Characterization of a metal plasma produced by cathodic arc for the hybrid technique of plasma immersion ion implantation and deposition

M. FAZIO

Trieste

Otro; Joint ICTP-IAEA College on Plasma Physics; 2012

Abdus Salam - International Center for Theoretical Physics

The aim of this work is the study of a Ti plasma employed for surface treatment by metal plasma immersion ion implantation and deposition (MePIIID). This technique involves biasing the substrate by high voltage negative pulses while it is immersed in a metal plasma produced by a cathodic arc. During the pulses, the ions are implanted onto the substrate and when the bias is off they condense on the surface, hence the technique combines ion implantation and deposition. The applications of the coatings thus obtained are wide, including medical implants, enhancement of tribological properties of stainless steel, modification of superconductors, amongst others. It has been found that the implantation modifies profoundly the structure of the coatings which turn out to be nanostructured. In order to understand the origin of this surface modification, the plasma produced by this technique has been studied by a spherical Langmuir probe and calorimetric measurements. The collisionless Lam theory has been used to derive plasma parameters from probe measurements. A heat transfer model was employed to infer the energy transfer of the ions from the calorimetric measurements and the ion density. Finally, collisionless sheath models (matrix and Child law sheath models) have been applied in order to study the evolution of the implantation current and the energy delivered to the surface.