Metal-ion implantation and deposition using cathodic-arcs

Blake P. Wood [(505) 665-6524] (P-24), Hans Snyder [(505) 665-8364] (P-24), 

Cathodic-arcs can produce plumes of highly charged ions from any conducting material. We are investigating the basic physics of cathodic-arcs, and pursuing three particular applications: (1) deposition of diamond-like-carbon (DLC) films, (2) direct metal-ion Plasma Source Ion Implantation (PSII), and (3) implantation/deposition of adherent ceramic metal-oxide, -nitride, and -carbide films.

Using our high-voltage PSII modulator (20 us, 60 A, 50 kV pulses at 2 kHz) to implant a metal-ion plasma greatly increases the adherence of subsequently deposited metal or metal-oxide ceramic films. We have found that we can deposit adherent, stochiometric erbium oxide (erbia) of several microns thickness on a variety of substrates.


The photo above shows a filtered cathodic arc. The solenoid windings of the magnetic duct filter are in series with the current driving the arc, thus producing the magnetic field only while the arc is in operation. This particular source is typically run at 100 A arc current with a 10% duty cycle (25 Hz, 4 ms pulses) during the deposition step. These parameters yield a deposition rate of about 3 microns/hour for erbia. We also operate a DC cathodic-arc, built by the Efremov Institute in St. Petersburg, Russia, which achieves an erbia deposition rate of 12 microns/hour when operated at 80 A arc current. The SEM image below shows a 3 micron erbia coating deposited on the inside of a stainless steel cup after the cup has been beaten inside out with a hammer. The ceramic erbia coating has cracked, but not delaminated, demonstrating superior adhesion.


In related research, we are working to deposit highly adherent coatings of refractory metal on the inside surfaces of pipes. The principal challenge here is figuring out a way to create or transport the metal-ion plasma inside the pipe, and then to pulse bias the pipe so as to achieve ion implantation. In other words, it is a problem of establishing an appropriate ground reference, since in a long pipe, the plasma might be expected to simply float up to the applied bias. Our colleagues in MST-4 (Nastasi and Walter) are pursuing the same goal using a plasma created out of a organo-metallic gas, rather than our cathodic-arc based approach.

This page last updated by Blake P. Wood, on 10/13/99. bwood@lanl.gov

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