high-voltage power semiconductor devices on SiC

摘要

The 4H SiC epitaxial wafer of thickness 50~100 m, it is grown on the substrate of the off-angle 4 . From the inspection of the epitaxial wafer, in the range of 2~6cm ^-2 , surface morphological defect density was obtained. These epitaxial wafer, consistent carrier lifetime is obtained in the range of 2~3 s. By BPD density was reduced to less than 10cm ^-2 , in the epi-wafer, very low BPD density has been confirmed. Using the epitaxial wafer having a thickness of 50~100 m, to prepare a diode. By the high-pressure test, close blocking voltage to the theoretical value for the 4H-SiC has been demonstrated. 50 m in devices fabricated on the epitaxial film having a thickness, 8kV higher blocking voltage ones, 80 m in devices fabricated on the membrane of thickness, 10kV high blocking voltage ones, resulting. The failure analysis, triangular defects formed by particles present in surface damage or epitaxy is a fatal flaw, it was confirmed that the reverse bias operation of the device is caused to stop functioning. In addition, the leakage current in the high blocking voltage of the JBS diode, the correlation between the screw dislocation density was observed. The main source of basal plane dislocations in the epitaxial layer was also observed that from the crystal growth process.