1200 V 6 A SiC BJTs with very low VCE_(sat) and fast switching

摘要

SiC BJTs with 1200 V and 6 A rating were fabricated. Very low collector-emitter saturation voltages Vcesat=0.5 V at lc=6 A (Jc=140 A/cm2) and T=25 °C, and VCE(sat)=0.85 V at lc=6 A and T=150 °C were measured. The common emitter current gain at lc=6 A is 75 at T=25 °C and 45 at T=150°C, respec-tively. Long-term stability tests with DC current stress of the base-collector diode indicate that the BJTs are free from VCE(sat) degradation by recombination induced stacking fault formation. A SPICE model was developed for the 6 A BJT including the parasitic capacitances of the internal pn junctions, as well as temperature dependence of the cu;rrent gain and the collector series resistance. The IC-VCE characteristics of the BJT are in good agreement with the SPICE model at T=25 °C and at T=150 °C. Switching measurements were performed showing VCE voltage rise- and fall-times in the range of 20-30 ns. The switching behaviour is in qualitative agreement with SPICE simulations, which show significant influence of parasitic capacitances of the BJT die and stray inductances of the package.