Showing papers on "Power MOSFET published in 2023"

Integrating 10-kV SiC MOSFET Into Battery Energy Storage System With a Scalable Converter-Based Self-Powered Gate Driver

Abstract: In the hardware design of battery energy storage system (BESS) interface, in order to meet the high-voltage requirement of grid side, integrating 10-kV silicon-carbide (SiC) MOSFET into the interface could simplify the topology by reducing the component count. However, the conventional gate driver design is challenging and inextensible in BESS, since the high-voltage rating and high dv/dt bring the requirements of high-voltage isolation and low common-mode capacitance. Therefore, in this article, a scalable converter-based self-powered (SCS) gate driver is further proposed. A 5-kV input power extracting converter based on a voltage-balanced SiC MOSFET stack is constructed to self-power the gate driver, which exhibits simplification of basic topology and sufficient gate driver power handling capability regardless of the switching requirement of main loop power device. Besides this, the power extracting converter is designed to act as a clamping resistor-capacitor-diode (RCD) snubber circuit, which makes the SCS gate driver scalable to the series connection of power devices. Analysis and design consideration are given in detail, followed by the experimental verification using 10-kV/10-A SiC MOSFETs.

Small-Signal Impedance and Split C-V Characterization of High-κ SiC Power MOSFETs

Abstract: In this work, the improvement of SiC power MOSFET performance achieved using high-κ gate-dielectrics instead of the standard SiO2 is investigated by means of advanced gate-impedance characterization. The benefit of using high-κ gate-dielectrics with high dielectric constant is demonstrated by comparing SiC MOSFETs with pure high-κ, a stack of SiO2/high-κ, as well as pure SiO2. Namely, the fabricated high-κ SiC MOSFETs show a superior performance to commercial SiC MOSFETs with SiO2/SiC interface with respect to channel resistance and interface quality. The proposed characterization approach is non-destructive and applicable to packaged power devices.

Short-circuit and Avalanche Robustness of SiC Power MOSFETs for Aerospace Power Converters

Abstract: Silicon Carbide (SiC) power MOSFETs are emerging as powerful switches to be used where compactness and light weight of the circuit are mandatory, as in aerospace converters, because the switching speed of SiC devices is faster than their silicon (Si) counterpart and therefore smaller inductors can be used. On the other hand, the operation out of the safe operating area of power semiconductor devices becomes critical especially where device, circuit and system reliability are important. In the aerospace sector, SiC devices still lag Si IGBTs and the gap needs to be filled. In this paper, a review of the principal failure mechanisms during short circuit (SC) and unclamped inductive switching (UIS) events on SiC power MOSFETs is presented.

Investigation of Lateral Gallium Oxide MOSFET with Discrete Field Plate by Calibrated Numerical Simulation

Abstract: The main barrier preventing the simulation design and optimization of wide bandgap semiconductor power devices is poor numerical convergence. Currently, the uncalibrated two-dimensional electric field distribution is the main foundation for the breakdown voltage optimization of gallium oxide power devices. This work achieves proper calibration of the current-voltage (I-V) characteristics as well as the breakdown voltage evaluation by enhancing the numerical method. An optimal set of structural parameters for a lateral gallium oxide MOSFET with a discrete field plate is designed using the suggested method. Thanks to the improved electric field profile, the breakdown voltage is increased by 19.7%, and on-state resistance did not degrade. This work resolves the wide-bandgap semiconductors' poor convergence problem and offers a workable strategy for the subsequent theoretical simulation and optimization of gallium oxide power devices.

Assessing, Controlling and Understanding Parameter Variations of SiC Power MOSFETs in Switching Operation

Abstract: Semiconductor manufacturers and researchers have recently revealed that under specific bipolar gate switching conditions SiC MOSFETs exhibit parameter drift dynamics different from those typically observed in static qualification stress tests. In response to this finding, we present an approach for assessing the worst-case drift of data-sheet-relevant electrical parameters in a simple and transparent manner for a large variety of application profiles. We also introduce an empirical model that may explain the drift dynamics observed under gate switching stress; and discuss a recently developed interface characterization technique that has the potential to reveal the nature of point defects at the SiC/SiO2 interface presumably related to the gate switching instability in SiC MOSFETs.

Extended Analysis of Power Cycling Behavior of TO-Packaged SiC Power MOSFETs

Abstract: This paper presents an extended analysis of TO-packaged SiC power MOSFETs after power cycling (PC) tests. Namely, it is shown that initially present voids in soft lead-based solder die attach disappear not only after certain number of active PC tests, but also after thermal shock tests. Hereby, the conclusion that solder die attach is not the weak spot of SiC power MOSFET packages with an epoxy mold compound (EMC) encapsulation is further supported. Furthermore, an electro-thermo-mechanical (ETM) model developed in-house is used to correlate the dominant wear-out failure of bond wires to the PC test parameters such as heating current, temperature amplitude, and heating on-time, as well as to the thickness of top source die metallization.

Review on the Reliability Mechanisms of SiC Power MOSFETs: A Comparison Between Planar-Gate and Trench-Gate Structures

Abstract: To clarify the current research situation and offer a better understanding of the reliability for silicon carbide (SiC) power metal-oxide-semiconductor field-effect transistors (MOSFETs), a comparison among the reliability mechanisms between planar-gate and trench-gate SiC power MOSFETs, which have not been comprehensively summarized, is made in this work. The latest studies focusing on the reliability issues of commercial SiC MOSFET products, including the planar-gate device, the double-trench device and the asymmetric trench-gate device, are reviewed. For the existing of the gate trenches and the unique structures protecting them, SiC trench-gate MOSFETs express quite different instability phenomena from the planar-gate ones under various ultimate and long-term electro-thermal stresses. The influences of these stresses closely related to the practical operation conditions on SiC power MOSFETs, including the avalanche stress, the short-circuit (SC) stress, the surge current stress of the body diode, and the switching stress, are discussed and reviewed in details.

Analysis and Hardening of SEGR in Trench VDMOS with Termination Structure

Abstract: Single-event gate-rupture (SEGR) in the trench vertical double-diffused power MOSFET (VDMOS) occurs at a critical bias voltage during heavy-ion experiments. Fault analysis demonstrates that the hot spot is located at the termination of the VDMOS, and the gate oxide in the termination region has been damaged. The SEGR-hardened termination with multiple implantation regions is proposed and simulated using the Sentaurus TCAD. The multiple implantation regions are introduced, leading to an increase in the distance between the gate oxide and the hole accumulation region, as well as a decrease in the resistivity of the hole conductive path. This approach is effective in reducing the electric field of the gate oxide to below the calculated critical field, and results in a lower electric field than the conventional termination.

Comparison of Gamma Irradiation Effects on Short Circuit Characteristics of SiC MOSFET Power Devices between Planar and Trench Structures

Abstract: The short circuit withstand energy (SCWE) variations, and short circuit withstand time (SCWT) variations, of planar and trench silicon carbide (SiC) metal-oxide-semiconductor field-effect transistor (MOSFET) power devices are studied after exposure to a total ionizing dose (TID). The results for ON bias are explored. The SCWE and SCWT are studied for planar and trench SiC MOSFET power devices tested for TID with gamma irradiation. A higher degradation phenomenon for the SCWE and SCWT are observed for the planar SiC MOSFET. The physical mechanisms for these variations are analyzed and confirmed by technology computer-aided design (TCAD) simulation.

Modeling of parallel power MOSFETs in steady-state

Abstract: In high-power applications, multiple power MOSFETs are connected in parallel and treated as a single switch in order to handle much larger total currents. In this paper, a parallel power MOSFETs model from the turnoff state until they reach their steady state is introduced. The model represents the relationship between each power MOSFET's gate voltage and the current distribution among them. The study's key purpose is to use the model for dealing with the asymmetry in sharing current and power loss between these semiconductor devices during the steady state region.

Evaluation of Neutron Radiation Impact for 1200V class 4H-SiC MOSFET at Gate Switching Mode with TCAD Simulation

Abstract: We evaluated and analyzed power SiC MOSFETs with gate switching mode during neutron irradiation with our commercial single event effect (SEE) Analyzer. Based on evaluation and analysis, we found i) difference of radiation robustness characteristics, ii) switching mode to be worse condition than non-switching (DC bias condition) mode for 1200 V rated SiC MOSFETs, and iii) temperature dependence with three manufactures’ SiC MOSFETs. In order to clarify the difference between the switching mode and non-switching mode effect, and between the electrical characteristics of the devices, we extracted device-related parameters through physical structure analysis and systematically investigated the cause of the difference by performing simulations with TCAD. As a result, we found that the distribution of electric field according to the gate structure and oxide thickness of SiC MOSFET affects to SiC MOSFET radiation robustness. It was also observed that one of the acceleration factors for increased cross section was higher temperature during irradiation test.

Temperature Dependence of the Channel and Drift Resistance of SiC Power MOSFETs Extracted from I-V and C-V Measurements

Abstract: SiC power MOSFETs show very promising electrical performance for efficient and reliable high temperature operation. This work presents a novel approach for the determination of the temperature dependence of SiC power MOSFET’s channel and drift resistance components in the on-state, which are extracted based on current-voltage (I-V) and capacitance-voltage (C-V) measurements without the need of data extrapolation. The results show that the channel resistance has weak, whereas the drift resistance has strong temperature dependence.

Robustness of SiC MOSFETs under Repetitive High Current Pulses

Abstract: In this paper the robustness of state of the art SiC MOSFETs is analyzed under repetitivehigh current pulses far beyond the nominal values specified in their data sheets. SiC MOSFETs aremore and more used in many power electronics-based applications, such as industrial motor controlunits. During start-up events or load changes of such motors sudden high current pulses may occur.This imposed stress might trigger the drift of electrical parameters that can limit the operating rangeand lifetime of commercially available SiC MOSFETs. Nevertheless, the tested devices withstoodmillions of repetitive high current pulses several times higher than the rated nominal current withoutany signs of degradation.

Investigation of BV_dss instability in trench power MOSFET through DLTS, electrical characterization and TCAD simulations

Abstract: In this paper, we investigated the drain to source breakdown voltage (BV dss ) instability during avalanche current drain stress of Shielded Gate MOSFET (SG-MOSFET) structure and we propose a new methodology to correlate electrical results to TCAD simulations. The presence of positive charged states at the Field Plate (FP) oxide/Si interface was confirmed by Capacitance Deep Level Transient Spectroscopy (C-DLTS). Thus, it was implemented in TCAD simulations that predict the experimental behavior of two architectures. Thanks to these results, walk-in contributors were discriminated to suggest a pathway to increase device robustness with a slight Ron impact.

Impact of Temperature on Neutron Irradiation Failure-in-Time of Silicon and Silicon Carbide Power MOSFETs

Abstract: Accelerated neutron tests on silicon (Si) and silicon carbide (SiC) power MOSFETs at different temperatures and drain bias voltages were performed at the ChipIr facility (Didcot, UK). A super-junction silicon MOSFET and planar SiC MOSFETs with different technologies made by STMicroelectronics were used. Different test methods were employed to investigate the effects of temperature on neutron susceptibility in power MOSFETs. The destructive tests showed that all investigated devices failed via a single-event burnout (SEB) mechanism. Non-destructive tests conducted by using the power MOSFET as a neutron detector allowed measuring the temperature trend of the deposited charge due to neutron interactions. The results of the destructive tests, in the −50 °C–180 °C temperature range, revealed the lack of a common trend concerning the FIT temperature dependence among the investigated SiC power MOSFETs. Moreover, for some test vehicles, the FIT-temperature curves were dependent on the bias condition. The temperature dependence of the FIT values, observed in some SiC devices, is weaker with respect to that measured in the Si MOSFET. The results of the non-destructive tests showed a good correlation between the temperature trends of the deposited charge with those of FIT data, for both Si and SiC devices.

A New Multi-stage SiC MOSFET Gate Drive Circuit for Improving Device Switching Characteristics

Abstract: SiC MOSFETs are particularly suitable for high power density high frequency applications due to their fast switching speed, low power loss, and high thermal conductivity. However, the high switching frequency also leads to voltage spikes and high switching oscillations. This paper proposes a new multi-level SiC MOSFET drive circuit and control method, which can adjust the gate resistance of the main control chip to optimize the switching characteristics of SiC MOSFETs, effectively solving the shortcomings of traditional gate drive circuits in dealing with voltage spikes and switching oscillations.

Power electronic devices

Abstract: The key component of power converters is the power semiconductor device, also called power electronic device. Different from the semiconductors used in the electronic field, power electronic devices generally have larger rated values of current and voltage. The power rating of the power electronic devices also covers a wide range, from several watts to several megawatts, targeting different applications. The power electronic devices can be classified into three types according to the controlling features, that is, uncontrolled devices, half-controlled devices, and fully controlled devices. The uncontrolled devices mainly refer to different types of power diodes. The half-controlled devices mainly refer to thyristors, in which the turn-on event is controllable while the turn-off is not. The fully controlled devices refer to the three-terminal semiconductors in which the control terminal can determine both the turn-on and turn-off states. The power MOSFET (metal-oxide-semiconductor field-effect transistor), IGBT (insulated gate bipolar transistor), GTO (gate-turn-off thyristor), and Power BJT (bipolar junction transistor) are all fully controlled devices. The power electronic devices are also key components in power electronic modeling and simulation, and they are exactly where the differences are from and where the challenges are raised compared the other electrical circuit simulations. In this chapter the commonly used power electronic devices including power diodes, thyristors, power BJT, power MOSFET, and IGBT are introduced. The physics structures and operating principle are described to help the readers to be familiar with those devices. Then the static characteristics and dynamic characteristics of these devices are presented to better understand the working mechanism of power electronics and their behaviors in the circuit and prepare the fundamentals to model these devices in real-time simulations.

Active Clamp Circuit for Online ON-State Voltage Measurement of High Voltage SiC MOSFETs Power Module

Abstract: This paper deals with online measurement of degradation sensitive electrical parameters of silicon carbide (SiC) power MOSFET. The purpose is to target a health monitoring approach for power module allowing more reliable power electronic converter. The on-state resistance $\mathbf{R}_{\mathbf{DS}_{\mathbf{ON}}}$ is one of the key aging indicator of SiC MOSFETs as it can provide information on both chip and packaging degradation. This on-state resistance can be deduced using both the on-state current and voltage of the power semiconductor. This paper focuses on an on-state voltage measurement circuit for medium-to-high voltage SiC power modules for aerospace applications up to 3.3 kV. In the literature, power module bondwires resistance can not be measured due to high switching voltage oscillations. An on-state voltage measurement circuit that can withstand such oscillations is proposed. The dedicated circuit is successfully tested on a double pulse bench for various module base plate temperatures and compared to data obtained with a static curve tracer Keysight B1505. Finally, the proposed circuit scope of application is discussed in a PWM inverter context.

Research on Effect of High Temperature on SiC MOSFET Electrical Characteristic Parameters

Abstract: With the social economy gets better, the development of power electronic systems is increasing rapidly and the application of urban rail transit and high-speed railway is more and more. The traction power system of locomotive and the power system of platform door are particularly important. As the core component of the two systems, high-temperature characteristics of SiC MOSFET is imminent to study. In this paper, the working principle of SiC MOSFET is introduced firstly, the physical factors that affect the high temperature characteristics of the device are theoretically derived, and then the trend of the threshold voltage, transconductance and on resistance of the device changing with the temperature is obtained. Finally, the simulation and experimental verification are carried out. This research lays a foundation for the application of devices in rail transit.

A 400W, 99.3% Efficient GaN Buck-Boost Converter

Abstract: This paper presents a high-efficiency high-power density 500kHz gallium nitride (GaN) based buck-boost converter. State-of-the-art silicon-based buck-boost converters are limited by the poorer device figure of merit (FOM) of silicon technology, namely these converters suffer from large capacitance related switching losses which limit the switching frequency and deteriorate the efficiency and power density. GaN power devices with much better FOM provide lower conduction loss and switching loss at the same time even at elevated switching frequencies. However, quantitative benefits of replacing Si-MOSFETs with GaN FETs are not well-defined in many cases. The focus of this paper is to quantify the impact in a buck-boost converter which is becoming increasingly important due to the proliferation of battery-powered electronics systems. Experimental results are presented in order to show the superior performance of the GaN-based converter in comparison to the state-of-the-art Si-MOSFETs converters. The experimental results show very high efficiency (up to 99.3%) in a wide range of operations and high-power density. The prototype achieves a power density of 110W/cm ³ using IHLP6767GZ01 inductor and 35W/cm ³ using IHLP8787MZ5A inductor.

Breakdown Characteristics of Ga2O3-on-SiC Metal-Oxide-Semiconductor Field-Effect Transistors

Abstract: Ultra-wide bandgap semiconductor gallium oxide (Ga2O3) features a breakdown strength of 8 MV/cm and bulk mobility of up to 300 cm2V−1s−1, which is considered a promising candidate for next-generation power devices. However, its low thermal conductivity is reckoned to be a severe issue in the thermal management of high-power devices. The epitaxial integration of gallium oxide thin films on silicon carbide (SiC) substrates is a possible solution for tackling the cooling problems, yet premature breakdown at the Ga2O3/SiC interface would be introduced due to the relatively low breakdown strength of SiC (3.2 MV/cm). In this paper, the on-state properties as well as the breakdown characteristics of the Ga2O3-on-SiC metal-oxide-semiconductor field-effect transistor (MOSFET) were investigated by using the technology computer-aided design (TCAD) approach. Compared with the full-Ga2O3 MOSFET, the lattice temperature of the Ga2O3-on-SiC MOSFET was decreased by nearly 100 °C thanks to the high thermal conductivity of SiC. However, a breakdown voltage degradation of >40% was found in an unoptimized Ga2O3-on-SiC MOSFET. Furthermore, by optimizing the device structure, the breakdown voltage degradation of the Ga2O3-on-SiC MOSFET is significantly relieved. As a result, this work demonstrates the existence of premature breakdown in the Ga2O3-on-SiC MOSFET and provides feasible approaches to further enhance the performance of hetero-integrated Ga2O3 power devices.

Finite Element-Based Monitoring of Solder Degradation in Discrete SiC MOSFETs

Abstract: Many of the reliability methods used in power electronics require extensive experimental data, resulting in long product design cycles. This work focuses on developing a simulation-driven approach to assess the reliability of a discrete silicon carbide MOSFET by monitoring $2^{\mathrm{n}\mathrm{d}}$ level solder degradation under power cycling in the thermal and thermo-mechanical domains. Active power cycling tests are performed to determine the loading condition at which end-of-life is reached due to a 20% increase in thermal resistance. Numerical analysis using finite element simulations is conducted to gain a physical understanding of the failure criterion from a mechanical point of view. The proposed methodology aims to accelerate the quality assurance and product qualification processes of discrete power electronic devices.

Conduction Mechanism and Influencing Factors of SiC MOSFET

Abstract: With the rapid development of the microelectronics industry, power semiconductor devices are getting more and more attention from the industry. At the same time, discussions on the application of power semiconductor materials have never stopped. Over the years, SiC material has stood out because of its superior physical characteristics. Compared with traditional Si MOSFET technology, SiC MOSFET technology has better physical characteristics in some aspects and has a broader market prospect. This paper introduces the conduction mechanism of SiC MOSFET and its performance factors, and the volume effect, bias temperature instability, and threshold voltage drift of SiC MOSFET are discussed. This paper is helpful in understanding the broad application prospects of SiC MOSFET technology and the difference and reform between SiC MOSFET and traditional Si MOSFET.

A 500kHz ZVS Class E Type DC-DC converter with Two Anti-Series MOSFETs Topology

Abstract: Power converters powered by batteries have been widely used in many applications, such as outdoor emergency lighting, electric motorcycle charger, unmanned aerial vehicle supply and so on. This paper presents a 500 kHz zero-voltage-switching (ZVS) Class E type DC-DC converter with two anti-series MOSFETs used for battery-powered applications. The low-side MOSFET is adopted as the main switch to realize the working operation of traditional Class E resonant converter, while the high-side anti-series MOSFET is used to implement the regulation of the converter output voltage based on pulse width modulation (PWM). Both active switches are ZVS operated so that a high efficiency can be achieved. By changing the high-side MOSFET duty cycle, the ac voltage of the resonant tank is also changed to regulate the output voltage consequently. The control method is simple, and the operating frequency is constant, which is beneficial for the design of the resonant components. A 100-W prototype is built to verify the validity of the proposed control method for which a 94.85% efficiency has been achieved.

Silicon Carbide Power Devices: Progress and Future Outlook

Abstract: Silicon Carbide (SiC) power devices have become commercialized and are being adopted for many applications after 40 years of effort to produce large diameter wafers and high performance device structures. This paper provides a historical perspective of the key breakthroughs that were needed to make progress towards this goal. The JBS rectifier concept was a critical innovation required to make SiC power Schottky rectifiers viable. The Baliga-Pair or Cascode concept was an intermediate step to realize a practical SiC power switch in the 1990s. An essential unique innovation created in the 1990s was the shielded planar SiC power MOSFET structure that is now commonly used for commercial products. Shielded trench-gate SiC power MOSFETs were also proposed in the 1990s which led to commercial products in the last 5 years. Although achieving a low specific on-resistance in SiC power MOSFETs was essential at the inception of the technology, its penetration into power electronics applications is now driven by performance metrics for high frequency circuits. Device structural enhancements to improve the high frequency figures-of-merit are described that have led to major strides in performance. This includes the JBSFET concept where a JBS diode is integrated into the MOSFET structure to suppress current flow through the body diode; the SG and BG MOSFET structures which reduce the gate-drain charge; and the OCTFET structure where the gate-drain overlap area is reduced. Future developments in SiC power devices include increasing the blocking voltage rating to expand the applications spectrum. In addition, a SiC monolithic bi-directional switch has been demonstrated to allow implementation of matrix converters; and a SiC monolithic reverse blocking switch has been demonstrated to allow deployment of current source inverters.

SiC MOSFET Based Dual Active Half-Bridge Converter for Energy Storage Systems : Design and Analysis

Abstract: Abstract This article presents the performance evaluation of isolated Dual Active Half-Bridge (DAHB) converter with discrete SiC MOSFET devices. Novelty of this paper is that a DAHB converter without resonant network provides soft-switching to its SiC MOSFETs. The impact of resonant network on SiC MOSFET DAHB under two different modes is evaluated. The soft-switching characteristics, zero voltage switching and zero current switching operations are achieved by using resonant network. The discrete switching devices, SiC MOSFETs are used to develop the DAHB module. The experimental investigations are performed on DHB converter system with 330V-500V with switching frequency, 100 kHz operated at 700W output power to obtained 96.5% efficiency.