Radioactivation monitoring of the density of wear-resistant AlN and CrN coatings on silicon

In this work, the mass and linear thicknesses of AlN and CrN coatings deposited onto silicon substrates by magnetron sputtering were measured, respectively, by a combination of the methods of nondestructive radioactivation analysis on proton beams of the U-120M cyclotron and optical micro-interferometry. It is shown that, at linear thicknesses in the range of 2.2 – 5.7 $\mu$m, the coating density is close to the values for bulk materials AlN (3.26 g/cm$^3$) and CrN (5.9 g/cm$^3$), and the stoichiometry of nitrides is controlled by the parameters of magnetron deposition. The technique can also be used to determine the density of wear-resistant coatings from carbides and metal oxides.