Step Coverage Research Articles

Reconnecting River-City: A Visibility and Accessibility Assessment of the Ping River’s View Characters in Chiang Mai City

A river’s landmarks have advantages in attracting people to engage with natural/historical settings. However, uncontrolled development can have negative effects on the visual and obstruct people’s access. In this context, researchers have highlighted obstacles to these landmarks and suggested features of the relationship between the visibility and accessibility to these landmarks, aiming to preserve heritage sites. This project evaluated riverscape landmarks to develop a strategic urban design that uses scientific and spatial toolkits to maintain the historic landmark on the riverside in Chiang Mai city. The methodology utilized for GIS included visibility and accessibility assessments as variables for analyzing interconnections and classification utilizing the statistical method of hierarchical clustering analysis (HCA). The findings indicate differences in the accessibility of angular step coverage (ASC) and walking distance coverage (WDC), which have an impact on landmark designation. The city-level landmarks have the highest ASC, while various religious landmarks display the highest visibility. These factors have a unique impact on the HCA results, which are categorized into six groups that are consistent with the historical content and purpose of the landmarks. The clustered groups represent the strategic design of the riverscape, which necessitates policies to enhance the potential for preserving these icons as part of the historic landscape.

Impact of plasma power on plasma enhanced atomic layer deposited TiO2 as a spacer

As the size of devices is scaled down, micro-patterning technology is increasing in importance. In micro-patterning, spacers require precise thickness and uniform deposition at low temperature. To meet these requirements, atomic layer deposition (ALD), which can be controlled to an accurate thickness, was introduced. Therefore, we investigated plasma-enhanced ALD using radicals for high reactivity. Optical emission spectroscopy and a Langmuir probe were used to evaluate plasma properties such as radical intensity and plasma density at different plasma powers. Regardless of plasma power, growth per cycle and compositions of Ti and O remained constant. X-ray photoelectron spectroscopy showed that application of 500 W decreased the area of Ti2O3 from 20.2 % to 4.5 % compared with 100 W due to the increased amount of oxygen radicals. X-ray reflectivity results showed a 4.09 g/cm3 density of TiO2 film at 100 W, which increased to 4.2 g/cm3 at 500 W, indicating a decrease of Ti2O3. Meanwhile, the wet etch rate of TiO2 film was 1.72 Å/min at 100 W and 0.8 Å/min at 500 W, and the denser film had superior etch resistance. Finally, transmission electron microscopy showed that step coverage of TiO2 films improved from 90.9 % to 99.9 % with increasing power. Thus, application of high power effectively improved the properties of TiO2 films.

Printed Interconnects for Heterogeneous Systems Integration on Flexible Substrates

AbstractHeterogeneous integration on flexible substrates has been explored in recent years to meet the high‐performance and flexible form factors requirements of several emerging applications. Reliable interconnects, in both 2D and 3D layouts, are critical for the effective use of these systems. But it is challenging to employ conventional bonding and interconnect technology due to considerable mismatches in mechanical and thermal properties. For example, the ultra‐thin chips (UTCs) are too fragile to withstand the static or oscillating forces applied during conventional bonding. In this regard, printing of metal tracks on flexible substrates is a promising alternative to access the contact pads on integrated circuits (ICs), as the interconnects on diverse substrates can be realized at room temperature processing using as much materials as needed. Further, it is easier to attain step coverage. Considering the above attractive features, and the challenges associated with conventional bonding techniques, this article focuses on the development of high‐resolution printing interconnects in both 2D and 3D layouts and explores various printing routes available for high density integration. The article also discusses major conventional interposers/interconnects forming methods and their limitations for flexible hybrid electronics along with few examples of printed interconnects to highlight the opportunities for future.

Modulation of the morphological and optical properties of CVD grown non-Stochiometric [formula omitted] nanostructures by various substrate angles

Gallium oxide (Ga2O3) nanostructures (NSs) were synthesized via atmospheric pressure chemical vapor deposition (APCVD) technique assisted by hydrogen. The geometrical orientation in terms of the substrate angle was studied to investigate its influence on the morphological, compositional and optical properties of the material. The results revealed that the geometry, stoichiometry and optical parameters of Ga2O3 could be tuned by substrate angle variations during deposition. Tilting the substrate was found to enhance the step coverage of the substrate and the Ga/O atomic ratio above the stoichiometric value. Bandgap of the films was observed to vary inversely (ranged between 4.590 and 4.664eV) to the Ga/O atomic ratio. The refractive index at wavelength of 632.8 nm, dispersion and single oscillator energy of the prepared films were also evaluated, and were found to be in the range of 2.129–3.265, 20.952–56.520eV and 5.309–6.387eV, respectively, with the increase of substrate angle.

High-temperature atomic layer deposition of silicon oxide films using Tris(dimethylamino)silane and ozone

Atomic layer deposition (ALD) benefits from high process temperatures when the substrate is not temperature-sensitive because the films deposited at higher temperatures exhibit better electrical properties. In this study, we investigated the ALD process of silicon oxide films by alternating injections of tris(dimethylamino)silane (tris-DMAS) and O3/O2 at temperatures ranging from 400 to 700 °C. The saturation dose of tris-DMAS was 1.5 × 106 L at 400 °C. Self-limiting growth with a growth rate of approximately 0.9 Å/cycle was observed up to 600 °C, allowing excellent step coverage. However, at 700 °C, the growth rate increased significantly to 4.6 Å/cycle, carbon and nitrogen impurities were detected by secondary ion mass spectrometry, and step coverage was poor, supporting the thermal decomposition of tris-DMAS at this temperature. Therefore, the optimum temperature for ALD SiO2 using tris-DMAS is 600 °C for application as an insulating film on high aspect ratio patterns. At this temperature, the leakage current density was 0.58 nA/cm2, and the oxide-trapped charge density was 4.0 × 1010 cm−2.

First-Principles computation-driven mechanism study of tungsten growth on alumina surfaces with TiN nano-islands

Strong comprehension of the tungsten film deposition process on Al2O3 substrate with TiN adhesion layer is essential to achieve high quality metal gate, but the fundamental mechanism of this process is yet to be fully understood. This study employs first-principles density functional theory (DFT) calculations to explore the mechanisms of tungsten film growth on alumina surfaces while focusing on amorphous/α-Al2O3 and interfaces with TiN nano-islands. Tungsten atoms are strongly bonded on the Al2O3/TiN interface compared to their bonding on the Al2O3 or TiN surface, regardless of the crystallinity of Al2O3. Moreover, amorphous Al2O3 surfaces exhibit stronger adsorption energies and present higher diffusion barriers for tungsten atoms compared to their crystalline counterparts, α-Al2O3, and TiN surfaces, which were also confirmed by electronic structure analysis. This enhanced adhesion on amorphous substrates suggests a potential pathway through which improve the step coverage and uniformity of tungsten thin films while addressing common issues such as void formation and non-uniform layering in high-aspect-ratio structures. Post-deposition annealing can help create crystalline tungsten films with superior conductivity. The insights gained from this work offer a computational perspective on the atomic-level interactions governing tungsten deposition, and they are expected to help producing high-quality thin films in semiconductor technologies.

Synthesis of high conformalty Ti-Six-N films using (CH3)3CCl and SiH4; density functional theory simulation and film characterization

The step coverage of the atomic layer deposition (ALD) of Ti-N thin films was improved by the addition of (CH3)3CCl, and Si atoms were added during the Ti-N deposition to form a Ti-Six-N thin film. By ALD, four to eight cycles of the gas (CH3)3CCl/TiCl4/NH3 formed the Ti-N layer and, subsequently, one to two cycles of the gas SiH4/NH3 added Si atoms to formed the Ti-Six-N layer. The ALD process was repeated to form a thin film Ti-Six-N 150 Å (bilayer of (Ti-N) 80 Å + (Six-N) 70 Å) while adjusting the amounts of (CH3)3CCl and SiH4. The crystallinity of Ti-N was studied by X-ray diffraction (XRD), and its composition was studied using X-ray photoelectron spectroscopy and secondary ion mass spectrometry. The composition of the Ti-Six-N film was studied using electron energy loss spectroscopy and selected area electron diffraction, and its roughness was confirmed using atomic force microscopy. Transmission electron microscope was used to measures the thickness and composition of the Ti-Six-N film through location in a test pattern with an aspect ratio of 50:1. Step coverage improved to 99.9 % compared to conventional ALD Ti-N when using (CH3)3CCl. Additionally, (CH3)3CCl was more effective at lower temperatures (460 °C compared to 530 °C), and the effect of the (CH3)3CCl flow rate was saturated above 300 sccm.As the amount of (CH3)3CCl increased, the growth per cycle decreased from 0.29 Å/cycle to 0.15 Å/cycle. The addition of Si to the Ti-N film facilitated leakage gain by increasing the difference in the work function between the electrode and the capacitor, material but may have the side effect of pillar bending due to a decrease in crystallinity and hardness. We verified that the XRD (200)/(111) peak ratio decreased as the Si content increased. As a result, the optimal conditions for electrode Ti-Six-N were confirmed as follows: 300 sccm (CH3)3CCl Ti-N, SiH4 10 sccm Six-N combination.Furthermore, the Ti-Six-N layer can serve as the bottom electrode of a capacitor reduce the manufacturing process steps, and be a candidate for a solution for the electrode of the capacitor of a 5 nm node memory device.

Effects of oxygen sources on the growth characteristics and dielectric properties of atomic-layer-deposited TiO2 films for aluminum electrolytic capacitors

TiO2 is a promising high dielectric material which can be introduced into aluminum anode foils for realizing miniaturization, lightweight, and high quality of aluminum electrolytic capacitors because of its excellent permittivity. However, the complex porous framework of etched aluminum foil gives rise to the low step coverage and residual carbon impurities of TiO2 films, which can restrict the specific capacitance improvement. In this work, the TiO2 films were deposited by atomic layer deposition (ALD) using O3, O2 plasma (O2*), H2O as oxygen sources, respectively. The effects of oxygen sources on step coverage, carbon impurity content, crystalline structure, oxygen vacancies (OVs) concentration and band gap (Eg) of TiO2 films were studied. Besides, the capacitor performances of aluminum foils were investigated. The O3–TiO2 films showed the best conformability and the least carbon impurity content, while the O2*-TiO2 films exhibited the lowest step coverage due to the directionality of plasma. And the highest carbon impurity content in H2O–TiO2 films was caused by the poor reactivity of H2O. Moreover, the anatase TiO2 peak intensity of H2O–TiO2 films through sintering and anodization was the highest due to the highest deposited mass. The O3–TiO2 films were found to be optimally insulating by characterization of OVs concentration and Eg. Surprisingly, the composite dielectric films using O3 as oxygen source exhibited the excellent withstanding voltage of 21.9 V, while the specific capacitance of 159.9 μF cm-2 was maintained, and there were about 45.89% and 33.63% enhancements in the specific capacitance and CV compared with those without TiO2. These outstanding properties demonstrate that O3 is more favorable for depositing high-performance ALD TiO2 films on aluminum electrolytic capacitors.

양자점 디스플레이 분야에서의 원자층증착법 응용

Atomic layer deposition (ALD) is gaining traction in the semiconductor industry due to its ability to meet the demands of high aspect ratios and densities. This is attributed to its excellent step coverage and uniformity, which are based on the self-limiting deposition process. Its applications have expanded to include various components such as memory device capacitors, gate oxides, metal barriers, and charge transport channels. Moreover, ALD is being explored for diverse purposes not only within the semiconductor field but also in displays and optoelectronics. This review aims to explore the versatility of ALD deposition methods, widely utilized in the semiconductor industry, and their potential applications in the display and optoelectronics sectors. Additionally, we present future prospects for ALD applications in display based on current approaches.

Tailoring indium oxide film characteristics through oxygen reactants in atomic layer deposition with highly reactive liquid precursor

Indium oxide (InOx) films were deposited via atomic layer deposition (ALD) using a novel liquid indium precursor, dimethyl[N1-(tert-butyl)–N2,N2-dimethylethane-1,2-diamine]indium (DMITN). In this process, the reactant (H2O, O3, or O2 plasma) and substrate temperature (100–250 ℃) were varied. The DMITN precursor showed excellent reactivity with all three reactants. The growth characteristics (ALD window, growth per cycle, and step coverage) and film properties (impurities, stoichiometry, oxygen bonding state, crystallinity, film density, and electrical properties) differed based on the ALD process employed, ascribed to the distinct thermal energies and inherent reactivities of the chosen oxidants. As the oxidation energy of the reactants increased (H2O < O3 < O2 plasma), the growth per cycle (GPC) and the oxygen–indium bond ratio of InOx increased. Crystallinity analysis also revealed significant differences depending on the reactants, where the Hall mobility was predominantly influenced by the crystal alignment. The step coverage at an aspect ratio of 40:1 was markedly superior with the use of H2O and O3 reactants (approximately 95 %) compared to that with O2 plasma (approximately 74 %). These findings highlight the capability of controlling the growth and properties of InOx films by judiciously selecting the reactant, emphasizing the versatility of the DMITN precursor in ALD processes.

Multi-objective model transformation chain exploration with MOMoT

Context:The increasing complexity of modern systems leads to an increasing amount of artifacts that are used along the model-based software and systems development lifecycle. This also includes model transformations, which serve for mapping models between representations, e.g., for verification and validation purposes. Objectives:Model repositories manage this variety of artifacts and promote reusability, but should also enable the bundling of compatible artifacts. Therefore, model transformations should be reused and arranged into transformation chains to support more complex transformation scenarios. The resulting transformation should correspond to the user’s interest in terms of quality criteria such as model coverage, transformation coverage, and number of transformation steps, thus assembling such chains becomes a multi-objective problem. Methods:A novel multi-objective approach for exploring possible transformation chains residing in model repositories is presented. MOMoT, a model-driven optimization framework, is leveraged to explore the transformation space spanned by the repository. For demonstration, three differently populated repositories are considered. Results:We have extended MOMoT with an exhaustive, multi-objective search that explores the entire model transformation space defined by graph transformation rules, allowing all possible transformation chains to be considered as solution. Accordingly, the optimal solutions were identified in the demonstration cases with negligible computation time. Conclusion:The approach assists modelers when there are multiple chains for transforming an input model to a specified output model to consider. Our evaluation shows that the approach elicits all legitimate transformation chains, thus enabling the modelers to consider trade-offs in view of multiple criteria selection.

The IndagApp mobile app: an inquiry-based science teaching resource: usability evaluation with pre-service teachers

Virtual laboratories and simulations have emerged as innovative solutions for science teaching. However, existing resources have various limitations and constraints including cognitive load/mental burden and limited coverage of all necessary steps in scientific inquiry, focusing mainly on the experimental simulation. To bridge this gap and address these challenges, the present study introduces the design and usability evaluation of IndagApp, an innovative educational resource explicitly developed to support inquiry-based science teaching. A convergent mixed methods design and a convenience sampling of 90 pre-service teachers were used. The findings indicate that IndagApp exhibits a high level of technological and pedagogical usability. Feedback from the users was incorporated to improve the app, resulting in its final version, which incorporates best practices from existing literature on authentic inquiry-based science teaching. IndagApp is freely accessible in the Spanish language, and compatible with Android 5.0 + smartphones and tablets, as well as PCs running Windows 7 or above operating systems. This research provides a timely and significant educational resource that may assist educators in enacting reform-oriented teaching practices.

Plasma enhanced atomic layer deposition of silicon nitride using magnetized very high frequency plasma

To obtain high-quality SiN x films applicable to an extensive range of processes, such as gate spacers in fin field-effect transistors (FinFETs), the self-aligned quadruple patterning process, etc, a study of plasma with higher plasma density and lower plasma damage is crucial in addition to study on novel precursors for SiN x plasma-enhanced atomic layer deposition (PEALD) processes. In this study, a novel magnetized PEALD process was developed for depositing high-quality SiN x films using di(isopropylamino)silane (DIPAS) and magnetized N2 plasma at a low substrate temperature of 200 °C. The properties of the deposited SiN x films were analyzed and compared with those obtained by the PEALD process using a non-magnetized N2 plasma source under the same conditions. The PEALD SiN x film, produced using an external magnetic field (ranging from 0 to 100 G) during the plasma exposure step, exhibited a higher growth rate (∼1 Å/cycle) due to the increased plasma density. Additionally, it showed lower surface roughness, higher film density, and enhanced wet etch resistance compared to films deposited using the PEALD process with non-magnetized plasmas. This improvement can be attributed to the higher ion flux and lower ion energy of the magnetized plasma. The electrical characteristics, such as interface trap density and breakdown voltage, were also enhanced when the magnetized plasma was used for the PEALD process. Furthermore, when SiN x films were deposited on high-aspect-ratio (30:1) trench patterns using the magnetized PEALD process, an improved step coverage of over 98% was achieved, in contrast to the conformality of SiN x deposited using non-magnetized plasma. This enhancement is possibly a result of deeper radical penetration enabled by the magnetized plasma.

Current-Dependent Resistance in TES Wiring Superimposed Nb Striplines

During the characterization of the demonstration model of the Cryogenic AntiCoincidence (CryoAC) Detector (ACS-10), a current-dependent parasitic resistance was found in series with the TES network on board the detector. Analysis was possible because the resistance rises for currents above 11 μ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mu$$\\end{document}A, and is therefore not observed at low bias excitation. A comparison of measurements of the TES across its Nb wiring at different temperatures suggested that the source of resistance was in the wiring and not in the TES network. After several analysis of the wiring fabrication steps, FIB-FE-SEM studies of film sections and tests of niobium film quality, we understood that the parasitic resistance was due to point contact in the Nb step coverage caused by film cracks. The fracture was due to the wall steepness and thickness of the films, since rapid step coverage is less mechanically stable and the stress on the films is proportional to the fourth power of the thickness. Therefore, all thicknesses in the wiring were reduced to the minimum optimum step coverage values and the first negative lithography parameters were optimized to reduce the wall film angle. The samples after this optimization showed no current-dependent series resistance to TES.

C-Axis Aligned Composite InZnO via Thermal Atomic Layer Deposition for 3D Nanostructured Semiconductor.

Amorphous oxide semiconductors have been widely studied for various applications, including thin-film transistors (TFTs) for display backplanes and semiconductor memories. However, the inherent instability, limited mobility, and complexity of multicomponent oxide semiconductors for achieving high aspect ratios and conformality of cation distribution remain challenging. Indium-zinc oxide (IZO), known for its high mobility, also faces obstacles in instability resulting from high carrier doping density and low ionization energy. To address these issues and attain a balance between mobility and stability, adopting a highly aligned structure such as a c-axis aligned crystalline IGZO could be advantageous. However, limited studies have reported enhanced electrical performance using crystalline IZO, likely attributed to the high thermal stability of the individual components (In2O3 and ZnO). Here, we first propose a c-axis aligned composite (CAAC) IZO with superior TFT properties, including a remarkable performance of field-effect mobility (μFE) of 55.8 cm2/(V s) and positive-bias-temperature-stress stability of +0.16 V (2 MV/cm, 60 °C, 1 h), as well as a low subthreshold swing of 0.18 V/decade and hysteresis as 0.01 V, which could be obtained through optimization of growth temperature and composition using thermal atomic layer deposition. These results surpass those of TFTs based on nanocrystalline/polycrystalline/amorphous-IZO. We conducted a thorough investigation of CAAC-IZO and revealed that the growth temperature and cation distribution profoundly influence the crystal structure and device properties. Finally, we observed excellent compositional conformality and 97% step coverage of IZO on a high-aspect-ratio (HAR) structure with an aspect ratio reaching 40:1, which is highly promising for future applications. Our results include a detailed investigation of the influence of the crystal structure of IZO on the film and TFT performance and suggest an approach for future applications.

Atomic layer deposition of multicomponent amorphous oxide semiconductors with sequential dosing of metal precursors

Atomic layer deposition (ALD) is a suitable method for depositing amorphous oxide semiconductors (AOSs) because it has the potential for achieving high performance in complex structures owing to its excellent step coverage and atomic-scale controllability. Multicomponent AOSs are typically deposited using the ALD with a super-cycle method. In this study, multicomponent AOSs, i.e., IZO, ITO, and ITZO, were deposited using ALD by employing a sequential dosing of metal precursors. Their compositions were adjusted by varying the dose time of the indium precursor. Subsequently, we applied the IZO, ITO, and ITZO films in thin-film transistors (TFTs), which demonstrated normal transfer characteristics. The TFT containing ITZO with 73.9 at% indium exhibited a turn-on voltage of −1.01 V, subthreshold swing of 0.09 V/dec, and field-effect mobility of 35.9 cm2/(V s).

Growth of conformal TiN thin film with low resistivity and impurity via hollow cathode plasma atomic layer deposition

Copper has been used as an interconnect material in integrated semiconductor devices because of its excellent conductivity, mechanical strength, and electromigration resistance. Introducing a diffusion barrier layer using transition metals such as Ti, Ta, W, Mo, and their nitrides can effectively prevent copper diffusion into the transistor region. TiN is widely used as the diffusion barrier. Plasma-enhanced atomic layer deposition (PEALD), which uses plasma to activate molecular reactions, can be used to fabricate high-quality thin films at lower temperatures than thermal atomic layer deposition. However, its high electrical resistivity and poor step coverage are disadvantageous for its adoption in highly scaled three-dimensional structures. In this study, TiN thin films were fabricated using PEALD with a hollow cathode plasma (HCP) source. The fabricated TiN exhibited a high density (5.29 g/cm3), which was very close to the theoretical density of TiN. Moreover, it has low electrical resistivity (132 μΩ cm) and excellent step coverage (&amp;gt;98%) in a trench pattern with a high aspect ratio of 32:1. These results suggest the possible application of the PEALD of TiN films using HCP sources in semiconductor device manufacturing.

Fabrication of the low-k films with tunable k value as spacers in advanced CMOS technology

In advanced CMOS technology, a suitable spacer scheme is crucial to alleviate the effects of increasing parasitic resistance and capacitance on device performance as the critical dimensions shrinking. Low dielectric constant (low-k) films, possessing a tunable k value ranging from 3.5 to 6.5, were fabricated using plasma-enhanced atomic layer deposition in a single chamber. The fabrication process involved the deposition of the SiN film via SiH2I2 with N2 plasma, as well as the deposition of the SiOX, SiOCN, and SiON films using diisopropylamino silane with O2, Ar/O2, and N2/O2 plasmas, respectively. The introduction of groups containing carbon (C) tended to loosen the film structure, due to its weak bond strength with Si, thus made distinctions in structural and electrical stability. We developed such a process which can adjust the C-group concentration and O, N content to tune the film k value. The SiOx, SiOCN, SiON, and SiN films had high breakdown strength of 9.04, 7.23, 9.41, and over 11 MV cm−1, and meanwhile low leakage current density of 2.42 × 10−9, 4.78 × 10−8, 1.29 × 10−9, and 9.26 × 10−10 A cm−2, respectively. The films exhibited remarkable thermal stability, enhanced breakdown strength, and suppressed leakage with annealing treatment, which could be attributed to the desorption of —CHX groups. Moreover, the low-k materials demonstrated excellent step coverage both in the inner-spacer cavity and on sidewalls, exploring the potential application as spacers in advanced CMOS structure.

Effect of Surface Pretreatment to Reduce the Incubation Period of Iridium Thin Films Grown by ALD on the Oxide Surface

Iridium (Ir) has low figure of merit(×λ) and high melting temperature properties, so it has been recently spotlighted as a very important copper (Cu) alternative interconnect material in next-generation semiconductor devices. In particular, in the case of depositing a thin film using atomic layer deposition (ALD) technology, it can be expected to deposit extremely thin film with conformal, uniform and excellent step coverage characteristics even in a very complex structure or a trench structure of several nm dimension due to the inherent self-limiting characteristic of ALD. In this regard, ALD-Ir is considered as one of the most suitable metallization process for the application of advanced semiconductor interconnects. Therefore, considerable efforts have been conducted to develop a reliable ALD-Ir process having improved film qualities. And, ALD-Ir process with excellent thin film properties such as low electrical resistivity and negligible oxygen impurities was recently reported using Tricarbonyl (1,2,3-η)-1,2,3-tri(tert-butyl)-cyclopropenyl iridium (C18H27IrO3 or TICP) precursor and oxygen [1]. However, in the case of this TICP precursor, it was difficult to deposit extremely thin and continuous Ir films on the hydroxyl-terminated oxide layer due to its long incubation delay.Therefore, in this study, a method for depositing a very thin, uniform and continuous ALD-Ir thin film with low resistivity even on oxide materials was explored by reducing the incubation period and promoting nucleation using various surface pretreatment conditions. In addition, the nucleation behavior as well as film properties of ALD-Ir on the oxide material were systemically compared and analyzed according to the surface pretreatment conditions, and finally, ALD-Ir thin film with excellent properties on the oxide surface was obtained.

Enhancement of Conformality of Silicon Nitride Thin Films by ABC‐Type Atomic Layer Deposition

AbstractAtomic layer deposition (ALD) is utilized for the fabrication of miniaturized electronic devices with nanometer‐scale features. However, the conventional ALD process on high‐aspect‐ratio (HAR) substrates often results in the deposition of thin films with suboptimal conformality over the depth of the trench structures. This study introduces an ABC‐type ALD of silicon nitride (SiNx) employing vapor‐deliverable tert‐butyl chloride (TBC) as a surface inhibitor. Herein, density functional theory (DFT) calculations elucidate the surface reaction mechanisms, confirming the inhibition of the Si precursor by the t‐butyl moiety. Notably, the ABC‐type ALD exhibits reduced growth per cycle relative to the conventional process while avoiding detectable carbon contamination in the SiNx thin films. Applying this process to substrates with trench structures revealed a substantial improvement in conformality following the introduction of TBC. Furthermore, the step coverage of the deposited SiNx can be modulated by adjusting TBC exposure, enabling greater film thickness at the bottom than that at the top of the trench. The proposed method of modulating ALD processes holds potential for the high‐volume manufacturing of semiconductor devices with HAR structures.