Characteristic morphologies of triangular defects on Si-face 4H-SiC epitaxial films

• Two types of the triangular defects on the 4H-SiC epitaxial films were investigated.
• The one is with a single valley and the other one is with washboard-like morphology.
• The morphology like a single valley is formed by the 3C domains.
• The washboard-like morphology is formed by the 4H domains which cover the 3C layer.

Triangular defects with a characteristic morphology consisting of a 3C-type structure were investigated on Si-face 4H-SiC epitaxial films using electron microscopy. Two types of triangular defects were investigated: one with a single valley on the surface along the [112¯0] direction and another with several parallel ridges and valleys called “washboard-like defects”. The defects with a single valley had a characteristic domain structure consisting of four 3C crystals, which is similar to that of previously reported comet-shaped defects on the C-face. It is shown that the 3C domain in the washboard-like defect is covered by 4H layers with a washboard-like morphology.