Improvement of Thin Film Adhesion Due to Bombardment by Fast Argon Atoms

Sergey Grigoriev,Yury Melnik,Marina Volosova,Alexander Metel

doi:10.3390/coatings8090303

Sergey Grigoriev, Yury Melnik + Show 2 more

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https://doi.org/10.3390/coatings8090303

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Abstract

A new hollow cathode sputtering system is used for beam-assisted deposition of thin films on dielectric substrates. A copper target placed at the hollow cathode bottom is uniformly sputtered by argon ions from the glow discharge plasma filling the cathode. Through an emissive grid, sputtered copper atoms leave the cathode together with accelerated argon ions. On their way to the substrate, the ions—due to charge exchange collisions—turn into fast argon atoms bombarding the growing film. With increasing argon ion energy, continuous bombardment results in the film adhesion improvement and reduction of the deposition rate down to zero, at an energy of about 2 keV. The pulsed bombardment does not influence the film deposition rate, and results in a monotonic growth of the film adhesion up to 20 MPa when increasing the fast atom energy up to 10 keV.

Highlights

Electron beam and vacuum arc evaporation are widely used for deposition of thin films on various products at the gas pressure ranging from 0.01 to 1 Pa
The metal droplets arriving at the thin films from the arc cathode spots and nonuniformity of the discharge plasma in the process chamber are the main drawbacks of the vacuum arc
When the fast argon atoms bombard the growing film, the film adhesion mainly depends on their energy, and monotonically grows with the increase of the energy

Summary

Introduction

Electron beam and vacuum arc evaporation are widely used for deposition of thin films on various products at the gas pressure ranging from 0.01 to 1 Pa. The arc evaporation [1,2] is remarkable for a high deposition rate, and a high enough plasma density near the product surface. The arc evaporation [1,2] is remarkable for a high deposition rate, and a high enough plasma density near the product surface This ensures an adequate current of ions bombarding the negatively biased products. This enables modification of the surface properties and structure of the cutting tools made of high-speed steel and other industrial products [3]. For the deposition of thin films, not containing the droplets, the filtered vacuum arc plasma [4] can be used

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