INFLUENCE OF THE SUBSTRATE ON THE COMPOSITION OF PD-DOPED TIN OXIDE THIN-FILMS STUDIED BY EPMA AND SNMS

Pd-doped tin oxide thin films were deposited on oxidized silicon, alum ina and Si3N4, by using the pyrolysis of an aerosol produced by ultra- high frequency spraying. Elemental composition was studied by Electron Probe MicroAnalysis (EPMA) and Secondary Neutral Mass Spectroscopy (S NMS). Due to the penetration of the electron beam inside the film and the substrate, EPMA measurements were treated using a multilayer analy sis software with thin film correction model based on the description of rho(rho z) depth distribution of ionisations. The two methods lead to similar results. The nature of the substrate greatly influences the film composition. In the case of an oxide type substrate, a diffusion occurs between the substrate and the films, whereas no diffusion is o bserved with Si3N4 substrate.