ABSTRACT Porous Eu‐doped Pb(Zr,Ti)O 3 (PZT) thin films were prepared by a sol–gel route to investigate the coupled effects of Eu incorporation, surfactant‐induced porosity, and thermal treatment on crystallization and functional properties. Eu incorporation preserved the perovskite phase composition of dense PZT but resulted in pronounced grain refinement and strongly modified the electrical response. In porous Eu‐containing films, thermal history governed the structural evolution: fast annealing promoted formation of a well‐developed perovskite matrix with enlarged columnar grains and residual porosity while retaining ferroelectric functionality, whereas prolonged annealing enhanced Pb loss and suppressed complete perovskite crystallization. The interaction between Eu incorporation and porosity was particularly evident in photoluminescence. In the amorphous state, characteristic Eu 3 + intra‐4f emission was strongly enhanced after formation of the porous structure. Subsequent perovskite crystallization suppressed Eu 3 + emission and produced host/defect‐related bands near 360, 430, and 550 nm. These results demonstrate that Eu incorporation and porosity are coupled through crystallization and defect evolution, providing a route to tailor the structural, optical, and electrical properties of multifunctional PZT thin films.

Porous PZT films offer significant potential due to tunable electromechanical properties, yet the polarization behavior remains insufficiently understood because of discontinuous morphology and domain structures. In this work, we study the impact of porosity on the spontaneous polarization and electromechanical response of PZT thin films fabricated using a multilayer spin-coating technique with various concentrations (0–14%) of polyvinylpyrrolidone (PVP) as a porogen. Atomic force microscopy (AFM) and piezoresponse force microscopy (PFM) were employed to analyze the local topography, domain distribution, and polarization behavior of the films. The results indicate that increasing porosity leads to substantial changes in grain morphology, dielectric permittivity, and polarization response. Films with higher porosity exhibit a more fragmented polarization distribution and reduced piezoresponse, while certain orientations demonstrate enhanced domain mobility. Despite the decrease in overall polarization, the local coercive field remains relatively stable, suggesting structural stability during the local polarization switching. The findings highlight the crucial role of grain boundaries and local charge redistribution in determining local polarization behavior.

The impact of the spatial arrangement of the terminal methyl group in relation to the bridging ethylene group on the properties of PMO films has been studied using pairs of BTMSE-MTMS and TESDEMSE-MTMS precursors containing C-C bridging groups. TESDEMSE features a Si-attached CH3 group within the same molecule, forming hydrophobic films independently of MTMS concentration. Pure BTMSE-based films are hydrophilic and exhibit an increased dielectric constant due to water adsorption. The addition of MTMS to BTMSE introduces CH3 into the films, rendering them hydrophobic. The spatial arrangement of CH3 relative to C-C significantly affects hydrophobicity, dielectric properties, thermal stability, and porosity. The mechanical properties of the films also depend on the location of CH3 groups. TESDEMSE demonstrates potential as a single precursor for low-k film deposition. However, annealing (curing) at 430 °C reduces the concentration of C-C bonds, and this phenomenon is more pronounced in TESDEMSE-based films. Quantum chemical analysis indicates that the ethylene bridge is generally weaker than the terminal methyl group, with the presence of an adjacent methyl group further decreasing its stability. The low thermal stability of these films poses a challenge for certain practical applications.

A novel approach for the preparation of ferroelectric composite films has been successfully developed by combining sol-gel evaporation-induced self-assembly (EISA) of porous lead zirconate titanate (PZT) films with atomic layer deposition (ALD) of titania. The EISA process, which utilizes a Brij-type surfactant, facilitates the formation of large columnar perovskite grains with narrow (similar to 20 nm) interconnected pores. ALD, employing the thermal reaction of titanium isopropoxide with water, ensures uniform titania growth within the pores throughout the film thickness, as demonstrated by transmission electron microscopy and ellipsometric porosimetry. The resulting PZT-TiOx composite films exhibit a pronounced photovoltaic current under visible light illumination, attributed to electron excitation from the valence band to Ti3+ states, followed by movement via a hopping conduction mechanism. The photocurrent value varies with the direction of polarization. This behavior presents a potential method for controlling photoconductivity through polarization, with possible applications in electronic and photonic devices.

Organosilica films, composed of a silicon oxide network with terminal methyl groups, are widely utilized in various applications, including microelectronics. Many of these applications require high hydrophobicity and good mechanical properties, which pose a significant challenge because the Si-CH3 groups disrupt the Si-O-Si network. This issue becomes particularly pronounced in porous films. Here, we investigate whether material properties can be tuned by simply altering the spatial arrangement of methyl groups. To achieve this, we prepared copolymer films with one or two methyl groups bonded to a silicon atom, while maintaining a constant total amount of methyl groups. The films were deposited using a sol-gel technique combined with template self-assembly. The precursor content was varied to compare films with different proportions of Si-CH3 and Si(-CH3)2. Film characterization included FTIR, ellipsometric porosimetry, AFM, and WCA measurements and dielectric constant evaluations. Our findings indicate that precursors containing dimethyl groups enhance the connectivity of the Si-O-Si network, resulting in a higher Young's modulus and smaller pore size compared to films with an equivalent amount of methyl groups. However, the lower thermal stability of dimethyl bonds limits the thermal budget of these films. Thus, the spatial arrangement of organic groups within the polymer structure can be employed to tune material properties. These results expand the understanding of organic-inorganic hybrid materials and offer novel approaches for their applications.

Organosilica films with a silicon oxide network and terminal methyl groups are widely used for various applications, including microelectronics. Most of them require high hydrophobicity and good mechanical properties, which is a challenge because Si–CH3 blocks some directions of the metal–oxide network. Here, we discuss an alternate way to prepare organosilica films in which the methyl group is changed to dimethyl. The films were deposited by the sol–gel technique using a non-ionic surfactant to provide porosity. The precursor content was varied to compare the films with different contents of Si–CH3 and Si(–CH3)2. The characterization of the films includes FTIR, ellipsometric porosimetry, PFQNM AFM, wetting contact angle, and dielectric constant. We found that the use of precursors containing dimethyl groups leads to an increase in Si–O–Si network connectivity and hence a higher Young's modulus value compared to films containing the same amount of methyl groups. However, the lower thermal stability of the dimethyl bonds leads to some deterioration of hydrophobic behavior and related properties. These new results extend the knowledge of organic-inorganic hybrid materials and provide new approaches for their applications.

The effect of vacuum ultraviolet (VUV) radiation during ionized physical vapor deposition (IPVD) of tantalum barriers on various porous organosilicate glass low-k SiCOH films is studied using advanced diagnostics and quantum chemical calculations. VUV photons break the Si-C bonds, releasing hydrocarbon radicals from the pore surfaces. These radicals, trapped in pores that are partially sealed by tantalum deposition, can either react with tantalum to form carbide-like compounds, TaCx, or be redeposited in the pores as CHx polymers. This is evidenced by a decrease in CH3 groups that correlates with an increase in TaCx. The formation of TaCx poses a significant challenge in the back end of line (BEOL) technology when reducing the barrier thickness.

In this work, the effects of solvent type and surfactant (porogen) on the properties of porous methyl-modified spin-on films were investigated. A qualitative assessment of the defectivity of the formed films was carried out. The refractive index, dielectric permittivity, and porosimetric properties of the films were analyzed using the method of spectral ellipsometry, frequency dependence of capacitance analysis, and porosimetry. It was found that the film properties depend more strongly on the surfactant type than on the solvent type. The highest porosity value is obtained with the use of nonionic surfactant Brij® 76, which has a higher molecular weight. At the same time, at lower molecular weight, the ionic surfactant CTAB provides comparable porosity. Despite the high porosity, samples from film-forming solutions containing CTAB do not exhibit a lower dielectric constant, which is presumably due to their hydrophilicity or porogen residue. The lowest value of the dielectric constant k ≈ 2.1 is typical for films made from film-forming solutions containing Brij® 76. The application of other porogens allows us to obtain a k value 2.3–2.4.

Thin porous sol-gel organosilicate glass (OSG) films containing methylene (Me-OSG), ethylene (Et-OSG), or phenylene (Ph-OSG) bridges between Si atoms, along with terminal methyl groups, were spin-coated onto Si wafers. Porosity was generated using the Brij (R) L4 template. The investigation focused on examining the effects of annealing (200-1000 degrees C, 30 min) on the properties of the micro/mesoporous films. The changes in the properties of the films during the annealing process at different temperatures are impacted by the evaporation of solvents, condensation reactions, and destruction of the porogen (200-400 degrees C). Additionally, the degradation of terminal and bridging organic groups has been observed to occur within the temperature range of 200-600 degrees C. Finally, the films undergo densification through subsequent condensation and viscous sintering within a temperature range of 700-1000 degrees C. Ph-OSG films demonstrate remarkable resistance to temperatures of similar to 400 degrees C. Additionally, these films exhibit the highest Young's Modulus (YM) and the smallest pore radius (YM approximate to 6.7 GPa and R approximate to 1 nm after 400 degrees C annealing). It is important to acknowledge that these materials exhibit a relatively hydrophilic nature, significant shrinkage, and higher refractive index (RI) and dielectric constant (k) compared to the MeOSG and Et-OSG films. Me-OSG films demonstrate the highest hydrophobicity and porosity, along with minimal shrinkage, RI, and k. However, they also possess the largest pore radius (R = 1.7-2.2 nm after undergoing annealing at 400-550 degrees C). Modeling the concentrations of different species reveals that the predicted changes in concentrations are strongly dependent on the number of hydroxyl groups present on the surface of the pore walls. The decrease in the number and/or polarizability of OH groups leads to an increased impact of other species on the dielectric constant, resulting in higher computed values.

The degradation of a porous organosilicate glass low-k dielectric during the ionized physical vapor deposition of tantalum coating is studied. The main contribution to the damage is made by vacuum UV flux (10(14)-10(15) s(-1) cm(-2)) from the argon inductively coupled plasma of the ionizer, and the effect of the direct current magnetron sputter plasma is small. The damage by vacuum ultraviolet photons with an energy exceeding the band gap of the SiO2 matrix is associated not only with the removal of carbon-containing groups (terminal CH3 and bridging CH2) but also with the breaking of Si-O bonds in the Si-O-Si matrix followed by the formation of hydrophilic Si-OH and Si-H groups. Consequently, the degree of damage can be much higher than would be expected from the depth of CH3 group depletion.

The subtractive process of forming a metallization system for integrated circuits has been studied. Structures with aluminum and copper conductors with different pitches were used as models. The gaps between the conductors were filled using the chemical solution deposition technique. The formed organosilicate layers provided complete or partial planarization of the relief. Electrical measurements indicated a decrease in capacitance and leakage currents in structures with nanoporous dielectric layers.

Conductive LaNiO3 (LNO) films with an ABO3 perovskite structure deposited on silicon wafers are a promising material for various electronics applications. The creation of a well-defined columnar grain structure in CSD (Chemical Solution Deposition) LNO films is challenging to achieve on an amorphous substrate. Here, we report the formation of columnar grain structure in LNO films deposited on the Si-SiO2 substrate via layer-by-layer deposition with the control of soft-baking temperature and high temperature annealing time of each deposited layer. The columnar structure is controlled not by typical heterogeneous nucleation on the film/substrate interface, but by the crystallites' coalescence during the successive layers' deposition and annealing. The columnar structure of LNO film provides the low resistivity value ρ~700 µOhm·cm and is well suited to lead zirconate-titanate (PZT) film growth with perfect crystalline structure and ferroelectric performance. These results extend the understanding of columnar grain growth via CSD techniques and may enable the development of new materials and devices for distinct applications.

Porous ferroelectric lead zirconate titanate (PZT) films are a promising material for various electronic applications. This study focuses on understanding how the structure-directing agent, polyvinylpyrrolidone, can alter the structure and electrical properties of porous PZT films prepared through chemical solution deposition. Films with various porosities of up to ~40 vol.% and pore connectivities from 3-0 to 3-3 were prepared and studied by capacitance–voltage, dielectric hysteresis, transient current, photocurrent, and local current techniques. We have found that a linear decrease in material volume in a porous film is not the only factor that determines film properties. The creation of new internal grain boundaries plays a key role in changing electrical properties. This research expands the understanding of physical phenomena in porous ferroelectric films and may facilitate the development of new materials and devices.

Исследован субтрактивный процесс создания системы металлизации интегральных схем. В качестве модельных использованы структуры с алюминиевыми и медными проводниками, имеющие различный шаг. Заполнение зазоров между проводниками проводилось методом химического осаждения из раствора. Сформированные органосиликатные слои обеспечивали полную или частичную планаризацию рельефа. Электрические измерения свидетельствовали о снижении ёмкости и токов утечек в структурах с нанопористыми диэлектрическими слоями.

This article studies various methods for the formation of dielectric diffusion barriers between open areas of copper and an organosilicate low- k dielectric in the subtractive method of forming a metallization system, in which metal lines are first formed, and then a low- k dielectric is deposited. Films of dense and porous organosilicate glass deposited by chemical deposition from solutions are used as a low- k dielectric. A comparison is made between AlN barrier layers formed by atomic layer deposition and SiCN barriers deposited by plasma-assisted chemical vapor deposition. The successful formation of a model structure of copper metallization using AlN barriers is demonstrated.

Modification of spin-on-deposited porous PMO(periodic mesoporous organosilica) ultralow-k(ULK) SiCOHfilms (k= 2.33) containing both methyl terminal and methylenebridging groups by vacuum ultraviolet (VUV) emission from Xeplasma is studied. The temporal evolution of chemical composition,internal defects, and morphological properties (pore structuretransformation) is studied by using Fourier transform infraredspectroscopy, in situ laser ellipsometry, spectroscopic ellipsometry,ellipsometric porosimetry (EP), positron-annihilation lifetimespectroscopy (PALS), and Doppler broadening positron-annihila-tion spectroscopy. Application of the different advanced diagnosticsallows making conclusions on the dynamics of the chemical composition and pore structure. The time frame of the VUV exposure inthe current investigation can be divided into two phases. During thefirst short phase,film loses almost all of its surface methyl andmatrix bridging groups. An increase of material porosity due to removal of methyl groups with simultaneous matrix shrinkage isfound by in situ ellipsometry. The removal of bridging bonds leads to an increase of matrix intrinsic porosity. Nevertheless, when thetreated material is exposed to the ambient air, the sizes of micro- and mesopores and pores interconnectivity decrease with the VUVexposure time according to PAS and EP data. The last is the result of the additionalfilm shrinkage caused by atmosphere exposure.During the second phase the increase of mesopore size is detected by both EP and PAS. The increase of mesopore size goes all thetime as it is expected from in situ ellipsometry, but it is masked by the air exposure.

Porous ferroelectric lead zirconate-titanate (PZT) films with different internal structures are synthesized using a sol-gel technique and spin-on deposition on platinized silicon substrates. The films' porosity is engineered using various structure-directing agents: polyvinylpyrrolidone with a molecular weight of 360 000 (1-6.6 wt.%) and block copolymer surfactants Brij 30 and Brij 76 (30-60 wt.%). The films' structures are characterized by transmission electron microscopy. The PVP-based films contain large, elongated pores with diameters as large as 100 nm. By contrast, the films prepared from solutions with block copolymers exhibit a small pore size depending on the surfactant molecular weight (10-19 nm for Brij 30 and 20-27 nm for Brij 76), with a mostly uniform distribution of channel-like pores within the film volume. Despite their highly porous structures, all of the films show a columnar-grain perovskite structure with grains as large as several micrometers and curved grain boundaries. The films demonstrate ferroelectric behavior with dielectric hysteresis, and their permittivity decreases with increasing porosity. Thus, the Brij 30 and Brij 76 copolymer surfactants can be used to engineer fine porous structures in PZT films for various applications in electronics.

We applied time-domain Brillouin scattering (TDBS) for the characterization of porogen-based organosilicate glass (OGS) films deposited by spin-on-glass technology and cured under different conditions. Although the chemical composition and porosity measured by Fourier-transform infrared (FTIR) spectroscopy and ellipsometric porosimetry (EP) did not show significant differences between the films, remarkable differences between them were revealed by the temporal evolution of the Brillouin frequency (BF) shift of the probe light in the TDBS. The observed modification of the BF was a signature of the light-induced modification of the films in the process of the TDBS experiments. It correlated to the different amount of carbon residue in the samples, the use of ultraviolet (UV) femtosecond probe laser pulses in our optical setup, and their intensity. In fact, probe radiation with an optical wavelength of 356 nm appeared to be effective in removing carbon residue through single-photon absorption processes, while its two-photon absorption might have led to the breaking of Si-CH3 bonds in the OSG matrix. The quantum chemical calculations confirmed the latter possibility. This discovery demonstrates the possibility of local modifications of OSG films with a nanometric resolution via nonlinear optical processes, which could be important, among other applications, for the creation of active surface sites in the area-selective deposition of atomic layers.

This study aims hydrophobisation of a microporous phenylene-bridged organosilicate film via its surface modification with hexamethyldisilazane (HMDS) vapour to adapt it for use as a low dielectric constant material for advanced microelectronics technology. The microporous organosilicate film was spin-coated with 1,4-bis (triethoxysilyl) benzene, followed by soft baking at 120-200 degrees C and annealing at 390 degrees C in N2. Subtractive porosity was added using a sacrificial template - Brij (R) L4. This 1,4-phenylene-bridged film possessed a large Young's modulus and small pore size. However, due to steric effects during the film formation, a large amount of unreacted silanol remained on the surface. The HMDS-induced hydrophobisation reduced the number of residual silanols and adsorbed water molecules, despite the small pore size. A decrease in the hydrophilicity of the film surface led to an increase in the WCA value as well as a decrease in the dielectric constant and dielectric loss tangent. Ellipsometric porosimetry showed that the open porosity decreased without changes in the pore size distribution as a result of silylation by the HMDS vapour. However, the Fourier transform infrared spectra showed limited time-dependant temperature stability of the -CH3 groups introduced by the HMDS vapour treatment. The decrease in open porosity during the heat treatment of the hydrophobised film was significantly reduced because of the strengthening of the pore walls. Consequently, this film demonstrated lower shrinkage and larger Young's modulus.

Porous OSG low-k dielectrics deposited by using TEOS and MTEOS mixture with different ratios and Brij® 30 surfactant. The deposited samples contain a different concentration of terminal methyl groups that is proportional to MTEOS concentration. An increase in the methyl groups concentration by changing TEOS/MTEOS ratio decreases the open porosity, k-value, and Young’s modulus and increases the mean pore radius although the template concentration was kept constant. Plasma damage by fluorine radicals depends on the carbon concentration in the films. It can be reduced by 60% when the carbon concentration in the film exceeds 10 atomic percent as measured by XPS (the films deposited with TEOS/MTEOS ratio 40/60).