%0 Journal Article %J Applied Physics Letters %D 2006 %T Smoothing of ultrathin silver films by transition metal seeding %A André Anders %A Eungsun Byon %A Dong-Ho Kim %A Kentaro Fukuda %A Sunnie H.N. Lim %X

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.

%B Applied Physics Letters %G eng %L LBNL-59621 %1

Windows and Daylighting Group

%2 LBNL-59621 %0 Journal Article %J IEEE Transactions on Plasma Science %D 2004 %T Effect of Ion Mass and Charge State on Transport Vacuum Arc Plasmas Through a Biased Magnetic Filter %A Eungsun Byon %A Jong-Kuk Kim %A Sik-Chol Kwon %A André Anders %K Arc plasma %K cathodic vacuum arc %K ion charge states %K macroparticle filter %K plasma transport %X

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.

%B IEEE Transactions on Plasma Science %V 32 %P 433-439 %8 04/2004 %G eng %N 2 %M 8051531 %1

Windows and Daylighting Group

%2 LBNL-53728 %& 433 %R 10.1109/TPS.2004.826363 %0 Journal Article %J Applied Physics Letters %D 2003 %T Coalescence of Nanometer Silver Islands on Oxides Grown by Filtered Cathodic Arc Deposition %A Eungsun Byon %A Thomas W.H. Oates %A André Anders %X

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.

%B Applied Physics Letters %V 82 %P 1634-1636 %G eng %U http://dx.doi.org/10.1063/1.1558955 %1

Windows and Daylighting Group

%2 LBNL-51307 %! Appl. Phys. Lett. %& 1634 %0 Conference Paper %B The International Conference on Metallurgical Coatings and Thin Films (ICMCTF 2003) %D 2003 %T Effect of Underlayer on Coalescence of Silver Islands Grown by Filtered Cathodic Arc Deposition %A Eungsun Byon %A André Anders %X

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.

%B The International Conference on Metallurgical Coatings and Thin Films (ICMCTF 2003) %C San Diego %8 05/2003 %G eng %L LBNL-51568 %1

Windows and Daylighting Group

%2 LBNL-51568 %0 Journal Article %J Journal of Applied Physics %D 2002 %T Bias and Self-Bias of Magnetic Macroparticle Filters for Cathodic Arc Plasmas %A Eungsun Byon %A André Anders %X

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.

%B Journal of Applied Physics %V 93 %P 8890-8897 %G eng %L LBNL-51790 %1

Windows and Daylighting Group

%2 LBNL-51790