127 research outputs found
Modeling of Fowler-Nordheim current of metal/ ultra-thin oxide/ semiconductor structures
In this paper we present results of a modeling of the current-voltage characteristics of metal/ultra-thin oxide/semiconductor structures with negatively biased metal gate (V<0), when the oxide thickness varies from 45Ă
to 80Ă
. We analyze the theoretical influence of the temperature and Schottky effect on the Fowler-Nordheim (FN) conduction. The results obtained show that these influences depend on the electric field in the oxide and on the potential barrier at the metal/oxide interface. At the ambient temperature, the influence on this potential barrier is lower than 1.5%. However, it can reach 45% on the pre-exponential coefficient of the FN current. It is therefore necessary to consider in the FN classical conduction expression a correction term that takes account the temperature and Schottky effects. These results are validated experimentally by modeling the current-voltage characteristics of the realized structures at high field.In this paper we present results of a modeling of the current-voltage characteristics of metal/ultra-thin oxide/semiconductor structures with negatively biased metal gate (V<0), when the oxide thickness varies from 45Ă
to 80Ă
. We analyze the theoretical influence of the temperature and Schottky effect on the Fowler-Nordheim (FN) conduction. The results obtained show that these influences depend on the electric field in the oxide and on the potential barrier at the metal/oxide interface. At the ambient temperature, the influence on this potential barrier is lower than 1.5%. However, it can reach 45% on the pre-exponential coefficient of the FN current. It is therefore necessary to consider in the FN classical conduction expression a correction term that takes account the temperature and Schottky effects. These results are validated experimentally by modeling the current-voltage characteristics of the realized structures at high field
Exact and approximate modeling of electrical properties of metal /insulator/semiconductor structures
In this paper, we present the results of simulation concerning electrical properties of metal/insulator/semiconductor structures both in the absence and presence of charge in the insulator. After establishing different basic equations in integral forms, we have given these equations analytically by using the Maxwell-Boltzmann approximation. Then, we have analyzed the potentials and electrical fields in the insulator and at the insulator-semiconductor interface in terms of the voltage applied to the structure and the charge density. This has yielded to the analysis of the relative errors made on these electrical parameters as a function of respectively the field in the insulator, the semiconductor doping and the charge density. The obtained results show a validation of the Maxwell-Boltzmann approximation; in particular for the electrical field determination in the structure (error is lower than 1.8%). The errors made by using this approximation are interpreted in term of semiconductor interface degeneracy.In this paper, we present the results of simulation concerning electrical properties of metal/insulator/semiconductor structures both in the absence and presence of charge in the insulator. After establishing different basic equations in integral forms, we have given these equations analytically by using the Maxwell-Boltzmann approximation. Then, we have analyzed the potentials and electrical fields in the insulator and at the insulator-semiconductor interface in terms of the voltage applied to the structure and the charge density. This has yielded to the analysis of the relative errors made on these electrical parameters as a function of respectively the field in the insulator, the semiconductor doping and the charge density. The obtained results show a validation of the Maxwell-Boltzmann approximation; in particular for the electrical field determination in the structure (error is lower than 1.8%). The errors made by using this approximation are interpreted in term of semiconductor interface degeneracy
Les lymphomes de lâanneau de Waldeyer traitement et pronostic
Les lymphomes non Hodgkiniens (LNH) qui prennent naissance au niveau de lâanneau de Waldeyer constituent une entitĂ© bien particuliĂšre tant sur le plan clinique, thĂ©rapeutique que pronostique. Les auteurs rapportent une Ă©tude rĂ©trospective de 44 observations de LNH de lâanneau de Waldeyer colligĂ©es entre 1995 et 2002. Une chimiothĂ©rapie exclusive aĂ©tĂ© indiquĂ©e chez 80,6% des malades et une association chimio-radiothĂ©rapie a Ă©tĂ© rĂ©alisĂ©e chez 19,4%. Le taux de survie globale Ă©tait de 42% Ă 5 ans. Dans notre Ă©tude quatre facteurs de mauvais pronostic ont Ă©tĂ© individualisĂ©s : un Ăąge â„ Ă 40 ans, les stades dâAnn Arbor II, III et IV, un taux de LDH â„ 1,5 fois la normale et la survenue de rechute.Mots-clĂ©s : Lymphome, anneau de Waldeyer, chimiothĂ©rapie, radiothĂ©rapie, pronosti
International Consensus Statement on Rhinology and Allergy: Rhinosinusitis
Background: The 5 years since the publication of the first International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICARâRS) has witnessed foundational progress in our understanding and treatment of rhinologic disease. These advances are reflected within the more than 40 new topics covered within the ICARâRSâ2021 as well as updates to the original 140 topics. This executive summary consolidates the evidenceâbased findings of the document. Methods: ICARâRS presents over 180 topics in the forms of evidenceâbased reviews with recommendations (EBRRs), evidenceâbased reviews, and literature reviews. The highest grade structured recommendations of the EBRR sections are summarized in this executive summary. Results: ICARâRSâ2021 covers 22 topics regarding the medical management of RS, which are grade A/B and are presented in the executive summary. Additionally, 4 topics regarding the surgical management of RS are grade A/B and are presented in the executive summary. Finally, a comprehensive evidenceâbased management algorithm is provided. Conclusion: This ICARâRSâ2021 executive summary provides a compilation of the evidenceâbased recommendations for medical and surgical treatment of the most common forms of RS
Integrated imaging of avascular serous pigment epithelium detachment in age-related macular degeneration
IntroductionThis study describes the imaging of avascular serous pigment epithelial detachment (PED) in age-related macular degeneration (AMD) patients using confocal scanning laser ophthalmoscopy ..
Correction to: Magnetocaloric-Transport Properties Correlation in La0.8 Ca0.2MnO3-Doped Manganites
International audienc
Modeling of current-voltage characteristics of metal/ultra-thin oxide/semiconductor structures
In this paper we present the results of modeling concerning
current-voltage (V < 0) characteristics of metal/ultra-thin oxide/semiconductor
structures, where the oxide thickness varies from 45 Ă
to 80 Ă
. We analyze
the theoretical influence of the temperature and Schottky effect, on the
Fowler-Nordheim (FN) conduction. The results obtained show that these influences
depend on the electric field in the oxide and the potential barrier at the
metal/oxide interface. At the ambient temperature, the influence on this
potential barrier is lower than 1.5% . However, it can reach 45% on the
pre-exponential coefficient (K1). It is therefore necessary to consider in the FN
classical conduction expression a correction term that takes account of the
temperature and Schottky effects. These results are validated experimentally by
modeling at high field, the current-voltage characteristics of the realized
structures. At low field, we have determined the excess current [3],
which is due to defects localized in the oxide layer, according to the structure
area and the oxide thickness. By modeling this excess current, we show that it
is of FN type, and deduct that the effective defect barrier depends little on
the structure area and the oxide thickness. By taking into account the effective
barrier value and the corrective factors due to the temperature and Schottky
effect, we determine the defect effective area and show that it is related to
the breakdown field of the structures: when the defect effective area increases,
the breakdown field decreases
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