Fourier transform IR analysis of thin solid films

Große, Peter

doi:10.1016/0165-9936(89)87006-2

Cited by 8 publications

(1 citation statement)

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“…The dielectric response of the films has been determined using the transmission Fourier transform infrared ͑FTIR͒ spectroscopy, which is known to be a powerful tool for the analysis of semiconductor film systems. 32 Utilization of FTIR spectroscopy for studies of the soft-mode dynamics in FE films was demonstrated in Refs. 17, 28, 30, 31, and 33.…”

Section: Introductionmentioning

confidence: 99%

Origin of soft-mode stiffening and reduced dielectric response inSrTiO3thin films

et al. 2002

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The problem of the reduced dielectric response in thin films of high-permittivity materials is analyzed by studying the soft-mode response in several SrTiO 3 thin films by means of Fourier transform far infrared, monochromatic submillimeter, and micro-Raman spectroscopies. A 300-nm-thick metalorganic chemical vapor deposition film, quasiepitaxially grown on a ͑0001͒ sapphire substrate with a perfect ͗111͘ orientation, displays a ferroelectric transition near 125 K induced by a tensile residual stress, appearing apparently simultaneously with the antiferrodistortive transition. On the other hand, polycrystalline chemical solution deposition films grown on ͑0001͒ sapphire, and also tensile stressed, show a harder soft mode response without the appearance of macroscopic ferroelectricity. This effect, which increases with the film thickness, is explained by a strong depolarizing field induced by the percolated porosity and cracks ͑in the 10-nm scale͒ along the boundaries of columnar grains ͑normal to the probe field direction͒. Brick-wall model calculations showed that 0.2 vol. % of such a porosity type reduces the permittivity from 30000 to less than 1000. The activation of the forbidden IR modes in the Raman spectra in the whole 80-300-K temperature range studied is explained by the effect of polar grain boundaries, in analogy with the bulk ceramics.

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Section: Introductionmentioning

confidence: 99%