DETERMINATION OF CHEMICAL-COMPOSITION AND ITS RELATIONSHIP WITH OPTICAL-PROPERTIES OF TI-N AND TI-V-N SPUTTERED THIN-FILMS

In the investigation of thin films of transition metal nitrides, an es sential role is played by the accurate determination of their chemical composition. Actually the chemical composition depends on the deposit ion parameters and influences the optical properties. These relations are illustrated in thin films of TiNx and (Ti1-yVy)N-x deposited by re active magnetron sputtering from composite targets of the elements. By variation of the nitrogen partial pressure and the target composition , different samples have been obtained. The chemical composition has b een measured by electron probe microanalysis at low irradiation voltag es. The optical properties are evaluated by ex-situ ellipsometry. Usin g the screened Drude model, they are correlated with the differences i n composition. Adding vanadium or nitrogen in Ti-N is shown to have th e same effect on the optical properties.