Fabrication of a monolithic 4H-SiC junction barrier schottky diode with the capability of high current

There is a great interest in monolithic 4H-SiC Junction Barrier Schottky （JBS） diodes with the capability of a high forward current for industrial power applications. In this paper, we report large-area monolithic 4H-SiC JBS diodes fabricated on a 10 μm 4H-SiC epitaxial layer doped to 6×1015 cm-3. JBS diodes with an active area of 30 mm2 had a forward current of up to 330 A at a forward voltage of 5 V, which corresponds to a current density of 1100 A/cm2. A near ideal breakdown voltage of 1.6 kV was also achieved for a reverse current of up to 100 gA through the use of an optimum multiple floating guard rings （MFGR） termination, which is about 87.2% of the theoretical value. The differential specific-on resistance （RSP-ON） was meas- ured to be 3.3 mΩcm2, leading to a FOM （VB2/RSP-ON） value of 0.78 GW/cm2, which is very close to the theoretical limit of the tradeoff between the specific-on resistance and breakdown voltage for 4H-SiC unipolar devices.

Estimating the Limits in System Design for 48 V Automotive Power Applications

The design process in power electronics is driven by increased utilisation level of the used components to gain performance whilst keeping cost low. This article provides an overview on challenges in low-voltage high-current systems, e.g. used in automotive applications. The main content points are： topology selection--single systems vs. cascaded systems, PCB manufacturing technology overview, current measurement methods, bulk capacitor design （ceramic DC link） and PCB design instructions for high-current systems. The PCB design instructions target on optimised thermal design for maximised PCB utilisation and on optimised track design for a low inductance DC link interconnection. The paper bases on calculations, measurements and simulations.

A novel high voltage LIGBT with an n-region in p-substrate

A novel 4 μm thickness drift region lateral insulated gate bipolar transistor with a floating n-region （NR- LIGBT） in p-substrate is proposed. Due to the field modulation from the n-region, the vertical blocking capability is enhanced and the breakdown voltage is improved significantly. Low area cost, high current capability and short turn-off time are achieved because of the high average electric field per micron. Simulation results show that the blocking capability of the new LIGBT increases by about 58% when compared with the conventional LIGBT （C-LIGBT） for the same 100 μm drift region length. Furthermore, the turn-off time is shorter than that of the conventional LIGBT for nearly same blocking capability.

A thick SOI UVLD LIGBT on partial membrane

A thick SOI LIGBT structure with a combination of uniform and variation in lateral doping profiles （UVLD） on partial membrane （UVLD PM LIGBT） is proposed. The silicon substrate under the drift region is selectively etched to remove the charge beneath the buried oxide so that the potential lines can release below the membrane, resulting in an enhanced breakdown voltage. Moreover, the thick SOI LIGBT with the advantage of a large current flowing and a thermal diffusing area achieves a strong current carrying capability and a low junction temperature. The current carrying capability （VAnode = 6 V, VGate = 15 V） increases by 16% and the maximal junction temperature （1 mW/μm） decreases by 30 K in comparison with that of a conventional thin SO1 structure.