Paper PS1-TuM11
An Improved Cathodic Arc Plasma Source for Large Area Coatings

Tuesday, October 29, 2013, 11:20 am, Room 102 B

Cathodic arc plasmas are widely used in the hard coatings industry to produce binary and ternary metal nitrides and oxynitrides, some of them exhibiting superhardness (> 40 GPa) and high oxidation resistance at elevated temperature. High deposition rates (10-100 nm/min) and self-ion-assistance to film growth are attractive features of the arc deposition process. However, microscopic droplets or “macroparticles” produced at cathode spots have prevented broader application of this technology, for example to optical coatings or to thin films used in the electronics industry. Here we report on the development of a linear cathodic arc plasma source that can be coupled to a linear macroparticle filter. We aim to develop a plasma source suitable for high-rate, large-area coatings, where films are essentially free of macroparticles. Operation and performance of the improved source will be demonstrated with metal and metal oxide films.

Specifically, we deposited aluminum-doped zinc oxide (AZO), a transparent conducing oxide which is non-toxic and made from abundant materials, a prime candidate for replacing the more expensive indium tin oxide (ITO) in some applications. AZO deposited on glass by filtered cathodic arc plasma exhibit very high electron mobility (some samples exceeding 50 cm²/Vs) for moderately high carrier concentrations (~ 10²⁰ cm^-3), high transmittance in the visible and solar infrared (80-85%), with sheet resistance as low as 10 Ohms per square for relatively thick (~ 1 μm) films. AZO was also deposited on polycarbonate plastic at room temperature, with properties of interest to flexible electronics.