Deposition of boron–carbon multilayer coatings by RF plasma sputtering

Boron–carbon coatings are typically accomplished by ion-assisted methods that generate energetic species of tens to hundreds of electron volt to facilitate the nucleation and growth processes. These energetic particles simultaneously induce a significant intrinsic stress leading to the film delamination, limiting the achievable thickness of the films to approximately a few hundred nanometers and creating difficulties for their technical applications. In this paper we propose a plasma method using an RF (13.56 MHz) capacitive system as a deposition technique to realize B–C coatings with a low residual intrinsic stress. A stable coating has been obtained by deposition of a multilayered structure in conditions of very low deposition rate. SEM micrographs show that the layers making up the coating are dense, without pores or cracks, and with a good adhesion to the substrates.