Growth of 4H-SiC on rhombohedral (0 1 1¯ 4) plane seeds

We have investigated bulk growth of 4H-SiC crystals on rhombohedral (0 1 1¯ 4) plane seeds. In bulk 4H-SiC, the (0 1 1¯ 4) plane was found to form a stable mirror-like facet. It is inclined towards the (0 1 1¯ 0) plane and makes an angle of about 43° with the (0 0 0 1) plane. For comparison, an additional crystal was grown on a seed which was cut at the same angle of 43° to (0 0 0 1), but toward the [1 1 2¯ 0] direction. Etching features on three differently oriented planes cut from two characteristic crystals were compared in order to construct the entire three-dimensional picture of defect behavior in bulk 4H-SiC grown in non-conventional [0 1 1¯ 4] direction. The structural quality of the crystal grown on natural rhombohedral (0 1 1¯ 4) facet was sufficiently better than that of the crystal grown on the seed off-oriented toward the (1 1 2¯ 0) plane. The (0 1 1¯ 4) plane growth can be considered as promising for bulk growth of micropipe-free 4H-SiC crystals.