Grazing Incidence X-ray Diffraction Analysis Research Articles

Material screening for future diffusion barriers in Cu interconnects: Modeling of binary and ternary metal alloys and detailed analysis of their barrier performance

One of the challenges in the semiconductor industry is to find new barrier materials and copper (Cu) alternative solutions in interconnects. In this work, we focused to find alternative diffusion barrier materials. Different binary (CoMo, CoRu, CoTa, CoW, MoRu, RuTa, RuW) and ternary (CoMoTa, CoRuTa, MoRuTa) metal alloys were evaluated theoretically with the Miedema model to find the amorphous phase composition range. Afterward, thin films of the alloys with various compositions were deposited by magnetron sputtering and theoretical values were compared to the experimental results. From the experimental measurements, which included grazing incidence x-ray diffraction analysis and resistivity measurements, suitable binary and ternary alloys were chosen for diffusion analysis. By annealing thin film stacks at temperatures ranging from 500 to 675°C, diffusion was induced and detected by x-ray photoelectron spectroscopy depth profiles. Seventeen alloys were evaluated by their diffusion barrier effectiveness, and five of those, which include Ru60Ta40, Ru45W55, Mo47Ru53, Mo36Ru50Ta14, and Co40Mo35Ta25, showed excellent barrier properties against copper diffusion. Furthermore, all of the stated materials have a lower resistivity than TaN. Last, the adhesion of the best performing alloys to SiCOH and Cu was evaluated by the modified edge lift-off test. Only Ru45W55 had reasonable adhesion at both interfaces. The other materials showed low adhesion strength to Cu, which would make an adhesion promoter (liner), such as cobalt, necessary for the integration.

Enhanced remnant polarization in ferroelectric Hf0.5Zr0.5O2 thin film capacitors through Mo top electrode by post-metallization annealing treatment

Zr-doped HfO2 (Hf0.5Zr0.5O2) ferroelectric thin films have garnered considerable attention due to their appealing attributes, including a large bandgap (>5 eV), low crystallization temperature, and compatibility with CMOS technology. In this study, we present the achievement of a substantial remnant polarization in ferroelectric Hf0.5Zr0.5O2 thin films, fabricated through atomic layer deposition, with Mo and TiN serving as the top and bottom electrodes, respectively. The Mo/Hf0.5Zr0.5O2/TiN capacitor exhibited commendable ferroelectric behavior and demonstrated high endurance within a thermal budget ranging from 400 to 500 °C. Leveraging the relatively low thermal expansion coefficient of the Mo top electrode facilitated the induction of in-plane tensile strain, fostering an increased formation of the ferroelectric orthorhombic phase within the Hf0.5Zr0.5O2 layer. Elevating the post-metallization annealing temperature to 500 °C yielded a substantial increase in 2Pr (≈54 μC/cm2) with excellent endurance exceeding 106 cycles. The influence of annealing temperature on the morphological and structural properties of Hf0.5Zr0.5O2 thin films was comprehensively analyzed through atomic force microscopy and grazing incidence X-ray diffraction analysis.

Effect of substrate temperature on growth mechanism and properties of PEALD-MgO dielectric films for amorphous-IGZO TFTs

Magnesium oxide (MgO) films have been prepared by plasma enhanced atomic layer deposition with bis(cyclopentadienyl)magnesium precursor and oxygen plasma reactant at substrate temperature between 150 °C and 450 °C. The structural, morphological, optical, and chemical properties of the prepared MgO films were studied by spectroscopic ellipsometer, grazing incidence X-ray diffraction (GIXRD), field emission scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy (XPS). The electrical property of MgO film was obtained by performing capacitance-voltage measurement on the Al/MgO/Si structures. The experiment result shows that growth rate of MgO film decreases with the deposition temperature increased. GIXRD analysis presented that MgO films are cubic with predominantly (220) crystal orientation. XPS analysis shows that ratio of Mg/O is highest in MgO film prepared at 350 °C. To illustrate the possible applications of MgO film as a gate dielectric in thin film transistor (TFT), indium‑gallium‑zinc oxide (IGZO) was used as channel layer. The optimized IGZO/MgO TFT showed an electron mobility of 1.63 cm2/Vs, an on/off current ratio of 106, and a subthreshold swing of 0.50 V/decade at a low operation voltage of −0.11 V.

Evaluation of substrate temperature role on the structural, morphological, optical, and mechanical properties of magnetron sputtered Cu2Se thin films

Copper Selenide (Cu2Se) thin films were deposited on a float glass substrate using magnetron sputtering with a radio frequency (RF) source at a power of 70 W and by varying substrate temperatures (Tsub) from 50 °C to 400 °C with an interval of 50 °C. The influence of the Tsub on the morphological, structural, and mechanical characteristics of Cu2Se thin films was investigated using the Grazing Incidence X-ray diffraction (GIXRD), Raman spectra, Field Emission Scanning Electron Microscopy (FESEM) combined with energy-dispersive spectroscopy (EDS) and Nanoindentation. The results of the GIXRD analysis suggest that the cubic Cu2-xSe phase could be observed when the deposition took place at Tsub of 50 to 200 °C. However, for the films that were deposited at temperatures higher than this range, i.e., from 250 °C to 400 °C, the elements Cu and Se formed an intermediate phase. Raman bands assigned at 261 cm−1 confirm the cubic-Cu2Se phase. The average grain size measured from FESEM images increase with varying Tsub from 50 °C to 400 °C with a value of 230 nm to 320 nm. The variation in the Tsub results in the evolution of the microstructure and EDS shows the variation in the stoichiometric ratio of deposition. The energy of the band gap decreases with an increase in Tsub, leading to the overlapping of energy levels. The nanoindentation tests show that the hardness dropped as the Tsub increased from 50 °C to 400 °C. The Cu2Se film deposited at Tsub 50 °C had the highest hardness value of 1.91 ± 0.47 GPa.

Thermal stability of In1-xGaxSb nanofoams

This article presents the thermal stability of In1-xGaxSb films with different In/Ga relative concentration and different levels of porosity, subjected to thermal annealing. In1-xGaxSb films deposited by magnetron sputtering were transformed into nanofoams by irradiation with 16 MeV Au+7 and the structural and compositional characterization of the material, before and after annealing in vacuum, at 200 °C or 300 °C for 1 h, was performed by grazing incidence x-ray diffraction analysis (GIXRD) and Rutherford backscattering spectrometry (RBS), respectively. In1-xGaxSb films and nanofoams are remarkably stable under high temperatures, showing no significant redistribution or loss of Ga, In and Sb atoms. Thermal annealing induced the incorporation of C and O, slightly more pronounced in the nanofoams due to the increased surface to volume ratio. Thermal annealing induced an increase in crystallite size for all films and nanofoams, and the material remained porous after annealing.

Sputtering and structural modifications induced in silicon dioxide (SiO2) thin films under (10–40 MeV) Auq+ heavy ion irradiation

Surface sputtering and structural modifications induced in silicon dioxide thin films (SiO2/Si) deposited on silicon substrates and irradiated by swift (10–40 MeV) heavy Auq+ (q = +4, +6, +7, and +9) ions were investigated by grazing‐incidence X‐ray diffraction (GIXRD) spectroscopy, Rutherford backscattering (RBS) spectrometry and time‐of‐flight elastic recoil detection (ToF‐ERDA) technique. The GIXRD analysis of the as‐deposited and irradiated samples revealed increasing structural modifications of the SiO2 thin films under Auq+ ion impacts with increasing ion‐beam energy. The changes consisted of decreased grain sizes with increased strain accompanied by a phase transformation from crystalline to amorphous films. RBS analysis showed a decrease in the mean stoichiometric (O/Si) ratio from (2.2 ± 0.1) to (1.7 ± 0.1), due to preferential sputtering of oxygen, as the incident ion energy increased. The obtained RBS‐results were then completed by those of ToF‐ERDA analysis technique using a 40 MeV Au9+ heavy ion beam. The preferential sputtering yield ratios (YSi/YO) were determined experimentally both versus electronic stopping power and ion fluence. The obtained results were then compared to numerical values derived from the inelastic thermal spike (i‐TS) model, Sigmund's analytical formula and SRIM simulation code. A good agreement was observed between the measured preferential sputtering data and the i‐TS calculated values, when considering both nuclear elastic and electronic inelastic collision mechanisms. Besides, a close correlation is observed between the electronic stopping power dependent measured sputtering yields and the XRD peak intensity degradation per unit fluence. These observations suggest that the same mechanism of MeV heavy ion‐irradiation induced extended atomic disordering, occurs both in the case of structural modifications and surface sputtering. Finally, the obtained experimental results are discussed on the basis of the i‐TS model.

Thermal atomic layer etching of CoO using acetylacetone and ozone: Evidence for changes in oxidation state and crystal structure during sequential exposures

Thermal atomic layer etching (ALE) of CoO was demonstrated using sequential exposures of acetylacetone (Hacac) and ozone (O3). During the surface reactions, Hacac can remove CoO according to: CoO + 2Hacac → Co(acac)2 + H2O. Ozone was employed to eliminate carbon residue resulting from Hacac adsorption. In situ spectroscopic ellipsometry observed a linear decrease in CoO film thickness versus Hacac and O3 exposures with an etch rate of 0.43 Å/cycle at 250 °C. The surface of the CoO film was also observed to undergo changes in oxidation state and crystal structure with each reactant exposure. Ex situ grazing incidence X-ray diffraction (GIXRD) studies revealed that the initial h-CoO thin films were oxidized to c-Co3O4 by O3. Subsequently, the GIXRD analysis showed that the c-Co3O4 thin films were reduced to c-CoO by Hacac. X-ray photoelectron spectroscopy investigations confirmed the oxidation state of the various cobalt oxides. Quadrupole mass spectrometry measurements observed Co(acac)2 etch products during Hacac exposures on Co3O4 and CoO powder. Atomic force microscopy measurements also monitored a reduction in surface roughness during CoO ALE. These studies reveal that alternating changes in oxidation state and crystal structure occur during the sequential Hacac and O3 exposures that define CoO thermal ALE.

Improved mechanical and wear properties of H13 tool steel by nitrogen-expanded martensite using current-controlled plasma nitriding

Nitrogen-expanded martensite is a crystalline structure formed by incorporating nitrogen atoms into the interstitial sites of martensitic steels. It has recently gained significant industrial attention due to its excellent mechanical and wear-resistance properties. However, the major challenge in synthesizing nitrogen-expanded martensite is obtaining a phase free of iron or chromium nitrides precipitates. In this study, the effects of varying temperature (460, 480, and 500 °C) and plasma current density (0.5, 1.0, and 1.5 mA/cm2) during plasma nitriding of H13 tool steel were investigated to evaluate their influence on crystalline phases. The results of X-ray diffraction analysis indicate that expanded martensite free of nitride precipitates can be obtained at a temperature of 480 °C and low current density. Moreover, wear analysis using a ball-on-disk wear tester showed that the lowest wear rates were achieved under similar conditions. Grazing incidence X-ray diffraction analysis revealed that the outer region of the nitrided zone had a disordered structure, which could be attributed to a nano crystallization process. The nanoindentation analysis demonstrated that the expanded martensite phase has rigid-elastic properties characterized by high elastic energy (144.5 nJ) and high resistance to plastic deformation.

Chelate complexed multi-elemental printing performance of a small and cost efficient picoliter droplet printing device for micro preparation

We introduce an inexpensive modular picoliter pipetting device using modified commercially available thermal inkjet cartridges. The system is capable of reliable deposition of 65 elements. The printing solutions were modified to prevent the dissolution of Ni from the nozzle head, keeping those at a pH of >9. Loss of cations to the glass surfaces inside the nozzle head is prevented by forming anionic complexes with ethylenediaminetetraacetic acid in basic conditions. For some elements, e.g., Si, additives like tetramethylammonium hydroxide are necessary.The volumes of the droplets were obtained, weighing 30,000–360,000 droplets ejected by the printer using a laboratory scale. The droplet volume was within a range of 142–184 pL, depending on the formulation. The delivered elemental masses and the reproducibility were determined using total reflection X-ray fluorescence analysis and inductively coupled plasma optical emission spectrometry. Delivered masses were in the range of 0.98 pg – 11.9 pg per element and droplet.The shape of deposits of about 31 pg per element was studied using atomic force microscopy, optical microscopy, and confocal laser scanning microscopy. They were mostly spherical and ca. 14 μm in diameter and ca. 2 μm in height. The broad range of printable elements allows for the micro preparation of solid compounds for establishing a grazing incidence X-ray diffraction analysis library. As an example, the MgAl2O4 spinel was synthesized by printing of the formulation and subsequent calcination. Here we show its performance for the preparation of minerals in the context of recycling of critical elements from pyrometallurgical slags.

Morphological and microstructural evolutions of chemical vapor reaction-fabricated SiC under argon ion irradiation

Chemical vapor reaction (CVR) fabricated-SiC samples were irradiated with 300 keV Ar2+ ions in the fluence range of 5 × 1015 –1 × 1017 ions·cm−2. Raman spectrum and grazing incidence X-ray diffraction analysis display amorphization and lattice expansion of the irradiated CVR-SiC. Transmission electron microscope observations show that small black spots with an average diameter of 1.5 nm are formed at a low fluence of 5 × 1015 ions·cm−2. Moreover, large argon bubbles with an average diameter of 15.1 nm are formed at a high fluence of 1 × 1017 ions·cm−2, and the Ar concentration threshold for bubble formation is 8.83 at.%. The influence of implantation amorphization and Ar atom migration in CVR-SiC on the formation of Ar bubbles is discussed. The results provide a basis for understanding the noble-gas-induced irradiation behavior of CVR-SiC for preventing irradiation damages in future nuclear applications.

The effect of sputtering power on structural, mechanical, and electrical properties of Copper Selenide Thermoelectric thin films deposited by magnetron sputtering

Copper Selenide (Cu2Se) has received much attention as a potential thermoelectric and environmentally friendly material because of its exceptional thermoelectric performance. This study shows how Cu2Se thin films' structural, morphological, mechanical, and electrical properties are affected by varying the sputtering power deposited by radio frequency magnetron sputtering. By varying the sputtering power, the as-deposited Cu2Se thin film thickness values ranged from 436 to 1139 nm, measured by the stylus profilometer. Grazing incidence X-ray diffraction analysis was conducted to ascertain the phases present in the deposited films. It was observed that at higher sputtering power of 110 W, the Cu2-xSe phase was formed. Field Emission Scanning Electron Microscopy studies revealed that Cu2Se thin films deposited under varying sputtering power possess well-defined crystallinity with uniform distribution over the glass substrate. The grain size of the films increased with an increase in sputtering power. The nanoindentation studies showed that with varying sputtering power from 30 W to 110 W, hardness increased, having a maximum value of 2.4 ± 0.47 GPa for 110W sputtered film. The highest power factor of 15.6 μ W/cmK2 was achieved for a 110 W sputtered sample measured at a temperature of 450 °C, which is higher than that of all Cu2Se thin films, sputtered at different power.

Compositional mapping of Mo-doped ZnO thin films: Mechanical, nano-surface and ToF-SIMS analyses

ZnO and Mo-doped ZnO thin films were grown using the spray pyrolysis process with variations in Mo doping concentrations. The films were characterized with a comprehensive compositional analysis, including electron dispersive X-ray (EDX), X-rays photoelectron spectroscopy (XPS), and time-of-flight secondary ion mass spectrometry (ToF-SIMS), along with grazing incidence X-ray diffraction(GIXRD), atomic force microscopy (AFM), scanning electron microscopy (SEM) and UV–Vis spectroscopy to investigate their structural, morphological, optical and chemical compositions. Micro-hardness analysis was performed on films as a function of the Mo content. GIXRD analysis detected the presence of characteristic peaks of ZnO along the (100), (002) and (101) planes. The presence of Zn, O, and Mo in the synthesized samples was revealed by EDX, XPS, and ToF-SIMS results, which matched the experimental values of a pure and Mo:ZnO-x composition. XPS analysis revealed the Mo6+ oxidation state of molybdenum present in Mo:ZnO films. From UV–Vis absorption spectroscopy, the bang gap was observed to increase with Mo content, up 5 at.%, and located in the 3.18 – 3.24 eV interval. These results will be helpful in the synthesis of Mo:ZnO films for relevant applications, including sensing, optoelectronics and antimicrobial.

2D-monolayer formation of 3-monoacyl-sn-glycerols at the air/water interface. A comprehensive quantum chemical approach

Thermodynamic and structural aspects of the monolayer film formation of 3-monoacyl-sn-glycerol homologous series with the alkyl chain length n = 7–18 at the air/water interface are considered. The calculations are carried out within the framework of the semiempirical quantum chemical method PM3 and supported experimentally using surface pressure-area per molecule (π–A) isotherms, Brewster angle microscopy (BAM), as well as grazing incidence X-ray diffraction analysis (GIXD). A conformational analysis of 3-monoacyl-sn-glycerol monomers reveals three stable conformations of monomers with Monomer 1 as the possible basis for the construction of the most energetically advantageous structures of small clusters, which subsequently can form a 2D monolayer. Optimized tetramer structure of 3-monoacyl-sn-glycerol is considered as a unit cell of the 2D film with geometric parameters: a= 4.82 Å, b= 4.92 Å, and the angle between them θ = 91°. The molecular tilt angle of surfactant molecules with respect to the normal to the interface is 23.5°. These structural parameters are in good agreement with existing experimental data. The spontaneous clusterization threshold of 3-monoacyl-sn-glycerol at the air/water interface is 16 carbon atoms in the alkyl chain at standard temperature. The temperature dependences of the Ac area per film molecule at the beginning of the liquid-expanded–liquid-condensed (LE–LC) phase transition are analyzed. The values of the Ac change per 1 °C for 3-monoacyl-sn-glycerol are commensurable with corresponding values of other surfactant classes confirming the dominating role of intermolecular CH···HC interactions in the clusterization energy of surfactants.

Influence of Near-Surface Severe Plastic Deformation on the Corrosion Behavior of GTD-111 Nickel Superalloy in Hydrofluoric Acid Solution

High-energy shot peening (HESP) as a common near-surface severe plastic deformation (NS-SPD) was used to create a severely deformed surface with ultrafine grains and dense crystallographic defects (e.g., grain boundaries, dislocations, and twins) on GTD-111 Ni superalloy. The fluoride-induced corrosion performance of HESPed GTD-111 and its solution-annealed counterpart is comparatively studied using immersion tests, grazing-incidence x-ray diffraction analysis, electrochemical techniques, and glow discharge optical emission spectroscopy (GDOES). As supported by the immersion tests and electrochemical measurements, HESPed GTD-111 exhibits corrosion film with higher resistance and lower passivity current density at the expense of a higher initial corrosion rate. Both samples suffer pitting corrosion; however, the solution-annealed one shows deeper and larger pits. The dense distribution of crystallographic defects on the surface of the HESPed sample significantly increases the diffusion of alloying elements to the corrosion front. The GDOES depth profiles reveal that (i) a thicker corrosion film with a higher contribution of alloying elements (namely, Cr, Ti, Co, and Al) is developed on the HESPed sample, and (ii) the corrosion films formed on the solution-annealed and HESPed samples consist of an outer F-rich part and an inner O-rich region. The protective mechanism of NS-SPD is discussed by a physical model.

Substrate temperature: A governing factor for the structural, mechanical and chemical properties of sputtered CrAlN ternary coating

In this article, the effect of substrate temperature towards the structural, microstructural and mechanical properties of the Chromium-Aluminium-Nitride (CrAlN) films deposited on Si (100) and SS-304 substrates by Radio frequency magnetron sputtering was investigated. Different characterization techniques like Grazing Incidence X-Ray Diffraction (GIXRD), Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X-Ray Spectroscopy (EDS), Nanoindentation, etc. were carried out for establishing structural-mechanical property relationship. From GIXRD analysis, it was confirmed that the films exhibited FCC NaCl type structure with primary orientation along (200) direction. The grain size is in slightly increasing order till 300 °C and then it decreased, reaching the lowest value for the film deposited at 500 °C. After finding the ideal load for hardness measurement using load-variation analysis in nanoindentation, the hardness and elastic modulus measurements were carried out. The coating deposited at 400 °C showed the best mechanical properties having hardness and elastic modulus values of 22.97 ± 0.47 GPa and 218.72±2.24 GPa respectively. The coating also showed a high elastic recovery of 69.42%, suggesting the possibility of numerous industrial applications of CrAlN coating. High corrosion resistance indicating better chemical stability in all coatings was observed, when corrosion measurements were carried out in 3.5% NaCl solution.

Corrosion interpretation of the novel rare-element bearing bulk metallic glass: Electrochemical, thermodynamic, and surface analysis of the (Cu50Zr43Al7)100-xErx

Bulk metallic glasses (BMGs) have evoked considerable attention in recent years owing to unique properties. However, the surface and anticorrosive properties of this kind of material has not been widely investigated. In this paper, a novel BMG comprises Erbium (Er)-based rare element and high anticorrosive capacity has been introduced. Valorization of Er element (2, 4, 6% at.) in the Cu50Zr43Al7 protective film has been explored from the anticorrosive viewpoint. XRD (X-ray diffraction), GIXRD (Grazing Incidence X-ray Diffraction), AFM (Atomic force microscopy), SEM/EDS (scanning electron microscope/energy-dispersive X-ray spectroscopy), and XPS (X-ray photoelectron spectroscopy) analyses in cooperation with the detailed electrochemical experiments i.e., EIS (Electrochemical Impedance Spectroscopy) and potentiodynamic polarization tests were utilized for surface and corrosion studies. The EIS outcomes have demonstrated that the presence of the Er (at 2% at.) leads to higher corrosion resistance (Rct = 17490 Ω cm2, Rtotal = 7590 Ω cm2) at different time intervals than the other specimens. The proposed mechanism based on surface studies (GIXRD, SEM/EDS, AFM, and XPS) and thermodynamic interpretation imply that the formation of the Er2O3 as a robust protective film along with other types of metal-oxides on the BMG surface is responsible for the high corrosion resistance of this sample.

Investigation of thermally induced changes on structure, morphology and stoichiometry of sputter deposited titanium oxide thin films

We report here tailoring the properties of amorphous titanium oxide (a-TiOx) thin films by changing substrate heating as well as post-annealing. The a-TiOx thin films have been deposited on silicon substrates by direct current magnetron sputtering at a sputter power of 50 W without and with substrate heating (200°C) with no additional oxygen sources. After deposition, the films were annealed in vacuum for 1 hour at 300°C, 400°C, and 500°C. The influence of substrate heating and post-deposition annealing on the structure and surface morphology of the films along with their chemical states has been investigated. X-ray reflectivity analysis revealed that films deposited at 200°C were denser and thinner with low roughness than those deposited without substrate heating. Grazing incidence X-ray diffraction analyses showed that the films before and after annealing were amorphous; except for the ones deposited without substrate heating and were annealed at 500°C which showed slight crystallinity. From field emission scanning electron microscopy and atomic force microscopy images, distinct variations in the morphology of the films were also observed when films were deposited at 200°C X-ray photoelectron spectroscopy analysis showed that the a-TiOx films were oxygen deficient. It was observed that Ti was found in Ti4+ and Ti3+ states in the films and that the proportion of Ti4+ increased when the films were annealed at 500°C. Therefore, the structure, morphology, and chemical states of a-TiOx thin films can be tailored with substrate heating and post-annealing.

Mechanical behavior of ion-irradiated ODS RAF steels strengthened with different types of refractory oxides

One of the most promising candidates for constructing IV generation nuclear reactors is Oxide Dispersed Strengthening (ODS) Reduced Activation Ferritic (RAF) steel. It is known that introducing refractory oxides to the ferritic matrix makes it possible to obtain a brand-new kind of materials with an excellent set of properties. In the present work, the authors focused on verifying materials' structural and mechanical properties strengthened by three different types of refractory oxides submitted to ion-irradiation. Three materials with an elemental chemical composition of 12 %Cr, 2 %W, 0.3 %Ti, and strengthened with 0.3% Y2O3 or Al2O3 or ZrO2 were produced by mechanical alloying and subsequently consolidated by Spark Plasma Sintering technique. Manufactured materials have been submitted to high energy (500 keV) Ar-ion irradiation at room temperature with three fluences (up to 5x1015 ions/cm2). This procedure allowed to generate a thin, strongly damaged zone with approximate thickness of 230 nm. SEM/EBSD and TEM bservations, Grazing Incidence X-ray Diffraction analysis, and nanoindentation tests have been included in examination of modified layers. Implementation of these techniques allowed to reveal alteration of structural and mechanical features between unmodified material and radiation-affected layer. Obtained results showed a strong correlation between the strengthening oxide and materials' microstructural and mechanical behavior under radiation damage. It has been proved that below 1x1015 ions/cm2 mechanical properties in the modified layer of all materials are very similar. Reported behavior may be related to the efficient annealing of the radiation defect process. Above this limit, significant differences between the materials are visible. It is believed that described phenomenon is directly related to the presence of the structural features and their capacity to act as defect sinks. Consequently, type of dominant mechanisms occurring in modified layer is proposed.

Effect of La doping on dielectric constant and tetragonality of ZrO2 thin films deposited by atomic layer deposition

The electrical properties of La-doped ZrO2 thin films were studied for an application to cell capacitors in dynamic random-access memory. La-doped ZrO2 thin films were deposited by changing the ratio of ZrO2:La2O3 cycles using atomic layer deposition. Grazing-incidence X-ray diffraction analysis showed that the La-doped ZrO2 thin films had a tetragonal structure. The tetragonality (c/a) of La-doped ZrO2 thin films increased from 1.41 in undoped ZrO2 to 1.43 in La-doped ZrO2 with a 7.5% La content. X-ray photoelectron spectroscopy showed that the concentration of oxygen vacancies in ZrO2 thin films increased with increasing La concentration. The dielectric constant of La-doped ZrO2 was increased by 15% from 37 in undoped ZrO2 to 43 at a La doping concentration of 7.5%, and the leakage current was also improved. Therefore, La-doped ZrO2 thin films are expected to be an excellent candidate material for dynamic random-access memory cell capacitors owing to their high dielectric constant and low leakage current.

A novel approach to the role of iridium and titanium oxide in deactivation mechanisms of a Ti/(36 RuO2-x IrO2-(64-x) TiO2) coating in sodium chloride solution

Iridium and Titanium oxide are known as the corrosion-resistant and bonding agents for mixed metal oxide coatings. Based on this fact, this study aims to investigate the effect of these oxides on the deactivation mechanisms of a typical Ti/(36RuO2-xIrO2-(64-x)TiO2) in sodium chloride solution. The coating with quantities of 16, 26, and 36 wt. % titanium oxide is applied by thermal decomposition method. Then, a comprehensive analysis is carried out on the coating's morphology and microstructure by electron microscopy, energy dispersive spectroscopy, and grazing incidence X-Ray diffraction analysis. Additionally, cyclic voltammetry, accelerated lifetime test, and electrochemical impedance spectroscopy is performed to investigate the coating's electrochemical properties and corrosion behavior. The results show that the anode with the coating of nominal composition Ti/(36RuO2-38IrO2-26TiO2) provides a nanostructured morphology, solid solutions of (Ru, Ir)O2 and (Ru, Ir, Ti)O2, with maximum lifetime and optimum electrocatalytic activity. This composition results in an improved bonding of the coating components, which delays pitting corrosion of the coating in sodium chloride solution. Ultimately, the predominant corrosion and deactivation mechanism is changed into the general dissolution of the electrocatalytic component which has enhanced durability of the coating.