STRUCTURE AND MORPHOLOGY OF THIN SNO2 FILMS

The dependence of the structure and morphology of thin SnO2 films on the deposition technique was investigated. SnO2 films were prepared by chemical vapour deposition (CVD), spraying and r.f. sputtering methods. The substrates used were (100) p-type silicon wafers (2-5 ω cm). The investigation was carried out using transmission electron microscopy, selected area diffraction, reflection high energy electron diffraction, Auger electron spectroscopy and secondary ion mass spectrometry techniques. All layers studied with a thickness of about 100 nm were polycrystalline with grain sizes in the range 20-80 nm depending on the deposition conditions. The existence of the SnO phase was revealed in CVD and sprayed SnO2 films with a (110) preferred orientation parallel to the silicon surface. The most nearly perfect, single-phase, stoichiometric films with a (100) orientation perpendicular to the silicon surface were prepared by r.f. sputtering. © 1990.