bluuebunny/crossref_metadata_2025 huggingface dataset:
Makine Öğrenmesi Teknikleri ile Counter-Strike: Global Offensive Raunt Sonuçlarının Tahminlenmesi
Authors: SİNAP Vahid
Published: August 2023

Kamuya açık şekilde sunulan yapılandırılmış ve yapılandırılmamış büyük miktarlardaki verilerle birlikte Espor tahminlemeleri üzerine yapılan çalışmalar her geçen gün artmaktadır. Espor etkinliklerine yönelik tahminleme çalışmaları insan faktöründen büyük ölçüde etkilense de doğru çıktılara ulaşmada önemli birçok parametre sunan yapısıyla tahminlemelerin başarısını artırmaktadır. Bu bağlamda modellerin nasıl oluşturulacağı ve hangi makine öğrenmesi algoritmalarının seçileceği önem taşımaktadır. Bu çalışmada, Counter- Strike: Global Offensive adlı çevrimiçi oyundaki rauntların sonuçlarının tahminlemeye yönelik çeşitli makine öğrenmesi algoritmaları kullanılarak sınıflandırmalar gerçekleştirilmiştir. Araştırmada, Lojistik Regresyon, Karar Ağaçları, Rastgele Orman, XGBoost, Naive Bayes, K-En Yakın Komşu ve Destek Vektör Makinesi olmak üzere toplam yedi adet denetimli sınıflandırma algoritması kullanılmıştır. Bu algoritmaların performans ölçümünde Doğruluk, Kesinlik, Duyarlılık, F-Skor ve AUC değerleri hesaplanmıştır. Ayrıca, ROC eğrileri ve karışıklık matrisleri değerlendirilerek algoritmalar karşılaştırılmıştır. Bu ölçümler ve değerlendirmeler sonucunda Rastgele Orman algoritması %88 doğruluk oranı ile en başarılı algoritma olmuştur. Bunlara ek olarak, rauntların kazanılma durumları bağlamında Keşifsel Veri Analizleri yürütülerek Espor organizasyonlarına yönelik bazı önerilerde bulunulmuştur.
The Seoul National University AGN Monitoring Project. IV. Hα Reverberation Mapping of Six AGNs and the Hα Size–Luminosity Relation
Authors: Cho Hojin , Woo Jong-Hak , Wang Shu , Son Donghoon , Shin Jaejin , Rakshit Suvendu , Barth Aaron J. , Bennert Vardha N. , Gallo Elena , Hodges-Kluck Edmund , Treu Tommaso , Bae Hyun-Jin , Cho Wanjin , Foord Adi , Geum Jaehyuk , Jadhav Yashashree , Jeon Yiseul , Kabasares Kyle M. , Kang Daeun , Kang Wonseok , Kim Changseok , Kim Donghwa , Kim Minjin , Kim Taewoo , N. Le Huynh Anh , Malkan Matthew A. , Mandal Amit Kumar , Park Daeseong , Park Songyoun , Sung Hyun-il , U Vivian , Williams Peter R.
Published: August 2023

The broad-line region (BLR) size–luminosity relation has paramount importance for estimating the mass of black holes in active galactic nuclei (AGNs). Traditionally, the size of the Hβ BLR is often estimated from the optical continuum luminosity at 5100 Å, while the size of the Hα BLR and its correlation with the luminosity is much less constrained. As a part of the Seoul National University AGN Monitoring Project, which provides 6 yr photometric and spectroscopic monitoring data, we present our measurements of the Hα lags of high-luminosity AGNs. Combined with the measurements for 42 AGNs from the literature, we derive the size–luminosity relations of the Hα BLR against the broad Hα and 5100 Å continuum luminosities. We find the slope of the relations to be 0.61 ± 0.04 and 0.59 ± 0.04, respectively, which are consistent with the Hβ size–luminosity relation. Moreover, we find a linear relation between the 5100 Å continuum luminosity and the broad Hα luminosity across 7 orders of magnitude. Using these results, we propose a new virial mass estimator based on the Hα broad emission line, finding that the previous mass estimates based on scaling relations in the literature are overestimated by up to 0.7 dex at masses lower than 107
M
⊙.
Simulations of High-redshift [O iii] Emitters: Chemical Evolution and Multiline Diagnostics
Authors: Nakazato Yurina , Yoshida Naoki , Ceverino Daniel
Published: August 2023

Recent observations by the James Webb Space Telescope discovered a number of high-redshift galaxies with strong emission lines from doubly ionized oxygen. Combined with Atacama Large Millimeter/submillimeter Array observations of far-infrared lines, multiline diagnostics can be applied to the high-redshift galaxies in order to probe the physical conditions of the interstellar medium. We study the formation and evolution of galaxies using the FirstLight simulation suite, which provides outputs of 62 high-resolution, zoom-in galaxy simulations. We devise a physical model of H ii regions and calculate spatially resolved [O iii] line emission. We show that massive galaxies with stellar masses of M
* > 109
M
⊙ chemically evolve rapidly to z = 9. Young stellar populations in the star-forming galaxies boost the [O iii] line emission, rendering the ratio of line luminosity to star formation rate larger than that for low-redshift galaxies, which is consistent with recent observations. Measuring the flux ratios of rest-frame optical and far-infrared lines allows us to estimate the physical conditions such as density and metallicity of the star-forming gas in high-redshift [O iii] emitters.
BatAnalysis: A Comprehensive Python Pipeline for Swift BAT Survey Analysis
Authors: Parsotan Tyler , Laha Sibasish , Palmer David M. , Lien Amy , Cenko S. Bradley , Krimm Hans , Markwardt Craig
Published: August 2023

The Swift Burst Alert Telescope (BAT) is a coded-aperture gamma-ray instrument with a large field of view that primarily operates in survey mode when it is not triggering on transient events. The survey data consist of 80-channel detector plane histograms that accumulate photon counts over periods of at least 5 minutes. These histograms are processed on the ground and are used to produce the survey data set between 14 and 195 keV. Survey data comprise >90% of all BAT data by volume and allow for the tracking of long-term light curves and spectral properties of cataloged and uncataloged hard X-ray sources. Until now, the survey data set has not been used to its full potential due to the complexity associated with its analysis and the lack of easily usable pipelines. Here, we introduce the BatAnalysis Python package, a wrapper for HEASoftpy, which provides a modern, open-source pipeline to process and analyze BAT survey data. BatAnalysis allows members of the community to use BAT survey data in more advanced analyses of astrophysical sources, including pulsars, pulsar wind nebula, active galactic nuclei, and other known/unknown transient events that may be detected in the hard X-ray band. We outline the steps taken by the Python code and exemplify its usefulness and accuracy by analyzing survey data of the Crab Nebula, NGC 2992, and a previously uncataloged MAXI transient. The BatAnalysis package allows for ∼18 yr of BAT survey data to be used in a systematic way to study a large variety of astrophysical sources.
Shock Cooling and Possible Precursor Emission in the Early Light Curve of the Type II SN 2023ixf
Authors: Hosseinzadeh Griffin , Farah Joseph , Shrestha Manisha , Sand David J. , Dong 董 Yize 一泽 , Brown Peter J. , Bostroem K. Azalee , Valenti Stefano , Jha Saurabh W. , Andrews Jennifer E. , Arcavi Iair , Haislip Joshua , Hiramatsu Daichi , Hoang Emily , Howell D. Andrew , Janzen Daryl , Jencson Jacob E. , Kouprianov Vladimir , Lundquist Michael , McCully Curtis , Meza Retamal Nicolas E. , Modjaz Maryam , Newsome Megan , Gonzalez Estefania Padilla , Pearson Jeniveve , Pellegrino Craig , Ravi Aravind P. , Reichart Daniel E. , Smith Nathan , Terreran Giacomo , Vinkó József
Published: August 2023

We present the densely sampled early light curve of the Type II supernova (SN) 2023ixf, first observed within hours of explosion in the nearby Pinwheel Galaxy (Messier 101; 6.7 Mpc). Comparing these data to recently updated models of shock-cooling emission, we find that the progenitor likely had a radius of 410 ± 10 R
⊙. Our estimate is model dependent but consistent with a red supergiant. These models provide a good fit to the data starting about 1 day after the explosion, despite the fact that the classification spectrum shows signatures of circumstellar material around SN 2023ixf during that time. Photometry during the first day after the explosion, provided almost entirely by amateur astronomers, does not agree with the shock-cooling models or a simple power-law rise fit to data after 1 day. We consider the possible causes of this discrepancy, including precursor activity from the progenitor star, circumstellar interaction, and emission from the shock before or after it breaks out of the stellar surface. The very low luminosity (−11 mag > M > −14 mag) and short duration of the initial excess lead us to prefer a scenario related to prolonged emission from the SN shock traveling through the progenitor system.
Possible Detection of the Progenitor of the Type II Supernova SN 2023ixf
Authors: Pledger Joanne L , Shara Michael M
Published: August 2023

Stellar evolution theory predicts multiple pathways to the explosive deaths of stars as supernovae. Locating and characterizing the progenitors of well-studied supernovae is important to constrain the theory and to justify and design future surveys to improve on progenitor detections. Here we report the serendipitous preexplosion imaging, by the Hubble Space Telescope, of SN 2023ixf, one of the nearest extragalactic supernovae ever discovered, in the galaxy M101. The extremely red color and absolute magnitude

M

F
814
W

=
−

5.11

−
0.47

+
0.65

mag suggest that the progenitor was a red supergiant. Comparison with stellar evolutionary isochrones suggests it is within the relatively low initial mass range of ∼8–10 M
⊙ and that there is likely a lot of dust present at the supernova site.
Two Candidate Obscured Tidal Disruption Events Coincident with High-energy Neutrinos
Authors: Jiang Ning , Zhou Ziying , Zhu Jiazheng , Wang Yibo , Wang Tinggui
Published: August 2023

Recently, three optical tidal disruption event (TDE) candidates discovered by the Zwicky Transient Facility (ZTF) have been suggested to be coincident with high-energy neutrinos. They all exhibit unusually strong dust infrared echoes, with their peak times matching the neutrino arrival time even better than the optical peaks. We hereby report on two new TDE candidates that are spatially and temporally coincident with neutrinos by matching our sample of mid-infrared outbursts in nearby galaxies (MIRONG) with Gold alerts of IceCube high-energy neutrino events up to 2022 June. The two candidates show negligible optical variability according to their ZTF light curves and can therefore be classified as part of the growing population of obscured TDE candidates. The chance probability of finding two such candidates is about ∼3% by redistributing the MIRONG sources randomly in the Sloan Digital Sky Survey footprint, which will be as low as ∼0.1% (or ∼0.2%) if we limit to sources with increased fluxes (or variability amplitudes) comparable with the two matched sources. Our findings further support the potential connection between high-energy neutrinos and TDEs in dusty environments by increasing the total number of neutrino-associated TDE and TDE candidates to five, although the underlying physics remains poorly understood.
Hours-long Near-UV/Optical Emission from Mildly Relativistic Outflows in Black Hole–Neutron Star Mergers
Authors: Gottlieb Ore , Issa Danat , Jacquemin-Ide Jonatan , Liska Matthew , Tchekhovskoy Alexander , Foucart Francois , Kasen Daniel , Perna Rosalba , Quataert Eliot , Metzger Brian D.
Published: August 2023

The ongoing LIGO–Virgo–KAGRA observing run O4 provides an opportunity to discover new multimessenger events, including binary neutron star (BNS) mergers such as GW170817 and the highly anticipated first detection of a multimessenger black hole–neutron star (BH–NS) merger. While BNS mergers were predicted to exhibit early optical emission from mildly relativistic outflows, it has remained uncertain whether the BH–NS merger ejecta provides the conditions for similar signals to emerge. We present the first modeling of early near-ultraviolet/optical emission from mildly relativistic outflows in BH–NS mergers. Adopting optimal binary properties, a mass ratio of q = 2, and a rapidly rotating BH, we utilize numerical relativity and general relativistic magnetohydrodynamic (GRMHD) simulations to follow the binary’s evolution from premerger to homologous expansion. We use an M1 neutrino transport GRMHD simulation to self-consistently estimate the opacity distribution in the outflows and find a bright near-ultraviolet/optical signal that emerges due to jet-powered cocoon cooling emission, outshining the kilonova emission at early time. The signal peaks at an absolute magnitude of ∼−15 a few hours after the merger, longer than previous estimates, which did not consider the first principles–based jet launching. By late 2024, the Rubin Observatory will have the capability to track the entire signal evolution or detect its peak up to distances of ≳1 Gpc. In 2026, ULTRASAT will conduct all-sky surveys within minutes, detecting some of these events within ∼200 Mpc. The BH–NS mergers with higher mass ratios or lower BH spins would produce shorter and fainter signals.
Viability of zooplankton resting eggs in rice field sediment after pesticide applications
Authors: Plangklang Nattaporn , Athibai Sujeephon
Published: August 2023

Many herbicide products are commonly used in agricultural areas to prevent and eliminate weeds. Contamination from these toxicants in water might affect aquatic organisms not only in the active stage, but also in the diapause stage. To test the effect of herbicide on the resting eggs of zooplankton, we prepared two rice fields: one field without the application of pesticides (RF−NPA) and one with the application of pesticides (RF−PA) in a sampling year. We conducted a hatching experiment for 30 days. Twenty–four taxa of zooplankton were found. Sixteen species of these were rotifers, seven species were cladocerans and one taxon was an unidentified nauplius copepod. The species richness of zooplankton between RF–NPA (17 taxa) and RF–PA (16 taxa) was close, but species compositions between RF–NPA and RF–PA were different, indicated by the similarity index of 0.545. Lecanidae was the most diverse family of rotifers in both rice fields with nine species, while Chydoridae was the most diverse family of cladocerans (four species). The total abundance of zooplankton of RF−NPA was higher than RF−PA with 1,897 and 1,286 individuals, respectively. The Shannon–Wiener diversity index (H´) and Pielou’s evenness (J) in RF−NPA were higher than in RF−PA. The high species richness of zooplankton in both rice fields occurred on days 18 to 30. On the other hand, the highest abundance was recorded on day 18 for RF−NPA and on day 24 for RF−PA. The non-metric multidimensional scaling (NMDS) demonstrated significant differences in zooplankton community composition between RF–NPA and RF–PA (p < 0.05; ANOSIM test). According to the diversity indices, the RF–NPA has more diversity than the RF–PA, which might be a result of herbicide application in the sampling year. This study suggests that the toxicity of glyphosate should be a concern in terms of the biodiversity of rice field ecosystems.
A new species of Aulacaspis and a revived combination of Diaspididae (Hemiptera, Coccomorpha) from China
Authors: Niu Minmin , Cai Bo , Wei Jiufeng
Published: August 2023

A new species of armored scale insect, Aulacaspis fanjingshanensissp. nov. is described and illustrated based on adult female specimens collected on Rosaceae plants in China. A key to the Aulacaspis species known from Guizhou Province of China is provided. Our molecular study suggests that Aulacaspis schizosoma (Takagi, 1970) is not a true member of the genus Aulacaspis; the genus Superturmaspis Chen, 1983 is revived and A. schizosoma is transferred to it as Superturmaspis schizosoma (Takagi, 1970), revived combination, based on a molecular phylogeny.
Three new species of the genus Trilacuna Tong & Li, 2007 (Araneae, Oonopidae) from Yunnan Province, China
Authors: Ma Jimeng , Bian Dongju , Tong Yanfeng , Yang Zizhong , Zhang Zhisheng
Published: August 2023

Three new species of the genus Trilacuna Tong & Li, 2007, T. cangshan Tong, Yang & Zhang, sp. nov. (♂), T. wumanshan Tong, Yang & Zhang, sp. nov. (♂), and T. xiaoheishan Tong, Yang & Zhang, sp. nov. (♂♀) are described from Yunnan, China. Descriptions, diagnoses, and photographs are provided.
Activating the American Association of Colleges of Nursing Essentials Through Competency-Based Leadership in Graduate Student Organizations
Authors: Manderscheid Amy , McKay Anne , Slager Dianne , Butler April , Hubner Julie , Bekker Paige , Sabo Rebecca
Published: August 2023

Background:

As nursing programs across the nation shift toward a competency-based education model, academic institutions are working to quantify student learning outcomes based on the new American Association of Colleges of Nursing (
AACN, 2021
) Essentials, domains, competencies, and sub-competencies.

Method:

Leveraging AACN Essentials, faculty and graduate nursing students engage in student organizations with the focus of Population Health, Professionalism, and Personal, Professional and Leadership Development (
AACN, 2021
).

Results:

Graduate student members are involved in practicum activities throughout the course of their education. Through collaboration with faculty, the student body, and other community partners, student leaders integrate experiences applicable to professional roles outside of academia (
AACN, 2021
). As a result, students gain skills in leadership and communication, while also gaining confidence and professional identity formation.

Conclusion:

Other academic institutions may replicate this approach in promoting competency-based education, experiences and development in alignment with the AACN Essentials.

[
J Nurs Educ
. 2023;62(10):580–583.]
Comparison of Dynamic Vault Changes Following Implantation of Two Different Models of Phakic Intraocular Lenses
Authors: Brar Sheetal , Wadhokar Sanjali Tadas , Sriganesh Supriya Samak , Sriganesh
Published: August 2023

Purpose:

To compare the dynamic vault range (the difference in the central vault height from scotopic to photopic light condition) after implantation of the ICL/TICL (STAAR Surgical) and Eyecryl phakic/Eyecryl phakic toric intraocular lens (IOL) (Biotech Healthcare).

Methods:

This retrospective study included patients with myopia or myopic astigmatism eligible for phakic IOL implantation with either the ICL/TICL or Eyecryl phakic/Eyecryl phakic toric IOL. Vault changes in varying light conditions (scotopic, mesopic, and photopic) were assessed using an anterior segment optical coherence tomography–based tomographer and dynamic vault range (DVR) was compared between the two groups.

Results:

A total of 60 eyes from 36 patients (30 eyes in each group) with a mean age of 28.63 ± 6.36 years were included. The mean postoperative follow-up at the time of assessment was 9.4 ± 5.3 and 8.9 ± 5.28 months (
P
= .75) in the ICL and Eyecryl groups, respectively. The mean values of scotopic, mesopic, and photopic vault were 490.56 ± 238.64, 453.56 ± 224.30, and 373.96 ± 200.24 μm in the ICL group and 515.46 ± 174.34, 490.26 ± 184.04, 450.43 ± 173.92 μm in the Eyecryl group (
P =
.32, .24, and .05, respectively). The DVR was 116.6 ± 59.29 μm in the ICL group versus 65.03 ± 31.78 μm in the Eyecryl group (
P
< .001).

Conclusions:

The Eyecryl phakic IOL showed significantly fewer light-induced changes in the central vault height (DVR) compared to the ICL, which may be attributed to the difference in the material of the two phakic IOL models. This may be clinically significant in eyes with low postoperative vaults with respect to their follow-up and risk assessment of cataractogenesis in the long term.

[
J Refract Surg.
2023;39(8):546–554.]
Some algebraic properties on rough neutrosophic matrix and its application to multi-criteria decision-making
Authors: Jeni Seles Martina D. , Deepa G.
Published: August 2023

Rough set theory is a method of information processing for database systems. The neutrosophic matrix is a generalization of the fuzzy matrix, especially in handling indeterminacy situations. The concept of matrix theory and its energy in the neutrosophic environment help to determine the value of the uncertain matrix. In this paper, we correlate the rough set theory with the neutrosophic matrix theory to introduce the rough neutrosophic matrix (RNM). In this structure, lower and upper approximation neutrosophic matrices are used to deal with uncertain situations. We demonstrate that the given matrix plays a different role in decision-making situations and defined the proposed matrix's determinant, adjoint, algebraic properties and operations. Finally, derived the ranking function for a rough neutrosophic matrix's energy. The new multi-criteria decision-making (MCDM) approach was presented with the ranking formula, which was utilized to rank the alternatives, and numerical examples were provided to show how the proposed matrix and its energy could be applied to an MCDM problem.
Brand Narrative in the 21st Century
Authors: Denga Edna Mngusughun
Published: August 2023

Consumers assess the credibility of a brand by examining its brand narrative, which is crafted to distinguish it from other brands. Marketing professionals create narratives to promote their brands. Brand narratives emerge when there is a consistent and recurring set of meanings associated with a brand, portraying its place in the world. These narratives play a crucial role in reinforcing brand awareness, promotion, and positioning. Brands must effectively convey unique stories that enhance and deepen consumer relationships. As social creatures, people connect with narratives, making a robust brand narrative a powerful tool for interacting, listening to, and engaging with customers. While brand narratives are not a novel concept, social media has transformed the way they are executed. It serves as a form of content marketing, intriguing audiences without overtly promoting products or businesses.
Learning While Teaching
Authors: Vasconcelos Sandra Vieira
Published: August 2023

Focussing on a project carried out within the scope of an English Applied to Tourism course, this chapter describes a teaching and learning strategy, putting forward the underlying rationale and outlining its design, implementation, and assessment phases. The project, whose aims included fostering students' language and critical thinking skills, challenged Hotel Management students to collaborate to produce online training modules for their peers. Relying on the use of digital technologies, most particularly LMS, and cloud-based student engagement and graphic design tools (including Nearpod and Canva), these modules were peer-reviewed and implemented, with students acting as both facilitators and reviewers. Building on existing research on the affordances of peer learning within the scope of foreign language teaching, the author frames the different activities, reflecting on how peer learning strategies can enhance students' engagement and agency, offering insights that can support English for Specific Purposes (ESP) teachers, as well as other practitioners.
Transition Towards Hybrid Learning Environments in Higher Education Institutions
Authors: Joshi Marjo , Haavisto Timo , Taatila Vesa Pekka , Ravyse Werner , Luimula Mika
Published: August 2023

The recent COVID-19 pandemic forced organizations to find new solutions for remote collaboration and refine hybrid education in the context of applied, praxis-based learning. Various tech giants have started investing in more immersive remote communication technologies, such as metaverse. This paper discusses hybrid environments and metaverse in education at Turku University of Applied Sciences (Turku UAS) as the site of the study. The new strategy of the university aims to support people and organizations in a hybrid world where physical and virtual worlds are merged. At Turku UAS, VR environment is seen as a platform that uses social communication for real-life integration through both hands-on skill development and theoretical knowledge transfer. The metaverse technology and collaborative learning environments can be seen as testbeds for future pedagogy and work life. Examples of implementations of interactive technologies in different fields of education are presented. In addition, a revised hybrid education model with future possibilities is introduced.
Autonomous Creative Learning Strategy Directed to Higher Education Students in Health Area
Authors: Gomes Paulo Veloso , Donga João , Ferreira Sandra , Magalhães Renato , Sá Vítor J.
Published: August 2023

As digital native learners, Z and Alpha generation students upcoming new challenges for Higher Education Institutions. Their early contact with technological devices does not in itself confer the necessary digital skills to correctly apply technology in academic or professional contexts. Digital skills are fundamental to the future health professionals, improving their academic performance and prepares them for their integration into the labor market. The integration of information and communication technologies in the curricula of higher education courses in the health area is a differentiating factor for academic and professional enhancement. The Autonomous Creative Learning Strategy directed to higher education students in the health area is based on project-oriented approaches, combined with interactive and immersive based-gaming learning activities that appeal to creativity, autonomy and encourage proactivity, self-learning, and the constant search for continuous improvement.
Experimentation and Creation
Authors: Soares de Castro Geraldo Eanes , Lopes da Silva Susana Maria Sousa , Gonçalves Ricardo Jorge da Rocha
Published: August 2023

The chapter discusses the introduction of adaptive learning in art education to provide students with personalized educational content. The methodology of project work is important for fostering creative thinking and addressing pedagogical and artistic challenges. The Visual Arts and Artistic Technologies Course has a diverse curriculum that emphasizes the practical dimension of knowledge to stimulate observation and learning by doing. The curricular units adapt to meet the needs, expectations, and preferences of the students. The chapter proposes an analysis of the curriculum organization of the course using adaptive microlearning.
Alkali Wet Chemicals for Ru with Advanced Semiconductor Technology Nodes
Authors: Kikkawa Yuki , Suzuki Yuzan , Saito Kohei , Yarimizu Hiroto , Kanamori Satoko , Sato Tomoaki , Nagashima Toru
Published: August 2023

Wet chemicals for ruthenium (Ru) etching are required for the formation of reliable Ru interconnects in advanced semiconductor technology nodes. In the present study, a novel alkali wet etchant, referred to as TK-1, has been developed in order to overcome issues with conventional Ru etchants, such as a low etch rate and the formation of toxic RuO4 gas. Regardless of the Ru deposition process, TK-1 exhibits a high Ru etching selectivity of greater than 100 relative to dielectric and liner materials. It also suppresses the production of RuO4 during the etching process. TK-1 has potential applications for Ru recess etching during fully self-aligned via fabrication.
Selective Si3N4 Etching for 3D NAND Integration by Using Low Concentration of H3PO4
Authors: Park Tae Gun , Han Jong Won , Lim Sang Woo
Published: August 2023

This study investigated the etching kinetics of Si3N4 in various concentration of H3PO4 solution and the effect of Si3N4 etching enhancers on the etching process, particularly for 3D NAND trench structures. 30 wt% H3PO4 was used to etch Si3N4, which can produce higher Si3N4/SiO2 etching selectivity and similar Si3N4 etching rate compared to a conventional 85 wt% H3PO4. 30 wt% H3PO4 showed significantly improved etching performance for the Si3N4/SiO2 3D NAND structure as compared to 85 wt% H3PO4. In particular, the transportation ability of H3PO4 into 3D NAND trench structures can be improved by reducing viscosity of etchant, which can be obtained by reducing the concentration of H3PO4. In addition, Si3N4 etching enhancers were introduced to accelerate the Si3N4 etching kinetics in 30 wt% H3PO4. Addition of such additives improved the Si3N4 etching rate and Si3N4/SiO2 etching selectivity while suppressing oxide regrowth. The results provide valuable insights for optimizing selective Si3N4 etching process in 3D NAND structures.
New Quaternary Amines and Solvents for Photoresist Developing and Stripping Applications
Authors: Zhou Hui , Zhang Ke , Yan Ai Yu , White Victoria , Maus Ronald , Griot Thomas
Published: August 2023

Tetramethylammonium hydroxide (TMAH) and N-methyl pyrrolidinone (NMP) are commonly used in photoresist developing and stripping process, however, both of TMAH and NMP have been confirmed with CMR (Carcinogenic, Mutagenic and Reprotoxic) concerns. With more attention attracted to TMAH and NMP replacements, Huntsman developed a range of new quaternary amines products, including E-GRADE® Choline OH (Choline Hydroxide), E-GRADE® THEMAH (Tris (2-hydroxyethyl) methylammonium Hydroxide), XHE-125, XHE-128, XHE-138, XHE-145 and XHE-148, and solvents, E-GRADE® MEOX (3-Methyl-2-oxazolidinone) and XHE-123, which have been evaluated in comparison with the performance of TMAH and NMP.
Surface Characterization - Gallium Nitride Depth Profiling with LEIS
Authors: Natemeyer Steffen , Fischer Petra , Fischer Roland , Valtiner Markus
Published: August 2023

With the increasing use of III-nitride semiconductors, more knowledge is needed about the manufacturing processes and reactions with different chemicals. Gallium nitride semiconductors show a different behavior in wet chemistry compared to the known silicon technologies [4,5]. The different behavior can be explained, among other things, by the polar axis in the c-direction [0001] [6]. Surface characterization is necessary to gain a better understanding of the native surface and after different processes. We have used Low Energy Ion Scattering (LEIS) with its very high sensitivity for surface characterization to characterize the surface of different gallium nitride semiconductors and to establish a depth profile by sputtering [1,8].
Atomic Level Chemical and Structural Properties of Silicon Surface and Initial Stages of Oxidation
Authors: Laukkanen Pekka
Published: August 2023

This work aims to summarize previous results reported in literature on atomic level properties of the wet chemically treated hydrogen-terminated silicon surfaces and of the Si oxidation, in comparison to a model system of ultraclean Si surfaces prepared in ultrahigh vacuum (UHV) conditions. A literature review shows that a proper wet chemical treatment of Si(111) provides an atomically smooth, high-quality surface, similar to the model template obtained in UHV conditions after high temperature heating. However, it seems that Si(111) is an exception among semiconductor surfaces concerning the effects of wet chemistry. Although the insulator films grown by the atomic layer deposition (ALD) have replaced the thermal oxide of SiO2 in many applications, still an intermediate SiO2 layer is formed and often grown intentionally beneath the ALD film to improve the device performance. However, a detailed atomic structure of the SiO2/Si interface is still debatable, which might be due to differences in atomic level smoothness of the used Si(100) starting surfaces.
Evaluation and Optimization of Particle Removal with a Resist Peeling Method
Authors: Mercadier Thomas , Garnier Philippe , Loup Virginie , Tiron Raluca , Zhang Song , Higuchi Ayumi , Belmiloud Naser
Published: August 2023

The removal of particle contamination is key to maximize yield. Some common particle removal techniques are not relevant anymore when complex and fragile structures are present on the surface. This led to the development of new cleaning processes based on innovative concepts to improve particle removal efficiency without any pattern damage. Some of these processes rely on a resist film lift off. One of these particle removal processes is studied in this paper. The process consists in some resist spin-coating followed by a diluted ammonia dispense to remove this film, which results in particle removal. This specific resist film is made of two immiscible organic polymers. A study was conducted to understand how the organization of these two polymers in the film is key for the film lift-off and the cleaning efficiency. This organization was shown to depend on the substrate contact angle and the resist formulation. A surface preparation is required on hydrophobic surface to reduce their water contact angle and ensure the efficiency of the process. As a result, compared to a high velocity aerosol cleaning technique, this resist peeling process requires multiple steps and a significant process time. A Particle Removal Efficiency study was then performed on blanket wafers to determine and understand how the different process parameters impacted on the cleaning efficiency. It led to the optimization of this process efficiency on blanket wafers. A comparison between an optimized process and a high velocity aerosol cleaning technique underlined the potential of such a process. Compared to high velocity aerosol cleaning, it demonstrated higher efficiency on blanket wafers, without causing any pattern damage on patterned wafers. These results lead to promising perspectives for using this process in the cleaning of fragile structure or targeting small particles with high adhesion.
Monitoring of Trace Molecular Impurities in Clean-Room Air
Authors: Kenis Karine , Mertens Paul W. , Altamirano-Sanchez Efrain , Van Ongeval Joost , De Vita Marie
Published: August 2023

A new measurement system has been introduced to perform real-time measurements of molecular air contaminants at different location in a clean room down to a concentration of approximately 0.1 ppb. The system consists of an air sampling unit coupled to a proton transfer mass spectrometer and a Cavity Ring-Down Spectrometer. The measurements show that the time average concentrations of more than 10 different volatile impurity molecules exceed 1 ppb.
Etch Profile Prediction Model Using Convolutional Neural Network
Authors: Tokuyama Masahiro , Shinohara Kensuke
Published: August 2023

Etch profile control of the wafer surface is a key application for single-wafer wet process equipment. Wet etch processes are grouped into two types, either uniform flat etch profiles or specific non-flat etch profiles that are required for downstream processes. For both groups of etch profile it can consume time and resources to obtain the processing conditions to achieve the desired etch profile due to the complex interactions in the process. Etch profile prediction models can provide process engineers a valuable tool to identify processing conditions to get the desired etch profile in less time. In this paper, we introduce an etch profile prediction model using a Convolutional Neural Network [1] and validation of the prediction model against actual experimental data. We also investigated methods on how to select the comprehensive learning conditions and understand the relationship with prediction accuracy and the number of learning conditions. We found the choice of parameter type to describe a process condition can affect prediction accuracy. The prediction model reproduced the trend of etch profiles even when learned on a small dataset.
Application of Hydrosol to Aerosol Based Metrology to Predict Wafer Defects from Process Chemical Contamination
Authors: Oberreit Derek , Van Schooneveld Gary , Altun Ali , Walker Michael , Mizusugi Hans
Published: August 2023

A method for continuous measurement of particle and particle precursor material in high purity liquids using aerosolization and condensation particle courting (A+CPC) is presented. A process for correlating wafter defects with the concentration values measured using A+CPC using Sequential Spin Coating + Surface Enhanced Particle Sizing (SSC + SEPS) is described. The method was applied to monitor the rinsate of an ion exchange resin following the SEMI C93 guide. The results showed correlation between the methods and the concentration values were used to calculate a deposition factor (liquid concentration/surface concentration) on the order of 1E5 (#/ml)/(#/cm2).
Modeling of Capillary Pattern Collapse on Sub-5nm Pillars Using Molecular Dynamics
Authors: Bassett Derek W. , Aryal Dipak , Rotondaro Antonio
Published: August 2023

Molecular dynamics simulations were used to model <100> silicon pillars with diameter and spacing of 2.2nm and in a square lattice. Isopropanol (IPA) was added as a wetting liquid, and evaporation of the IPA was simulated to induce capillary forces that can cause pattern collapse. The cylinders were stable up to an aspect ratio of 8, while pillars higher than that collapsed. Additionally we simulated the thermal vibration of silicon pillars with diameters and spacing of both 2.2nm and 4.3nm without the presence of liquid at 300K. The Young's modulus of these pillars was estimated using the mean square displacement of the vibrating pillar tips, and results showed that the modulus decreases significantly from the bulk value for these structures.
On Gas-Phase Selective Dry Etching in 3D Inflections
Authors: Ingle Nitin
Published: August 2023

Semiconductor industry periodically goes through major transitions in the architectures and materials. The previous such transition was the Logic transition to FinFET and NAND transition to 3DNAND that revolutionized the two devices and accelerated PPAC (power, performance, area, cost) progress. Over the last decade, introduction of EUV lithography has driven the device miniaturization and furthered the cause of PPAC, but with the same architecture. The accelerating technological needs at lower cost point with better power efficiency are driving the current push in fundamental architectural changes and new materials introductions, especially in Logic and DRAM with a transition to 3D structures. This moves the critical etches from traditional RIE to selective isotropic etching. Furthermore, newer materials and requirements of better interfaces in these 3D structures are driving the need for dry selective treatments with good isotropicity and free of damage. This paper will give an overview of the current state of selective dry etch and progress in treatments.
Nanoparticle Analyzing Technique Review and Sub-10 nm Nanoparticle Sizing Methods Comparison
Authors: Liu Su Wen
Published: August 2023

This paper provides a comprehensive review of current nanoparticle analysis methods specifically designed for sub-20 nm particles. The techniques are categorized into three main groups: ensemble (I), single particle counting (II), and separating & counting (III) methods. The study further presents a comparative analysis of test results obtained using these three categories of methods on polydisperse polymer nanoparticles. For this investigation, four different tools capable of sub-10 nm particle analysis were utilized. The techniques employed in this study include dynamic light scattering (I), atomic force microscope (II), scanning mobility liquid particle sizer (III), and cryo-electron microscopy (I). The findings indicate that, for particles larger than 8 nm, the three tools—excluding dynamic light diffraction—yield similar results. Conversely, in the small size range (<7 nm), cryo-electron microscopy consistently demonstrates reliable outcomes.
Eco-Friendly SPM Alternative Resist Stripping with High-Concentration O3-Water Technology
Authors: Jizaimaru Takayuki , Funakoshi Takao , Sakai Takeshi , Fujimoto Hisashi , Shirai Yasuyuki
Published: August 2023

A large amount of chemicals and ultrapure water (UPW) have been used for wet cleaning process in the semiconductor manufacturing processes. One of the most commonly used cleaning solutions is Sulfuric acid (H2SO4) and Hydrogen Peroxide (H2O2) Mixture (SPM). It is used for resist stripping, etc. on a silicon wafer. As the cleaning process increases, so does the amount of chemicals used with the recent miniaturization. As a result, wastewater will also increase, and there are concerns about the impact on the environmental aspects. The technologies to reduce H2SO4 [1, 2] have been developed, but its consumption still persists. Therefore, in this paper, we developed high concentrated O3-water without using H2SO4, and conducted a resist stripping test verify its effectiveness as an alternative to SPM.
Pattern Collapse Simulation in CMOS Image Sensors Devices
Authors: Garnier Philippe , Sart Clement , Prevost Emilie , Dubois Jerome , Vianne Benjamin
Published: August 2023

Pattern collapse in CMOS image sensors is discussed, where silicon pillars are separated by trenches of few microns deep. Both analytical and numerical models are given and match experimental results. The trench profile is also taken into account to predict such collapse.
SiGe Selective Etching to Enable Bottom and Middle Dielectric Isolations for Advanced Gate-All-Around FET Architecture
Authors: Kawarazaki Hikaru , Nakano Teppei , Ishizu Takaaki , Tanaka Takayoshi , Liu Wen , Chen Jason , Kawashima Tomohiko , Wu Ai Ping , Sebaai Farid , Lai Ju Geng , Yusuke Oniki , Altamirano-Sanchez Efrain
Published: August 2023

Formulated chemical ACT® SG6xxx series demonstrated SiGe etching selective to SiGe with lower Ge concentration. SiGe etching rate on SiGe/Si multi-stack shown steep trend as a function of Ge concentration, resulting in 338 of selectivity between SiGe30% and SiGe15%. Also, apparent loss on SiN and SiO2 was not observed. Moreover, SiGe etch rate was not impacted by chemical flow in the beaker. It suggests reaction-controlled based etching, which leads to good within wafer uniformity in etching rate of 300mm wafer spin processing. In conclusion, ACT® SG6xxx series is a promising option for the formation of BDI/MDIs in Nanosheet, Forksheet and CFET.
Insights into FinFET Structure Collapse: A Reactive Force Field-Based Molecular Dynamics Investigation
Authors: Seki Ryuichi , Fujiwara Naozumi , Sato Masanobu , Okuno Yasutoshi , Kubo Momoji
Published: August 2023

As miniaturization progresses, pattern collapse during the drying step of wet cleaning processes has become a critical issue in the semiconductor industry. In this study, we used reactive molecular dynamics simulations to analyze pattern collapse, with a focus on bondings and reactions. To simulate pattern deformation during the drying process of wet cleaning, we created a FinFET model as a HAR structure. The surface of this model was terminated with hydrogen atoms. The widths between the patterns were changed in order to create a Laplace pressure difference when water molecules were placed on the surface. The model was simulated by placing water molecules up to half the height of the pattern. As a result, the pattern was deformed. Furthermore, by removing water molecules and changing the Laplace pressure balance, it was found that the pattern contacted each other at the tip. The pattern remained in contact when water molecules were removed from the model. In the contact area, the covalent bonds, such as Si-Si and Si-O-Si, were not formed, but instead, hydrogen-to-hydrogen van der Waals bonds were formed between patterns. We calculated the total van der Waals forces between hydrogen atoms at the contact surfaces using the Hamaker equation and calculated the elastic force of the patterns using the beam deflection formula. Our calculations showed that the total van der Waals forces between hydrogen atoms at the contact surfaces were larger than the elastic force of the patterns, indicating that van der Waals forces could be a factor in maintaining the contact of the patterns.
Sulfuric Acid Reduction in Post-Ash Cleans
Authors: Escarabajal Yann , Caron Loic , Garnier Philippe , Ma Jonathan , Mercadier Thomas , Richard Claire
Published: August 2023

Photoresist after implantation is commonly removed either by wet chemical dissolution with sulfuric acid, or by dry ash stripping followed with a wet cleaning. To prevent any photoresist residues, sulfuric acid is still conserved in post ash cleans as additional safety. However, by ensuring sufficient over ash time, SPM (Sulfuric acid Peroxide hydrogen Mixture) chemical need becomes less essential. This paper reevaluates the benefit of SPM after dry ash stripping regarding the environmental context. The advantages of dry ash stripping with clean, compared to wet stripping are outlined. The study introduces prior analyses on defectivity and material consumption. Finally, device matching and yield stability, defined as the main success criteria, are described.
Improvement of Fingering-Induced Pattern Collapse by Adjusting Chemical Mixing Procedure
Authors: Choi Jae Wook , Choi Sung Joon , Choi Joong Sup
Published: August 2023

Pattern collapse, also as known as leaning, has become one of the most common and challengeable defects in semiconductor manufacturing process due to device shrinkage. In single wafer wet cleaning, Isopropyl Alcohol (IPA) rinse is widely used after Deionized Water (DIW) rinse. Fingering instabilities are observed at the mixing boundary of IPA and DIW, where dry spots are formed due to unbalanced capillary force amid patterns. Unlike previous DRAM devices, we have found that recent 1x-nm DRAM devices have become more vulnerable to pattern collapse induced by dry spots related to fingering instability. In this paper, we examine factors and phenomenon related to fingering-induced leaning through both experiments and simulation analysis. In addition, we also propose improved rinsing methods which could prevent fingering and related pattern collapse by adjusting nozzle configurations (i.e. speed, flow rate and etc.).
Study on Alternative Dipole Material Wet Clean by pH Controlled Functional Water
Authors: Tanaka Yoichi , Gan Nobuko , Ogawa Yuuichi , Iino Hideaki , Chang Ren Jie , Homkar Suvidyakumar , Alessio Verni Giuseppe , Givens Michael , Lai Ju Geng , Pacco Antoine , Brus Stephan , Arimura Hiroaki , Oniki Yusuke , Altamirano-Sanchez Efrain , Holsteyns Frank , Horiguchi Naoto
Published: August 2023

This paper focuses on the mechanism and methodology of the dissolution of Alternative Dipole Material (ADM) and its inhibition through the use of functional waters. The study investigates the etching behavior of ADM in different solutions, examines the surface state of ADM before and after cleaning, and evaluates the impact of the functional water process on its electrical properties.
Nanosheet-Based Transistor Architectures for Advanced CMOS Scaling: Wet Etch and Gas Phase Etch Challenges in Confined Spaces
Authors: Mertens Hans
Published: August 2023

Nanosheet-based transistor architectures for advanced CMOS have sophisticated 3D geometries and aggressively scaled dimensions imposing new challenges to wet etch and gas phase etch. In this paper, we describe three nanosheet-based transistor architectures (nanosheet, forksheet, and CFET) as well as associated challenges for wet etch and gas phase etch at various stages of the process flow, including channel release, work function metal patterning, and controlled dielectric etchback for stacked source-drain formation. The compatibility of etch processes with confined spaces and high-aspect-ratio structures becomes increasingly important for novel nanosheet-based transistor architectures.
Parametric Studies on Particle Removal and Erosion in Nozzle Injection Megasonic Cleaning
Authors: Ishibashi Tomoatsu , Matsuo Hisanori , Watanabe Katsuhide , Sakota Riria , Usui Hidehisa , Ando Keita
Published: August 2023

The process of quickly removing abrasive particles of silica and ceria slurries is important in the use of CMP equipment. Megasonic cleaning of nozzle injection type is one of a variety of post-CMP cleaning methods and its performance including cleaning efficiency and erosion was explored experimentally with parametric studies. In the cleaning process, it is favorable to achieve both high efficiency and low damage. The cleaning efficiency was defined by particle removal efficiency (PRE) with a glass sample spin-coated with small silica particles; the damage was detected from mass loss of aluminum foils after the cleaning. The cleaning tests show that the performance of nozzle injection megasonic cleaning depends significantly on ultrasound frequency and water temperature. Toward more efficient and less erosive cleaning, the nozzle injection angle is also expected to play a key role.