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

Modeling of conduction properties of Schottky diodes in Polymer

This work deals with the modeling of experimental current-voltage (I-V) characteristics according to the temperature of P type Schottky diode in polymers. The results obtained show that conduction in the fabricated structures depends on temperature and bias the mode (forward or reverse). Under reverse bias, current increases significantly with temperature. This is due to the thermoionic conduction, affected by the lowering of the potential barrier at the metal /polymer interface due to the image charge effect. The analysis of current-voltage characteristics has enabled us to derive the saturation current and, also, the potential barrier at the metal/polymer interface according to temperature. It has been shown that the value of this barrier without image charge effect, is in the order of 0. 3eV. Under forward bias, current increases with temperature. It is of the thermoionic type at low voltage (-0.4 Volt<V< 0 Volt). It has been shown that the values of the ideality factor depend very little on temperature: varying from 1.5 to 4. However, saturation current increases with temperature: when temperature increases by approximately 6%, current increases by 20%. The values of saturation current for temperatures in excess of 200°K are confirmed by the values found in reverse bias. For temperatures less than 200°K, saturation currents in reverse mode are important relative to that obtained in forward mode. This is attributed to the electrical properties of polymer at low temperatures in reverse mode. At high voltages (V<-0.4 Volt), the current is attributed to the resistance effect of polymer. This resistance is evidenced by the high current and drops with temperature. Its analysis has allowed us to derive the mobility of the carrier charges: when temperature varies from 105°K to 425°K, mobility varies from 3 10-5(cm2V-1S-1) to 7 10-5(cm2V-1S-1).This work deals with the modeling of experimental current-voltage (I-V) characteristics according to the temperature of P type Schottky diode in polymers. The results obtained show that conduction in the fabricated structures depends on temperature and bias the mode (forward or reverse). Under reverse bias, current increases significantly with temperature. This is due to the thermoionic conduction, affected by the lowering of the potential barrier at the metal /polymer interface due to the image charge effect. The analysis of current-voltage characteristics has enabled us to derive the saturation current and, also, the potential barrier at the metal/polymer interface according to temperature. It has been shown that the value of this barrier without image charge effect, is in the order of 0. 3eV. Under forward bias, current increases with temperature. It is of the thermoionic type at low voltage (-0.4 Volt<V< 0 Volt). It has been shown that the values of the ideality factor depend very little on temperature: varying from 1.5 to 4. However, saturation current increases with temperature: when temperature increases by approximately 6%, current increases by 20%. The values of saturation current for temperatures in excess of 200°K are confirmed by the values found in reverse bias. For temperatures less than 200°K, saturation currents in reverse mode are important relative to that obtained in forward mode. This is attributed to the electrical properties of polymer at low temperatures in reverse mode. At high voltages (V<-0.4 Volt), the current is attributed to the resistance effect of polymer. This resistance is evidenced by the high current and drops with temperature. Its analysis has allowed us to derive the mobility of the carrier charges: when temperature varies from 105°K to 425°K, mobility varies from 3 10-5(cm2V-1S-1) to 7 10-5(cm2V-1S-1)

Ionizing Radiation Effect on the Electrical Properties of Metal/ultra-thin Oxide/Semiconductor Structures

This paper deals with the effects of X-ray radiation (7 Mrad (Si) dose) on the electrical properties of Metal/Oxide/Semiconductor (MOS) structures with ultra thin oxide layer (45 Å to 80 Å), P-type semiconductor (Si), and a chromium gate. These effects are investigated on the Fowler-Nordheim (FN) conduction and the excess current when the MOS structure is biased with a positive gate voltage (Vg>0) (inversion regime); and on the breakdown field when electrons are injected from the metal (accumulation regime, Vg0) (inversion regime); and on the breakdown field when electrons are injected from the metal (accumulation regime, Vg<0). By using the theoretical conduction model developed in a previous paper [1], we have found that the FN conduction parameters improve after radiation. We have interpreted this result, by modelling the excess current before and after radiation, by improving the conduction parameters of defects localized in the oxide layer. Thus the defect barrier was increased by 6.5% while the effective area decreased by 68%. The analysis of the radiation effect on breakdown distribution shows the degradation of the breakdown field after radiation. These results suggest that the ionising radiation can be involved in the formation of another type of defects in the oxide layer that can lead to the breakdown phenomenon but cannot impact the FN conduction mechanism

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

Evaluating the performance of a refrigerator by an external system using entanglement

We propose a model of a quantum thermal refrigeration machine interacting with an external atom via an entanglement phenomenon. The machine is formed by three qubits of two-level, where each one interacts locally with its proper reservoir at different temperatures. The second qubit of the refrigerator and the external qubit are initially prepared in an entangled state. The effect of the quantum refrigerator on the entanglement of the final atomic state is studied. It is shown that the survival of the entanglement of the atomic system (Qubits 2 and 4) depends on the temperature of the second reservoir. The heat flow from the cold bath (cooling power) to the hot bath is discussed, where we prove that the refrigeration may be enhanced by the energy coming from the entangled external qubit. Indeed, it is shown that the enhancement of cooling power by increasing the degree of entanglement

Fowler-Nordheim current modeling of metal/ultra-thin oxide/semiconductor structures in the inversion mode, defects characterization

In this paper, we present a simple model of Fowler-Nordheim (FN) current of metal/ultra-thin oxide/semiconductor (MOS) structures biased in the inversion mode ($V_{g }> 0$) (injection of electrons from the semiconductor). The oxide thickness varies from 45 Å to 110 Å, the gate is in chrome and the semiconductor is of P type. From the general models of the conduction by FN effect and by assuming a continuum energy in the inversion layer, we have shown by using the Wentzel-Kramers-Brillouin (WKB) approximation that the modeling of the FN current, cannot be made by using the classical model generally used in the case of electrons injection from the metal ($V_{g }< 0$). However, it requires to introduce in the classical model a corrective term due to the effects of the temperature, the oxide/semiconductor interface degeneracy (the Fermi energy is localized in the semiconductor conduction band) and the Schottky effect. The results obtained from the numerical simulation show that these effects, at the ambient temperature, on the potential barrier at the oxide/semiconductor interface is lower than 4% and the conduction pre-exponential value (K1) is higher than that obtained in the classical model ($K_1^o =10^{-6}$ A/V2) [J. Appl. Phys. 40, 278 (1969)]. These results are validated experimentally by modeling the current-voltage characteristics of MOS structures where the oxide thickness is 109 Å. For oxide thickness lower than 100 Å, we have found that the results of simulation disagree with those experimental. We have attributed this disagreement to the degradation of the conduction parameters by the presence of leakage current before stressing the MOS structure (LCBS). This leakage current is attributed to defects localized in the oxide layer. We have shown that the leakage current is of FN type and deduced the effective barrier of defects. By taking account of this barrier value and the corrective term due to the temperature, the oxide/semiconductor interface degeneracy and the Schottky effects (TDSEs), we have determined the defects effective area. From the comparison between these results and those obtained in the case of electrons injection from the metal ($V_{g} < 0$) [Eur. Phys. J. Appl. Phys. 9, 239 (2000)], we have concluded that the defects depth in the oxide layer is identical to the oxide thickness

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

Modeling of conduction properties of Schottky diodes in Polymer

This work deals with the modeling of experimental current-voltage (I-V) characteristics according to the temperature of P type Schottky diode in polymers. The results obtained show that conduction in the fabricated structures depends on temperature and bias the mode (forward or reverse). Under reverse bias, current increases significantly with temperature. This is due to the thermoionic conduction, affected by the lowering of the potential barrier at the metal /polymer interface due to the image charge effect. The analysis of current-voltage characteristics has enabled us to derive the saturation current and, also, the potential barrier at the metal/polymer interface according to temperature. It has been shown that the value of this barrier without image charge effect, is in the order of 0. 3eV. Under forward bias, current increases with temperature. It is of the thermoionic type at low voltage (-0.4 Volt&lt;V&lt; 0 Volt). It has been shown that the values of the ideality factor depend very little on temperature: varying from 1.5 to 4. However, saturation current increases with temperature: when temperature increases by approximately 6%, current increases by 20%. The values of saturation current for temperatures in excess of 200°K are confirmed by the values found in reverse bias. For temperatures less than 200°K, saturation currents in reverse mode are important relative to that obtained in forward mode. This is attributed to the electrical properties of polymer at low temperatures in reverse mode. At high voltages (V&lt;-0.4 Volt), the current is attributed to the resistance effect of polymer. This resistance is evidenced by the high current and drops with temperature. Its analysis has allowed us to derive the mobility of the carrier charges: when temperature varies from 105°