- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Advanced Silicon Carbide Devices and Processing || Investigation of SiC/Oxide Interface Structures by Spectroscopic Ellipsometry
摘要： We have investigated SiC/oxide interface structures by the use of spectroscopic ellipsometry. The depth profile of the optical constants of thermally grown oxide layers on SiC was obtained by observing the slope-shaped oxide layers, and the results suggest the existence of the interface layers, around 1 nm in thickness, having high refractive index than those of both SiC and SiO2. The wavelength dispersions of optical constants of the interface layers were measured in the range of visible to deep UV spectral region, and we found the interface layers have similar dispersion to that of SiC, though the refractive indices are around 1 larger than SiC, which suggests the interface layers are neither transition layers nor roughness layers, but modified SiC, e.g., strained and/or modified composition. By the use of an in-situ ellipsometer, real-time observation of SiC oxidation was performed, and the growth rate enhancement was found in the thin thickness regime as in the case of Si oxidation, which cannot be explained by the Deal-Grove model proposed for Si oxidation. From the measurements of the oxidation temperature and oxygen partial pressure dependences of oxidation rate in the initial stage of oxidation, we have discussed the interface structures and their formation mechanisms within the framework of the interfacial Si-C emission model we proposed for SiC oxidation mechanism.
关键词： interface state density,SiC-MOSFET,SiC/oxide interface,SiC oxidation mechanism,spectroscopic ellipsometry
更新于2025-09-23 15:22:29
-
[IEEE 2018 IEEE Energy Conversion Congress and Exposition (ECCE) - Portland, OR, USA (2018.9.23-2018.9.27)] 2018 IEEE Energy Conversion Congress and Exposition (ECCE) - Comparison Study of Surge Current Capability of Body Diode of SiC MOSFET and SiC Schottky Diode
摘要： The superior performance of the SiC MOSFETs operating in synchronous mode converter without external antiparallel SiC Schottky diodes have been demonstrated recently. However, there are few studies of the surge current capability of the SiC MOSFET's body diode, leading severe concern for its ruggedness in practical power converter applications. The purpose of this paper is to experimentally compare the non-repetitive surge current capability of the SiC MOSFET's intrinsic body diode and SiC Schottky diode, and analyze the physical mechanisms of their degradation after surge current stress. Their surge current capability and electrical characteristics before and after surge current stress are measured and analyzed. Experimental study shows that the non-repetitive peak surge current of the SiC MOSFET’s body diode is slightly larger than that of the SiC Schottky diodes. The degradation of the SiC Schottky diode after surge current stress is accompanied with the increase of drain leakage current, while the degradation of the SiC MOSFET after the body diode’s surge current stress is accompanied with the variation of the threshold voltage and input capacitance of the SiC MOSFET. The analysis shows that the degradation of the SiC MOSFET after the surge current stress may be correlated with the interface traps of SiC/SiO2 interface.
关键词： Body diode,SiC Schottky Diode,SiC MOSFET,Surge current
更新于2025-09-23 15:22:29
-
Effect of short-circuit stress on the degradation of the SiO2 dielectric in SiC power MOSFETs
摘要： This paper presents the impact of a short-circuit event on the gate reliability in planar SiC MOSFETs, which becomes more critical with increased junction temperature and higher bias voltages. The electrical waveforms indicate that a gate degradation mechanism takes place, showing a large gate leakage current that increases as the gate degrades more and more. A failure analysis has been performed on the degraded SiC MOSFET and then compared to the structure of a new device to identify possible defects/abnormalities. A Focused-Ion Beam cut is performed showing a number of differences in comparison to the new device: (i) cracks between the poly-silicon gate and aluminium source, (ii) metal particles near the source contact, and (iii) alterations in the top surface of the aluminium source. The defects have been correlated with the increase in gate-leakage current and drain-leakage current.
关键词： Focused-Ion Beam,Short circuit,Gate-oxide breakdown,Gate oxide,Degradation,Defects,Reliability,SiC MOSFET,Failure analysis,SEM
更新于2025-09-23 15:22:29
-
A Compact Series-Connected SiC MOSFETs Module and Its Application in High Voltage Nanosecond Pulse Generator
摘要： Nanosecond pulse discharge plasma has many prospects in industrial applications, and high voltage repetitive nanosecond pulse generators with compact design and light weight have become one of the key issues limiting its development in some applications. This paper presents a high voltage series-connected SiC MOSFETs module which can be served as the main switch in a repetitive high voltage nanosecond pulse generator. This kind of series-connected MOSFETs module with only single external gate driver requiring very few components is very suitable for compact assembly. By analyzing the working principle, three topologies of series-connected MOSFETs module are proposed. The switching behaviors of the three different topologies with four SiC MOSFETs series-connected are compared experimentally. The variation of switching characteristics of series-connection SiC MOSFETs module with different numbers of devices are investigated. The layout is also optimized to shorten pulse front time and improve output pulse quality. Furthermore, a 10 kV SiC MOSFETs module with a turn-on transition time ~10 ns is developed. The double pulse test result demonstrates excellent switching performances. Finally, a compact and high voltage pulse generator composed of three 10 kV SiC MOSFETs module is tailored, with a typical rise time ~40 ns and peak voltage of ~30 kV.
关键词： high voltage nanosecond pulse generator,series-connection,SiC MOSFET
更新于2025-09-23 15:22:29
-
Photovoltaic-Driven SiC MOSFET Circuit Breaker with Latching and Current Limiting Capability
摘要： This paper introduces a Solid State Circuit Breaker with Latching and Current Limiting capabilities for DC distribution systems. The proposed circuit uses very few electronic parts and it is fully analog. A SiC N-MOSFET driven by a photovoltaic driver and a maximum current detector circuit are the core elements of the system. This work details circuit operation under different conditions and includes experimental validation at 1 kVdc. Wide versatility, highly configurable, and very fast response, less than 1 μs in the case of short-circuit, are the most remarkable outcomes.
关键词： SiC MOSFET,Solid State Circuit Breaker (SSCB),fault current limiter,WBG semiconductors,DC power distribution
更新于2025-09-23 15:21:01
-
[IEEE 2018 15th China International Forum on Solid State Lighting: International Forum on Wide Bandgap Semiconductors China (SSLChina: IFWS) - Shenzhen, China (2018.10.23-2018.10.25)] 2018 15th China International Forum on Solid State Lighting: International Forum on Wide Bandgap Semiconductors China (SSLChina: IFWS) - Threshold Voltage Instability of 1200V SiC MOSFET Devices
摘要： 1200V 4H-SiC MOSFETs have been designed and fabricated sucessfully. The drain current Id = 20 A at Vg = 20 V, corresponding to Vd = 2.0 V. The stability of threshold voltage was studied soon. It is believed that the instability in device behavior during gate bias stress is due to capture of electrons by the SiC/gate dielectric interface traps and the gate dielectric near interface traps. A constant gate voltage of +20V/-10V is applied to the gate at a temperature of 150℃. The threshold voltage are monitored for device stability. Compare with three other commercial devices,the devices show little variation in the Vth.
关键词： threshold voltage,SiC MOSFET,interface states
更新于2025-09-19 17:15:36
-
[IEEE 2019 AEIT International Annual Conference (AEIT) - Florence, Italy (2019.9.18-2019.9.20)] 2019 AEIT International Annual Conference (AEIT) - Predictive Current Control for a Neutral Point Clamped Inverter Considering SiC-MOSFET as Switches and Using a Photovoltaic Power Source
摘要： This paper proposes a predictive current control of a three-phase 3-level neutral point clamped (3L-NPC) inverter. The main contribution of this paper is the analysis of the effects of the DC LINK voltage on the output of the 3L-NPC on a specific class of power semiconductor, namely SiC-MOSFET. The power source of the DC LINK is a photovoltaic array, the process to choose the number of series panels is a heuristic method. All analyses and results were conducted through simulations, using Matlab/Simulink.
关键词： Neutral point clamped converter,predictive current control,photovoltaic system,SiC-MOSFET
更新于2025-09-16 10:30:52
-
PID Control of a Three Phase Photovoltaic Inverter Tied to a Grid Based on a 120-Degree Bus Clamp PWM
摘要： This paper presents a new operating type of a three phase photovoltaic PID current control system connected to the low voltage distribution grid. This operating type introduces a 120-degree bus clamp PWM control method (120° BC-PWM). A 120° BC-PWM is a special switching sequences technique employing bus clamp sequences that use only one phase under a PWM and PID control state every 60° while the other phases are being clamped. The BC-PWM method was used to generate six PWM signals to control a three phase inverter system every 60° with constant power input and a small dc link film capacitor. The main objective of this paper is to use new PWM techniques with a PID current control method to reduce the switching losses of three phase inverters. The losses were reduced to 1/3th for each transistor by reducing the time operation for each transistor. The simulation results of the BC-PWM method show an improvement in the performance of the three phase inverter system connected to the grid. Simulation setup of the system obtained is built by using a SiC MOSFET, 5 kVA, 400 V line-line and 25 kHz switching frequency. The PID control is not continuously active for each phase but is operational in 60° and saturated at 120° in a half period. Following a proper tuning of the windup, it recovers very easily.
关键词： SIC MOSFET,current control,PWM,120-degree bus clamp,PID,three phase inverter
更新于2025-09-12 10:27:22
-
Recent Developments Accelerating SiC Adoption
摘要： The benefits of SiC devices for use in power electronics has been long understood, and over 25 years of sustained development in materials and devices has brought adoption to a tipping point [1,15]. It takes the confluence of many separate developments to build the necessary momentum for accelerated adoption, and we will examine these factors.
关键词： SiC MOSFET,SiC reliability,SiC Schottky Diode,SiC gate oxide,SiC Cascode,Supercascode,Silicon Carbide,SiC,SiC packaging,SiC applications,SiC epitaxy,SiC substrates
更新于2025-09-09 09:28:46
-
Investigation on the degradation indicators of short-circuit tests in 1.2?kV SiC MOSFET power modules
摘要： This paper provides a comprehensive investigation on both static characteristics and short-circuit performance of 1.2 kV SiC MOSFET power modules with 2nd generation planar technology. The experimental approach is based on the static characteristics measurements and the short-circuit tests with gradual increase of pulse time duration. If any variation of the static characteristics appears, the time duration of next short-circuit tests would keep the same with the last pulse duration (approach 1) or increase continuously (approach 2). The results of the short-circuit waveforms show a gate degradation which is further con?rmed with the measurement of the gate leakage current. Additionally, other degradation indicators, including positive shift of threshold voltage, drain leakage current and on-state resistance increase are evidenced and discussed in this paper. These can be used for early prediction of the degradation and failure in the short-circuit conditions.
关键词： SiC MOSFET,SiC power module,Short-circuit,Degradation indicators
更新于2025-09-09 09:28:46