized zirconia (YSZ) coatings deposited by the electron beam physical vapor deposition technique have been investigated by varying the key process variables such as vapor incidence angle and sample rotation speed. The tetragonal zirconia coatings formed under varying process conditions employed were found to have widely different surface and cross-sectional morphologies. The porosity, phase composition, planar orientation, hardness, adhesion, and surface residual stresses in the coated specimens were comprehensively evaluated to develop a correlation with the process variables. Under transverse scratch test conditions, the YSZ coatings exhibited two different crack formation modes, depending on the magnitude of residual stress. The influence of processing conditions on the coating deposition rate, column orientation angle, and adhesion strength has been established. Key relationships between porosity, hardness, and adhesion are also presented. (C) 2011 American Vacuum Society. [DOI: 10.1116/1.3563600]

  • 136.
    Rogström, Lina
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Nanostructured Materials. Linköping University, The Institute of Technology.
    Johansson, Mats
    Linköping University, Department of Physics, Chemistry and Biology, Nanostructured Materials. Linköping University, The Institute of Technology. Seco Tools AB, 737 82 Fagersta, Sweden.
    Ghafoor, Naureen
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, The Institute of Technology.
    Hultman, Lars
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, The Institute of Technology.
    Odén, Magnus
    Linköping University, Department of Physics, Chemistry and Biology, Nanostructured Materials. Linköping University, The Institute of Technology.
    Influence of chemical composition and deposition conditions on microstructure evolution during annealing of arc evaporated ZrAlN thin films2012In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 30, no 3, p. 031504-Article in journal (Refereed)
    Abstract [en]

    The influence of substrate bias and chemical composition on the microstructure and hardness of arc evaporated Zr1−xAlxN films with 0.12 < x < 0.74 is investigated. A cubic ZrAlN phase is formed at low aluminum contents (x < 0.38) whereas for a high Al-content, above x=0.70, a single-phase hexagonal structure is obtained. For intermediate Al-contents, a two-phase structure is formed. The cubic structured films exhibit higher hardness than the hexagonal structured ones. A low bias results in N-rich films with a partly defect-rich microstructure while a higher substrate bias decreases the grain size and increases the residual stress in the cubic ZrAlN films. Recrystallization and out-diffusion of nitrogen from the lattice in the cubic ZrAlN films takes place during annealing at 800 C, which results in an increased hardness. The cubic ZrAlN phase is stable to annealing temperatures of 1000 C while annealing at higher temperature results in nucleation and growth of hexagonal AlN. In the high Al-content ZrAlN films, formation of ZrN- and AlN-rich domains within the hexagonal lattice during annealing at 1000 C improves the mechanical properties.

  • 137. Rudenja, S.
    et al.
    Pan, Jinshan
    KTH, Superseded Departments, Materials Science and Engineering.
    Odnevall Wallinder, Inger
    KTH, Superseded Departments, Materials Science and Engineering.
    Leygraf, Christofer
    KTH, Superseded Departments, Materials Science and Engineering.
    Kulu, P.
    Mikli, V.
    Enhanced passivity of austenitic AISI 304 stainless steel by low-temperature ion nitriding2001In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 19, no 4, p. 1425-1431Article in journal (Refereed)
    Abstract [en]

    Low-temperature ion nitriding introduces interstitial nitrogen into the austenitic stainless steel matrix. An enhanced passivity of the nitrided stainless steel was detected by anodic potentiodynamic polarization in a 0.1 M H2SO4 + 0.05 M HCl electrolyte. Capacitance measurements by electrochemical impedance spectroscopy revealed a 3-4 nm thick oxide film on the surface of nitrided specimens that is two to three times thicker than on blank specimens. X-ray photoelectron spectroscopy analyses and Auger depth profiles indicate increased chromium uptake into the oxide film on the nitrided surface, supposedly through the kinetically stable oxide-metal interface enriched with nitrogen and nickel. Several possible mechanisms that influence passivation of the nitrided stainless steel may operate simultaneously. Among these mechanisms, austenite strengthening by interstitial nitrogen near the oxide/alloy interface associated with structural defects like dislocation branches and vacancies are most likely the explanation for the enhanced passivity of the nitrided stainless steel.

  • 138.
    Samuelsson, Mattias
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Plasma and Coating Physics.
    Lundin, Daniel
    Linköping University, Department of Physics, Chemistry and Biology, Plasma and Coating Physics. Linköping University, The Institute of Technology.
    Sarakinos, Kostas
    Linköping University, Department of Physics, Chemistry and Biology, Plasma and Coating Physics. Linköping University, The Institute of Technology.
    Bjorefors, Fredrik
    Uppsala University, Sweden.
    Walivaara, Bengt
    Impact Coatings, Linköping, Sweden.
    Ljungcrantz, Henrik
    Impact Coatings, Linköping, Sweden.
    Helmersson, Ulf
    Linköping University, Department of Physics, Chemistry and Biology, Plasma and Coating Physics. Linköping University, The Institute of Technology.
    Influence of ionization degree on film properties when using high power impulse magnetron sputtering2012In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 30, no 3, p. 031507-Article in journal (Refereed)
    Abstract [en]

    Chromium thin films are deposited by combining direct current magnetron sputtering and high power impulse magnetron sputtering (HiPIMS) on a single cathode in an industrial deposition system. While maintaining a constant deposition rate and unchanged metal ion energy distribution function, the fraction of the total power supplied by either deposition technique is altered, and thereby also the metal ion to metal neutral ratio of the deposition flux. It is observed that the required total average power needed to be proportionally increased as the HiPIMS fraction is increased to be able to keep a constant deposition rate. The influence on microstructure, electrical, and electrochemical properties of the films is investigated and shows improvements with the use of HiPIMS. However, considerable influence of the studied properties occurs already when only some 40% of the total power is supplied by the HiPIMS technique. Further increase of the HiPIMS power fraction results in comparatively minor influence of the studied properties yet significant deposition rate efficiency reduction. The results show that the degree of ionization can be controlled separately, and that the advantages associated with using HiPIMS can be obtained while much of the deposition rate reduction, often reported for HiPIMS, can be avoided.

  • 139. Samuelsson, Mattias
    et al.
    Lundin, Daniel
    Sarakinos, Kostas
    Björefors, Fredrik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Walivaara, Bengt
    Ljungcrantz, Henrik
    Helmersson, U.
    Influence of ionization degree on film properties when using high power impulse magnetron sputtering2012In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 30, no 3, p. 031507-Article in journal (Refereed)
    Abstract [en]

    Chromium thin films are deposited by combining direct current magnetron sputtering and high power impulse magnetron sputtering (HiPIMS) on a single cathode in an industrial deposition system. While maintaining a constant deposition rate and unchanged metal ion energy distribution function, the fraction of the total power supplied by either deposition technique is altered, and thereby also the metal ion to metal neutral ratio of the deposition flux. It is observed that the required total average power needed to be proportionally increased as the HiPIMS fraction is increased to be able to keep a constant deposition rate. The influence on microstructure, electrical, and electrochemical properties of the films is investigated and shows improvements with the use of HiPIMS. However, considerable influence of the studied properties occurs already when only some 40% of the total power is supplied by the HiPIMS technique. Further increase of the HiPIMS power fraction results in comparatively minor influence of the studied properties yet significant deposition rate efficiency reduction. The results show that the degree of ionization can be controlled separately, and that the advantages associated with using HiPIMS can be obtained while much of the deposition rate reduction, often reported for HiPIMS, can be avoided.

  • 140. Schaepkens, M
    et al.
    Oehrlein, G S
    Hedlund, Christer
    Uppsala universitet, Institutionen för materialvetenskap.
    Jonsson, Lars
    Uppsala universitet, Institutionen för materialvetenskap.
    Blom, Hans-Olof
    Uppsala universitet, Institutionen för materialvetenskap.
    Selective SiO2-to-Si3N4 etching in inductively coupled fluorocarbon plasmas: Angular dependence of SiO2 and Si3N4 etching rates1998In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. A16, no 6, p. 3281-Article in journal (Refereed)
  • 141.
    Schmidt, Susann
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, The Institute of Technology.
    Czigany, Zsolt
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Greczynski, Grzegorz
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, The Institute of Technology.
    Jensen, Jens
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, The Institute of Technology.
    Hultman, Lars
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, The Institute of Technology.
    Influence of inert gases on the reactive high power pulsed magnetron sputtering process of carbon-nitride thin films2013In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 31, no 1, p. 011503-Article in journal (Refereed)
    Abstract [en]

    The influence of inert gases (Ne, Ar, Kr) on the sputter process of carbon and carbon-nitride (CNx) thin films was studied using reactive high power pulsed magnetron sputtering (HiPIMS). Thin solid films were synthesized in an industrial deposition chamber from a graphite target. The peak target current during HiPIMS processing was found to decrease with increasing inert gas mass. Time averaged and time resolved ion mass spectroscopy showed that the addition of nitrogen, as reactive gas, resulted in less energetic ion species for processes employing Ne, whereas the opposite was noticed when Ar or Kr were employed as inert gas. Processes in nonreactive ambient showed generally lower total ion fluxes for the three different inert gases. As soon as N-2 was introduced into the process, the deposition rates for Ne and Ar-containing processes increased significantly. The reactive Kr-process, in contrast, showed slightly lower deposition rates than the nonreactive. The resulting thin films were characterized regarding their bonding and microstructure by x-ray photoelectron spectroscopy and transmission electron microscopy. Reactively deposited CNx thin films in Ar and Kr ambient exhibited an ordering toward a fullerene-like structure, whereas carbon and CNx films deposited in Ne atmosphere were found to be amorphous. This is attributed to an elevated amount of highly energetic particles observed during ion mass spectrometry and indicated by high peak target currents in Ne-containing processes. These results are discussed with respect to the current understanding of the structural evolution of a-C and CNx thin films.

  • 142. Shamrai, K P
    et al.
    Virko, V F
    Blom, Hans-Olof
    Uppsala universitet, Institutionen för materialvetenskap.
    Pavlenko, V P
    Taranov, V B
    Jonsson, Lars
    Uppsala universitet, Institutionen för materialvetenskap.
    Hedlund, Christer
    Uppsala universitet, Institutionen för materialvetenskap.
    Berg, Sören
    Uppsala universitet, Institutionen för materialvetenskap.
    Discharge disruptions in a helicon plasma source1997In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 15, no 6, p. 2864-2874Article in journal (Refereed)
    Abstract [en]

    We study experimentally and theoretically stable regimes and dischargedisruptions in a helicon plasma source. At fixed input power and gas pressure, stable operation of the source is possible below some critical value of magnetic field Bcr." role="presentation" style="display: inline; line-height: normal; word-spacing: normal; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">Bcr.Bcr. The plasma density increases with the magnetic field and reaches a maximum value nmax" role="presentation" style="display: inline; line-height: normal; word-spacing: normal; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">nmaxnmax at Bcr;" role="presentation" style="display: inline; line-height: normal; word-spacing: normal; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">Bcr;Bcr; after which the discharge disruption occurs. Both Bcr" role="presentation" style="display: inline; line-height: normal; word-spacing: normal; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">BcrBcr and nmax" role="presentation" style="display: inline; line-height: normal; word-spacing: normal; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">nmaxnmax increase almost linearly with the input power and the rate of increase is increasing with the pressure. Matching of the plasma load to the rf power source improves when approaching the disruption point, and becomes perfect at the critical field. The theory of discharge disruptions assumes the power absorption in a helicon source to arise from the linear conversion of helicon waves into electrostatic waves at the plasma edge. The calculated dependence of the absorbed power on the plasma density turns out to be nonmonotonic with minima at antiresonances of the electrostatic waveexcitation. This explains qualitatively principal peculiarities of dischargedisruptions. The calculated plasma impedance is in agreement with experimental value within a factor of 2.

  • 143.
    Silander, Isak
    et al.
    Umeå University, Sweden.
    Hausmaninger, Thomas
    Umeå University, Sweden.
    Zelan, Martin
    RISE - Research Institutes of Sweden, Safety and Transport, Measurement Science and Technology.
    Axner, Ove
    Umeå University, Sweden.
    Gas modulation refractometry for high-precision assessment of pressure under nonerature-stabilized conditions2018In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 36, no 3, article id 03E105Article in journal (Refereed)
    Abstract [en]

    The authors report on the realization of a novel methodology for refractometry - GAs modulation refractometry (GAMOR) - that decreases the influence of drifts in Fabry Perot cavity refractometry. The instrumentation is based on a dual Fabry-Perot cavity refractometer in which the beat frequency between the light fields locked to two different cavities, one measurement and one reference cavity, is measured. The GAMOR methodology comprises a process in which the measurement cavity sequentially is filled and evacuated while the reference cavity is constantly evacuated. By performing beat frequency measurements both before and after the finite-pressure measurement, zero point references are periodically created. This opens up for high precision refractometry under nontemperature-stabilized conditions. A first version of an instrumentation based on the GAMOR methodology has been realized and its basic performance has been scrutinized. The refractometer consists of a Zerodur cavity-block and tunable narrow linewidth fiber lasers operating within the C34 communication channel (i.e., around 1.55 μm) at which there are a multitude of fiber coupled off-the-shelf optical, electro-optic, and acousto-optic components. The system is fully computer controlled, which implies it can perform unattended gas assessments over any foreseeable length of time. When applied to a system with no active temperature stabilization, the GAMOR methodology has demonstrated a 3 orders of magnitude improvement of the precision with respect to conventional static detection. When referenced to a dead weight pressure scale the instrumentation has demonstrated assessment of pressures in the kilo-Pascal range (4303 and 7226 Pa) limited by white noise with standard deviations in the 3.2 N - 1 / 2 - 3.5 N - 1 / 2 mPa range, where N is the number of measurement cycles (each being 100 s long). For short measurement times (up to around 103 s), the system exhibits a (1 σ) total relative precision of 0.7 (0.5) ppm for assessment of pressures in the 4 kPa region and 0.5 (0.4) ppm for pressures around 7 kPa, where the numbers in parentheses represent the part of the total noise that has been attributed to the refractometer. As long as the measurement procedure is performed over short time scales, the inherent properties of the GAMOR methodology allow for high precision assessments by the use of instrumentation that is not actively temperature stabilized or systems that are affected by outgassing or leaks. They also open up for a variety of applications within metrology; e.g., transfer of calibration and characterization of pressure gauges, including piston gauges. 

  • 144.
    Silander, Isak
    et al.
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Hausmaninger, Thomas
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Zelan, Martin
    Axner, Ove
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Gas modulation refractometry for high-precision assessment of pressure under non-temperature-stabilized conditions2018In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 36, no 3, article id 03E105Article in journal (Refereed)
    Abstract [en]

    The authors report on the realization of a novel methodology for refractometry-GAs modulation refractometry (GAMOR)-that decreases the influence of drifts in Fabry Perot cavity refractometry. The instrumentation is based on a dual Fabry-Perot cavity refractometer in which the beat frequency between the light fields locked to two different cavities, one measurement and one reference cavity, is measured. The GAMOR methodology comprises a process in which the measurement cavity sequentially is filled and evacuated while the reference cavity is constantly evacuated. By performing beat frequency measurements both before and after the finite-pressure measurement, zero point references are periodically created. This opens up for high precision refractometry under nontemperature-stabilized conditions. A first version of an instrumentation based on the GAMOR methodology has been realized and its basic performance has been scrutinized. The refractometer consists of a Zerodur cavity-block and tunable narrow linewidth fiber lasers operating within the C34 communication channel (i.e., around 1.55 μm) at which there are a multitude of fiber coupled off-the-shelf optical, electro-optic, and acousto-optic components. The system is fully computer controlled, which implies it can perform unattended gas assessments over any foreseeable length of time. When applied to a system with no active temperature stabilization, the GAMOR methodology has demonstrated a 3 orders of magnitude improvement of the precision with respect to conventional static detection. When referenced to a dead weight pressure scale the instrumentation has demonstrated assessment of pressures in the kilo-Pascal range (4303 and 7226 Pa) limited by white noise with standard deviations in the 3.2N-1/2-3.5N-1/2 mPa range, where N is the number of measurement cycles (each being 100 s long). For short measurement times (up to around 103 s), the system exhibits a (1σ) total relative precision of 0.7 (0.5) ppm for assessment of pressures in the 4 kPa region and 0.5 (0.4) ppm for pressures around 7 kPa, where the numbers in parentheses represent the part of the total noise that has been attributed to the refractometer. As long as the measurement procedure is performed over short time scales, the inherent properties of the GAMOR methodology allow for high precision assessments by the use of instrumentation that is not actively temperature stabilized or systems that are affected by outgassing or leaks. They also open up for a variety of applications within metrology; e.g., transfer of calibration and characterization of pressure gauges, including piston gauges.

  • 145. Simpson, W C
    et al.
    Shuh, D K
    Hung, W H
    Hakansson, M C
    Kanski, J
    Karlsson, Ulf O
    KTH, School of Information and Communication Technology (ICT).
    Yarmoff, J A
    Role of surface stoichiometry in the Cl-2/GaAs(001) reaction1996In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 14, no 3, p. 1815-1821Article in journal (Refereed)
    Abstract [en]

    The room-temperature reaction of Cl-2 with GaAs(001)-4x6, -c(2x8), and -c(4x4) surfaces is studied with synchrotron soft x-ray photoelectron spectroscopy. The chemical composition of the reacted surfaces is found to depend on the stoichiometry of the starting surface. In all cases, the reaction occurs stepwise, with Ga and As monochlorides formed prior to the dichlorides. The Ga-rich surface is initially more reactive than either of the As-rich surfaces and it forms more GaCl than the As-rich surfaces, which instead form more AsCl. The sticking coefficient for chlorine on GaAs(001) decays exponentially with coverage. A contribution from Cl atoms comprising the surface dichlorides is identified in the Cl 2p core-level spectra. (C) 1996 American Vacuum Society.

  • 146.
    Souqui, Laurent
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Pedersen, Henrik
    Linköping University, Department of Physics, Chemistry and Biology, Chemistry. Linköping University, Faculty of Science & Engineering.
    Högberg, Hans
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, Faculty of Science & Engineering.
    Thermal chemical vapor deposition of epitaxial rhombohedral boron nitride from trimethylboron and ammonia2019In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 37, no 2, article id 020603Article in journal (Refereed)
    Abstract [en]

    Epitaxial rhombohedral boron nitride (r-BN) films were deposited on alpha-Al2O3(001) substrates by chemical vapor deposition, using trimethylboron, ammonia, and a low concentration of silane in the growth flux. The depositions were performed at temperatures from 1200 to 1485 degrees C, pressures from 30 to 90 mbar, and N/B ratios from 321 to 1286. The most favorable conditions for epitaxy were a temperature of 1400 degrees C, N/B around 964, and pressures below 40 mbar. Analysis by thin film x-ray diffraction showed that most deposited films were polytype-pure epitaxial r-BN with an out-of-plane epitaxial relationship of r-BN[001] parallel to w-AlN[001] parallel to alpha-Al2O3[001] and with two in-plane relationships of r-BN[110] parallel to w-AlN[110] parallel to alpha-Al2O3[100] and r-BN[110] parallel to w-AlN[110] parallel to alpha-Al2O3[(1) over bar 00] due to twinning. Published by the AVS.

  • 147.
    Ström, Valter
    et al.
    KTH, Superseded Departments, Physics.
    Rao, K Venkat
    KTH, Superseded Departments, Physics.
    Mapping local susceptibility using a scanning coaxial write/read head1998In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 16, no 4, p. 2687-2692Article in journal (Refereed)
    Abstract [en]

    A technique to study local susceptibility of magnetic material is introduced. We describe a unique probe based on a pair of write/read heads, to measure and model both the susceptibility components at any point on a surface. With this approach it is possible to map the strength and direction of the local in-plane uniaxial susceptibility at surfaces. The usefulness of our technique is validated by measurements on oriented gamma-Fe2O3 in a credit card. In addition, we present studies on an amorphous soft ferromagnet containing different defect structures to reveal the micromagnetic structural details around defects on a surface. Our approach has the distinct advantage of determining the local susceptibility and anisotropy on a length scale not possible by using other techniques available today.

  • 148.
    Svedberg, E B
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, The Institute of Technology.
    Birch, Jens
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, The Institute of Technology.
    Ivanov, Ivan
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, The Institute of Technology.
    Münger, Peter
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, The Institute of Technology.
    Sundgren, Jan- Erik
    Linköping University, Department of Physics, Chemistry and Biology, Thin Film Physics. Linköping University, The Institute of Technology.
    Asymmetric interface broadening in epitaxial Mo/W (001) superlattices grown by magnetron sputtering1998In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 16, no 2, p. 633-638Article in journal (Refereed)
    Abstract [en]

    The interfacial structure in epitaxial Mo/W(001) superlattices, grown by magnetron sputtering on MgO(001) substrates has been studied. The films were grown in Ar and Kr discharges at a substrate temperature of 700 degrees C, and the as-deposited samples were analyzed by x-ray diffraction and found to be epitaxial with no high-angle grain boundaries. The degree of interfacial intermixing, caused by fluxes of different energetic species impinging on the growth surface, was estimated using a combination of Monte Carlo binary collision computer codes and a gas scattering computational model. In the Ar discharge case, large asymmetries in the Mo/W and W/Mo interfaces were found, with the W/Mo interface being more than a factor of 2 broader than the Mo/W interface. Simulations of x-ray reflectivity curves using the calculated interface profiles as input parameters without any additional fitting parameters agreed very well with measured data. The overall good fit between the calculated and measured reflectivity curves using the calculated compositional profiles is an indicator that the growth simulations using TRIM based codes provides interface profiles that are reasonably accurate, which can be used as a starting point for further refinements of the details of the interface structures. (C) 1998 American Vacuum Society.

  • 149.
    Särhammar, Erik
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Berg, Sören
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Nyberg, Tomas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Hysteresis-free high rate reactive sputtering of niobium oxide, tantalumoxide, and aluminum oxide2014In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 2, p. 041517-Article in journal (Refereed)
    Abstract [en]

    This work reports on experimental studies of reactive sputtering from targets consisting of a metaland its oxide. The composition of the targets varied from pure metal to pure oxide of Al, Ta, and Nb. This combines features from both the metal target and oxide target in reactive sputtering. If a certain relation between the metal and oxide parts is chosen, it may be possible to obtain a high deposition rate, due to the metal part, and a hysteresis-free process, due to the oxide part. The aim of this work is to quantify the achievable boost in oxide deposition rate from a hysteresis-free process by using a target consisting of segments of a metal and its oxide. Such an increase has been previously demonstrated for Ti using a homogeneous substoichiometric target. The achievable gain in deposition rate depends on transformation mechanisms from oxide to suboxides due to preferential sputtering of oxygen. Such mechanisms are different for different materials and the achievable gain is therefore material dependent. For the investigated materials, the authors have demonstrated oxide deposition rates that are 1.5–10 times higher than what is possible from metal targets in compound mode. However, although the principle is demonstrated for oxides of Al, Ta,and Nb, a similar behavior is expected for most oxides.

  • 150.
    Tengstrand, O.
    et al.
    Linköping University, Sweden.
    Nedfors, N.
    Uppsala University, Sweden.
    Fast, Lars
    RISE, SP – Sveriges Tekniska Forskningsinstitut, SP Elektronik, EMC.
    Flink, A.
    Linköping University, Sweden; Impact Coatings AB, Sweden.
    Jansson, U.
    Uppsala University, Sweden.
    Eklund, A.
    Linköping University, Sweden.
    Hultman, L.
    Linköping University, Sweden.
    Structure and electrical properties of Nb-Ge-C nanocomposite coatings2014In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 32, no 4, p. 41509-Article in journal (Refereed)
    Abstract [en]

    Nb-Ge-C nanocomposite thin films were deposited by dc magnetron sputtering using three elemental targets. The films consist of substoichiometric NbC x in a nanometer-thick matrix of amorphous C and Ge. Films with no Ge contain grains that are elongated in the growth direction with a (111) preferred crystallographic orientation. With the addition of ∼12 at. % Ge, the grains are more equiaxed and exhibit a more random orientation. At even higher Ge contents, the structure also becomes denser. The porous structure of the low Ge content films result in O uptake from the ambient. With higher C content in the films both the amount of amorphous C and C/Nb-ratio increases. The contact resistance was measured by four-point technique as a function of contact force between 0 and 10 N. The lowest contact resistance (1.7 mΩ) is obtained at 10 N. The resistivity varies between 470 and 1700 μΩ·cm depending on porosity and O content. 

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