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 45Å to 80Å. 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 45Å to 80Å. 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 l’anneau de Waldeyer traitement et pronostic

Les lymphomes non Hodgkiniens (LNH) qui prennent naissance au niveau de l’anneau de Waldeyer constituent une entité bien particulière tant sur le plan clinique, thérapeutique que pronostique. Les auteurs rapportent une étude rétrospective de 44 observations de LNH de l’anneau de Waldeyer colligées entre 1995 et 2002. Une chimiothérapie exclusive aété indiquée chez 80,6% des malades et une association chimio-radiothérapie a été réalisée chez 19,4%. Le taux de survie globale était de 42% à 5 ans. Dans notre étude quatre facteurs de mauvais pronostic ont été individualisés : un âge ≥ à 40 ans, les stades d’Ann Arbor II, III et IV, un taux de LDH ≥ 1,5 fois la normale et la survenue de rechute.Mots-clés : Lymphome, anneau de Waldeyer, chimiothérapie, radiothérapie, 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 (ICAR‐RS) 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 ICAR‐RS‐2021 as well as updates to the original 140 topics. This executive summary consolidates the evidence‐based findings of the document. Methods: ICAR‐RS presents over 180 topics in the forms of evidence‐based reviews with recommendations (EBRRs), evidence‐based reviews, and literature reviews. The highest grade structured recommendations of the EBRR sections are summarized in this executive summary. Results: ICAR‐RS‐2021 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 evidence‐based management algorithm is provided. Conclusion: This ICAR‐RS‐2021 executive summary provides a compilation of the evidence‐based 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

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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 Åto 80 Å. 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

Lanthanum Deficiency Effect on the Structural, Magnetic, and Transport Properties of the La0.8−x □ x Ca0.2MnO3 Manganites Oxides

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