Conventional transmission electron microscopy (TEM) was conducted to identify crystallographic defects under some types of ''device-killing'' surface morphological faults on an epitaxial film grown on a 4H-SiC (0001) off-cut substrate. The ''comet'' fault composed of a nucleus and a tail is accompanied by 3C-SiC of zinc blende structure. The ''triangular defect'' characterized by its isosceles shape is associated with stacking fault (SF) on the (0001) 4 H plane. Based on TEM contrast analysis, stacking faults on {111} planes introduced in a 3C-SiC ''comet'' fault and the formation mechanism of ''triangular defect'' are discussed.