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关键词： 2-D materials (2DMs)   gate-all-around (GAA) FET   MoS2   multichannel   nanosheet field-effect transistor (NS-FET)   TCAD simulation  

摘要： In this work, we explore the 3-D integration of single layer (SL) and bilayer (BL) MoS(2 )in stacked gate-all-around (GAA) nanosheet field-effect transistor (NS-FET) using fully calibrated TCAD simulation for the future technology node. Our research primarily focuses on a comparative analysis between multichannel stacked SL- and BL-MoS2 NS-FETs with various-width Si NS-FETs, which show that BL-MoS2NS-FET outperforms its Si NS-FET counter part for sub-5-nm technology nodes. The results show that the vertical stacking of SL- and BL-MoS2NS-FET significantly enhances the switching performance metrics and provides strong immunity against short-channel effects at aggressively scaled technology nodes over50-nm wide Si NS-FET counterpart. On the other hand, the Schottky barrier (SB)-type contact with MoS2NS-FETs is found to have inferior ON-state and OFF-state characteristics compared to doped-type contacts. Moreover, the CMOS inverter based on BL-MoS2 demonstrates the potential for lower power consumption at iso-frequency and higher operating frequency at iso-power compared to SL-MoS(2 )and Si NS-FETs. Our research underscores that MoS(2 )with stacked NS-FETs offers a promising solution for advancing technology nodes to 1 nm and beyond.

关键词： Light emitting diodes   Lighting   Modulation   Visible light communication   MOSFET   Circuits   Schottky diodes   Switching-mode power supplies   orthogonal frequency division multiplexing (OFDM)   visible light communication (VLC)   internal modulation   LED drivers   efficacy   illumination  

摘要： Visible light communications (VLC) is a promising technology that combines the ubiquity of illumination devices with broadband communication to provide connectivity. The most recent VLC communication standards specify orthogonal frequency division multiplexing (OFDM) as the underlying modulation due to its spectral efficiency and compatibility with existing broadband modems. However, a key challenge remains in realizing VLC modulators capable of generating OFDM signal compatible with the primary illumination function, while ensuring the efficacy of the luminaires. In this paper, a novel method is proposed to integrate OFDM modulation into a switching power supply. Commutating diodes in the DC/DC converter are replaced by light-emitting diodes (LEDs) which are used for communication while the larger illumination string of LEDs is left unmodulated preserving the quality of illumination and luminaire lifetime. Biasing the switching MOSFET to its saturation region during its off states allows for the MOSFET to act as an amplifier, amplifying the OFDM communication signal and injecting it to the light-emitting commutating diode (LECD). As a result, energy efficient LED drivers capable of OFDM signal transmission are realized. Both simulation and experimental results are provided to demonstrate the feasibility of this approach, showcasing superior performance compared to existing literature in terms of component count, efficacy, illumination quality, and reliability. Notably, based on simulation results, the efficacy of our approach surpasses the bias-T approach by approximately 6.25%.

关键词： MOSFET   Transistors   MOSFET circuits   Degradation   Electric variables measurement   Threshold voltage   Logic gates   Radiation effects   total ionizing dose (TID)   ultrathin body and buried oxide fully depleted silicon on insulator (UTBB FD-SOI)  

摘要： The electrical behavior of 22-nm ultrathin body and buried oxide fully depleted silicon on insulator (UTBB FD-SOI) MOSFETs has been investigated up to a total ionizing dose (TID) radiation of 100 Mrad(Si). At high TID levels, the radiation-induced parameter degradation of test devices is obvious. By exploring the channel length and width dependence, we demonstrate that the high TID effect of UTBB FD-SOI devices is mainly governed by trapped charges in buried oxides (BOX) layer, and TID effects in shallow trench isolation (STI) and spacer oxide are negligible. Furthermore, the TID radiation-induced drain bias induce barrier lowering (DIBL) effect in UTBB FD-SOI nMOSFETs is also observed, which limits the radiation tolerance of devices in the saturation region. Finally, based on technology computer aided design (TCAD) simulations, the related mechanisms for subthreshold slope degradation and radiation-induced DIBL effect of UTBB FD-SOI technology are proposed, respectively.

关键词： Temperature sensors   Temperature measurement   MOSFET   Costs   Silicon carbide   Power supplies   Multichip modules  

摘要： Excellent switching performances and higher levels of integration are two critical topics for intelligent power modules (IPM). This article proposes a novel and cost effective 1.2 kV/400 A SiC half-bridge power module based on the Source Turn-off (STO) MOSFET. STO MOSFET is a driver integrated MOSFET architecture that can achieve ultra-fast turn-on and turn-off operations beyond the traditional voltage source gate driver approach. A built-in current and temperature monitoring features are also integrated. The IPM integrates discrete SiC devices, direct bond copper (DBC) base plate, STO gate driver, auxiliary power supply, current monitor, temperature monitor, and decoupling caps, making it plug-and-play ready.

关键词： Legged locomotion   Robots   MOSFET   Prosthetics   Energy conversion   Copper   Supercapacitors   Conversion boundary   energy conversion efficiency   human dynamics  

摘要： Wearable robots involve human-robot interactions, and capturing the electrical energy from human dynamics during interactions is gaining increasing interest. However, previous studies have not thoroughly investigated the maximum mechanical energy and the efficiency of mechanical-to-electrical energy conversion between robotic prostheses and humans. In this study, the effects of motor rotation speed omega(mo), pulsewidth modulation (PWM) duty cycle D, replacing mosfet and replacing a motor on efficiency eta were investigated through theoretical analysis, a bench test, and walking experiments (N = 5). The theoretical analysis involved studying the energy flowchart during the mechanical-to-electrical energy conversion using a bench test. Then, walking experiments were conducted and the results showed that replacing a motor led to a 6% and 10% increase in energy regeneration at 1.3 and 1.1 m/s (self-selected), respectively. Based on the efficiency obtained from a bench test and walking experiments, the maximum mechanical power for a robotic prosthesis was obtained and ranged from 4.35 to 8.23 W, which showed the possibility of a 100% self-charged-powered robotic prosthesis. This study presents a feasible approach to analyze and improve the efficiency of mechanical-to-electrical energy conversion between robots and humans.

关键词： Analytical models   MOSFET   Semiconductor device modeling   Batteries   Voltage   Silicon carbide   Silicon   Analytical Model   Power Losses Analysis   Power Semiconductor Devices   Standalone Photovoltaic-Battery System (SBPS)  

摘要： This paper presents a comprehensive methodology for the selection of power semiconductor devices in a standalone photovoltaic (PV)-battery system (SPBS) based on power loss analysis. The SPBS configuration is modeled analytically, and the waveforms for the system are obtained in a Hardware-In-the-Loop (HIL) and by simulation environment using Matlab. The study focuses on identifying the most cost-effective power semiconductor devices by assessing power loss at three distinct operating points. The algorithm evaluates losses in each component, facilitating the selection of optimal devices for enhanced system performance. The evaluation is performed for different operational modes, incorporating worst-case scenarios for current and voltage, providing a robust analysis of system behavior. By emphasizing the importance of power loss analysis in isolated PV systems, this research contributes to the advancement of energy efficiency in SPBS. The proposed methodology enables the identification of power semiconductor devices experiencing the highest losses, aiding in the selection of components that minimize overall losses and maximize energy utilization from PV panels and batteries.

关键词： Stress   Stress measurement   Kinetic theory   Threshold voltage   Temperature measurement   MOSFET   Analytical models   Semiconductor device reliability   single defects   charge trapping   semiconductor device modeling  

摘要： Charge trapping at oxide defects poses a serious reliability concern in MOS transistors. For scaled technology nodes, the impact of charge-trapping events on the device behavior becomes even more severe. These events can be seen as discrete steps in the device current, allowing for single-defect analysis. In this context, random telegraph noise (RTN) analysis and time-dependent defect spectroscopy (TDDS) have become very popular in exploring the physical origin of charge trapping at single defects. To improve the accuracy of single-defect analysis, we conduct a Monte Carlo analysis of trap occupancy, enabling us to extract information about the charge emission time of fixed oxide traps from charge capture time data recorded under different stress conditions. The newly gained knowledge is beneficial for accurately calibrating defect models used to explain the charge-trapping dynamics of defects.

关键词： Double Gate MOSFET   Gate to Gate Capacitance   Gate to channel capacitance   QSCV  

摘要： In the present work, the authors have studied the Quasi-Static Capacitance-Voltage (QSCV) characteristics of 10 nm gate length double gate (DG) NMOSFETs of different channel materials namely, Si, Ge, and In0.53Ga0.47As, the results are reported using Silvaco ATLAS TCAD. The QSCV approach provides the advantage of immunity against frequency-dependent effects and has the ability to measure the small capacitance in the range of 100 fF. In this device, we consider the self-consistent solution of Schrodinger's equation with Poisson's equation. Further, the conduction band splitting in multiple sub-bands has been considered with light doping in the channel region. For this, the authors have studied C-V behaviour of the devices by observing the effect of metal gate work function engineering (using Ta, W, Mo, Ni, Au and Pt), channel engineering (using Si, In0.53Ga0.47As and Ge) and variation of channel thickness (2 nm, 5 nm, 10 nm and 1502 nm) with gate oxide (SiO2) of thickness 1.2 nm. In further studies, SiO2 was replaced its EOT with HfO(2 )and results were again studied. The comparison of the behavior of C-V curve has been done for the above-mentioned channel materials. It was found that there is a significant reduction in inversion mode Capacitance with voltage for all the channel materials used for both SiO2 based devices and with HfO2 based devices. This has been attributed to quantization which results in a decrease in the overall gate to channel capacitance (C-GC) and hence increases the threshold voltage in MOS device. The quantization effect is lightly seen in Si for channel thickness of 2 nm, however for the same thickness, quantization is seen in Ge. Also for In0.53Ga0.47As quantization is seen for channel thickness of 2nm, 5nm, and 10 nm because of its low electron effective mass. The QSCV characteristics are also used to measure oxide thickness, flat-band voltage, threshold voltage, maximum depletion region thickness, distribution of charges in dielectric, in

关键词： body diode   MOSFET switching   power electronics   power electronics devices   reverse recovery   SiC MOSFETs  

摘要： This paper investigates the behavior of SiC MOSFETs body diode reverse recovery as a function of different operating conditions. The knowledge of their effects is crucial to properly designing and driving power converters based on SiC devices, in order to optimize the MOSFETs commutations aiming at improving efficiency. Indeed, reverse recovery is a part of the switching transient, but it has a significant role due to its impact on recovery energy and charge. The set of different operating conditions has been properly chosen to prevent or force the snappy recovery of the device under testing. The experimental results and specific software simulations have revealed phenomena unknown in the literature. More specifically, the analysis of the reverse recovery charge, Qrr, revealed two unexpected phenomena at high temperatures: it decreased with increasing gate voltage;the higher the device threshold, the higher the Qrr. TCAD-Silvaco (ATLAS v. 5.29.0.C) simulations have shown that this is due to a displacement current flowing in the drift region due to the output capacitance voltage variation during commutation. From the analysis of the snappy recovery, it has emerged that there is a minimum forward current slope, below which the reverse recovery cannot be snappy, even for a high current level. Once this current slope is reached, Qrr varies with the forward current only.