Showing papers by "Pascal Bevilacqua published in 2019"

Advanced Electrical characterisation of high voltage 4H-SiC PiN diodes

Abstract: This paper reports the design, the processing, the static characterisation, the switching behaviour and the high current stress test of 10 kV aimed 4H-SiC bipolar diodes. The actual breakdown voltage of the selected devices is between 7 kV and 8 kV. The switching characterisations show a good behaviour with a trr of only 90 ns. No degradation was observed after the application of 10 000 high current pulses during the stress tests.

Benefits of GaN transistors and embedding in PCB laminates

Abstract: More electrical vehicles, either automotive or aeronautics, should benefit of the electrical performances of GaN power transistors. High-speed switching opens the possibility for higher switching frequency and the consequential benefit on the size of passive components. Efficiency and power density should be improved by overcoming some strong challenges. Reducing the parasitic components within the switching cell is a prime concern. Embedding transistors has been experimented, with a special care given to the issue of thermal management. Multiple chips per switch may be necessary to address medium power applications but paralleling GaN transistors is not straightforward. A multi-phase converter architecture may circumvent the latter problem, as PCB technology is especially suited to managing complex interconnnects. Embedding not only the active devices, but also the passive components may introduce additional degrees of freedom. If a proper design approach is considered and some limitations are reasonably taken into account, combining the advantages of GaN transistors and their embedding technologies is promising solution. The paper proposes a review of the state of art and discusses some specific results to support the pros and cons of mixing GaN transistors and embedding in printed circuit board.

High-Voltage SiC-JFET Fabrication and Full Characterization

Abstract: This paper reports the design, the processing, the static characterisation, the switching behaviour and the high current stress test of 10 kV aimed 4H-SiC bipolar diodes. The actual breakdown voltage of the selected devices is between 7 kV and 8 kV. The switching characterisations show a good behaviour with a t rr of only 90 ns. No degradation was observed after the application of 10 000 high current pulses during the stress tests.

Effects of the laser beam size on the Optical Beam Induced Current (OBIC) for the study of Wide Band Gap (WBG) Semi-Conductor Devices

Abstract: UV Laser is used to generate electron-hole pairs into Wide Band-Gap (WBG) semiconductors (SiC, GaN or Ga2O3). In the space charge region, the electric field drives the collected carriers and a current, so-called Optical Beam induced Current (OBIC), can be measured. The induced current is then directly related to the electrical field in the device. The OBIC, is a non-destructive technique, which has been previously successfully used to characterize High Voltage (HV) SiC devices [1, 2, 3, 4]. In order to fully benefit of the advantages provided by WBG semiconductors materials and to avoid premature breakdown of the high voltage devices, it is mandatory to have efficient peripheral protections such as a MESA, a JTE and JTE rings…The OBIC characterization can help the technology computer-aided design (TCAD) and the device process to optimize the efficiency of the periphery protection by analyzing the electric field distribution in the structure and especially at the junction periphery. In this talk, we will present an in-house testbench called micro-OBIC which will allow us to characterize HV PiN diodes with a micro-meter spatial resolution.