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

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

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

Capital Budgeting Use In Canada: Sophistication And Risk Attributes

This study uses a sample of 80 of the 1989 financial Posts Top 500 Canadian Corporations to test for correlation between the selection of capital budgeting techniques and three variables measuring the degree of environmental uncertainty: (1) firms systematic risk (i.e., firms beta), (2) industrys systematic risk (i.e., industry beta), and (3) managements self assessment of its corporate risk

Analysis of water conveying aluminum oxide/silver nanoparticles due to mixed convection through four square cavity's variable hot (cold) walled

The present work focuses on the measurement of the general entropy and the heat exchanges that occur inside a square-shaped cavity by changing the cold and hot wall in four cases filled with a hybrid nano-liquid (Al2O3-Ag/water) with a cylinder installed inside it. After validating the model, the parametric study has been conducted based on Rayleigh number (Ra), Hartman number (Ha), Darcy number (Da), Solid volume fraction (φ) and Porosity (ε) aspects. An effective finite element method was employed to solve the problem of flow in a dimensionless form of governing equations towards flow and thermal behaviors of nanofluid which is laminar and incompressible. Using the COMSOL Multiphysics® software computer suite, the equations for energy, motion, and continuity were resolved. Nusselt number calculations are presented to quantify heat transport via mixed convection. In the case studies, the entropy generation improves regardless of where the heated wall is located, except for the third case, where it is higher than the others. The findings are demonstrated with a higher Rayleigh number Ra, average Nusselt number, and entropy production. The heat transfer rate (HTR) can be effectively adjusted by making use of the magnetic field. The process of producing entropy in the third cavity, where the hot wall mediates the right wall, is the crucial observation made through this effort

Mathematical Entropy Analysis of Natural Convection of MWCNT&mdash;Fe3O4/Water Hybrid Nanofluid with Parallel Magnetic Field via Galerkin Finite Element Process

Heat transfer in a symmetrical cavity with two semi-cylinders was explored in this study. Several parameters, such as (103&le;Ra&le;106), (10&minus;5&le;Da&le;10&minus;2), (0.02&le;&#981;&le;0.08), (0.2&le;&epsilon;&le;0.8), and (0&le;Ha&le;100) were selected and evaluated in this research. The outcome of the magnetic field and the temperature gradient on the nanofluid flow is considered. The geometric model is therefore described using a symmetry technique. The flow issue for the governing equations has been solved using the Galerkin finite element method (G-FEM), and these solutions are presented in dimensionless form. The equations for energy, motion, and continuity were solved using the application of the COMSOL Multiphysics&reg; software computer package. According to the results, there is a difference in the occurrence of the magnetic parameter and an increase in heat transmission when the right wall is recessed inward. The heat transmission is also significantly reduced when the right wall is exposed to the outside. The number of Nusselt grows directly proportional to the number of nanofluids in the environment. In contrast, all porous media with low Darcy and Hartmann numbers, high porosity, and low volume fraction have high Nusselt numbers. It is found that double streamlines for the hot side and single cooling for Darcy, Rayleigh, and Hartmann numbers. A cold isotherm at various physical parameters is needed in the top cavity. Rayleigh&rsquo;s number and a solid volume fraction raise Darcy&rsquo;s number, increasing heat transmission inside the cavity and thermal entropy determines entropy components

Mathematical Entropy Analysis of Natural Convection of MWCNT—Fe₃O₄/Water Hybrid Nanofluid with Parallel Magnetic Field via Galerkin Finite Element Process

Heat transfer in a symmetrical cavity with two semi-cylinders was explored in this study. Several parameters, such as (103≤Ra≤106), (10−5≤Da≤10−2), (0.02≤ϕ≤0.08), (0.2≤ε≤0.8), and (0≤Ha≤100) were selected and evaluated in this research. The outcome of the magnetic field and the temperature gradient on the nanofluid flow is considered. The geometric model is therefore described using a symmetry technique. The flow issue for the governing equations has been solved using the Galerkin finite element method (G-FEM), and these solutions are presented in dimensionless form. The equations for energy, motion, and continuity were solved using the application of the COMSOL Multiphysics® software computer package. According to the results, there is a difference in the occurrence of the magnetic parameter and an increase in heat transmission when the right wall is recessed inward. The heat transmission is also significantly reduced when the right wall is exposed to the outside. The number of Nusselt grows directly proportional to the number of nanofluids in the environment. In contrast, all porous media with low Darcy and Hartmann numbers, high porosity, and low volume fraction have high Nusselt numbers. It is found that double streamlines for the hot side and single cooling for Darcy, Rayleigh, and Hartmann numbers. A cold isotherm at various physical parameters is needed in the top cavity. Rayleigh’s number and a solid volume fraction raise Darcy’s number, increasing heat transmission inside the cavity and thermal entropy determines entropy components