bluuebunny/crossref_metadata_2025 huggingface dataset:
Study of aquatic plants and ecological- physics Tempe Lake, Sulawesi Selatan
Authors: Nugraha Media Fitri Isma , Julzarika Atriyon , Radjamuddin Alias , Reflinur Reflinur , Yunita Rossa , Enggarini Wening , Novita Hessy
Published: July 2019

Aquatic plants are an indicator of the fertility of an aquatic region. The waters of Lake Tempe are the largest waters of the lake area in South Sulawesi. Lake Tempe is located in the western part of Wajo District, precisely in Tempe District, about 7 km from Sengkang City towards the banks of the Walanae River in southern Sulawesi. The area is about 13,000 ha with a maximum depth of 5.5 m and can reach more than 30,000 ha during floods, and during the dry season, the inundation area reaches only 1,000 ha with a maximum depth of 1 m, located above the continental and Australian and Asian plates. This lake is one of the tectonic lakes in Indonesia. Every year silting the lake occurs. The Tempe hydro vegetation and eco-physical research were carried out in October 2017. The purpose of this study was to record aquatic plant species that live in Tempe Lake and observe ecological changes and physical properties of Lake Tempe. Aquatic plants are expected to be able to filter lake water. The results obtained are physical conditions of sharp-smelling water, unpleasant taste, dark brown, and cloudy color. Chemical indicators of NH3-N waters (0.2976-0.0634), PO4-P (0.0172-0.0844) NO2-N (undetectable), NO3-N (1.7131-1.9335), Sulphate (27.761900 - 37.047620), DO (6.88-7.18) and pH (7.88-8.02). There are 14 species of aquatic plants found in these waters. The most dominant species is water hyacinth. In the case of Tempe lake water vegetation results in siltation of the lake area.Keywords: Aquatic plant, Biodiversity, Species, Tempe lake,
Superconducting switching due to a triplet component in the Pb/Cu/Ni/Cu/Co2Cr1−xFexAly spin-valve structure
Authors: Kamashev Andrey Andreevich , Garif’yanov Nadir Nurgayazovich , Validov Aidar Azatovich , Schumann Joachim , Kataev Vladislav , Büchner Bernd , Fominov Yakov Victorovich , Garifullin Ilgiz Abdulsamatovich
Published: July 2019

We report the superconducting properties of the Co2Cr1−xFexAly/Cu/Ni/Cu/Pb spin-valve structure the magnetic part of which comprises the Heusler alloy layer HA = Co2Cr1−xFexAly with a high degree of spin polarization (DSP) of the conduction band and a Ni layer of variable thickness. The separation between the superconducting transition curves measured for the parallel (α = 0°) and perpendicular (α = 90°) orientation of the magnetization of the HA and the Ni layers reaches up to 0.5 K (α is the angle between the magnetization of two ferromagnetic layers). For all studied samples the dependence of the superconducting transition temperature Tc on α demonstrates a deep minimum in the vicinity of the perpendicular configuration of the magnetizations. This suggests that the observed minimum and the corresponding full switching effect of the spin valve is caused by the long-range triplet component of the superconducting condensate in the multilayer. Such a large effect can be attributed to a half-metallic nature of the HA layer, which in the orthogonal configuration efficiently draws off the spin-polarized Cooper pairs from the space between the HA and Ni layers. Our results indicate a significant potential of the concept of a superconducting spin-valve multilayer comprising a half-metallic ferromagnet, recently proposed by A. Singh et al., Phys. Rev. X 2015, 5, 021019, in achieving large values of the switching effect.
Kepler Planet Occurrence Rates for Mid-type M Dwarfs as a Function of Spectral Type
Authors: Hardegree-Ullman Kevin K. , Cushing Michael C. , Muirhead Philip S. , Christiansen Jessie L.
Published: July 2019

Previous studies of planet occurrence rates largely relied on photometric stellar characterizations. In this paper, we present planet occurrence rates for mid-type M dwarfs using spectroscopy, parallaxes, and photometry to determine stellar characteristics. Our spectroscopic observations have allowed us to constrain spectral type, temperatures, and, in some cases, metallicities for 337 out of 561 probable mid-type M dwarfs in the primary Kepler field. We use a random forest classifier to assign a spectral type to the remaining 224 stars. Combining our data with Gaia parallaxes, we compute precise (∼3%) stellar radii and masses, which we use to update planet parameters and occurrence rates for Kepler mid-type M dwarfs. Within the Kepler field, there are seven M3 V to M5 V stars that host 13 confirmed planets between 0.5 and 2.5 Earth radii and at orbital periods between 0.5 and 10 days. For this population, we compute a planet occurrence rate of

planets per star. For M3 V, M4 V, and M5 V, we compute planet occurrence rates of

,

, and

planets per star, respectively.
Alarming Eating Behaviours among Adolescents in Egypt
Authors: Abd El-Shaheed Azza , Mahfouz Nermine N. , Moustafa Rehab S.I. , Elabd Mona A
Published: July 2019

BACKGROUND: Adolescence is a phase of rapid growth and increased nutritional needs. It includes the stressful burden of pubertal changes, both physically and psychologically. Moreover, it is associated with the utmost need for independence and identity formation. An adolescent finds a great way to practice taking their own decisions by making personal food choices. But unfortunately, wrong dietary choices lead to unsatisfactory nutritional status.
AIM: To investigate the prevalence of six eating behaviours among adolescents.
SUBJECTS AND METHODS: A case-control study was conducted on ninety Egyptian adolescents from 10 to 18 years old. Anthropometric measurements were taken. Body Mass Index (BMI) was calculated. The cases were forty-five children with body mass index ≥ 85th percentile. The control group involved forty-five of matched peers with body mass index ˂ 85th centile. A questionnaire form was constructed according to local customs in Egypt.
RESULTS: Two unhealthy behaviours were mostly found in our study group. The first and the predominant one was multitasking while eating practised by 92.1% of candidates and showing the equal distribution in both groups. The second was skipping breakfast and was adopted by 51.7% of the study group with a significantly higher distribution in the ˂ 85th centile group.
CONCLUSION: Faulty eating is a behaviour encountered in adolescence irrespective to BMI category. Thus, a normal BMI does not reflect healthy dietary behaviours.
Timing of Treatment of Open Fractures of the Distal Radius in Patients Younger Than 65 Years
Authors: Tareen Jarid , Kaufman Adam M. , Pensy Raymond A. , O'Toole Robert V. , Eglseder W. Andrew
Published: July 2019

The authors aimed to characterize surgical and functional outcomes of open fractures of the distal radius in patients younger than 65 years. At their level I trauma center, the authors conducted a retrospective review of 92 patients (age range, 16–64 years) who had 94 open fractures of the distal radius (average follow-up, 30 months; range, 3–95 months). Sixty-four fractures received definitive treatment at the time of initial débridement; 30 received definitive fixation and soft tissue coverage after staged débridement. Primary surgical outcome was development of deep surgical site infection requiring repeat surgical débridement; secondary surgical outcome was surgical complications requiring reoperation. Functional outcome was assessed by wrist range of motion. Overall infection rate was 15% (14 of 94 fractures). Seven (11%) of 64 fractures in the immediate definitive fixation group developed infection compared with 7 (23%) of 30 fractures in the staged treatment group (
P
=.13). Twenty-one (33%) of 64 fractures in the immediate definitive fixation group required reoperation compared with 15 (50%) of 30 in the staged treatment group (
P
=.11). Deep surgical site infections and surgical complications associated with open fractures of the distal radius are driven by soft tissue injury. [
Orthopedics
. 2019; 42(4):219–225.]
Sexualités Transactionnelles et backlash en Martinique
Authors: Zebina Mylenn Zobda , Thirot Myriam , Merle Sylvie
Published: July 2019

Les sexualités transactionelles (ST) recouvrent un ensemble de conduites sexuelles qui donnent lieu à des avantages matériels et/ou financiers attendus explicitement ou implicitement d’un-e partenaire/client-e. Des conduites qui relèvent de la prostitution au sens strict (sexualité « extraordinaire ») aux échanges économico-sexuels avec un partenaire « ressource » (sexualité « ordinaire »). L’étude des ST en Martinique a permis d’explorer ces conduites sexuelles, dont seule la prostitution exercée par les femmes d’origine étrangères avait été jusqu’alors étudiée. Les ST des femmes étrangères mais aussi martiniquaises, des hommes homosexuels, hétérosexuels et des transsexuelles révèlent l’existence de conduites sexuelles protéiformes, dont certaines donnent lieu à une stigmatisation et à un backlash, tandis que d’autres semblent acceptées socialement. Quelles sont alors les ST qui font l’objet d’un backlash ? Par quels canaux ce dernier s’exerce-t-il ? Quelles stratégies sont adoptées par les individus stigmatisés ou stigmatisables pour y faire face ? Ces questionnements nourrissent une réflexion plus générale sur les normes de genre qui régissent les comportements sexués en matière de sexualité en Martinique : est-on en présence d’un modèle qui conteste le double standard sexuel qui définit les rôles sociaux de sexe (le genre et les rapports sociaux qu’il implique) ou qui le reconduit, en s’appuyant sur le backlash comme police de genre ?
Deconstructing Gender Roles and Digesting the Magic of Folktales and Fairy Tales in Annie Proulx’s Omnivorous Wyoming Stories
Authors: Meillon Bénédicte
Published: July 2019

Going beyond the extensive literature dealing with Annie Proulx’s deconstruction of myths tied to the West, this paper delves into her palimpsestuous Wyoming short stories that transgress dominant norms and conventions of genres and genders. Focusing on Proulx’s grotesque, feminist revisions of old folktales and fairy tales, this article contends that her art of the short story provides an efficient tool to tinker with the rigid, ideological discourses reinforced by such tales when it comes to gender stereotypes. Recuperating the magic from older forms of short narratives, Proulx’s omnivorous, postmodernist tales thrive on potent fragments and mythèmes that both foreground and rekindle the ignition power of imaginative discourse. Her subversive mythopoeia and playful, self-reflexive writing thus pave the way for liberating flights of fancy that cross the boundaries between established genres and gender.
Les récits produits en psychothérapie : un défi pour la narratologie
Authors: Revaz Françoise
Published: July 2019

Les récits produits lors d’entretiens psychothérapeutiques bousculent certaines idées-reçues véhiculées par les théories narratologiques classiques sur le récit de soi : la rétrospection, la véracité, la mise en ordre ou la clôture. De plus, les récits produits par les patients sont rarement monologiques ; ils sont plutôt coconstruits avec les autres membres de la famille ainsi qu’avec le thérapeute. En prenant appui sur un corpus enregistré d’entretiens psychothérapeutiques, on montrera dans cet article que l’émergence de narrativité au fil des entretiens nécessite des outils d’analyse qui puissent rendre compte non seulement du produit fini que peut être un récit, mais aussi du processus dynamique du récit en train de se construire avec ses bribes, ses inachèvements, ses hésitations et ses ouvertures sur l’avenir.
Récits interactifs et expérience de liberté
Authors: Compagno Dario
Published: July 2019

Les jeux et spécialement les jeux vidéo nous permettent de vivre une expérience impossible à réaliser autrement : celle du choix. Afin de comprendre la portée de cette considération, nous comparerons le modèle de l’action développé par E. Anscombe à celui de l’action racontée développé par A. J. Greimas, en montrant leur incompatibilité et leur insuffisance face aux actions interactives des jeux vidéo. Nous introduirons alors deux pensées capables d’enrichir notre compréhension. D’abord, celle d’A. Schopenhauer, que nous mobilisons pour décrire la nature hybride de l’avatar, à la foi personnage fictif et véhicule de la volonté réelle du joueur. Ensuite, la pensée d’U. Eco qui, à travers le concept d’ouverture, va permettre de caractériser l’expérience de liberté et de responsabilité associée à l’action interactive.
Des récits et des élèves
Authors: Reuter Yves
Published: July 2019

Dans cet article, après avoir rappelé le cadre didactique « autonomiste » au sein duquel je me situe, je reviens sur plusieurs recherches menées sur le récit afin de proposer quelques pistes de réflexion sur des questions proprement didactiques. Ces questions concernent notamment les fonctions des récits dans les différentes disciplines, la prise en compte des contenus dans l’analyse des textes d’élèves, les méthodes d’analyse pertinentes en didactique, le statut didactique des types de récits et la position d’apprentissage.
Pour une relecture et un emploi cognitifs des schémas narratifs structuralistes
Authors: Fragonara Aurora
Published: July 2019

L’article propose d’interroger le statut et l’emploi des schémas structuralistes, souvent jugés figés et contraignants, dans l’analyse des récits. Après avoir passé en revue les différentes conceptualisations théoriques des schématisations, nous en interrogeons le statut gnoséologique, à l’aide de la critique de l’ontologisme des structures proposée par U. Eco et du concept d’énaction, qui permet de comprendre l’émergence des schèmes mentaux. Nous expliquons ce fonctionnement énactif à l’aide de l’analyse de la structure narrative du Petit Prince, afin de mettre en évidence la portée heuristique et gnoséologique de la démarche schématisante. Cette illustration montre la validité des modélisations structuralistes, tout en évitant les soupçons de prescriptivisme.
Narrations d’hier et d’aujourd’hui sur des forums et des blogs d’apprentis lecteurs
Authors: Moinard Pierre
Published: July 2019

L’article interroge les diverses manifestations d’un travail interprétatif au cours d’échanges à distance entre jeunes lecteurs de récits. Seront examinés des forums et blogs scolaires en classes de 3e, 2e et 1e ainsi que des forums non scolaires. La première partie expose un cadre théorique (intégrant des notions de didactique de la littérature) et méthodologique permettant de distinguer diverses expressions de la réflexion des jeunes lecteurs sur et par les récits. Dans la deuxième partie, l’examen de fils de discussion sur un forum d’adolescents lecteurs montre comment les contributeurs manifestent des prises de recul sur eux-mêmes et sur le monde (moral et social) à travers les appréciations partagées de romans sériels. La troisième partie de l’article décrit comment des échanges asynchrones scolaires peuvent favoriser l’appropriation de récits du passé et conduire au partage de leurs interprétations.
Les épisodes autonomes : écarts formels et narratifs dans The X-Files et Buffy The Vampire Slayer
Authors: Després Elaine
Published: July 2019

Les genres télésériels évoluent depuis l’émergence du médium, ils se raffinent, se complexifient, s’hybrident, répondant aux exigences et aux compétences spectatorielles grandissantes de son public. Les genres permettent ainsi l’émergence de formules, que l’on adopte pour mieux se les approprier, et à partir desquelles les créateurs peuvent construire la matrice qui donnera à leur œuvre sa structure unique. Entre les séries canoniques des débuts et les grands feuilletons d’aujourd’hui, les années 1990 ont donné naissance à plusieurs séries hybrides, notamment dans le sous-genre du fantastique (par exemple, The X-Files et Buffy The Vampire Slayer), qui combinent des épisodes sériels et feuilletonnants. Au cœur de ces séries se trouvent des épisodes autonomes, souvent les plus appréciés, qui s’écartent de la matrice et proposent des innovations ou des jeux fictionnels, narratifs ou transtextuels.
Regarder des séries sur Netflix : l’illusion d’une expérience spectatorielle augmentée
Authors: Campion Benjamin
Published: July 2019

Par ses outils de lecture vidéo et son rythme de diffusion, Netflix promet aux amateurs de séries une expérience « immédiate » remédiant à cette attente par essence télévisuelle qui sépare chaque épisode du suivant. Le spectateur devient ainsi son propre programmateur, libre de regarder des séries au moment et au rythme qui lui conviennent le mieux. Cependant, cette promesse d’un pouvoir élargi sur la sérialité s’accompagne de renoncements tacites que l’on peut décliner en trois catégories : 1) Accéder à l’ensemble d’une saison sans devoir se plier à un rythme de diffusion par émiettement empêche de rêver collectivement la série. Sans un temps d’attente imposé entre chaque épisode, le spectateur perd naturellement de sa faculté à anticiper la suite et à s’interroger sur les significations de l’œuvre qu’il suit sur le long cours. 2) Parce qu’il est disponible sans attendre et se lance automatiquement jusqu’à terminer la saison en cours, l’épisode unitaire vu sur Netflix se fond dans la masse saisonnière. The OA (Netflix, 2016-) en fournit une illustration symptomatique en ne faisant apparaître son générique d’« ouverture » de pilote qu’au bout d’environ une heure, apparentant ce qui a précédé à un prologue ne pouvant être jugé intrinsèquement qu’à la lumière des épisodes suivants. 3) Après avoir implémenté une option de saut automatique du générique de fin (et du « Précédemment… ») en 2013, Netflix propose désormais au spectateur de zapper le générique de début de chaque épisode d’une même saison afin de n’en conserver que le « corps ». Ces options oblitèrent des fonctions narratives qu’il est pourtant important de rappeler, comme la préparation indicielle du spectateur aux rebondissements à venir, ou le prolongement de la diégèse par l’accompagnement musical.
La construction d’un tissage émotionnel au féminin dans la série Outlander
Authors: Bénédic-Meyer Diane
Published: July 2019

Avec quatre saisons diffusées et une cinquième en tournage, la série américano-britannique Outlander (Starz, 2014- ) représente un cas d’étude pertinent pour explorer la manière dont le format sériel donne à voir la cohérence du personnage. Créé par Ron Moore, le showrunner de Battlestar Galactica (Sci-Fi, 2003-2009), Outlander prête une attention toute particulière au réalisme émotionnel de ses personnages au sein d’un monde fictionnel marqué par la science-fiction et l’Histoire. Claire Beauchamp, jeune infirmière de la seconde guerre mondiale, se retrouve mystérieusement propulsée dans le contexte mouvementé de l’Ecosse jacobite. Le tissage émotionnel du personnage féminin se construit sur la durée de la série feuilletonesque où chaque épisode est différent et participe à l’étirement du personnage. Le corpus étudié comprend les deux premières saisons de la série ainsi que la première moitié de la saison 3 jusqu’aux retrouvailles du couple de Claire et Jamie après vingt ans de séparation (« A. Malcolm », épisode 305).Cet article entend démontrer comment l’adaptation sérielle permet à la fois de rationaliser un contenu très riche et parfois décousu et d’intensifier la narration pour mieux donner à voir les facettes du personnage. La série se prête d’autant plus à cette démonstration qu’elle débute comme une adaptation fidèle du matériau littéraire d’origine de Diana Gabaldon pour s’en émanciper peu à peu. L’adaptation sérielle se dote de motifs narratifs spécifiques pour dire l’authenticité du regard féminin de Claire comme le foyer narratif unique ou le female gaze. Il sera aussi intéressant de voir comment le tissage émotionnel de Claire se développe au sein de la matrice du couple notamment par le biais d’une conversation de l’absence. Enfin, la prise en compte du genre féminin du public de la série amènera à explorer la culture participative au féminin à l’heure des réseaux sociaux.
La sérialité aux bords de la fiction télévisée, ou l’intermédialité comme mise en crise du « tout narratif » sériel
Authors: Saute-Requin
Published: July 2019

Les approches narratologiques des séries télévisées tendent à occulter les richesses et les innovations formelles dont font preuve ces objets audiovisuels, dont la complexité dépasse le cadre strictement narratif. Le succès des approches narratologiques, dont la pertinence n’est nullement mise en cause, loin s’en faut, s’explique historiquement par les voies de son intégration dans le champ universitaire et les discours qui en déterminent la réception. Des méthodes développées dans d’autres champs disciplinaires, concernant d’autres arts ou objets culturels, peuvent cependant être sollicitées pour expliquer et rendre compte de la richesse et du succès des séries télévisées. Nous chercherons ici à poser les bases de cette réflexion, conçue comme un exercice d’ouverture du regard.
Generating an Artificial Nest Building Pufferfish in a Cellular Automaton Through Behavior Decomposition
Authors: Portegys Thomas E.
Published: July 2019

A species of pufferfish builds fascinating circular nests on the sea floor to attract mates. This project simulates the nest building behavior in a cellular automaton using the morphognosis model. The model features hierarchical spatial and temporal contexts that output motor responses from sensory inputs. By considering the biological neural network of the pufferfish as a black box, and decomposing only its external behavior, an artificial counterpart can be generated. In this way a complex biological system producing a behavior can be filtered into a system containing only functions that are essential to reproduce the behavior. The derived system not only has intrinsic value as an artificial entity but also might help to ascertain how the biological system produces the behavior.
Transformative Learning and Lean Six Sigma Programs
Authors: Gordon Kimberley , Ross Kendall
Published: July 2019

In the competitive world of recruiting, the better an applicant can apply what has already been learned to a new environment, the greater the career opportunity. This study captured the transformative learning experience of students, guided by their instructors and industry partners, related to learning and executing Lean Six Sigma principles in a variety of environments. Lean Six Sigma principles which seek to reduce inefficiencies and thus improve the customer experience have long since been associated with manufacturing. Expanding the application of Lean Six Sigma from blue-collar settings to include white-collar and green-collar work provides students additional problem-solving approaches to process challenges in all-collar environments. Additionally, the experience aided students in viewing customers from both internal and external lenses, linked customer loyalty to organization success, and demonstrated the value such skills were to both personal career growth. Suggestions for faculty and recommendations for future studies are included.
An Improved Data Collection Algorithm for Wireless Sensor Networks
Authors: Reddy Vemula Manohar , An Min Kyung , Cho Hyuk
Published: July 2019

This article studies the minimum latency collection scheduling (MLCS) problem in wireless sensor networks (WSNs). The MLCS problem targets to compute a schedule with minimum number of timeslots that guarantees to collect data from all nodes to a sink node without any collision. Several scheduling algorithms have been proposed for the NP-hard problem, and they assign timeslots based on hop distances among nodes. The proposed algorithm not only uses hop distances, but also partitions a network into square cells and assign timeslots based on cell distances among nodes. The latency performance of the proposed algorithm is compared with an existing algorithm whose approximation ratio is currently the best, and the simulations show that the proposed algorithm performs better.
Sustainable Supply Chain Management
Authors: Anilkumar E.N.  , Sridharan R.
Published: July 2019

Sustainability, the simultaneous management of economic, environmental and social dimensions in a supply chain is a challenging research area in supply chain management. Researchers have adopted different techniques to integrate the three components of sustainability. But the relationship between different sustainability initiatives and the performance outcomes are still to be analyzed systematically. In the present study, the review of various works published in sustainable supply chain management domain is carried out with a hybrid method of meta-analysis and content analysis. The research papers were selected based on different theories of sustainable development. The theories considered in the present study are the following; theory of population ecology, resource-based view theory, natural resource-based view theory, resource dependence theory, stakeholder theory, and transaction cost economics theory. The developments in the sustainable supply chain management area and the methodologies used for modelling and analysis are reviewed using this hybrid method by carefully analyzing the literature published during the period 2005-2017. This review will enable researchers in identifying the potential areas for research on sustainable supply chain management.
High Temperature SiC Reactor Cleaning Using Chlorine Trifluoride Gas Achieved by Purified Pyrolytic Carbon Coating Film
Authors: Kurashima Keisuke , Shioda Kohei , Habuka Hitoshi , Ito Hideki , Mitani Shinichi , Takahashi Yoshinao
Published: July 2019

A reactor cleaning technique for the silicon carbide (SiC) chemical vapor deposition (CVD) method has been developed using chlorine trifluoride (ClF3) gas. The purified pyrolytic carbon film was studied as the improved coating film of the susceptor. At the temperatures up to 570 °C, the purified pyrolytic carbon film could have no serious damage after the exposure to the ClF3 gas, to enable the high temperature and high speed cleaning.
Surface Morphology of 4H-SiC after Thermal Oxidation
Authors: Woerle Judith , Šimonka Vito , Müller Elisabeth , Hössinger Andreas , Sigg Hans , Selberherr Siegfried , Weinbub Josef , Camarda Massimo , Grossner Ulrike
Published: July 2019

Step-controlled growth of 4H-SiC epitaxial layers leads to the formation of a step-bunched morphology along the surface with larger macrosteps, composed of smaller microsteps of several Si-C bilayer heights. As thermal oxidation is an orientation-dependent process, a multi-faceted surface is expected to exhibit a different oxidation behavior compared to a perfectly planar surface. In this work, step-bunched surfaces after oxidation are investigated by high-resolution atomic force microscopy (HR-AFM) and transmission electron microscopy (TEM) indicating a morphological change in the early stages of thermal oxidation. An orientation-dependent oxidation model is used to correctly describe variations of the oxide thicknesses at isolated macrosteps.
Subthreshold Drain Current Hysteresis of Planar SiC MOSFETs
Authors: Asllani Besar , Castellazzi Alberto , Planson Dominique , Morel Hervé
Published: July 2019

V

TH
instabilities of SiC MOSFET are made of a permanent and a recoverable part. VTH hysteresis is a recoverable instability which affects the operation of the device since the threshold voltage depends on the negative bias applied previously. In this paper, the phenomenon is assessed through experiments and TCAD simulation. The results are in good agreement and show that the VTH hysteresis is mainly caused by the hole trapping in the oxide near the interface. The C(V) characteristics of the measured device is similar to the simulated device having a concentration of 1012 holes/cm2 trapped at the interface.
First Principles Study of the Influence of the Local Steric Environment on the Incorporation and Migration of NO in a-SiO2
Authors: Mistry Manesh V. , Cottom Jonathon , Patel K. , El-Sayed A.M. , Pobegen Gregor , Aichinger Thomas , Shluger Alexander L.
Published: July 2019

The NO anneal has been shown to effectively remove 99% of defects in SiC based devices. However, the details of interactions of NO molecules with amorphous (a)-SiO2 and SiC/SiO2 interface are still poorly understood. We use DFT simulations to investigate the NO incorporation energies in a-SiO2, and how these are affected by the steric environment. The results explain the ease with which NO molecules incorporate into a-SiO2 and give an insight into the diffusion paths they take during annealing. We highlight the importance of exhaustive sampling for exploring NO diffusion pathways.
Characterization of SiO2/SiC Near-Interface Oxide Traps with Constant-Capacitance Deep-Level Transient Spectroscopy
Authors: Okada Hiroshi
Published: July 2019

A quantitative analysis method was proposed for near-interface oxide traps (NITs) at the SiC-MOS interface. Based on the tunneling capture model for electrons to the traps, characteristic parameters of NITs were clearly extracted from the pulse width dependence of the constant-capacitance deep-level transient spectroscopy (CC-DLTS) signal amplitude measured under isothermal conditions. To exclude capture processes other than direct tunneling, the pulse voltage was set to the flat-band voltage. The validity of the assumed model, in which the majority of the traps are localized at the interface and not distributed through the whole depth of the oxide, was demonstrated through comparison of the experimental results for two samples with different oxide thickness. The density of NITs at the MOS interface fabricated on 4H-SiC oxidized in a N2O atmosphere slowly decreases with the energy depth. The capture cross-section at the interface has no energy dependence, and has a value of 10-19 cm2.
A Temperature Independent Effect of Near-Interface Traps in 4H-SiC MOS Capacitors
Authors: Pande Peyush , Dimitrijev Sima , Haasmann Daniel , Moghadam Hamid Amini , Tanner Philip , Han Ji Sheng
Published: July 2019

In this paper we report temperature independent near-interface traps (NITs) in the gate oxide of N-type MOS capacitors. The measurements were performed by a recently developed direct-measurement technique, which detected NITs with energy levels between 0.13 eV to 0.23 eV above the bottom of conduction band. These traps are also spatially localized close to the SiC surface, as evidenced by the fact that they are not observed at measurement frequencies below 6 MHz. The temperature independence indicates that this localized defect is different from the usually observed NITs whose density is increased by temperature-bias stress.
Identification of Near-Interface Trap Distribution by Parameter Estimation
Authors: Yamashita Yusuke
Published: July 2019

To identify the near-interface trap (NIT) distribution of a metal oxide semiconductor (MOS) capacitor, we propose a new evaluation method by parameter estimation through optimization. The MOS capacitor was fabricated with Al/SiO2 (75 nm)/SiC and measured by the capacitance transient (C-t) method. In addition, C-t signals were calculated from the assumed NIT distribution model. Then, the calculated C-t signals were modified to fit the measured signals by optimization of the parameters of the NIT model. The two types of NITs, deep (Ec – Et = 0.57 eV) and shallow (Ec – Et = -0.02 eV or-0.18 eV), were revealed by this method.
Optical Discrimination of TSDs and TEDs in 4H-SiC Substrates and Epitaxial Layers by Phase Contrast Microscopy Method
Authors: Hattori Ryo , Oku Osamu , Sugie Ryuichi , Murakami Kazutsugu , Kuzuhara Masaaki
Published: July 2019

Phase contrast microscopy (PCM) technique was demonstrated as the effective non-destructive discrimination method of TSDs and TEDs in 4H-SiC epitaxial layers in comparison with conventional polarized light microscopy, PL topography, KOH etch pit inspection and X-ray topography. The appearance of TSDs and TEDs by the PCM method is subtly modified by not only the consisting burgers vector but also the crystalline quality of the epitaxial layer or the substrate as the background. To extract more detailed information on the dislocations, the PCM inspection requires further investigation.
Detecting Basal Plane Dislocations Converted in Highly Doped Epilayers
Authors: Nishihara Yoshitaka , Kamei Koji , Momose Kenji , Osawa Hiroshi
Published: July 2019

Suppression of the forward voltage degradation is essential in fabricating bipolar devices on silicon carbide. Using a highly N–doped 4H–epilayer as an enhancing minority carrier recombination layer is a powerful tool for reducing the expansion of BPDs converted at the epi/sub interface; however, these BPDs cannot be observed by using the near–infrared photoluminescence in the layer. Near–ultraviolet photoluminescence was instead used to detect BPDs as dark lines. In addition, a short BPD converted near the epi/sub interface and contributing to the degradation was detected. When this evaluation was applied to the fabrication of a pin diode including a highly N–doped 4H–epilayer, the Vf shift was suppressed in comparison with that in a diode without the layer.
Variation of Vanadium Incorporation in Semi-Insulating SiC Single Crystals Grown by PVT Method
Authors: Lee Chae Young , Choi Jeong Min , Kim Dae Sung , Park Mi Seon , Jang Yeon Suk , Lee Won Jae , Yang In Seok , Kim Tae Hee , Chen Xiu Fang , Xu Xian Gang
Published: July 2019

Two SiC crystals were grown using SiC source powder with different level of purity and then the effect of the purity of SiC source materials on the final electrical properties has been systematically observed. Furthermore, the variation of vanadium amount according to the growth direction of vanadium doped semi-insulated SiC single crystals has been investigated. The quality of SiC crystal grown using SiC source powder with higher purity was definitely better than SiC crystal with lower purity. SiC crystals having an average resistivity value of about 1×1010 Ωcm were successfully obtained. In the result of COREMA measurement, the use of high purity SiC powder was revealed to obtain wafers with better uniformity in resistivity value.
Comparison of Ranges for Al Implantations into 4H-SiC (0001) Using Channeled Ions and an Ion Energy in the Bethe-Bloch Region
Authors: Mochizuki Kazuhiro , Kosugi Ryoji , Yonezawa Yoshiyuki , Okumura Hajime
Published: July 2019

Ranges for Al implantations into 4H-SiC (0001) were compared between channeled-ion implantation (without using a MeV implanter) and non-channeled ion implantation using an ion energy E0 in the Bethe–Bloch region (IIBB). Since the latter (i.e., projected range of 7.5 μm at E0 = 26 MeV) was larger than the former (i.e., maximum channeled range of 3.4 μm at E0 = 900 keV), IIBB was concluded to be suitable to minimize the repeat count of epitaxial growth/ion implantation steps used in the fabrication of 4H-SiC superjunction power devices.
Effects of Thermal Annealing Processes in Phosphorous Implanted 4H-SiC Layers
Authors: Severino Andrea , Mello Domenico , Boninelli Simona , Roccaforte Fabrizio , Giannazzo Filippo , Fiorenza Patrick , Calabretta Cristiano , Calcagno Lucia , Piluso Nicolo , Arena Giuseppe
Published: July 2019

Silicon carbide (SiC) is an attractive material for power devices owing to the availability of high-quality epitaxial wafers and superior physical properties, such as its high breakdown electric field strength, high electron mobility, and low anisotropy. Ion implantation is a key process for both n- and p-type selective doping of SiC devices. A subsequent annealing in the temperature range of 1600- 1800°C is required to remove the damage induced by the implantation process and to electrically activate the implanted dopants. The aim of this work is the investigation of the effect of thermal annealing on the damage induced by Phosphorous ion implantation to produce n-type regions.
A Comparative Study of the Crystal Growth Techniques of Silicon Carbide, Technology Adaption and the Road to Low Cost Silicon Carbide Materials
Authors: Parthasarathy Santhana Raghavan , Drachev Roman , Bathey Bala , Chou Henry
Published: July 2019

The growing demand for power electronic device for automotive, photovoltaic, transportation, motor drives creates an enormous demand for widebandgap semiconducting materials such as silicon carbide (SiC) and gallium nitride (GaN). While GaN based devices can be used for low voltages, SiC is the workhorse for voltages >600. Progress in the availability of larger diameter SiC wafers has driven the final cost of device assembly down. In this paper we compare different growth techniques for growing high quality SiC crystals, technology adaption and road to low cost SiC materials. GT Advanced Technologies has been involved in SiC sublimation equipment manufacturing since the year 2000 and the results from our 100 mm and 150 mm SiC crystals show high epi-quality.
Chlorine Trifluoride Gas Distributor Design for Single-Crystalline C-Face 4H-Silicon Carbide Wafer Etcher
Authors: Kurashima Keisuke , Kawasaki Ryohei , Irikura Kenta , Okuyama Shogo , Habuka Hitoshi , Takahashi Yoshinao , Kato Tomohisa
Published: July 2019

The etching rate profile over the 50-mm diameter single-crystalline C-face 4H-SiC wafer by ClF3 gas was numerically evaluated by means of the numerical calculation accounting for the transport phenomena. The etching rate uniformity is expected to be improved by means of adjusting the pinhole diameter and their arrangement of the gas distributor.
Multi-Barrier Height Characterization and DLTS Study on Ti/W 4H-SiC Schottky Diode
Authors: Zhang Teng , Raynaud Christophe , Planson Dominique
Published: July 2019

Schottky barrier height (SBH) has been characterized on 4H-SiC Schottky diodes with metal contact of Ti/W by Current-Voltage (I-V) and Capacitance-Voltage (C-V) measurements between 80 K and 400 K. Multi-barrier has been recognized and calculated according to different models. No clear difference has been found between single barrier diode and diode with multi-barrier from DLTS tests. Evolution on the I-V characteristics has been observed after high temperature annealing. The effect of annealing at room temperature (RT) and high temperature DLTS scan (stress under high temperature) have also been studied on both static characteristics and DLTS results.
Temperature Dependence of dV/dt Impact on the SiC-MOSFET
Authors: Nakata Shuhei , Tanaka Shota
Published: July 2019

Recentlly, high speed switching circuits using SiC power device have been developed for reduction of switching loss and downsizing of electric products. The high speed switching leads to the rapid changing of the drain voltage (dV/dt) during the switching period. This paper reports the effects of the dV/dt impact on the self-turn-on and the characteristics of SiC-MOSFET, especially the temperature dependence. The results shows that the gate bias voltage to suppress the self-turn-on is negatively correlated with the temperature. And it is also found that the dV/dt impact breaks down the gate source insulation and the dV/dt value to the breakdown is positively correlated with the temperature.
Design of a 4H-SiC RESURF n-LDMOS Transistor for High Voltage Integrated Circuits
Authors: Weisse Julietta , Mitlehner Heinz , Frey Lothar , Erlbacher Tobias
Published: July 2019

In this work, a lateral 4H-SiC n-LDMOS transistor, based on the principle of a reduced surface field due to charge compensation, is investigated by numerical simulations, in order to find adequate fabrication parameters for a lightly doped p-type epitaxy in combination with a higher doped channel region. The purpose of this work is the integration into an existing technology for a 10 V 4H-SiC-CMOS process. The simulations predict in a blocking voltage of 1.3 kV in combination with an On-resistance of 17 mΩcm2 for a device with a RESURF structure with a total implanted Al concentration of 6∙1016 cm-3 and a depth of 1 μm, a field plate of 5 μm and a drift region of 20 μm. The threshold voltage varies from 5 V to 10 V, depending on the thickness of the gate oxide (50 nm to 100 nm).
Improved Device Characteristics Obtained Using a Novel High-K Dielectric Stack for 4H-SiC n-IGBT: HfO2-SiO2- AlN
Authors: Kotamraju Siva , Vudumula Pavan
Published: July 2019

We report on a novel method of stacking multiple oxide layers on 4H-SiC 20 kV IGBT. Instead of SiO2/SiC interface which is common for any SiC based MOS device, we found that the AlN/SiC interface would yield better results. We have performed 2D numerical simulations to analyze static characteristics for three combinations of dielectric stacks on IGBT: HfO2-SiO2, HfO2-AlN, and HfO2-SiO2-AlN (by maintaining the same equivalent oxide thickness value). In addition to higher transconductance (gm) and lower subthreshold swing (SS), the device with AlN/SiC interface offer comparatively lower RSP,ON and higher mobility with respect to temperature. Nevertheless, with a partial compromise on device characteristics improvement, insertion of SiO2 in the dielectric stack helps in suppressing the subthreshold current owing to higher band offset with respect to SiC. The turn off characteristics of the device is analysed using a clamped inductive circuit. Device with AlN/SiC has shown better dIc/dt and fall time compared to SiO2/SiC interface.
Improvement of Switching Characteristics in 6.5-kV SiC IGBT with Novel Drift Layer Structure
Authors: Watanabe Naoki , Yoshimoto Hiroyuki , Mori Yuki , Shima Akio
Published: July 2019

6.5-kV SiC IGBT with novel drift layer structure is developed to eliminate collector voltage steepening during turn-off and thus to suppress a ringing noise. The proposed IGBT has a depletion-controlled structure (DCS) of a two-step drift layer to suppress the increase of a depletion layer during the turn-off. We fabricated n-channel SiC IGBTs with DCS designed for a blocking voltage of 6.5 kV. Also, we applied our original backside-grinding-last (BG-last) process that enables low switching loss. The DCS device successfully reduced a riging of the gate voltage and had a turn-off loss of 17.6 mJ with 3.6-kV and 32-A switching operation. Although this value is larger than that of the conventional devices (8.8 mJ) due to a tail current, it is still quite low compared with the reported switching loss of SiC IGBTs with the proper switching curves, which is estimated to be 46.1 mJ with the same rated voltage and current.
TCAD Model Calibration of High Voltage 4H-SiC Bipolar Junction Transistors
Authors: Johannesson Daniel , Nawaz Muhammad , Nee Hans Peter
Published: July 2019

In this project, a Technology CAD (TCAD) model has been calibrated and verified against experimental data of a 15 kV silicon carbide (SiC) bipolar junction transistor (BJT). The device structure of the high voltage BJT has been implemented in the Synopsys Sentaurus TCAD simulation platform and design of experiment simulations have been performed to extract and fine-tune device parameters and 4H-SiC material parameters to accurately reflect the 15 kV SiC BJT experimental results. The set of calibrated TCAD parameters may serve as a base for further investigations of various SiC device design and device operation in electrical circuits.
High-Voltage SiC-JFET Fabrication and Full Characterization
Authors: Asllani Besar , Bevilacqua Pascal , Zaoui Abderrahime , Grosset Gregory , Planson Dominique , Morel Hervé
Published: July 2019

3.3 kV Power JFETs have been designed, fabricated and measured in the framework of the FilSiC project. The paper presents the main characterization results with classical static and dynamic xmeasurements as well as double pulse tests for switching characterization. The study is completed by a data-sheet evaluation for the measured components and an evaluation of the associated safe operating area.
Creation of Color Centers in SiC PN Diodes Using Proton Beam Writing
Authors: Chiba Yoji , Yamazaki Yuichi , Makino Takahiro , Sato Shin Ichiro , Yamada Naoto , Satoh Takahiro , Kojima Kazutoshi , Lee Sang Yun , Hijikata Yasuto , Ohshima Takeshi
Published: July 2019

We demonstrated that silicon vacancy (VSi) can be created in SiC pn junction diode by proton beam writing (PBW) without degradation of the diode performance. The VSi showed the same specific emission for both optically and electrically excitation, which suggests that electrically controllable VSi was created. In addition, optically detected magnetic resonance (ODMR) signal was successfully detected from optically excited VSi at room temperature. This result suggests that VSi introduced into the device by PBW still maintain spin manipulating capability, which is an important step toward realizing SiC devices internally equipped with a VSi-based quantum sensor.
Electrophysical and Optical Properties of 4H-SiC UV Detectors Irradiated with Electrons
Authors: Kalinina Evgenia V. , Lebedev Alexander A. , Kozlovski Vitalii V. , Zabrodski Vladimir , Strel'chuk Anatoly M. , Nikitina Irina P.
Published: July 2019

Comparative studies of the structural, electrophysical properties and spectral sensitivity of 4H-SiC photodetectors of ultraviolet radiation in the spectral range of 200-400 nm were carried out before and after electron irradiations. Photodetectors with Cr Schottky barriers with thickness of 20 nm and 8 mm diameter were formed on n-4H-SiC CVD epitaxial layers with a thickness of 5 μm and concentration Nd-Na= (1-4) х1014 cm-3. Cr/4H-SiC photodiodes were irradiated by electrons at 0.9 MeV energy with doses (0.2-1) x1016 cm-2.
1200 V SiC MOSFETs with Stable VTH under High Temperature Gate Bias Stress
Authors: Franchi Jimmy , Domeij Martin , Lee Kwang Won
Published: July 2019

In this work, threshold voltage drift of SiC MOSFET devices have been investigated. The drift during positive gate bias application was found to be moderate for three commercial grade devices, while the results for negative gate bias application differ widely. We demonstrate ON Semiconductor SiC MOSFETs with threshold voltage stability under both positive and negative bias stress due to an improved gate oxide process, and the influence of high field stress on the threshold voltage is additionally discussed. A long term transient high temperature gate bias stress is shown to cause a slight positive shift in the threshold voltage of the ON Semiconductor devices, while the on resistance remains constant.
Capability of SiC MOSFETs under Short-Circuit Tests and Development of a Thermal Model by Finite Element Analysis
Authors: Cavallaro Daniela , Pulvirenti Mario , Zanetti Edoardo , Saggio Mario
Published: July 2019

The aim of this paper is to analyze the SiC MOSFETs behavior under short circuit tests (SCT). In particular, the activity is focused on a deep evaluation of short circuit dynamic by dedicated laboratory measurements conducted at different conditions supported and compared by means of a robust physical model developed by Finite Element Approach.
Comparative Study on the Repetitive Unclamped-Inductive-Switching Capability(R-UIS) of 1200V 160mOhm SiC Planar Gate MOSFETs
Authors: Ji In Hwan , Chowdhury Sauvik , Powell Blake , Chatty Kiran , Banerjee Sujit , Matocha Kevin
Published: July 2019

This paper presents the comparative study on the repetitive unclamped inductive load switching capabilites in comercialized 1200V, 160mΩ rated SiC MOSFETs. Recently released Littelfuse-Monolith 1200V 160 mOhm design (LSIC1MO120E0160) manufactured through 150mm high volume CMOS compatible process demonstrated excellent R-UIS capabilities: no parametric shift on key electrical performances such as on-resistance, threshold voltage, breakdown voltage and drain leakage current after 100000 cycles of R-UIS stress. Both Competitor A and B design with planar gate showed R-UIS capabilities. All critical parameters were within the datasheet specification after R-UIS test. Competitor A design was equivalent to LSIC1MO120E0160. Competitor B design showed the drain leakage increase after 2000 cycle of R-UIS stress. Competitor C design with trench gate did not exhibit any R-UIS capabilities.