Surface defects generated by extrinsic origins on 4H-SiC epitaxial-wafers observed by scanning electron microscopy.

Surface defects on 4H-SiC wafers with an epitaxial layer grown by chemical vapor deposition (CVD) were observed using scanning electron microscopy (SEM). Commercially available epitaxial-wafers with four or eight deg-off surface from the [0001] toward the [112¯0] directions were used for this experiment. 3C-SiC particles, triangular-defects, comets, obtuse-triangular-shaped-defects and micro-holes were identified in the SEM images.

Surface defects generated by intrinsic origins on 4H-SiC epitaxial wafers observed by scanning electron microscopy.

Surface defects with intrinsic origins in an epitaxial layer on 4H-SiC wafers were observed by scanning electron microscopy. Commercially available 4H-SiC epitaxial wafers with 4° or 8° off-axis angles from the [0001] direction toward the [112¯0] direction were used in this experiment. Various types of defects, including micropipes, pits, carrots, stacking faults and wide terrace and high step structures, were observed and clearly identified.