01782nas a2200205 4500008003900000022001400039245008700053210006900140260001200209300001100221490000700232520110700239653003601346653001901382653004001401100002101441700001801462700001901480856007701499 2014 d a0963-025200aAsymmetric particle fluxes from drifting ionization zones in sputtering magnetrons0 aAsymmetric particle fluxes from drifting ionization zones in spu c04/2014 a0250070 v233 a

Electron and ion fluxes from direct current and high-power impulse magnetron sputtering (dcMS and HiPIMS) plasmas were measured in the plane of the target surface. Biased collector probes and a particle energy and mass analyzer showed asymmetric emission of electrons and of singly and doubly charged ions. For both HiPIMS and dcMS discharges, higher fluxes of all types of particles were observed in the direction of the electrons' E x B drift. These results are put in the context with ionization zones that drift over the magnetron's racetrack. The measured currents of time-resolving collector probes suggest that a large fraction of the ion flux originates from drifting ionization zones, while energy-resolving mass spectrometry indicates that a large fraction of the ion energy is due to acceleration by an electric field. This supports the recently proposed hypothesis that each ionization zone is associated with a negative–positive–negative space charge structure, thereby producing an electric field that accelerates ions from the location where they were formed.

10aInstrumentation and measurement10aPlasma physics10aSurfaces, interfaces and thin films1 aPanjan, Matjaž1 aFranz, Robert1 aAnders, André uhttps://facades.lbl.gov/publications/asymmetric-particle-fluxes-drifting01036nas a2200169 4500008003900000022001400039245008800053210006900141260001200210300001600222490000700238520048400245100001900729700001700748700002200765856007900787 2014 d a0093-381300aDrifting Ionization Zone in DC Magnetron Sputtering Discharges at Very Low Currents0 aDrifting Ionization Zone in DC Magnetron Sputtering Discharges a c10/2014 a2578 - 25790 v423 a

Discharges with crossed electric and magnetic fields are known to develop instabilities that are crucial in the transport of charged particles. Sputtering magnetrons are no exception. While most recent studies focused on traveling ionization zones in high power impulse magnetron sputtering, we show here fast camera images of magnetron discharges at very low current. A single drifting ionization zone is always present, even down to the threshold current of about 10 mA.

1 aAnders, André1 aNi, Pavel, A1 aAndersson, Joakim uhttps://facades.lbl.gov/publications/drifting-ionization-zone-dc-magnetron01455nas a2200253 4500008003900000022001300039245012000052210006900172260001200241300001100253490000800264520065900272653002000931653001500951653002200966653002300988653001501011100001901026700002101045700001801066700002201084700001801106856007701124 2013 d a0003695100aDrifting potential humps in ionization zones: The “propeller blades” of high power impulse magnetron sputtering0 aDrifting potential humps in ionization zones The propeller blade c10/2013 a1441030 v1033 a

Ion energy distribution functions measured for high power impulse magnetron sputtering show features, such as a broad peak at several 10 eV with an extended tail, as well as asymmetry with respect to E × B, where E and B are the local electric and magnetic field vectors, respectively. Here it is proposed that those features are due to the formation of a potential hump of several 10 V in each of the traveling ionization zones. Potential hump formation is associated with a negative-positive-negative space charge that naturally forms in ionization zones driven by energetic drifting electrons.

10aElectric fields10aionization10aplasma ionization10asputter deposition10asputtering1 aAnders, André1 aPanjan, Matjaž1 aFranz, Robert1 aAndersson, Joakim1 aNi, Pavel, A. uhttps://facades.lbl.gov/publications/drifting-potential-humps-ionization01830nas a2200241 4500008003900000022001300039245013000052210006900182260001100251300001400262490000800276520103900284653002701323653003701350653002201387653001801409100002201427700002001449700001701469700001401486700001901500856006901519 2013 d a0927024800aModeling of optical and energy performance of tungsten-oxide-based electrochromic windows including their intermediate states0 aModeling of optical and energy performance of tungstenoxidebased c1/2013 a129 - 1350 v1083 a

Tungsten-oxide-based electrochromic (EC) windows are currently the most robust and matured dynamic windows where the transmittance of visual light and near-infrared radiation can be controlled by a small applied voltage. In its standard application, the window is commonly either in its clear or colored state. In this contribution, we study the optical and energy performance of such window in the fully bleached and fully colored state as well as when it is kept in intermediate states. Different configurations in terms of placement of the EC layer stack and possible additional low-emissivity (low-E) coating within the insulated glass unit are considered. Using optical data and software tools we find that even a small coloration has a significant effect on the energy performance because the solar heat gain coefficient is readily reduced by the absorption of the EC layer stack. We compare the performance of the EC windows to commercially available solar-control (spectrally selective) low-E windows.

10aElectrochromic windows10aEnergy efficient window modeling10aEnergy simulation10aSmart windows1 aLim, Sunnie, H.N.1 aIsidorsson, Jan1 aSun, Lizhong1 aKwak, Leo1 aAnders, André uhttps://facades.lbl.gov/publications/modeling-optical-and-energy01380nas a2200229 4500008003900000022001300039245009800052210006900150260001200219300001100231490000800242520068000250653001400930653001500944653002300959653002200982653002001004100002201024700001701046700001901063856006801082 2013 d a0003695100aSpectroscopic imaging of self-organization in high power impulse magnetron sputtering plasmas0 aSpectroscopic imaging of selforganization in high power impulse  c07/2013 a0541040 v1033 a

Excitation and ionization conditions in traveling ionization zones of high power impulse magnetron sputtering plasmas were investigated using fast camera imaging through interference filters. The images, taken in end-on and side-on views using light of selected gas and target atom and ion spectral lines, suggest that ionization zones are regions of enhanced densities of electrons, and excited atoms and ions. Excited atoms and ions of the target material (Al) are strongly concentrated near the target surface. Images from the highest excitation energies exhibit the most localized regions, suggesting localized Ohmic heating consistent with double layer formation.

10aAluminium10aionization10aIonizing radiation10aplasma ionization10avisible spectra1 aAndersson, Joakim1 aNi, Pavel, A1 aAnders, André uhttps://facades.lbl.gov/publications/spectroscopic-imaging-self01722nas a2200229 4500008003900000022001300039245013700052210006900189260001200258300001100270490000800281520098700289653001201276653001501288653002001303653001901323653002201342100001901364700001701383700001801400856007401418 2012 d a0021897900aDrifting localization of ionization runaway: Unraveling the nature of anomalous transport in high power impulse magnetron sputtering0 aDrifting localization of ionization runaway Unraveling the natur c03/2012 a0533040 v1113 a

The plasma over a magnetron’s erosion “racetrack” is not azimuthally uniform but concentrated in distinct dense ionization zones which move in the E x B direction with about 10% of the electron E x B/B2 drift velocity. The ionization zones are investigated with a gated camera working in concert with a streak camera for Al, Nb, Cu, and W targets in Ar or Kr background gas. It is found that each ionization zone has a high plasma density edge, which is the origin of a plasma-generating electron jet leaving the target zone. Each region of strong azimuthal plasma density gradient generates an azimuthal electric field, which promotes the escape of magnetized electrons and the formation of electron jets and plasma flares. The phenomena are proposed to be caused by an ionization instability where each dense plasma zone exhibits a high stopping power for drifting high energy electrons, thereby enhancing itself.

10aCameras10aionization10aMagnetic fields10aPlasma density10aplasma ionization1 aAnders, André1 aNi, Pavel, A1 aRauch, Albert uhttps://facades.lbl.gov/publications/drifting-localization-ionization01539nas a2200241 4500008003900000022001400039245011000053210006900163260001100232300001400243490000700257520076200264653003001026653002201056653002601078100001701104700002801121700002201149700001501171700001601186700001901202856007601221 2012 d a0884-291400aImproved structural and electrical properties of thin ZnO:Al films by dc filtered cathodic arc deposition0 aImproved structural and electrical properties of thin ZnOAl film c3/2012 a857 - 8620 v273 a

Transparent conducting oxide films are usually several 100-nm thick to achieve the required low sheet resistance. In this study, we show that the filtered cathodic arc technique produces high-quality low-cost ZnO:Al material for comparably smaller thicknesses than achieved by magnetron sputtering, making arc deposition a promising choice for applications requiring films less than 100-nm thick. A mean surface roughness less than 1 nm is observed for ZnO:Al films less than 100-nm thick, and 35-nm-thick ZnO:Al films exhibit Hall mobility of 28 cm2/Vs and a low resistivity of 6.5 × 10−4 Ωcm. Resistivity as low as 5.2 × 10−4 Ωcm and mobility as high as 43.5 cm2/Vs are obtained for 135-nm films.

10aphysical vapor deposition10aPlasma deposition10aTransparent conductor1 aZhu, Yuankun1 aMendelsberg, Rueben, J.1 aLim, Sunnie, H.N.1 aZhu, Jiaqi1 aHan, Jiecai1 aAnders, André uhttps://facades.lbl.gov/publications/improved-structural-and-electrical01241nas a2200181 4500008003900000022001400039245012000053210006900173260001200242300001100254490000700265520064300272100001900915700001900934700001800953700002000971856006800991 2012 d a0022-372700aThe ‘recycling trap’: a generalized explanation of discharge runaway in high-power impulse magnetron sputtering0 arecycling trap a generalized explanation of discharge runaway in c01/2012 a0120030 v453 a

Contrary to paradigm, magnetron discharge runaway cannot always be related to self-sputtering. We report here that the high density discharge can be observed with all conducting targets, including low sputter yield materials such as carbon. Runaway to a high density discharge is therefore generally based on self-sputtering in conjunction with the recycling of gas atoms in the magnetic field-affected pre-sheath. A generalized runaway condition can be formulated, offering a pathway to a time-dependent model for high-power impulse magnetron sputtering that includes rarefaction and an explanation for the termination of runaway.

1 aAnders, André1 aČapek, Jiří1 aHála, Matêj1 aMartinu, Ludvik uhttps://facades.lbl.gov/publications/recycling-trap-generalized01830nas a2200181 4500008003900000245010000039210006900139300001800208490000700226520121300233100002801446700002201474700001701496700001601513700002401529700001901553856007601572 2011 d00aAchieving high mobility ZnO:Al at very high growth rates by dc filtered cathodic arc deposition0 aAchieving high mobility ZnOAl at very high growth rates by dc fi a232003-2320070 v443 a

Achieving a high growth rate is paramount for making large-area transparent conducting oxide coatings at a low cost. Unfortunately, the quality of thin films grown by most techniques degrades as the growth rate increases. Filtered dc cathodic arc is a lesser known technique which produces a stream of highly ionized plasma, in stark contrast to the neutral atoms produced by standard sputter sources. Ions bring a large amount of potential energy to the growing surface which is in the form of heat, not momentum. By minimizing the distance from cathode to substrate, the high ion flux gives a very high effective growth temperature near the film surface without causing damage from bombardment. The high surface temperature is a direct consequence of the high growth rate and allows for high-quality crystal growth. Using this technique, 500–1300 nm thick and highly transparent ZnO : Al films were grown on glass at rates exceeding 250 nm min−1 while maintaining resistivity below 5 × 10−4 Ω cm with electron mobility as high as 60 cm2 V−1 s−1.

1 aMendelsberg, Rueben, J.1 aLim, Sunnie, H.N.1 aZhu, Yuankun1 aWallig, Joe1 aMilliron, Delia, J.1 aAnders, André uhttps://facades.lbl.gov/publications/achieving-high-mobility-znoal-very01433nas a2200289 4500008003900000022001400039245009300053210006900146260001200215300001600227490000700243520053600250653001100786653002100797653001600818653002800834653002000862100002200882700002500904700002600929700002800955700001800983700001901001700002701020700002401047856007201071 2011 d a1530-698400aDynamically Modulating the Surface Plasmon Resonance of Doped Semiconductor Nanocrystals0 aDynamically Modulating the Surface Plasmon Resonance of Doped Se c10/2011 a4415 - 44200 v113 a

Localized surface plasmon absorption features arise at high doping levels in semiconductor nanocrystals, appearing in the near-infrared range. Here we show that the surface plasmons of tin-doped indium oxide nanocrystal films can be dynamically and reversibly tuned by postsynthetic electrochemical modulation of the electron concentration. Without ion intercalation and the associated material degradation, we induce a > 1200 nm shift in the plasmon wavelength and a factor of nearly three change in the carrier density.

10adoping10aindium tin oxide10ananocrystal10aspectroelectrochemistry10asurface plasmon1 aGarcia, Guillermo1 aBuonsanti, Raffaella1 aRunnerstrom, Evan, L.1 aMendelsberg, Rueben, J.1 aLlordes, Anna1 aAnders, André1 aRichardson, Thomas, J.1 aMilliron, Delia, J. uhttps://facades.lbl.gov/publications/dynamically-modulating-surface00712nas a2200157 4500008003900000022001400039245004300053210004100096260001200137300001600149490000700165520027300172100001900445700001600464856007400480 2011 d a0093-381300aA Plasma Lens for Magnetron Sputtering0 aPlasma Lens for Magnetron Sputtering c11/2011 a2528 - 25290 v393 a

A plasma lens, consisting of a solenoid and potential-defining ring electrodes, has been placed between a magnetron and substrates to be coated. Photography reveals qualitative information on excitation, ionization, and the transport of plasma to the substrate.

1 aAnders, André1 aBrown, Jeff uhttps://facades.lbl.gov/publications/plasma-lens-magnetron-sputtering01624nas a2200193 4500008004100000245010000041210006900141260001200210490000700222520098500229653002401214653000901238653001301247653003401260653002801294100001701322700001901339856007201358 2010 eng d00aSupersonic metal plasma impact on a surface: an optical investigation of the pre-surface region0 aSupersonic metal plasma impact on a surface an optical investiga c04/20100 v433 a

Aluminum plasma, produced in high vacuum by a pulsed, filtered cathodic arc plasma source, was directed onto a wall where if formed a coating. The accompanying "optical flare" known from the literature was visually observed, photographed, and spectroscopically investigated with appropriately high temporal (1 μs) and spatial (100 μm) resolution. Consistent with other observations using different techniques, it was found that the impact of the fully ionized plasma produces metal neutrals as well as desorbed gases, both of which interact with the incoming plasma. Most effectively are charge exchange collisions between doubly charged aluminum and neutral aluminum, which lead to a reduction of the flow of doubly charged before they reach the wall, and a reduction of neutrals as the move away from the surface. Those plasma-wall interactions are relevant for coating processes as well as for interpreting the plasma properties such as ion charge state distributions.

10acathodic arc plasma10aions10aneutrals10aoptical emission spectroscopy10aplasma-wall interaction1 aNi, Pavel, A1 aAnders, André uhttps://facades.lbl.gov/publications/supersonic-metal-plasma-impact01581nas a2200181 4500008004100000050001500041245011400056210006900170520095200239100001901191700002201210700001701232700002201249700002001271700002001291700001601311856007201327 2009 eng d aLBNL-1881E00aHigh quality ZnO:Al transparent conducting oxide films synthesized by pulsed filtered cathodic arc deposition0 aHigh quality ZnOAl transparent conducting oxide films synthesize3 a

Aluminum-doped zinc oxide, ZnO:Al or AZO, is a well-known n-type transparent conducting oxide with great potential in a number of applications currently dominated by indium tin oxide (ITO). In this study, the optical and electrical properties of AZO thin films deposited on glass and silicon by pulsed filtered cathodic arc deposition are systematically studied. In contrast to magnetron sputtering, this technique does not produce energetic negative ions, and therefore ion damage can be minimized. The quality of the AZO films strongly depends on the growth temperature while only marginal improvements are obtained with post-deposition annealing. The best films, grown at a temperature of about 200°C, have resistivities in the low to mid 10-4Ω cm range with a transmittance better than 85% in the visible part of the spectrum. It is remarkable that relatively good films of small thickness (60 nm) can be fabricated using this method.

1 aAnders, André1 aLim, Sunnie, H.N.1 aYu, Kin, Man1 aAndersson, Joakim1 aRosén, Johanna1 aMcFarland, Mike1 aBrown, Jeff uhttps://facades.lbl.gov/publications/high-quality-znoal-transparent01603nas a2200121 4500008004100000050001400041245006300055210006300118260001200181520119200193100001901385856007701404 2008 eng d aLBNL-170E00aDeposition Rates of High Power Impulse Magneton Sputtering0 aDeposition Rates of High Power Impulse Magneton Sputtering c04/20083 a

High power impulse magnetron sputtering (HIPIMS) is seen by many as the new paradigm in sputtering. It provides significant self-ion assistance to film growth. However, many noticed that deposition rates are reduced, often to less than 50%, compared to direct current (DC) sputtering rates at the same power input. It is argued here that the reduction is based on the physics of sputtering and self-sputtering, and it should not come as a surprise. Four effects can be distinguished (i) the yield effect caused by the less-than-linear increase of sputtering yield with ion energy, (ii) the impedance effect, influencing what fraction of the target-anode voltage drops in the sheath, (iii) the species effect associated with a change of ions causing sputtering, and (iv) the return effect associated with flux splitting in selfsputtering. The paper is completed by considering some business implications, in particular; it is argued that HIPIMS is a different technology and that its value should be judged comprehensively, not just by rates. Finally, the special case of temperature dependent sputtering is considered, which in some cases may lead to rates exceeding the DC rates.

1 aAnders, André uhttps://facades.lbl.gov/publications/deposition-rates-high-power-impulse01524nas a2200157 4500008004100000050001500041245011400056210006900170260003600239490000600275520094200281100001901223700002401242700002701266856007301293 2008 eng d aLBNL-1089E00aElectrochromically switched, gas-reservoir metal hydride devices with application to energy-efficient windows0 aElectrochromically switched gasreservoir metal hydride devices w aEindhoven, Netherlandsc08/20030 v13 a

Proof-of-principle gas-reservoir MnNiMg electrochromic mirror devices have been investigated. In contrast to conventional electrochromic approaches, hydrogen is stored (at low concentration) in the gas volume between glass panes of the insulated glass units (IGUs). The elimination of a solid state ion storage layer simplifies the layer stack, enhances overall transmission, and reduces cost. The cyclic switching properties were demonstrated and system durability improved with the incorporation a thin Zr barrier layer between the MnNiMg layer and the Pd catalyst. Addition of 9% silver to the palladium catalyst further improved system durability. About 100 full cycles have been demonstrated before devices slow considerably. Degradation of device performance appears to be related to Pd catalyst mobility, rather than delamination or metal layer oxidation issues originally presumed likely to present significant challenges.

1 aAnders, André1 aSlack, Jonathan, L.1 aRichardson, Thomas, J. uhttps://facades.lbl.gov/publications/electrochromically-switched-gas01914nas a2200253 4500008004100000245013900041210006900180260002500249490000800274520105500282653001901337653000801356653003601364653001601400653000801416100002201424700002001446700002901466700003101495700001901526700002301545700001901568856007301587 2008 eng d00aFunctionalization of Hydrogen-free Diamond-like Carbon Films using Open-air Dielectric Barrier Discharge Atmospheric Plasma Treatments0 aFunctionalization of Hydrogenfree Diamondlike Carbon Films using aBoulder, COc08/20080 v2543 a

A dielectric barrier discharge (DBD) technique has been employed to produce uniform atmospheric plasmas of He and N2 gas mixtures in open air in order to functionalize the surface of filtered-arc deposited hydrogen-free diamond-like carbon (DLC) films. XPS measurements were carried out on both untreated and He/N2 DBD plasma-treated DLC surfaces. Chemical states of the C 1s and N 1s peaks were collected and used to characterize the surface bonds. Contact angle measurements were also used to record the short- and long-term variations in wettability of treated and untreated DLC. In addition, cell viability tests were performed to determine the influence of various He/N2 atmospheric plasma treatments on the attachment of osteoblast MC3T3 cells. Current evidence shows the feasibility of atmospheric plasmas in producing long-lasting variations in the surface bonding and surface energy of hydrogen-free DLC and consequently the potential for this technique in the functionalization of DLC-coated devices.

10aCell viability10aDLC10aIon implantation and deposition10awettability10aXPS1 aEndrino, Jose, L.1 aMarco, Jose, F.1 aPoolcharuansin, Phitsanu1 aPhani, Ayalasomayajula, R.1 aAllen, Matthew1 aAlbella, José, M.1 aAnders, André uhttps://facades.lbl.gov/publications/functionalization-hydrogen-free01116nas a2200145 4500008004100000050001400041245010200055210006900157300001100226490000700237520061100244100002200855700001900877856007400896 2008 eng d aLBNL-190E00aGasless sputtering: Opportunities for ultraclean metallization, coatings in space, and propulsion0 aGasless sputtering Opportunities for ultraclean metallization co a2215030 v923 a

Pulsed magnetron sputtering was demonstrated in high vacuum: no sputter gas was used at any time. Sustained selfsputtering was initiated by multiply charged ions from a short vacuum arc. Copper ion currents to an ion collector in excess of 30 A were measured, implying a plasma density of about 6 x1018 m-3. This technology may prove useful for metal coatings free of noble gas inclusions and suggests that magnetrons could operate in the vacuum of space. In addition to coating objects in space, the momentum of the sputtered atoms and ions may be utilized in space thrusters.

1 aAndersson, Joakim1 aAnders, André uhttps://facades.lbl.gov/publications/gasless-sputtering-opportunities01008nas a2200157 4500008004100000245008100041210006900122260001200191300001000203490000700213520048800220100002200708700002800730700001900758856007300777 2008 eng d00aObservation of Ti4+ ions in a high power impulse magnetron sputtering plasma0 aObservation of Ti4 ions in a high power impulse magnetron sputte c08/2008 a715040 v933 a

Multiply charged titanium ions including Ti4+ were observed in high power impulse magnetron sputtering discharges. Mass/charge spectrometry was used to identify metal ion species. Quadruply charged titanium ions were identified by isotope-induced broadening at mass/charge 12. Due to their high potential energy, Ti4+ ions give a high yield of secondary electrons, which in turn are likely to be responsible for the generation of multiply charged states.

1 aAndersson, Joakim1 aEhiasarian, Arutiun, P.1 aAnders, André uhttps://facades.lbl.gov/publications/observation-ti4-ions-high-power01049nas a2200121 4500008004100000050001500041245009000056210006900146520059600215100002200811700001900833856007500852 2008 eng d aLBNL-1641E00aSelf-sputtering far above the runaway threshold: an extraordinary metal ion generator0 aSelfsputtering far above the runaway threshold an extraordinary 3 a

When self-sputtering is driven far above the runaway threshold voltage, energetic electrons are made available to produce excess plasma far from the magnetron target. Ionization balance considerations show that the secondary electrons deliver the necessary energy to the remote zone. Thereby, such a system can be an extraordinarily prolific generator of useable metal ions. Contrary to other known sources, the ion current to a substrate can exceed the discharge current. For gasless self-sputtering of copper, the useable ion current scales exponentially with the discharge voltage.

1 aAndersson, Joakim1 aAnders, André uhttps://facades.lbl.gov/publications/self-sputtering-far-above-runaway01050nas a2200133 4500008004100000050001400041245013600055210006900191260002500260490000700285520052900292100001900821856007600840 2008 eng d aLBNL-171E00aSelf-sputtering runaway in high power impulse magnetron sputtering: The role of secondary electrons and multiply charged metal ions0 aSelfsputtering runaway in high power impulse magnetron sputterin aBoulder, COc08/20040 v923 a

Self-sputtering runaway in high power impulse magnetron sputtering is closely related to the appearance of multiply charged ions. This conclusion is based on the properties of potential emission of secondary electrons and energy balance considerations. The effect is especially strong for materials whose sputtering yield is marginally greater than unity. The absolute deposition rate increases ~ Q1/2, whereas the rate normalized to the average power decreases ~ Q-1/2, with Q being the mean ion charge state number.

1 aAnders, André uhttps://facades.lbl.gov/publications/self-sputtering-runaway-high-power01963nas a2200145 4500008004100000050001400041245012200055210006900177300001500246490000700261520143500268100001801703700001901721856007701740 2008 eng d aLBNL-679E00aSpatial distribution of average charge state and deposition rate in high power impulse magnetron sputtering of copper0 aSpatial distribution of average charge state and deposition rate a135210-1-60 v413 a

The spatial distribution of copper ions and atoms in high power impulse magnetron sputtering (HIPIMS) discharges was determined by (i) measuring the ion current to electrostatic probes and (ii) measuring the film thickness by profilometry. A set of electrostatic and collection probes were placed at different angular positions and distances from the target surface. The angular distribution of the deposition rate and the average charge state of the copper species (including ions and neutrals) were deduced. The discharge showed a distinct transition to a high current mode dominated by copper self-sputtering when the applied voltage exceeded the threshold of 535 V. For a lower voltage, the deposition rate was very low and the average charge state was found to be less than 0.4. For higher voltage (and average power), the absolute deposition rates were much higher, but they were smaller than the corresponding direct current (DC) rates if normalized to the same average power. At the high voltage level, the spatial distribution of the average charge state showed some similarities with the distribution of the magnetic field, suggesting that the generation and motion of copper ions is affected by magnetized electrons. At higher voltage, the average charge state increases with the distance from the target and locally may exceed unity, indicating the presence of significant amounts of doubly charged copper ions.

1 aHorwat, David1 aAnders, André uhttps://facades.lbl.gov/publications/spatial-distribution-average-charge01696nas a2200193 4500008004100000245018300041210006900224260001200293300001100305490000700316520097400323100002301297700002601320700002201346700001901368700002101387700001801408856007601426 2008 eng d00aThe structure and electron energy loss near edge structure of tungsten oxide thin films prepared by pulsed cathodic arc deposition and plasma-assisted pulsed magnetron sputtering0 astructure and electron energy loss near edge structure of tungst c04/2008 a1752160 v203 a

The microstructure and energy-loss near-edge structure (ELNES) of pulsed cathodic arc and pulsed magnetron sputtered WO3 thin films were investigated. It was found that the cathodic arc deposited material consisted of the α-WO3 phase with a high degree of crystallinity. In contrast, the magnetron sputtered material was highly disordered making it difficult to determine its phase. A self-consistent real space multiple scattering approach was used to calculate the NES of the various phases of WO3. Each phase was found to exhibit a unique NES allowing different phases of WO3 to be identified. The real space approach also allowed the origin of the main features in the NES to be investigated as the cluster size increased. The calculated NES for the room temperature γ-WO3 was found to compare well to previous X-ray absorption spectra and to NES obtained by full-potential band structure calculation.

1 aField, Matthew, R.1 aMcCulloch, Dougal, G.1 aLim, Sunnie, H.N.1 aAnders, André1 aKeast, Vicki, J.1 aBurgess, R.W. uhttps://facades.lbl.gov/publications/structure-and-electron-energy-loss01940nas a2200181 4500008004100000245004500041210004200086260001200128490000700140520137800147653003101525653003001556653003801586653001801624100001901642700002401661856007301685 2007 eng d00aA low-energy linear oxygen plasma source0 alowenergy linear oxygen plasma source c04/20070 v783 a

A new version of a constricted plasma source is described, characterized by all metal-ceramic construction, a linear slit exit of 180 mm length, and cw operation typically 50 kHz at an average power of 1.5 kW. The plasma source is here operated with oxygen gas, producing streaming plasma that contains mainly positive molecular and atomic ions, and to a much lesser degree, negative ions. The maximum total ion current obtained was about 0.5 A. The fraction of atomic ions reached more than 10% of all ions when the flow rate was less then 10 SCCM O2, corresponding to a chamber pressure of about 0.5 Pa for the selected pumping speed. The energy distribution functions of the different ion species were measured with a combined mass spectrometer and energy analyzer. The time-averaged distribution functions were broad and ranged from about 30 to 90 eV at 200 kHz and higher frequencies, while they were only several eV broad at 50 kHz and lower frequencies, with the maximum located at about 40 eV for the grounded anode case. This maximum was shifted down to about 7 eV when the anode was floating, indicating the important role of the plasma potential for the ion energy for a given substrate potential. The source could be scaled to greater length and may be useful for functionalization of surfaces and plasma-assisted deposition of compound films.

10aatomic and molecular ions10aConstricted plasma source10aion energy distribution functions10aoxygen plasma1 aAnders, André1 aYushkov, Georgy, Yu uhttps://facades.lbl.gov/publications/low-energy-linear-oxygen-plasma01644nas a2200205 4500008004100000245011300041210006900154260001200223300001400235490000800249520093200257653003001189653002701219653002401246653002301270653002501293100002301318700001901341856007801360 2007 eng d00aPhysical properties of erbium implanted tungsten oxide films deposited by reactive dual magnetron sputtering0 aPhysical properties of erbium implanted tungsten oxide films dep c05/2007 a5264-52690 v5153 a

Amorphous and partially crystalline WO3 thin films were prepared by reactive dual magnetron sputtering and successively implanted by erbium ions with a fluence in the range from 7.7 x 1014 to 5 x 1015 ions/cm2. The electrical and optical properties were studied as a function of the film deposition parameters and the ion fluence. Ion implantation caused a strong decrease of the resistivity, a moderate decrease of the index of refraction and a moderate increase of the extinction coefficient in the visible and near infrared, while the optical band gap remained almost unchanged. These effects could be largely ascribed to ion-induced oxygen deficiency. When annealed in air, the already low resistivities of the implanted samples decreased further up to 70°C, whereas oxidation, and hence a strong increase of the resistivity, was observed at higher annealing temperatures

10aDual magnetron sputtering10aelectrical resistivity10aEr ion implantation10aoptical properties10atungsten oxide films1 aMohamed, Sodky, H.1 aAnders, André uhttps://facades.lbl.gov/publications/physical-properties-erbium-implanted01855nas a2200145 4500008004100000050001500041245005500056210005500111520137800166100001901544700002201563700001801585700002801603856007801631 2007 eng d aLBNL-6214700aPhysics of High Power Impulse Magnetron Sputtering0 aPhysics of High Power Impulse Magnetron Sputtering3 a

High power impulse magnetron sputtering is characterized by discharge pulses whose target power density exceeds conventional sputtering power densities by two orders of magnitude or more; the goal is to provide a large flux of ionized sputtered material. The processes of pulse evolution are briefly reviewed, including secondary electron emission, self-sputtering, and rarefaction. Using a pulse power supply capable of providing constant voltage for target peak power densities up to 5 kW/cm2, the evolution of the current-voltage characteristics was investigated for copper and titanium. It is shown that the characteristic cannot be reduced to value pairs. Rather, a strong but reproducible development exists. The details depend on the argon pressure and applied voltage. Each target material exhibits a distinct and sharp transition to a high current regime that appears to be dominated by metal plasma. Despite the higher sputter yields for copper, the transition to the high current regime occurs much earlier and stronger for titanium, which may be attributed to a higher secondary electron yield and hence a higher density of electrons confined in the magnetron structure. At high currents, the closed-drift Hall current generates a magnetic field that weakens plasma confinement, thereby enabling large ion currents to reach a biased substrate.

1 aAnders, André1 aAndersson, Joakim1 aHorwat, David1 aEhiasarian, Arutiun, P. uhttps://facades.lbl.gov/publications/physics-high-power-impulse-magnetron01619nas a2200109 4500008004100000050001500041245008500056210006900141520120400210100001901414856007601433 2007 eng d aLBNL-6190300aPlasma and Ion Assistance in Physical Vapor Deposition: A Historical Perspective0 aPlasma and Ion Assistance in Physical Vapor Deposition A Histori3 a

Deposition of films using plasma or plasma-assist can be traced back surprisingly far, namely to the 18th century for arcs and to the 19th century for sputtering. However, only since the 1960s the coatings community considered other processes than evaporation for large scale commercial use. Ion Plating was perhaps the first important process, introducing vapor ionization and substrate bias to generate a beam of ions arriving on the surface of the growing film. Rather independently, cathodic arc deposition was established as an energetic condensation process, first in the former Soviet Union in the 1970s, and in the 1980s in the Western Hemisphere.

About a dozen various ion-based coating technologies evolved in the last decades, all characterized by specific plasma or ion generation processes. Gridded and gridless ion sources were taken from space propulsion and applied to thin film deposition. Modeling and simulation have helped to make plasma and ions effects to be reasonably well understood. Yet—due to the complex, often non-linear and non-equilibrium nature of plasma and surface interactions—there is still a place for the experienced ion and plasma "sourcerer."

1 aAnders, André uhttps://facades.lbl.gov/publications/plasma-and-ion-assistance-physical01287nas a2200145 4500008004100000050001500041245006900056210006700125520078700192100001900979700002000998700002301018700002201041856007801063 2006 eng d aLBNL-6173300aFiltered cathodic arc deposition with ion-species-selective bias0 aFiltered cathodic arc deposition with ionspeciesselective bias3 a

A dual-cathode arc plasma source was combined with a computer-controlled bias amplifier such as to synchronize substrate bias with the pulsed production of plasma. In this way, bias can be applied in a material-selective way. The principle has been applied to the synthesis metal-doped diamond-like carbon films, where the bias was applied and adjusted when the carbon plasma was condensing, and the substrate was at ground when the metal was incorporated. In doing so, excessive sputtering by too-energetic metal ions can be avoided while the sp3/sp2 ratio can be adjusted. It is shown that the resistivity of the film can be tuned by this species-selective bias. The principle can be extended to multiple-material plasma sources and complex materials.

1 aAnders, André1 aPasaja, Nitisak1 aSansongsiri, Sakon1 aLim, Sunnie, H.N. uhttps://facades.lbl.gov/publications/filtered-cathodic-arc-deposition-ion01487nas a2200109 4500008004100000050001500041245005600056210005600112520112300168100001901291856006701310 2006 eng d aLBNL-6166500aMetal plasmas for the fabrication of nanostructures0 aMetal plasmas for the fabrication of nanostructures3 a

A review is provided covering metal plasma production, the energetic condensation of metal plasmas, and the formation of nanostructures using such plasmas. Plasma production techniques include pulsed laser ablation, filtered cathodic arcs, and various forms of ionized physical vapor deposition, namely magnetron sputtering with ionization of sputtered atoms in radio frequency discharges, self-sputtering, and high power impulse magnetron sputtering. The discussion of energetic condensation focuses on the control of kinetic energy by biasing and also includes considerations of the potential energy and the processes occurring at subplantation and implantation. In the final section on nanostructures, two different approaches are discussed. In the top-down approach, the primary nanostructures are lithographically produced and metal plasma is used to coat or fill trenches and vias. Additionally, multilayers with nanosize periods (nanolaminates) can be produced. In the bottom-up approach, thermodynamic forces are used to fabricate nanocomposites and nanoporous materials by decomposition and dealloying.

1 aAnders, André uhttps://facades.lbl.gov/publications/metal-plasmas-fabrication01925nas a2200241 4500008004100000245007500041210006900116260001200185300001400197490000800211520114900219653003001368653003801398653001601436653001901452653003701471100001901508700002001527700002201547700002201569700002101591856007101612 2006 eng d00aPlasma biasing to control the growth conditions of diamond-like carbon0 aPlasma biasing to control the growth conditions of diamondlike c c01/2007 a4628-46320 v2013 a

It is well known that the structure and properties of diamond-like carbon, and in particular the sp3/sp2 ratio, can be controlled by the energy of the condensing carbon ions or atoms. In many practical cases, the energy of ions arriving at the surface of the growing film is determined by the bias applied to the substrate. The bias causes a sheath to form between substrate and plasma in which the potential difference between plasma potential and surface potential drops. In this contribution, we demonstrate that the same results can be obtained with grounded substrates by shifting the plasma potential. This plasma biasing (as opposed to substrate biasing) is shown to work well with pulsed cathodic carbon arcs, resulting in tetrahedral amorphous carbon (ta-C) films that are comparable to the films obtained with the conventional substrate bias. To verify the plasma bias approach, ta-C films were deposited by both conventional and plasma bias and characterized by transmission electron microscopy (TEM) and electron energy loss spectrometry (EELS). Detailed data for comparison of these films are provided.

10aDiamond-like carbon films10aElectron energy loss spectroscopy10aPlasma bias10aSubstrate bias10atransmission electron microscopy1 aAnders, André1 aPasaja, Nitisak1 aLim, Sunnie, H.N.1 aPetersen, Tim, C.1 aKeast, Vicki, J. uhttps://facades.lbl.gov/publications/plasma-biasing-control-growth01066nas a2200157 4500008004100000050001500041245006800056210006800124520054600192100001900738700001800757700001700775700002000792700002200812856007400834 2006 eng d aLBNL-5962100aSmoothing of ultrathin silver films by transition metal seeding0 aSmoothing of ultrathin silver films by transition metal seeding3 a

The nucleation and coalescence of silver islands on coated glass was investigated by in-situ measurements of the sheet resistance. Sub-monolayer amounts of transition metals (Nb, Ti, Ni, Cr, Zr, Ta, and Mo) were deposited prior to the deposition of silver. It was found that some, but not all, of the transition metals lead to coalescence of silver at nominally thinner films with smoother topology. The smoothing effect of the transition metal at sub-monolayer thickness can be explained by a thermodynamic model of surface energies.

1 aAnders, André1 aByon, Eungsun1 aKim, Dong-Ho1 aFukuda, Kentaro1 aLim, Sunnie, H.N. uhttps://facades.lbl.gov/publications/smoothing-ultrathin-silver-films02166nas a2200193 4500008004100000245011300041210006900154300001400223490000800237520149200245653003001737653001501767653002301782653001501805653003501820100002301855700001901878856007501897 2006 eng d00aStructural, optical and electrical properties of WOxNy films deposited by reactive dual magnetron sputtering0 aStructural optical and electrical properties of WOxNy films depo a2977-29830 v2013 a

Thin films of tungsten oxynitrides were prepared by dual magnetron sputtering of tungsten using argon/oxygen/nitrogen gas mixtures with various nitrogen/oxygen ratios. The presence of even relatively small amounts of oxygen led to close-to-stoichiometric WO3, with little incorporation of nitrogen, therefore the films were labeled as WOx(Ny). Oxygen had a great effect not only on the composition but on the structure of WOx(Ny) films, as shown by Rutherford backscattering and X-ray diffraction, respectively. Significant incorporation of nitrogen occurred only when the nitrogen partial pressure exceeded 89% of the total reactive gas pressure. Sharp changes in the stoichiometry, deposition rate, room temperature resistivity, electrical activation energy and optical band gap were observed when the nitrogen/oxygen ratio was high. The deposition rate increased from 0.31 to 0.89 nm/s, the room temperature resistivity decreased from 1.65 × 108 to 1.82 × 10− 2 Ω cm, the electrical activation energy decreased from 0.97 to 0.067 eV, and the optical band gap decreased from 3.19 to 2.94 eV upon nitrogen incorporation into the films. WOx(Ny) films were highly transparent as long as the nitrogen incorporation was low, and were brownish (absorbing) and partially reflecting as nitrogen incorporation became significant.

10aDual magnetron sputtering10aelectrical10aoptical properties10astructural10atungsten oxynitride thin films1 aMohamed, Sodky, H.1 aAnders, André uhttps://facades.lbl.gov/publications/structural-optical-and-electrical02708nas a2200109 4500008003900000245010700039210006900146260002300215520227300238100001902511856006802530 2005 d00aEnergetic or Not Energetic: Considerations for Fabricating Nanostructures by Physical Vapor Deposition0 aEnergetic or Not Energetic Considerations for Fabricating Nanost aSingaporec06/20053 a

Physical vapor deposition (PVD) has greatly matured in terms of growth modeling and equipment available. For this reason, and the often-required limitation to low-temperature processing, it is app ealing to utilize PVD methods not only for thin films but also for the synthesis of nanostructures. This is true even as many other methods enjoy the advantage of not needing high vacuum equipment.

PVD techniques are traditionally classified by the method of vapor generation, though here it is argued that a physically meaningful classification can be based on the energetics of film-forming species. At the low end of the energy scale, evaporation methods can be used to produce columnar structures with significant porosity. Sputtering at high pressure results in similar properties. This regime is preferred for sculptured structures, which involves moving tilted substrates (chiral films, chevrons, etc. [1]). As the energy is increased, so is the mobility of surface atoms, and we enter an energy regime that is widely used in thin film deposition by magnetron sputtering. Recently, high power pulsed sputtering has evolved as an energetic extension of conventional sputtering [2]. The enhanced degree of ionization enables the efficient application of bias techniques. Additionally, species seem to have higher kinetic energy. Ultimately, one would like to have fully ionized plasmas to fully exploit biasing, which can be done by using filtered cathodic arc plasmas [3]. Considering the high-energy range, substrates can be ion-treated by immersing them in a plasma and applying high voltage pulses, a technique known as plasma-based ion implantation.

Nanostructures are preferentially fabricated at either the low energy (< 1 eV, e.g. for sculptured films) or very high energy (> 1 keV, e.g. metal filling of lithographically produced nanotrenches [4], or formation of precipitates or bubbles by ion implantation [5]). At the intermediate energy range, ~ 100 eV, nanoscale processing of interfaces is used to obtain coatings with superior adhesion. Subplantation growth is facilitated at this energy, which is especially important for tuning the structure and properties of diamond-like carbon and a range of nitride and oxide materials.

1 aAnders, André uhttps://facades.lbl.gov/publications/energetic-or-not-energetic01196nas a2200109 4500008004100000050002300041245006200064210006100126520080500187100001900992856007501011 2005 eng d aLBNL-54220 Journal00aPhysics of Arcing, and Implications to Sputter Deposition0 aPhysics of Arcing and Implications to Sputter Deposition3 a

Arcing on sputter targets and negatively biased substrates is known as one of the most challenging issues in physical vapor deposition of thin films and coatings. This is particularly true when high-rate deposition with reactive gases, large area deposition, and high power pulsed sputtering are considered. Much progress has been made in the development of power supplies that can handle arcing events with minimal damage to target and substrate. However, relatively little is known about the processes leading to arcs and the physics of the arcing events themselves. In this contribution, the issue of arcing is approached from the point of view of arc physics. Current knowledge of arcing and arc suppression is reviewed.

(Note: PDF contains both LBNL-54220 & LBNL-54220 Journal.)

1 aAnders, André uhttps://facades.lbl.gov/publications/physics-arcing-and-implications-001373nas a2200109 4500008004100000050001500041245006000056210005900116520099400175100001901169856007501188 2005 eng d aLBNL-5712700aPlasma and Ion Sources in Large Area Coatings: A Review0 aPlasma and Ion Sources in Large Area Coatings A Review3 a

Efficient deposition of high-quality coatings often requires controlled application of excited or ionized particles. These particles are either condensing (film-forming) or assisting by providing energy and momentum to the film growth process, resulting in densification, sputtering/etching, modification of stress, roughness, texture, etc. In this review, the technical means are surveyed enabling large area application of ions and plasmas, with ion energies ranging from a few eV to a few keV. Both semiconductor-type large area (single wafer or batch processing with ~ 1000 cm2) and in-line web and glass-coating-type large area (> 107 m2 annually) are considered. Characteristics and differences between plasma and ion sources are explained. The latter include gridded and gridless sources. Many examples are given, including sources based on DC, RF, and microwave discharges, some with special geometries like hollow cathodes and E x B configurations.

1 aAnders, André uhttps://facades.lbl.gov/publications/plasma-and-ion-sources-large-area02360nas a2200145 4500008004100000050001500041245010000056210006900156300001400225490000700239520185100246100002302097700001902120856007502139 2005 eng d aLBNL-5761000aPlasma-Based Ion Implantation and Deposition: A Review of Physics, Technology, and Applications0 aPlasmaBased Ion Implantation and Deposition A Review of Physics  a1944-19590 v333 a

After pioneering work in the 1980s, plasma-based ion implantation (PBII) and plasma-based ion implantation and deposition (PBIID) can now be considered mature technologies for surface modification and thin film deposition. This review starts by looking at the historical development and recalling the basic ideas of PBII. Advantages and disadvantages are compared to conventional ion beam implantation and physical vapor deposition for PBII and PBIID, respectively, followed by a summary of the physics of sheath dynamics, plasma and pulse specifications, plasma diagnostics, and process modelling. The review moves on to technology considerations for plasma sources and process reactors. PBII surface modification and PBIID coatings are applied in a wide range of situations. They include the by-now traditional tribological applications of reducing wear and corrosion through the formation of hard, tough, smooth, low-friction and chemically inert phases and coatings, e.g. for engine components. PBII has become viable for the formation of shallow junctions and other applications in microelectronics. More recently, the rapidly growing field of biomaterial synthesis makes used of PBII&D to produce surgical implants, bio- and blood-compatible surfaces and coatings, etc. With limitations, also non-conducting materials such as plastic sheets can be treated. The major interest in PBII processing originates from its flexibility in ion energy (from a few eV up to about 100 keV), and the capability to efficiently treat, or deposit on, large areas, and (within limits) to process non-flat, three-dimensional workpieces, including forming and modifying metastable phases and nanostructures. We use the acronym PBII&D when referring to both implantation and deposition, while PBIID implies that deposition is part of the process.

1 aPelletier, Jacques1 aAnders, André uhttps://facades.lbl.gov/publications/plasma-based-ion-implantation-and01188nas a2200145 4500008004100000245007500041210006900116490000700185520069000192100002000882700001900902700002100921700002600942856007400968 2004 eng d00aCharge-State-Resolved Ion Energy Distributions of Aluminum Vacuum Arcs0 aChargeStateResolved Ion Energy Distributions of Aluminum Vacuum 0 v973 a

The charge-state-resolved ion energy distributions of metal ions present in a cathodic arc plasma have been measured and analyzed. Contrary to literature data, lower energies were observed for higher charged ions. The observations were explained by opposing acceleration by pressure gradient and electron-ion coupling, and deceleration by part of the discharge voltage. The distributions were well fitted by shifted Maxwellian distributions, giving additional information on plasma parameters. These results are of importance for an improved understanding of the evolution of ion energy distributions, and is hence instrumental for future progress in thin film growth modelling.

1 aRosén, Johanna1 aAnders, André1 aMráz, Stanislav1 aSchneider, Jochen, M. uhttps://facades.lbl.gov/publications/charge-state-resolved-ion-energy01808nas a2200241 4500008004100000022001500041245010500056210006900161260001200230300001200242490000700254520105000261653001501311653002401326653002201350653002501372653002101397100001801418700001801436700001901454700001901473856007401492 2004 eng d a0093-3813 00aEffect of Ion Mass and Charge State on Transport Vacuum Arc Plasmas Through a Biased Magnetic Filter0 aEffect of Ion Mass and Charge State on Transport Vacuum Arc Plas c04/2004 a433-4390 v323 a

The effect of ion mass and charge state on plasma transport through a 90 deg.-curved magnetic filter is experimentally investigated using a pulsed cathodic arc source. Graphite, copper, and tungsten were selected as test materials. The filter was a bent copper coil biased via the voltage drop across a low-ohm, selfbias resistor. Ion transport is accomplished via a guiding electric field, whose potential forms a trough shaped by the magnetic guiding field of the filter coil. Evaluation was done by measuring the filtered ion current and determination of the particle system coefficient, which can be defined as the ratio of filtered ion current, divided by the mean ion charge state, to the arc current. It was found that the ion current and particle system coefficient decreased as the mass-to-charge ratio of ions increased. This result can be qualitatively interpreted by a very simple model of ion transport that is based on compensation of the centrifugal force by the electric force associated with the guiding potential trough.

10aArc plasma10acathodic vacuum arc10aion charge states10amacroparticle filter10aplasma transport1 aByon, Eungsun1 aKim, Jong-Kuk1 aKwon, Sik-Chol1 aAnders, André uhttps://facades.lbl.gov/publications/effect-ion-mass-and-charge-state01152nas a2200133 4500008004100000050001500041245007500056210006900131300001400200490000700214520069900221100001900920856007900939 2004 eng d aLBNL-5587600aObservation of Self-Sputtering in Energetic Condensation of Metal Ions0 aObservation of SelfSputtering in Energetic Condensation of Metal a6137-61390 v853 a

The condensation of energetic metal ions on a surface may cause self-sputtering even in the absence of substrate bias. Charge-state-averaged self-sputtering yields were determined for both zirconium and gold ions generated by a cathodic vacuum arc. Films were deposited on differently biased substrates exposed to streaming Zr and Au vacuum arc plasma. The self-sputtering yields for both metals were estimated to be about 0.05 in the absence of bias, and exceeding 0.5 when bias reached - 50 V. These surprisingly high values can be reconciled with binary collision theory and molecular dynamics calculations taking high the kinetic and potential energy of vacuum arc ions into account.

1 aAnders, André uhttps://facades.lbl.gov/publications/observation-self-sputtering-energetic01576nas a2200133 4500008004100000050001500041245013500056210006900191300001200260490000700272520107000279100001901349856007401368 2004 eng d aLBNL-5621400aTime-Dependence of Ion Charge State Distributions of Vacuum Arcs: An Interpretation Involving Atoms and Charge Exchange Collisions0 aTimeDependence of Ion Charge State Distributions of Vacuum Arcs  a205-2090 v333 a

Experimentally observed charge state distributions are known to be higher at the beginning of each arc discharge. Up to know, this has been attributed to cathode surface effects in terms of changes of temperature, chemical composition and spot mode. Here it is shown that the initial decay of charge states of cathodic arc plasmas may at least in part due to charge exchange collisions of ions with neutrals that gradually fill the discharge volume. Sources of neutrals may include evaporated atoms from macroparticles and still-hot craters of previously active arc spots. More importantly, atoms are also produced by energetic condensation of the cathodic arc plasma. Self-sputtering is significant when ions impact with near-normal angle of incidence, and ions have low sticking probability when impacting at oblique angle of incidence. Estimates show that the characteristic time for filling the near-cathode discharge volume agrees well with the charge state decay time, and the likelihood of charge exchange is reasonably large to be taken into account.

1 aAnders, André uhttps://facades.lbl.gov/publications/time-dependence-ion-charge-state01261nas a2200145 4500008004100000245009600041210006900137300001400206490000700220520078700227100001801014700002401032700001901056856004001075 2003 eng d00aCoalescence of Nanometer Silver Islands on Oxides Grown by Filtered Cathodic Arc Deposition0 aCoalescence of Nanometer Silver Islands on Oxides Grown by Filte a1634-16360 v823 a

Ultrathin silver films have been deposited on glass and oxide-coated glass using filtered cathodic arc deposition and, for comparison, magnetron sputtering. The energetic differences between these deposition methods lead to initially different film properties. Silver films made by cathodic arc deposition show an earlier onset of island coalescence, indicating a lower aspect ratio than islands produced by evaporation and sputtering. However, the as-deposited films are thermodynamically unstable, exhibiting changes on a timescale of minutes. While films of islands tend to increase their sheet resistance with time, the sheet resistance of contiguous films shows a decrease. Both effects can be explained by silver mobility driven to minimize film and interfacial energy.

1 aByon, Eungsun1 aOates, Thomas, W.H.1 aAnders, André uhttp://dx.doi.org/10.1063/1.155895502094nas a2200133 4500008004100000050001500041245010000056210006900156260002300225520159700248100001801845700001901863856007801882 2003 eng d aLBNL-5156800aEffect of Underlayer on Coalescence of Silver Islands Grown by Filtered Cathodic Arc Deposition0 aEffect of Underlayer on Coalescence of Silver Islands Grown by F aSan Diegoc05/20033 a

Ultrathin silver films that are not continuous show relatively high absorption in the visible and low reflection in the infrared. For low-emissivity application on window glass, coalescence of silver islands is crucial for obtaining the desired optical properties of the coating, namely high transparence in the visible and high reflectivity in the infrared. It is well known that the energy of ions arriving at the substrate and the type of underlayer affect nucleation and growth of silver islands. There are a number of studies on nucleation and growth, but little is known about coalescence of silver islands synthesized by more energetic condensation, e.g. filtered cathodic vacuum arc (FCVA). In this work, the effect of underlayer on nucleation and growth of silver films deposited by FCVA was investigated by transmission electron microscopy (TEM) and atomic force microscopy (AFM). The results arescompared with data obtained by magnetron sputtering.

From the results, plane and titanium-oxide-coated glass requires more material to achieve the same value of resistance than for the zinc oxide coated glass. It is related with the energy of interaction between the surface and the silver atom. Silver films made by cathodic arc deposition show an earlier onset of island coalescence and formation of short links. It was found that silver islands in energetic deposition exhibit a reduced aspect ratio when compared to evaporation and sputtering. Nb underlayer affects nucleation and growth of coalescence of silver only in the case of few monolayer of Nb was introduced.

1 aByon, Eungsun1 aAnders, André uhttps://facades.lbl.gov/publications/effect-underlayer-coalescence-silver01779nas a2200133 4500008004100000050001500041245006000056210006000116300001200176490000800188520135100196100001901547856007901566 2003 eng d aLBNL-5168300aFundamentals of Pulsed Plasmas for Materials Processing0 aFundamentals of Pulsed Plasmas for Materials Processing a301-3110 v1833 a

Pulsed plasmas offer the use of much higher power (during each pulse) compared to continuously operated plasmas, and additional new parameters appear such as pulse duty cycle. Pulsed processing may help meeting the demands of increasingly sophisticated materials processes, including thin film deposition, plasma etching, plasma cleaning of surfaces, and plasma immersion ion implantation. The high kinetic energy of ions allows processes to occur far from thermodynamic equilibrium. Pulsed plasmas are driven by external pulsed power sources, and one has to consider the power source and the plasma as a coupled system. The dynamic plasma impedance is a key quantity from an electrical engineering point of view. From a plasma physics point of view, one needs to consider the dynamics of plasma species, their density and energy distribution, ionization and recombination reactions, and, most importantly, the development of transient sheaths. Dimensionless scaling parameters are a useful tool putting the variety of plasma parameters in relation to characteristic quantities. This is illustrated by several examples of pulsed processes relevant to thin film deposition. The emerging technology of pulsed sputtering is discussed in detail including the possibility to achieve the mode of self-sustained self-sputtering during each pulse.

1 aAnders, André uhttps://facades.lbl.gov/publications/fundamentals-pulsed-plasmas-materials01509nas a2200121 4500008004100000050001500041245006200056210006100118260003400179520108200213100001901295856007301314 2003 eng d aLBNL-5422000aPhysics of Arcing, and Implications to Sputter Deposition0 aPhysics of Arcing and Implications to Sputter Deposition aSaarbrucken, Germanyc07/20043 a

Arc and glow discharges are defined based on their cathode processes. Arcs are characterized by collective electron emission, which can be stationary with hot cathodes (thermionic arcs), or nonstationary with cold cathodes (cathodic arcs). A brief review on cathodic arc properties serves as the starting point to better understand arcing phenomena in sputtering. Although arcing occurs in both metal and reactive sputtering, it is more of an issue in the reactive case. Arcing occurs if sufficiently high field strength leads to thermal runaway of an electron emission site. The role of insulating layers and surface potential adjustment through current leakage is highlighted. In the situation of magnetron sputtering with racetrack, the need for a model with two spatial dimensions is shown. In many cases, arcing is initiated by breakdown of dielectric layers and inclusions. It is most efficiently prevented if formation and excessive charge-up of dielectric layers and inclusions can be avoided.

(Note: PDF contains both LBNL-54220 & LBNL-54220 Journal.)

1 aAnders, André uhttps://facades.lbl.gov/publications/physics-arcing-and-implications01095nas a2200169 4500008004100000245008300041210006900124260003000193520049900223653002000722653002200742653002400764653001500788100001900803700002400822856007900846 2003 eng d00aSurface Engineering of Glazing Materials and Structures Using Plasma Processes0 aSurface Engineering of Glazing Materials and Structures Using Pl aTampere, Finlandc06/20033 a

A variety of coatings is commercially produced on a very large scale, including transparent conducting oxides and multi-layer silver-based low-emissivity and solar control coatings. A very brief review of materials and manufacturing process is presented and illustrated by ultrathin silver films and chevron copper films. Understanding the close relation between manufacturing processes and bulk and surface properties of materials is crucial for film growth and self-assembly processes.

10anano-structures10aplasma processing10asurface engineering10athin films1 aAnders, André1 aMonteiro, Othon, R. uhttps://facades.lbl.gov/publications/surface-engineering-glazing-materials01602nas a2200145 4500008004100000050001500041245008200056210006900138300001400207490000700221520112200228100001801350700001901368856006901387 2002 eng d aLBNL-5179000aBias and Self-Bias of Magnetic Macroparticle Filters for Cathodic Arc Plasmas0 aBias and SelfBias of Magnetic Macroparticle Filters for Cathodic a8890-88970 v933 a

Curved magnetic filters are often used for the removal of macroparticles from cathodic arc plasmas. This study addresses the need to further reduce losses and improving plasma throughput. The central figure of merit is the system coefficient κ defined as a filtered ion current normalized by the plasma-producing arc current. The coefficient κ is investigated as a function of continuous and pulsed magnetic field operation, magnetic field strength, external electric bias, and arc amplitude. It increases with positive filter bias but saturates at about 15 V for relatively low magnetic field (~10 mT), whereas stronger magnetic fields lead to higher κ with saturation at about 25 V. Further increase of positive bias reduces κ. These findings are true for both pulsed and continuous filters. Bias of pulsed filters has been realized using the voltage drop across a self-bias resistor, eliminating the need for a separate bias circuit. Almost 100 A of filtered copper ions have been obtained in pulsed mode, corresponding to κ ≈ 0.04. The results are interpreted by a simplified potential trough model.

1 aByon, Eungsun1 aAnders, André uhttps://facades.lbl.gov/publications/bias-and-self-bias-magnetic01325nas a2200109 4500008003900000245008200039210006900121260001200190520091800202100001901120856007601139 2002 d00aMaterials, processes, and issues in low-emissivity and solar control coatings0 aMaterials processes and issues in lowemissivity and solar contro c12/20023 a

Research at DOE and other laboratories can help addressing the durability, performance, and cost issues associated with the energy-saving coatings on glass used in windows of residential and commercial buildings. A brief review is presented on the status of energy-savings coatings, including material systems and processes to manufacture them. Issues such as durability, enhanced performance, dynamic coatings, and multifunctional coatings are considered. Industry and the Department of Energy have overlapping areas of interest, and therefore laboratories should and can have a role in energy-savings research and development of industrial relevance. The report includes specific recent results obtained at Berkeley Lab. It is argued that the properties of ultrathin silver films are determined both by the kinetics of the deposition process and the post-deposition thermodynamics of the material system.

1 aAnders, André uhttps://facades.lbl.gov/publications/materials-processes-and-issues-low01128nas a2200205 4500008004100000245008600041210006900127260001200196300001000208490000700218520044500225653003000670653002000700653002300720653003500743100001900778700002400797700002300821856007800844 1999 eng d00aEvaluation of the Plasma Distribution of a Quasi-Linear Constricted Plasma Source0 aEvaluation of the Plasma Distribution of a QuasiLinear Constrict c02/1999 a82-830 v273 a

The quasi-linear constricted plasma source is a downstream plasma source with ten linearly aligned discharge cells. Each cell operates on the basis of a constricted glow discharge. The plasma output can easily be monitored by the plasma-emitted light. The information is not only intuitive but can also be used to operate on-line feedback control of the plasma source which is important for large-area plasma processing of materials.

10aConstricted plasma source10agas plasma flow10aplasma diagnostics10aplasma processing of materials1 aAnders, André1 aMacGill, Robert, A.1 aRubin, Michael, D. uhttps://facades.lbl.gov/publications/evaluation-plasma-distribution-quasi01711nas a2200229 4500008004100000245008000041210006900121490000800190520094800198100002501146700002301171700003101194700001901225700002101244700002701265700001901292700002901311700002301340700002101363700002101384856007601405 1997 eng d00aPressure Controlled GaN MBE Growth Using a Hollow Anode Nitrogen Ion Source0 aPressure Controlled GaN MBE Growth Using a Hollow Anode Nitrogen0 v4493 a

GaN films were grown on sapphire substrates at temperatures below 1000 K utilizing a Hollow Anode nitrogen ion source. A Ga flux limited growth rate of ~0.5 μm/h is demonstrated. Active utilization of strain and the assistance of a nitrogen partial pressure during buffer layer growth are found to be crucial issues that can improve the film quality. The best films exhibit a full width at half maximum of the x-ray rocking curves of 80 arcsec and 1.85 meV for the excitonic photoluminescence measured at 4 K. A Volmer-Weber three dimensional growth mode and the spontaneous formation of cubic GaN inclusions in the hexagonal matrix are observed in the investigated growth temperature range. It is argued that this growth mode contributes to a limitation of the carrier mobility in these films that did not exceed 120 cm2/Vs through a minimum canier concentration of ~1015 cm-3 was achieved.

1 aLeung, Michael, S.H.1 aKlockenbrink, Ralf1 aKisielowski, Christian, F.1 aFujii, Hiroaki1 aKrüger, Joachim1 aSubramanya, Sudhir, G.1 aAnders, André1 aLiliental-Weber, Zuzanna1 aRubin, Michael, D.1 aWeber, Eicke, R.1 aKrüger, Joachim uhttps://facades.lbl.gov/publications/pressure-controlled-gan-mbe-growth02822nas a2200217 4500008004100000024001100041245005700052210005700109260002700166520217700193653002802370653002002398100001902418700001902437700002302456700001602479700002102495700001802516700001902534856005102553 1995 eng d aUC-42600aFormation of Metal Oxides by Cathodic Arc Deposition0 aFormation of Metal Oxides by Cathodic Arc Deposition aSan Diego, CAc04/19953 a

Metal oxide thin films are of interest for a number of applications. Cathodic arc deposition, which is an established and industrially applied technique for the formation of nitrides (e.g. TIN), can also be used for metal oxide thin film formation. A cathodic arc plasma source with the desired cathode material is operated in an oxygen atmosphere of appropriate pressure, and metal oxides of various stoichiometric composition can be formed on different substrates. We report here on a series of experiments on metal oxide formation by cathodic arc deposition for different applications. Black copper oxide has been deposited on accelerator components to increase the radiative heat transfer between the parts. Various metal oxides such as tungsten oxide, niobium oxide, nickel oxide and vanadium oxide have been deposited on ITO glass to form electrochromic films for window applications. Tantalum oxide films are of interest for replacing polymer electrolytes. Optical waveguide structures can be formed by refractive index variation using oxide multilayers. We have synthesized multilayers of Al2O3/Y2O3/Al2O3/Si as possible basic structures for passive optoelectronic integrated circuits, and Al2-xErxO3 thin films with a variable Er concentration which is a potential component layer for the production of active optoelectronic integrated devices such as amplifiers or lasers at a wavelength of 1.53 pm. Aluminum and chromium oxide films have been deposited on a number of substrates to impart improved corrosion resistance at high temperature. Titanium sub-oxides which are electrically conductive and corrosion resistant and stable in a number of aggressive environments have been deposited on various substrates. These sub-oxides are of great interest for use in electrochemical cells. Common features of all these depositions are the high deposition rate typical for cathodic arc deposition, the good adhesion of the films due to the high metal ion energy, and the advantage of an environmentally clean method in comparison to wet-chemical oxide formation techniques.

10aCathodic arc deposition10aOxide formation1 aAnders, Simone1 aAnders, André1 aRubin, Michael, D.1 aWang, Zhien1 aRaoux, Sebastien1 aKong, Fanping1 aBrown, Ian, G. uhttp://dx.doi.org/10.1016/0257-8972(95)02508-101322nas a2200157 4500008004100000024001100041245005600052210005500108260001200163300001200175490000600187520085400193100001901047700001901066856007901085 1995 eng d aUC-42600aWorking Principle of the Hollow-Anode Plasma Source0 aWorking Principle of the HollowAnode Plasma Source c11/1995 a571-5750 v43 a

The hollow-anode discharge is a special form of glow discharge. It is shown that a drastically reduced anode area is responsible for a positive anode voltage drop of 30-40 V and an increased anode sheath thickness. This leads to ignition of a relatively dense plasma in front of the anode hole. Langmuir probe measurements inside a specially designed hollow anode plasma source give an electron density and temperature of ne=109-1011 cm-3 and Te=1-3 eV, respectively (nitrogen, current 100 mA, flow rate 5-50 scc min-1). Driven by a pressure gradient, the 'anode' plasma is blown through the anode hole and forms a bright plasma jet streaming with supersonic velocity (Mach number 1.2). The plasma-stream can be used, for instance, in plasma-assisted deposition of thin films.

1 aAnders, André1 aAnders, Simone uhttps://facades.lbl.gov/publications/working-principle-hollow-anode-plasma