Theoretical and experimental analyses of safe operating area (SOA) of 1200-V 4H-SiC BJT
ABSTRACT The safe operating area (SOA) of 1200-V SiC bipolar junction transistor (BJT) is investigated by experiments and simulations. The SiC BJT is free of the second breakdown even under the turn-off power density of 3.7 MW/cm2. The theoretical boundary of reverse-biased SOA caused by the false turn-on is obtained by simulations. The short-circuit capability of the 1200-V SiC BJT is also investigated theoretically and experimentally. Self-heating is considered by the nonisothermal simulation, and 1800-K maximum local temperature is the simulated critical temperature of device failure. The surface condition is very critical for short-circuit capability. From simulations, when the interface trap density increases, the critical temperature decreases. This is believed to be the reason why the experimental results show much shorter short-circuit withstand time than the simulation showed.
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ABSTRACT: We demonstrate 4H-SiC bipolar junction transistors (BJTs) with an enhanced current gain over 250. High current gain was achieved by utilizing optimized device geometry as well as optimized surface passivation, continuous epitaxial growth of the emitter-base junction, combined with an intentional deep-level-reduction process based on thermal oxidation to improve the lifetime in p-SiC base. We achieved a maximum current gain (β) of 257 at room temperature and 127 at 250°C for 4H-SiC BJTs fabricated on the (0001)Si-face. The gain of 257 is twice as large as the previous record gain. We also demonstrate BJTs on the (000-1)C-face that showed the highest β of 439 among the SiC BJTs ever reported.Materials Science Forum 05/2012; 717-720:1117-1122. DOI:10.4028/www.scientific.net/MSF.717-720.1117
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ABSTRACT: This paper seeks to provide insight into state-of-the-art 1.2 kV Silicon Carbide (SiC) power semiconductor devices, including the MOSFET, BJT, SJT, and normally-on and normally-off JFET. Both commercial and sample devices from the semiconductor industry's well-known manufacturers; namely Cree, GE, ROHM, Fairchild, GeneSiC, Infineon, and SemiSouth, are evaluated in this study. To carry out this work, static characterization of each device is performed under increasing temperatures (25-200 °C). Dynamic characterization is also conducted through double-pulse tests. Accordingly, the paper describes the experimental setup used and the different measurements conducted, which comprise: threshold voltage, current gain, specific on-resistance, and the turn on and turn off switching energies. For the latter, the driving method used for each device is described in detail. Furthermore, for the devices that require on-state dc currents, driver losses are also taken into consideration. Key trends and observations are reported in an unbiased manner throughout the paper and summarized in the conclusion.Power Electronics and Applications (EPE), 2013 15th European Conference on; 01/2013
Conference Paper: Static and Dynamic Characterization of a >13kV SiC p-ETO Device[Show abstract] [Hide abstract]
ABSTRACT: This study addresses the transient and steady-state performance of a >13 kV SiC p-ETO. The developed SiC p-ETO is based on a 1 cm2, 15 kV SiC p-GTO with an extremely low differential resistance. Static performance of the device, including the on-state voltage drop at different temperatures and different currents is carried out in this paper. Furthermore, transient performance of the device, including the turn off energy and also the Safe Operating Area (SOA) of the device has been studied. Also, the superior performance of the p-type SiC-ETO has been exploited to design and implement a solid-state circuit breaker. The studies verify the superiority of the SiC pETO compared to other solid state devices for this application.2014 IEEE 26th International Symposium on Power Semiconductor Devices & IC's (ISPSD), Waikoloa, Hawaii, USA; 06/2014