Papers by Keyword: Switching Characteristics

Paper TitlePage

Authors: Vladimir A. Ilyin, Alexey V. Afanasyev, Yuri S. Demin, Boris V. Ivanov, Alexey F. Kardo-Sysoev, Victor V. Luchinin, Sergey A. Reshanov, Adolf Schöner, K.A. Sergushichev, A.A. Smirnov
Abstract: The paper reports on the studies of static and dynamic characteristics of 30 kV diode stacks based on 4H-SiC drift step recovery diodes (DSRDs). It was found that the optimal performance in terms of blocking voltage and switching speed can be achieved with 2 kV DSRD dies. Fifteen 2 kV DSRD dies were connected in series and sealed with molding compound. The stacks were dynamically tested in a special oscillator circuit. Repetitive voltage pulses of 30.5 kV with the leading edge of 1.6 ns were demonstrated.
Authors: Tsuyoshi Yamamoto, Takeshi Endo, Nobuyuki Kato, Hiroki Nakamura, Toshio Sakakibara
Abstract: 4H-SiC SBDs have been commercialized for power application devices. However, the maximum current of these SBDs is 20A. In this work, we designed a JBS (junction barrier Schottky) diode structure and the fabrication processes to be optimized. The current and breakdown voltage were over 100 A and 660 V at Ir = 1 mA/cm2, respectively. The recovery characteristics of the JBS diode are much superior to those of the Si-FRD while it is comparable to those of the commercially available SiC-SBD at elevated temperatures up to 125°C..
Authors: Kazuhiro Fujikawa, Kenichi Sawada, Takashi Tsuno, Hideto Tamaso, Shin Harada, Yasuo Namikawa
Abstract: 400V/2.5A 4H-SiC JFETs having a reduced surface field (RESURF) structure were fabricated. Measurements on the static and switching characteristics were carried out. The on-resistance was 0.86 W. The turn-on time (ton) and the turn-off time (toff) were 8ns and 10 ns, respectively. The fabricated JFETs showed low on-resistance and fast switching characteristics. 4H-SiC RESURF-type JFETs, which is a sort of lateral transistor, are preferable to a module configuration of switching devices. Moreover, they are promising for application to DC power supplies with higher efficiency and smaller size owing to their low on-resistance and fast switching characteristics.
Authors: Vidya Naidu, Sivaprasad Kotamraju
Abstract: Silicon Carbide (SiC) based MOS devices are one of the promising devices for high temperature, high switching frequency and high power applications. In this paper, the static and dynamic characteristics of an asymmetric trench gate SiC IGBT with high-k dielectrics- HfO2 and ZrO2 are investigated. SiC IGBT with HfO2 and ZrO2 exhibited higher forward transconductance ratio and lower threshold voltage compared to conventionally used SiO2. In addition, lower switching power losses have been observed in the case of high-k dielectrics due to reduced tail current duration.
Authors: Olivier Berry, Youness Hamieh, Stéphane Raël, Farid Meibody-Tabar, Sébastien Vieillard, Dominique Bergogne, Hervé Morel
Abstract: This paper presents a study on a SiC JFET leg of a 3-leg Voltage Source Inverter (VSI). The switching curves obtained with the JFET working in free wheeling mode are shown to point out drain-to-gate interaction effects. Indeed, during the drain-source voltage variations, the JFET gate-source voltage can have considerable variations, because of the electrical coupling induced by the gate-drain capacitance Cgd. When the gate-source voltage variation becomes too negative, there is a risk of occurrence of the phenomenon of punch-through in the gate-source junction. Conversely, when it is enough positive, the JFET may conduct and lead to a leg short-circuit. To decrease these undesired effects for the JFET legs and consequently for the SiC JFET inverter, an external gate-source capacitor is used. This solution is studied and optimized by simulation on an inverter leg.
Authors: Siddharth Potbhare, Neil Goldsman, Akin Akturk, Aivars J. Lelis
Abstract: We present detailed mixed-mode simulations of a DC-DC converter based on 4H-SiC DMOSFETs. The mixed-mode modeling enables the use of complex physics based models for the interface trap occupation and surface mobility that are typical for 4H-SiC devices, and apply them to a practical circuit application such as a DC-DC boost converter. The mixed mode simulations are performed for a reduced DC-DC converter circuit to evaluate the performance of the DMOSFET when it has an inductive load. The current inside the device and its power dissipation during switching are evaluated numerically. Further, the mixed-mode device simulation shows that the majority carriers (electrons) inside the 4H-SiC DMOSFET require a finite time to go from the ON (strongly inverted) to the OFF (depleted) state, thereby causing power dissipation and heating during the turn-off period. The peak power is dissipated in the JFET region of the device which indicates that maximum heat and therefore maximum temperature may be generated there.
Authors: Reinhold Schörner, Peter Friedrichs, Dethard Peters, Heinz Mitlehner, Benno Weis, Dietrich Stephani
Authors: Peter Friedrichs, Heinz Mitlehner, Rainer Kaltschmidt, Ulrich Weinert, Wolfgang Bartsch, Christian Hecht, Karl Otto Dohnke, Benno Weis, Dietrich Stephani
Authors: Masayuki Imaizumi, Yoichiro Tarui, Shin Ichi Kinouchi, Hiroshi Nakatake, Yukiyasu Nakao, Tomokatsu Watanabe, Keiko Fujihira, Naruhisa Miura, Tetsuya Takami, Tatsuo Ozeki
Abstract: Prototype SiC power modules are fabricated using our class 10 A, 1.2 kV SiC-MOSFETs and SiC-SBDs, and their switching characteristics are evaluated using a double pulse method. Switching waveforms show that both overshoot and tail current, which induce power losses, are suppressed markedly compared with conventional Si-IGBT modules with similar ratings. The total switching loss (MOSFET turn-ON loss, turn-OFF loss and SBD recovery loss) of SiC power modules is measured to be about 30% of that of Si-IGBT modules under the generally-used switching condition (di/dt ~250A/μs). The three losses of SiC modules decrease monotonically with a decrease in gate resistance, namely switching speed. The result shows the potential of unipolar device SiC power modules.
Authors: Rajesh Kumar Malhan, S.J. Rashid, Mitsuhiro Kataoka, Yuuichi Takeuchi, Naohiro Sugiyama, F. Udrea, G.A.J. Amaratunga, T. Reimann
Abstract: Static and dynamic behavior of the epitaxially grown dual gate trench 4H-SiC junction field effect transistor (JFET) is investigated. Typical on-state resistance Ron was 6 – 10mΩcm2 at VGS = 2.5V and the breakdown voltage between the range of 1.5 – 1.8kV was realized at VGS = −5V for normally-off like JFETs. It was found that the turn-on energy delivers the biggest part of the switching losses. The dependence of switching losses from gate resistor is nearly linear, suggesting that changing the gate resistor, a way similar to Si-IGBT technology, can easily control di/dt and dv/dt. Turn-on losses at 200°C are lower compared to those at 25°C, which indicates the influence of the high internal p-type gate layer resistance. Inductive switching numerical analysis suggested the strong influence of channel doping conditions on the turn-on switching performance. The fast switching normally-off JFET devices require heavily doped narrow JFET channel design.
Showing 1 to 10 of 10 Paper Titles