New High-Voltage Unipolar Mode p+ Si/n– 4H-SiC Heterojunction Diode
We demonstrate a new high-voltage p+ Si/n- 4H-SiC heterojunction diode (HJD) by numerical simulation and experimental results. This HJD is expected to display good reverse recovery because of unipolar action similar to that of a SiC Schottky barrier diode (SBD) when forward biased. The blocking voltage of the HJD is almost equal to the ideal level in the drift region of n- 4H-SiC. In addition, the HJD has the potential for a lower reverse leakage current compared with the SBD. A HJD was fabricated with p+-type polycrystalline silicon on an n--type epitaxial layer of 4H-SiC. Measured reverse blocking voltage was 1600 V with low leakage current. Switching characteristics of the fabricated HJD showed nearly zero reverse recovery with an inductive load circuit.
Roberta Nipoti, Antonella Poggi and Andrea Scorzoni
T. Hayashi et al., "New High-Voltage Unipolar Mode p+ Si/n– 4H-SiC Heterojunction Diode", Materials Science Forum, Vols. 483-485, pp. 953-956, 2005