A study of the fundamental problems in ferroelectric films

The results obtained in the fabrication of ferroelectric thin films on sili con substrates coated with conductive layers to serve as electrodes are rep orted. The deposited materials, by laser ablation in an oxygen atmosphere a t pressures of the order of 200 mTorr at different temperatures were BaTiO3 , PMNT and SET. A KrF excimer laser with 248 nm wavelength and working flue nce of the order of 1 J/cm(2) was used. The targets used in the ablation pr ocess were fabricated by the conventional ceramic technique and their compo sition and microstructure were characterized before they were used in the d epositions. The materials used for electrodes were Pt, RuO2 and TiN films, deposited by DC or RF ion sputtering. It was found that the mechanical, mic rostructural and dielectric properties of the ferroelectric films strongly depend on the material used as bottom electrode. Some results of the studie s performed by transmission and scanning electron microscopy, X-ray diffrac tion and dielectric hysteresis are presented.