Carbon vacancy control in p+-n silicon carbide diodes for high voltage bipolar applications

Controlling the carbon vacancy (V C ) in silicon carbide (SiC) is one of the major remaining bottleneck in manufacturing of high voltage SiC bipolar devices, because V C provokes recombination levels in the bandgap, offensively reducing the charge carrier lifetime.In literature, prominent V C evolutions have been measured by capacitance spectroscopy employing Schottky diodes, however the trade-offs occurring in the p + -n diodes received much less attention.In the present work, applying similar methodology, we showed that V C is re-generated to its unacceptably high equilibrium level at ∼2×10 13 V C /cm 3 by 1800 • C anneals required for the implanted acceptor activation in the p + -n components.Nevertheless, we have also demonstrated that the V C eliminating by thermodynamic equilibrium anneals at 1500 • C employing carbon-cap can be readily integrated into the p + -n components fabrication resulting in ≤10 11 V C /cm 3 , potentially paving the way towards the realization of the high voltage SiC bipolar devices.