Schottky barrier diode (SBD) was fabricated by MOCVD using bistrimethylsilylmethane
(BTMSM, C7H20Si2) precursor. The 4H-SiC substrates which had different
crystallographic characteristics were used for the comparison of the crystallinity effect on the
electrical properties of the SBDs. From the measurement of the reverse I-V characteristics of the
SBDs with micropipes, it is shown that the origin of the main leakage path and early breakdown (or
ohmic behavior in reverse bias) in 4H-SiC SBDs is the grain boundaries caused by the inclusions or
other defects. The best performance of SBD were shown in the epilayer grown at 1440 oC using
high quality substrate, and the breakdown voltage and reverse leakage current were about 450 V
and 10-9 A/cm2, respectively.