Although various silicon carbide (SiC) power devices with very high blocking voltages\nover 10 kV have been demonstrated, basic issues associated with the device operation are still not\nwell understood. In this paper, the promise and limitations of high-voltage SiC bipolar devices are\npresented, taking account of the injection-level dependence of carrier lifetimes. It is shown that the\nmajor limitation of SiC bipolar devices originates from band-to-band recombination, which becomes\nsignificant at a high-injection level. A trial of unipolar/bipolar hybrid operation to reduce power loss\nis introduced, and an 11 kV SiC hybrid (merged pin-Schottky) diodes is experimentally demonstrated.\nThe fabricated diodes with an epitaxial anode exhibit much better forward characteristics than diodes\nwith an implanted anode. The temperature dependence of forward characteristics is discussed.
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