Reliability Concerns for Flying SiC Power MOSFETs in Space

SiC power MOSFETs are space-ready in terms of typical reliability measures. However, single event burnout (SEB) often occurs at voltages 50% or lower than specified breakdown. Data illustrating burnout for 1200 V devices is reviewed and the space reliability of SiC MOSFETs is discussed

Radiation effects in high speed III-V integrated circuits

The article of record as published may be found at http://dx.doi.org/10.1142/S0129156403001612International Journal of High Speed Electronics and Systems, v. 13, p. 277 (2003).The types of applications affected by radiation effects in W-V devices have significantly changed over the last four decades. For most applications W-V ICs have provided sufficient radiation hardness. Some expectations for hardened soft error applications did not materialize until much later. Years of research defined that not only material properties. but device structures. layout practices and circuit design influenced how m-v devices were susceptible to certain radiation effects. The highest performance ill-V ICs due to their low power-speed energy products will provide challenges in ionizing radiation environments from sea level to space

STUDY OF RADIATION EFFECTS IN GAN-BASED DEVICES

Radiation tolerance of wide-bandgap Gallium Nitride (GaN) high-electron-mobility transistors (HEMT) has been studied, including X-ray-induced TID effects, heavy-ion-induced single event effects, and neutron-induced single event effects. Threshold voltage shift is observed in X-ray irradiation experiments, which recovers over time, indicating no permanent damage formed inside the device. Heavy-ion radiation effects in GaN HEMTs have been studied as a function of bias voltage, ion LET, radiation flux, and total fluence. A statistically significant amount of heavy-ion-induced gate dielectric degradation was observed, which consisted of hard breakdown and soft breakdown. Specific critical injection level experiments were designed and carried out to explore the gate dielectric degradation mechanism further. Transient device simulations determined ion-induced peak transient electric field and duration for a variety of ion LET, ion injection locations, and applied drain voltages. Results demonstrate that the peak transient electric fields exceed the breakdown strength of the gate dielectric, leading to dielectric defect generation and breakdown. GaN power device lifetime degradation caused by neutron irradiation is reported. Hundreds of devices were stressed in the off-state with various drain voltages from 75 V to 400 V while irradiated with a high-intensity neutron beam. Observing a statistically significant number of neutron-induced destructive single-event-effects (DSEEs) enabled an accurate extrapolation of terrestrial field failure rates. Nuclear event and electronic simulations were performed to model the effect of terrestrial neutron secondary ion-induced gate dielectric breakdown. Combined with the TCAD simulation results, we believe that heavy-ion-induced SEGR and neutron-induced SEGR share common physics mechanisms behind the failures. Overall, experimental data and simulation results provide evidence supporting the idea that both radiation-induced SBD and HBD are associated with defect-related conduction paths formed across the dielectric, in response to radiation-induced charge injection. A percolation theory-based dielectric degradation model is proposed, which explains the dielectric breakdown behaviors observed in heavy-ion irradiation experiments

Wide-bandgap Semiconductors in Space: Appreciating the Benefits but Understanding the Risks

Dr. Jean-Marie Lauenstein, NASA Goddard Space Flight Center, will present the radiation challenges of adopting wide-bandgap semiconductors for space applications. Wide-bandgap devices are attractive for space applications due to improved performance such as faster switching speeds, lower power losses, and their ability to operate at higher temperature as compared with their silicon counterparts. Their tolerance to total ionizing dose levels (> 100 krad(Si)) further enhances the desirability of these technologies. This short course will focus on silicon carbide and gallium nitride power rectifying, switching, and RF devices as these technologies are now readily available commercially. The radiation hardness assurance issues presented by the heavy-ion radiation environment will be discussed

Cosmic Ray Failures in Power Semiconductors

Cosmic rays are particles radiating from the galaxy to the earth. From these particles, high-energy neutrons are seen to cause failures when they collide with the base nuclei in power semiconductors. These collisions can trigger different failure mechanisms depending on the component type. Moreover, the failures are random and occur within nanoseconds without any prior sign. This thesis introduces cosmic ray failures as a phenomenon in power semiconductors, the affecting factors, the estimation of failure probabilities, and existing testing procedures. Also, a test setup with natural terrestrial radiation was developed to compare test results from artificial radiation sources. Lastly, methods to improve the cosmic ray robustness of power semiconductors were discussed. The affecting factors are the blocking voltage, junction temperature, altitude, and radiation flux. The voltage was seen to be the most effective factor because when a certain voltage threshold is achieved, the failure rates increase exponentially. The junction temperature and altitude can be included in the estimation of failure probability with formulas composed of experimental data. Lastly, radiation flux was seen to be dependent on solar activity, latitude, and altitude. For quantifying cosmic ray failures, three different empirical models were presented. Comparison between these models showed differences and indicated the need for testing with real hardware to get accurate failure rates. However, these models as well as Monte Carlo techniques and TCAD simulations were noted to help in the early phase of development to adjust the radiation robustness. The test setup developed in this thesis was the first step for cosmic ray testing at Danfoss Drives. The setup included multiple IGBT power modules with the gates short-circuited to ensure a blocking state. During the test, a high collector-emitter voltage was applied constantly. Six failures occurred during the test and showed a good match to the estimation from accelerated tests. Regarding the methods for reducing cosmic ray failures, adjusting the width of the drift region was seen to be effective. Also, surrounding the components with neutron-attenuating materials seemed to decrease the probability of failures. Lastly, some previous research results were combined in the comparison of silicon and silicon carbide. It seemed that the latter should be more robust supporting the trend of using silicon carbide in high-voltage applications

大電力用半導体デバイスの宇宙線故障率計算手法

Power semiconductor devices are susceptible to catastrophic failures when exposed to energetic particles present in cosmic radiation. The most serious failure mechanism is single event burnout (SEB). SEB in terrestrial operating condition is a widely recognized problem due to the usage of high Power semiconductor devices in many terrestrial applications. However, the recent increase in the aircraft power requirement and subsequent demand for high power semiconductor devices in avionics indicates the importance of expanding SEB study to higher altitudes. Moreover, the SEB failure rate in avionic system is many times higher than terrestrial electronics due to the increase in cosmic ray flux at high altitudes. The calculation of SEB failure rate of power devices plays critical role in power device selection to make the system robust against cosmic radiation. The failure rate calculation using modeling approaches is very easy and offers many advantages compare to real life tests and accelerated tests. However, empirical formula proposed by Zeller from the accelerating testing result can only be applicable to evaluate the failure rate at sea level. In this research, a universal failure calculation method is proposed to evaluate the failure rate of any high power semiconductor device. Unique feature of decoupling between failure cross section and cosmic ray flux spectrum in the proposed method makes it possible to calculate the failure rate in any radiation condition like terrestrial conditions, aviation altitudes, space environment etc. The failure rate results shown for PiN diodes of 100 μm (1) and 300 μm (3) due to the interaction of cosmic ray neutrons up an altitude of 60 km. First chapter provides the basic introduction about purpose of this work, the research objectives and importance of proposed failure rate calculation method. Second chapter describes the origin of radiation along with the radiation environment. The interaction of radiation with the matter and in particular the discovery of Single Event Effects in electronic integrated circuits is discussed. Moreover, we discussed the reason for considering the cosmic ray neutrons in the present work. Third chapter presents the literature review about energetic particle interaction with the high power semiconductor devices. The phenomena leading to device destruction also discussed in various power devices in detail. Fourth chapter describes the Single Event Burnout simulation of PiN diode. The physical process leading to the failure is shown for 300 μm and 100 μm PiN diode using the simulation results. The transient current waveforms are shown to differentiate the burnout and non-burnout situations. Fifth chapter introduces the proposed universal failure rate calculation method. Various components of the failure calculation method are discussed in detail. The threshold charge for device destruction obtained from simulation results is shown for 300 μm and 100 μm PiN diode. Sixth chapter presents results obtain from the proposed method. The calculated failure rate at sea level is validated with the Zeller results. Further, altitude dependent failure rate up to 60 km is obtained using the neutron spectrum from EXPACS database. In addition, the cutoff energy dependence on failure rate also briefly discussed.九州工業大学博士学位論文 学位記番号: 生工博甲第428号 学位授与年月日: 令和4年3月25日1 Introduction|2 Radiation and its effects on Electronics|3 SEB in High power semiconductor devices|4 Simulation of Single Event Burnout phenomena of PiN Diode|5 Proposed Universal SEB Failure rate calculation method|6 Failure rate results|7 Conclusion九州工業大学令和3年

AC solar cells: An embedded "all in one" PV power system

Journal ArticlePower converters constructed from discrete components are difficult to mass produce, and the installation involves a significant labor cost to have the proper interconnection among the panel, inverter and the grid. These facts indicate that the present PV technology may not be able to address the challenges involved in reaching the DOE target of $1/W. Therefore, a paradigm shift in the design of the entire PV power system is needed to reach this goal. In order to increase the converter reliability and watts/$, the active and passive elements of a power converter (especially capacitors and active switches such as MOSFETs, JFETs or IGBTs) could be embedded on the same substrate material used for fabricating the p-n junctions in the photovoltaic panel. To the knowledge of the author, there is no prior work in cell level power conversion, and therefore, this project idea could be considered as an "Out of the box" kind. A novel fabrication process is proposed in this paper demonstrating the integration of PV cells and two major components needed to build a power converter. Because of the cell level power conversion, PV panels constructed from these cells are likely to be immune to partial shading and hot-spot effects. The end goal of this research is to produce 120V/240V ac output directly from the panel. An extremely accurate device simulator (*Silvaco Athena/Atlas) was used to generate reasonably accurate characteristics of the proposed PV system

Discussion on Electric Power Supply Systems for All Electric Aircraft

The electric power supply system is one of the most important research areas within sustainable and energy-efcient aviation for more- and especially all electric aircraft. This paper discusses the history in electrication, current trends with a broad overview of research activities, state of the art of electrication and an initial proposal for a short-range aircraft. It gives an overviewof the mission prole, electrical sources, approaches for the electrical distribution system and the required electrical loads. Current research aspects and questions are discussed, including voltage levels, semiconductor technology, topologies and reliability. Because of the importance for safety possible circuit breakers for the proposed concept are also presented and compared, leading to a initial proposal. Additionally, a very broad review of literature and a state of the art discussion of the wiring harness is given, showing that this topic comes with a high number of aspects and requirements. Finally, the conclusion sums up the most important results and gives an outlook on important future research topics

Development of a Hybrid-Electric Aircraft Propulsion System Based on Silicon Carbide Triple Active Bridge Multiport Power Converter

Constrained by the low energy density of Lithium-ion batteries with all-electric aircraft propulsion, hybrid-electric aircraft propulsion drive becomes one of the most promising technologies in aviation electrification, especially for wide-body airplanes. In this thesis, a three-port triple active bridge (TAB) DC-DC converter is developed to manage the power flow between the turbo generator, battery, and the propulsion motor. The TAB converter is modeled based on the emerging Silicon Carbide (SiC) Metal-Oxide-Semiconductor Field Effect Transistor (MOSFET) modules operating at high switching frequency, so the size of the magnetic transformer can be significantly reduced. Different operation modes of this hybrid-electric propulsion drive based on the SiC TAB converter are modeled and simulated to replicate the takeoff mode, cruising mode, and regenerative charging mode of a typical flight profile. Additionally, soft switching is investigated for the TAB converter to further improve the efficiency and power density of the converter, and zero voltage switching is achieved at heavy load operating conditions. The results show that the proposed TAB converter is capable of achieving high efficiency during all stages of the flight profile

Radiation Effects in Integrated Circuits, and Radiation Hardening Techniques

Radiation from natural and artificial elements bombards the earth The radiation environment depends on energy distribution and particle spectra. Radiation affects most electronic components, especially ICs (ICs). High nuclear reactors and space radiation damage electronic components, but the earth's electronic components also do. Semiconductors are radiation-sensitive, hence ICs need radiation shielding. The operation and performance of devices are affected by these effects. Radiation type, energy, flux, and exposure period affect damage. Gamma rays and neutrons are indirect ionizing radiation. These beams harm silicon-based semiconductors like transistors. Radiation can damage semiconductors, especially ICs. As a result of displacement damage and ionizing radiation, semiconductors degrade in three devices. Insulator traps charge. (2) minor carrier recombination modifications Various-energy particles generate different ionization and displacement damage. In the research of radiation effects and consequences, it's vital to look at how radiation affects semiconductors and integrated circuits. Radiation hardening decreases radiation damage. Radiation hardening renders electronics ionizing or non-ionizing radiation-resistant. To assure appropriate operation, IC, sensor, and military aircraft makers adopted hardening. Keywords: Hardening Technique, Integrated Circuits, Radiation DOI: 10.7176/CEIS/13-5-04 Publication date:October 31st 202