Evaluation of thermal properties of thin films by IR radiometry using a comprehensive set of Zr-O-N thin films

Abstract Modulated Infrared Radiometry is a photothermal technique which allows thermal characterization of coatings, whose properties are determined by applying the “Extremum Method”. The objective of this work is to apply this method on a set of films where all the parameters influencing the model are adjusted systematically in a matrix of 36 different samples. Thus, Zr-O-N films were deposited by sputtering varying three factors: i) composition/bonding of the film: metallic Zr, crystalline metallic-type Zr-O-N and disordered Zr-O-N (films deposited in the metallic, reactive and poisoned regimes of the hysteresis curve, respectively); ii) each film was deposited simultaneously on three different substrates: steel, glass and silicon; iii) in each batch, four different thicknesses were grown. Each type of film was deposited with 4 different thicknesses, on top of 3 different substrates, in the same batch, maximizing their similarity. In general, the results allow to discriminate among films and are consistent regardless the type of substrate, although some dispersion of data is observed. The trends of the thermal parameters depending on the thickness were explained in terms of the films' microstructural/chemical characteristics, and the influence of each substrate. The values of the thermal parameters agree with those found in literature, reflecting the nature of the films.