Traditionally, the term hard coatings refer to the property of high hardness in mechanical sense with good tribological properties . With the development of modern technology in the areas of optical, optoelectronic, microelectronic and related defense applications, the definition of the term hard coatings can be extended. Thus, a system which operates satisfactorily, in a given environment can be said to be hard with respect to that environment . Most of the hard coatings are ceramic compounds such as oxides, carbides, nitrides (AlN), ceramic alloys, cermets, metastable materials such as Diamond-Like Carbon (DLC). Their properties and environmental resistance depend on the composition, stoichiometry, impurities, microstructure, imperfections, and in the case of coatings, the preferred orientation (texture). In this paper we shall take a look at some characteristics - physicochemical and optical of AlN and DLC layers synthesized by physical vapor deposition – RF magnetron sputtering in an industrial high vacuum deposition system. The influence of the process parameters on the growth rate, morphology, topography and chemical bonding structure will be presented.