Surface properties of hard protective coatings studied by optical techniques

• Results of optical study of coatings obtained by ion sputtering method have been presented.
• The results of topography investigation by 3 measurement techniques have been shown.
• The DLC, C and SiC films exhibited a low surface roughness and high correlation length.
• The ellipsometric results have been used to analyze the BRDF data.

The paper describes optical study of SiC, C and NiC layers deposited on Si substrates by double beam ion sputtering (DBIS) method. The following optical methods: ellipsometry, bidirectional reflection distribution function (BRDF) and total integrated scattering (TIS) studies have been applied. The obtained results allowed us to determine the refractive indices, extinction coefficients and the roughness parameters of DBIS films. Also surface profiles of optical constants determined from scanning ellipsometric measurements have been presented. The power spectral density functions (PSD) of surface roughness for studied samples have been determined. The influence of the deposition technology on film topography has been discussed.