ICMCTF2009 Session B2-1: Arc and E-Beam Coatings and Technologies

Monday, April 27, 2009 10:00 AM in Room Golden West

Monday Morning

Start	Invited?	Item
10:00 AM	Invited	B2-1-1 Metallic Film Deposition using a Vacuum Arc Plasma Source with a Refractory Anode I. Beilis, R.L. Boxman (Tel Aviv University, Israel) A plasma source has been developed utilizing the Hot Refractory Anode Vacuum Arc (HRAVA) mode. These arcs are initiated as cathode spot arcs whose plasma jets initially deposit cathode material on a refractory anode. The anode is heated by the arc, and a dense plasma plume is formed by re-evaporation of cathode material from the anode. The steady-state HRAVA mode is reached when the anode is sufficiently hot that there is no net deposition of cathodic material on it, and a plasma plume expands radially. Thin films of cathodic material are formed on substrates arranged radially around the electrode axis. Macroparticle-free films form on substrates having a direct line of sight to the anode, but not to the cathode. HRAVAs with current I=150-340 A, Cu, Ti, and Cr cathodes, graphite, Mo and W anodes and 5 10 mm inter-electrode gaps were investigated theoretically and experimentally. The time to reach steady state with a graphite anode decreased from ~90 s to 60 s when I inc reased from 175 to 340 A. The anode surface temperature linearly increased with I: on a graphite anode from 1950 K to 2200 K when I increased from 175 to 340A, and on a W anode from 2250 to 2500 K when I increased from 150 to 250 A. The temperature distribution on the asymmetric anodes with inclined front surfaces was asymmetric, and their maximum temperature was higher than for symmetric ones by about 50–100 K. The difference between the maximum and minimum temperatures on the anode surface increased as the inter-electrode gap decreased. The deposition rate was determined by measuring the deposited film thickness by profilometry -- in 300 A arcs with Cu cathodes, at distances of L=110 and 80 mm from the arc axis, 2.0 and 3.6 µm/min respectively. The HRAVA Cr deposition rate at L=80 mm for I=200 to 300 A was 0.72 to 1.4 µm/min, and for Ti at L=100 mm, 0.88 to 1.8 µm/min. HRAVA thickness distribution was axially symmetric within 10% and the mass deposition rate was ~400 mg/min and was almost MP-free. The steady-state HRAVA deposition rate was 2.3 µm/min, compared to the Filtered Vacuum Arc Deposition (FVAD) rate which was 0.25 µm/min. Furthermore, the area deposited by the HRAVA source was 100 cm² (8 cm from the electrodes axis), while the area deposited by the FVAD source was 30 cm² (70 cm from the cathode). The cathode utilization efficiency using HRAVA was 40 times greater than with FVAD.
10:40 AM		B2-1-3 Investigation of Electrochromic Properties of Nickel Oxide Films Prepared by Electrom Beam Evaporation D.R. Sahu, T.-J. Wu, J.-L. Huang (National Cheng Kung University, Taiwan) Electrochromic nickel oxide films were deposited by electron beam evaporation method. Films were charcterized and anlysed using XRD, SEM, AFM, ESCA Cyclic voltamettry and UV-Vis spectrophotometer. The vairation in the electrochromic properties of NiOx films as a functions of electron beam power along with thickness are studied. XRD anlaysis indicted that different electron beam power led to the deposition of film with different orientation with different electrochromic behhaviour. The optimum performances of the film are attributed with highest ratio of (111) plane orientation. The thinner film possesses better efficiency than the thicker film. However performance of the thinner film is deteriorated after subjection to 800 cycling tests. The details electrochromic properties of the films will be discussed during presentation.
11:00 AM		B2-1-4 Surface Modification of Iron Containing Aluminum Alloys by Treating with Copper Plasma Produced with Cathodic Arc B. Corlu, M. Urgen (Istanbul Technical University, Turkey) In this study, we describe a novel approach for modification of surfaces by the help of cathodic arc plasma and its bias voltage dependent interaction with the substrates. As an example, alloying and surface modificaiton of aluminum with cathodic arc plasma of copper is given. Surfaces of aluminum alloys with iron contents of 0.2 and 1% was modified with cathodic arc physical vapor deposition (CA-PVD) using copper cathodes. The effect of successively applied bias voltages of -150V and -1000 V was investigated on the resulting microstructural surface features of the alloys. Surface modification processes were performed below and above 500° C. In the experiments conducted below 500° C, the modified surface predominantly consisted of Al₂Cu intermetallics, accompanied with a small amount of α-aluminum solid solution. However, in experiments conducted above 500° C melting and resolidification of the copper deposited substrate surface took place corresponding to -1000V and -150V bias voltages respectively. A eutectic-like microstructure, containing α-aluminum, Al₂Cu phases, and iron containing intermetallic quasicrystal structures were obtained.
11:20 AM		B2-1-6 Optical Reflective Performance of Copper Alloy Thin Films with Ti-Zr and Al-Zr Additions C.-Y. Su (National Taipei University of Technology, Taiwan); C.-Y. Tsay (Feng Chia University, Taiwan); C.-W. Chang (National Taipei University of Technology, Taiwan); C.-H. Hsu (Tatung University, Taiwan); C.-K. Lin (Feng Chia University, Taiwan) Copper alloy with additions of less than 3 wt.% of Ti-Zr or Al-Zr are prepared by vacuum arc remelter (VAR). After rolling, heat treating, and cutting, homemade targets with a diameter of 2” are available for DC sputtering onto silicon and/or glass substrates. After deposition, the chemical compositions of the thin films are examined and compared with those of the original targets. The optical reflective performances of the as-deposited films and those after a durability test at 50 oC with 85% humidity for 24 hours are investigated. Experimental results show that Cu-Ti-Zr thin films are superior in reflectivity than those of the Cu-Al-Zr films. Cu thin film with Ti-Zr additions exhibits a reflectivity around 70%, obviously better than those of the Cu-Al-Zr films (less than 40%). An average decrease of ~10% in reflectivity can be noticed after durability test. The optical reflective performance of copper alloy thin films with respect to composition, microstructure, and surface morphology will be addressed in the present study.