Area-selective atomic layer deposition of ZnO by area activation using electron beam-induced deposition

Area-selective atomic layer deposition (ALD) of ZnO was achieved on SiO2 seed layer patterns on H-terminated silicon substrates, using diethylzinc (DEZ) as the zinc precursor and H2O as the coreactant. The selectivity of the ALD process was studied using in situ spectroscopic ellipsometry and scanning electron microscopy, revealing improved selectivity for increasing deposition temperatures from 100 to 300 °C. The selectivity was also investigated using transmission electron microscopy and energy-dispersive X-ray spectroscopy. Density functional theory (DFT) calculations were performed to corroborate the experimental results obtained and to provide an atomic-level understanding of the underlying surface chemistry. A kinetically hindered proton transfer reaction from the H-terminated Si was conceived to underpin the selectivity exhibited by the ALD process. By combining the experimental and DFT results, we suggest that the trend in selectivity with temperature may be due to a strong DEZ or H2O physisorption on the H-terminated Si that hampers high selectivity at low deposition temperature. This work highlights the deposition temperature as an extra process parameter to improve the selectivity

Characteristics of social drinkers with and without a hangover after heavy alcohol consumption

Background: A number of social drinkers claim that they do not experience next-day hangovers despite consuming large quantities of alcohol. The aim of this study was to investigate the characteristics of drinkers who claim to be hangover immune and compare them with drinkers who do report having hangovers. Methods: A total of 36 social drinkers participated in a naturalistic study consisting of a hangover day (alcohol consumed) and a control day (no alcohol consumed). Data were collected on alcohol consumption, demographics, sleep, next-day adverse effects, and mood. Data from drinkers with a hangover (N=18) were compared with data from drinkers who claim to be hangover immune (N=18). Results: Drinkers with a hangover reported drowsiness-related symptoms, symptoms related to reduced cognitive functioning, and classic hangover symptoms such as headache, nausea, dizziness, weakness, and stomach pain. Corresponding mood changes comprised increased feelings of depression, anger-hostility, fatigue, and reduced vigor-activity. In contrast, hangover-immune drinkers reported relatively few hangover symptoms, with only mild corresponding severity scores. The reported symptoms were limited to drowsiness-related symptoms such as sleepiness and being tired. The classic hangover symptoms were usually not reported by these drinkers. Conclusion: In contrast to drinkers with a hangover, for those who claim to be hangover immune, next-day adverse effects of alcohol consumption are limited to a mild increase in drowsiness-related symptoms

Recent Developments in Modeling Heteroepitaxy/Heterogeneous Nucleation by Dynamical Density Functional Theory

Crystallization of supersaturated liquids usually starts by epitaxial growth or by heterogeneous nucleation on foreign surfaces. Herein, we review recent advances made in modeling heteroepitaxy and heterogeneous nucleation on flat/modulated surfaces and nanoparticles within the framework of a simple dynamical density functional theory, known as the phase-field crystal model. It will be shown that the contact angle and the nucleation barrier are nonmonotonous functions of the lattice mismatch between the substrate and the crystalline phase. In continuous cooling studies for substrates with lattice mismatch, we recover qualitatively the Matthews–Blakeslee mechanism of stress release via the misfit dislocations. The simulations performed for particle-induced freezing will be confronted with recent analytical results, exploring thus the validity range of the latter. It will be demonstrated that time-dependent studies are essential, as investigations based on equilibrium properties often cannot identify the preferred nucleation pathways. Modeling of these phenomena is essential for designing materials on the basis of controlled nucleation and/or nano-patterning

Atomic Layer Deposition of 2D Metal Dichalcogenides for Electronics, Catalysis, Energy Storage, and Beyond

2D transition metal dichalcogenides (TMDCs) are among the most exciting materials of today. Their layered crystal structures result in unique and useful electronic, optical, catalytic, and quantum properties. To realize the technological potential of TMDCs, methods depositing uniform films of controlled thickness at low temperatures in a highly controllable, scalable, and repeatable manner are needed. Atomic layer deposition (ALD) is a chemical gas-phase thin film deposition method capable of meeting these challenges. In this review, the applications evaluated for ALD TMDCs are systematically examined, including electronics and optoelectonics, electrocatalysis and photocatalysis, energy storage, lubrication, plasmonics, solar cells, and photonics. This review focuses on understanding the interplay between ALD precursors and deposition conditions, the resulting film characteristics such as thickness, crystallinity, and morphology, and ultimately device performance. Through rational choice of precursors and conditions, ALD is observed to exhibit potential to meet the varying requirements of widely different applications. Beyond the current state of ALD TMDCs, the future prospects, opportunities, and challenges in different applications are discussed. The authors hope that the review aids in bringing together experts in the fields of ALD, TMDCs, and various applications to eventually realize industrial applications of ALD TMDCs.Peer reviewe

Insomnia and Stress: Associations with Mental Resilience and Mood

Introduction: The aim of this study was to investigate the association between insomnia symptoms, psychological health, mental resilience, and stress. Methods: A survey was held among young Dutch adults, aged 18 to 30 years old. The insomnia subscale of the SLEEP-50 questionnaire was completed. In addition, prior night\u27s bedtime, time of sleep onset, and arising time were recorded. Psychological wellbeing was assessed using the 5-item World Health Organization (WHO-5) Well-Being Index and mental resilience was assessed using the Brief Resilience Scale. Mood was assessed with the short-form Profiles of Mood States (POMS-SF), and the Depression Anxiety Stress scale (DASS) and Eysenck personality questionnaire scales of extraversion and neuroticism were completed. Insomnia scores were associated with sleep and mood and personality outcomes. In addition, mood and personality of those who screen positive for insomnia (score \u3e; 19) were compared to those who score negative for insomnia. Results: N=2489 subjects completed an online survey. Of them, 83.4% were women (N=2075). Insomnia score correlated significantly (p\u3c0.0001) with sleep quality (r =-0.720), number of nightly awakenings (r = 0.489), and sleep onset latency (r = 0.552), but not with total sleep time. The insomnia score correlated significantly with all psychological, mood and health assessments (p\u3c0.05). Those who screened positive for insomnia (i.e. a score\u3e;19) scored significantly lower (p\u3c0.0001) on general health, wellbeing, and mental resilience, extraversion, and the POMS-SF mood scale vigor-activity. They scored significantly higher on the DASS stress, anxiety and depression scales, neuroticism, and the POMS-SF mood scales tension-anxiety, depression, anger-hostility, and fatigue. The observed differences and associations were significantly more pronounced in women when compared to men. Conclusion: Insomnia is associated with poorer psychological health and mood, reduced metal resilience, and increased levels of stress, anxiety and depressive symptoms

Area-Selective Atomic Layer Deposition of Two-Dimensional WS2 Nanolayers

With downscaling of device dimensions, two-dimensional (2D) semiconducting transition metal dichalcogenides (TMDs) such as WS 2 are being considered as promising materials for future applications in nanoelectronics. However, at these nanoscale regimes, incorporating TMD layers in the device architecture with precise control of critical features is challenging using current top-down processing techniques. In this contribution, we pioneer the combination of two key avenues in atomic-scale processing: area-selective atomic layer deposition (AS-ALD) and growth of 2D materials, and demonstrate bottom-up processing of 2D WS 2 nanolayers. Area-selective deposition of WS 2 nanolayers is enabled using an ABC-type plasma-enhanced ALD process involving acetylacetone (Hacac) as inhibitor (A), bis( tert-butylimido)-bis(dimethylamido)-tungsten as precursor (B), and H 2S plasma as the co-reactant (C) at a low deposition temperature of 250 °C. The developed AS-ALD process results in the immediate growth of WS 2 on SiO 2 while effectively blocking growth on Al 2O 3 as confirmed by in situ spectroscopic ellipsometry and ex situ X-ray photoelectron spectroscopy measurements. As a proof of concept, the AS-ALD process is demonstrated on patterned Al 2O 3/SiO 2 surfaces. The AS-ALD WS 2 films exhibited sharp Raman ( E 2 g 1 and A 1g) peaks on SiO 2, a fingerprint of crystalline WS 2 layers, upon annealing at temperatures within the thermal budget of semiconductor back-end-of-line processing (≤450 °C). Our AS-ALD process also allows selective growth on various TMDs and transition metal oxides while blocking growth on HfO 2 and TiO 2. It is expected that this work will lay the foundation for area-selective ALD of other 2D materials

Investigating the difference in nucleation during Si-based ALD on different surfaces for future area-selective deposition

Area-selective atomic layer deposition (AS-ALD) allows nanostructures of arbitrary composition and lateral shape to be built with atomic precision on pre-selected substrate locations. Most current approaches for AS-ALD are based on local inhibition (e.g. with self-assembled monolayers) or activation. However, for some applications of AS-ALD (e.g. in self-aligned fabrication) it is relevant to be able to exploit differences in chemical behavior of a pre-patterned substrate. For this reason, investigating inherent differences in nucleation on diverse substrates is of crucial importance for developing future AS-ALD processes. In this paper we are focussing on substrates of silicon and silicon-based dielectric materials (SiC, Si0 2 and SiNx) used in electronics. </p