Stability of the platinum electrode during high temperature annealing

The modifications of the structure, electrical resistivity and surface morphology of platinum thin films on Pt/Ti/Si and Pt/TiO2/boron-phosphor-silicate glass/Si structures resulted from high-temperature annealing in the presence of oxygen were studied. It was established that regardless of the sublayers used while annealing caused platinum to recrystallize and texturize in the direction [111], and the texture is suppressed in the directions [200] and [220]. The annealing caused the drop of the volume resistivity of thin films from 0.2 to ca. 0.15 μOhm×m, and practically shown no dependence on the film thickness in case it exceeded 200 nm. As a result of recrystallization Pt films became unsmooth at low annealing temperatures and as the temperature increased hillocks were formed on the film surface. Relaxation of the compressive stress in the Pt film, facilitating the reduction of its free energy and modification of the lattice parameter towards the equilibrium value, is known to be the major hillock formation mechanism. The level of intrinsic stress in the film and the annealing temperature both determine the initial hillock formation. The final hillock height, density, and size are related to the Pt layer thickness, sublayer structure, and to the annealing time and temperature. Optimization of the sublayer structure and annealing modes makes it possible to increase the annealing temperature to ca. 780°С without causing any substantial damages to Pt microrelief. That enables us to use these structures as the bottom electrode in ferroelectric memory cells

Oxygen pressure influence on properties of nanocrystalline linbo3 films grown by laser ablation

10.3390/nano10071371Nanomaterials1071-1

Influence of target-substrate distance during pulsed laser deposition on properties of LiNbO3 thin films

This paper shows the results of studying the influence of target-substrate distance during pulsed laser deposition on electrical properties of LiNbO3 thin films. It has been shown that changing the target-substrate distance we can obtain thin films with a different composition. EDX spectra indicate that the LiNbO3 thin films fabricated under 120 mm target-substrate distance depleted Nb (0.7 atm. %) compare to LiNbO3 films fabricated under 20 mm target-substrate distance (11.0 atm. %). Varying target-substrate distance in the range from 20 mm to 120 mm charge carrier mobility increasing from 24 cm2/Vcenterdots to 395 cm2/Vcenterdots and concentration of charge carrier decreasing from 3centerdot1013 cm-3 to 1centerdot1012 cm-3. Obtained results can be used under development and fabrication of integral acousto-optic and surface acoustic wave (SAW) devices

Ferroelectric properties of strontium-bismuth tantalate thin film deposited by rf magnetron sputtering method

Исследованы характеристики сегнетоэлектрических тонких пленок танталата стронция-висмута (SBT), нанесенных методом ВЧ магнетронного распыления на Pt/TiOx/SiO2/Si подложки. Установлены зависимости диэлектрической проницаемости, остаточной поляризации и коэрцитивной силы пленок SBTот режимов последующего отжига. При температуре отжига 800° C получены пленки с остаточной поляризацией 2Pr= 3,02 мкКл/см 2 , коэрцитивной силой 2Ec= 140 кВ/см. Диэлектрическая проницаемость и тангенс угла диэлектрических потерь на частоте 1,0 МГц составляли соответствен-но = 125 и tg= 0,067. Температура Кюри пленок достигала 310–315° С.Characteristics of ferroelectric thin films of strontium-bismuth tantalate (SBT), which were deposited by means of HF magnetron sputtering on Pt/TiO2/SiO2/Si substrates, are investigated. The dependences of permittivity, residual polarization, and coercitivity of SBT films on the modes of subsequent annealing are established. Films with the residual polarization of 2Pr = 3.02 μC/cm 2 and coercitivity of 2Ec = 140 kV/cm are obtained at the annealing temperature of 800°C. The dielectric constant and loss tangent at the frequency of 1.0 MHz were accordingly equalto ε = 125 and tg= 0.067. The Curie temperature of the films reached 310–315° C