The main mechanisms of leakage currents in thin lead zirconate titanate (PZT) ferroelectric films prepared by the sol–gel method are discussed. Four specific regions are determined in I–V dependencies. At very weak fields (10–20 kV/cm), the current falls with the voltage increase as a result of depolarization. In the low fields region (about 70–100 kV/cm), the leakage current decreases with the decrease of voltage ramp speed and its components are the ohmic and displacement currents. In the high fields region (≥130 kV/cm), the leakage current increases with the decrease of step voltage ramp in contrast to the previous case. Possible conductivity mechanisms are the Poole– Frenkel emission and hopping conduction. In the transition region between above-mentioned ones (from 80–90 to ∼130 kV/cm), an abrupt unstable increase of current is observed caused by breakdown of reverse bias Schottky barrier. Depolarization currents are studied for sol–gel PZT films prepared at different preparation conditions.

Organosilicate glass-based porous low dielectic constant films with different ratios of terminal methyl to bridging organic (methylene, ethylene and 1,4-phenylene) groups are spin-on deposited by using a mixture of alkylenesiloxane with organic bridges and methyltrimethoxysilane, followed by soft baking at 120–200 °C and curing at 430 °C. The films’ porosity was controlled by using sacrificial template Brij^® L4. Changes of the films’ refractive indices, mechanical properties, k-values, porosity and pore structure versus chemical composition of the film’s matrix are evaluated and compared with methyl-terminated low-k materials. The chemical resistance of the films to annealing in oxygen-containing atmosphere is evaluated by using density functional theory (DFT). It is found that the introduction of bridging groups changes their porosity and pore structure, increases Young’s modulus, but the improvement of mechanical properties happens simultaneously with the increase in the refractive index and k-value. The 1,4-phenylene bridging groups have the strongest impact on the films’ properties. Mechanisms of oxidative degradation of carbon bridges are studied and it is shown that 1,4-phenylene-bridged films have the highest stability. Methylene- and ethylene-bridged films are less stable but methylene-bridged films show slightly higher stability than ethylene-bridged films.

The review article provides an overview of the most important and popular techniques for evaluating the porosity of thin films developed for various applications. These methods include ellipsometric porosimetry (EP), positron annihilation (lifetime) spectroscopy (PAS/PALS), and grazing incidence small-angle x-ray scattering (GISAXS). Special attention is given to the challenges associated with interpreting the measured data and the inherent limitations of each method. It is demonstrated that EP, GISAXS, and PALS are all informative for studying the pore structure in thin films, with each method offering unique insights. GISAXS, in particular, allows for the evaluation of three-dimensional mesostructures, including pore arrangement, pore spacing, and structural order. On the other hand, PALS has a unique advantage in its capability to analyze extremely small isolated pores (free volume). The advantage of EP lies in its simplicity and the possibility to analyze multiple properties from the same set of measurements. The cross-evaluation of different methods offers important insights into the complex pore structure of materials, highlighting the significance of appropriate modeling and interpretation of data.

Low temperature etching of organosilicate low-k dielectrics in CF3Br and CF4 plasmas is studied. The chemical composition of pristine and etched low-k films was measured by Fourier transform infrared spectroscopy. Reduction of plasma-induced damage at low process temperature is observed. It is shown that the plasma damage reduction is related to protective effects of accumulated reaction products (CHxFyBrz, SiBrx after CF3Br, and CFx polymers after CF4 plasma). The reaction products could then be removed by thermal annealing for the pores to become empty. In the case of CF4 plasma, the thickness of CFx polymer increases with the temperature reduction, which is measured by ellipsometry. This polymer layer leads to a strong decrease in the diffusion rate of fluorine atoms and, as a consequence, to reduction of plasma-induced damage. Bromine containing reaction products are less efficient for low-k surface protection against the plasma damage.

Chemical composition, pore structure and mechanical properties of porous organosilicate low-k films with terminal and bridging organic groups are studied. It is shown that BTMSE based low-k films with alkyl bridge between the Si atoms have non-uniform pore structure with internal voids (ink-bottle like pores) while the films with terminal alkyl groups have pores with cylindrical shape. All studied spin-on deposited films have better mechanical properties than PECVD films with similar chemical composition and porosity. The best mechanical properties showed alkyl bridged low-k films. Moreover, the Young's modulus increases with BTMSE content because of higher concentration of bridging bonds.