In order to realize a high break-down SiC-SBD (Schottky barrier
diode), we investigated the rela-tionship between the reverse
breakdown voltage and the oxide overlap width in a field- plate
(FP)-type SiC-SBD. The reverse breakdown voltage of a FP-t...
In order to realize a high break-down SiC-SBD (Schottky barrier
diode), we investigated the rela-tionship between the reverse
breakdown voltage and the oxide overlap width in a field- plate
(FP)-type SiC-SBD. The reverse breakdown voltage of a FP-type
SiC-SBD greatly depended on the oxide overlap width. The FP-type
SiC-SBD was also found to have higher breakdown characteristics
with increasing oxide overlap width, A 30-$\mu$m oxide overlap
width exhibited an approximately 880-V reverse breakdown voltage, in
sharp contrast, a 10-$\mu$m oxide overlap width showed only a 300-V
reverse breakdown voltage. There are two origins for the reverse
breakdown phenomenon in a FP-type SiC-SBD. One is crystal defects,
such as micropipes in the SiC substrate and stacking faults in the
drift layer, and is associated with lower reverse voltages. The other is due to oxide destruction in the oxide overlap region and is
associated with higher reverse voltages. The oxide destruction in
the oxide overlap region is due to the electric field concentration
at high reverse voltages.