Basal plane dislocation structures and single Shockley-type stacking fault shapes in 4H-SiC epitaxial layers

The correspondence with experimentally observed expanded shapes of single Shockley-type stacking faults (1SSFs), which are referred to as the final expansion shapes, is affected not only by the expansion limiting boundaries, such as the substrate/epi-layer interface and the n/p interface of PiN diodes or epitaxial layer surface, but also by where the expansion initiation point is located. In this study, these findings were derived for the first time by estimating the final expansion shape, and the results affirmed that the location of the basal plane dislocation (BPD) segment is as important as the structure of the BPD itself. We also reorganised the 1SSF expansion shapes according to the BPD structure, such as further considering three negative Burgers vectors, line directions, and types of layers with different facing direction of tetrahedrons, which corresponds to a total of 72 classifications. We were able to demonstrate through experimental analysis that the necessity of the Burgers vector on the negative side of BPD cannot be ignored, particularly when analysing the characteristic of the 1SSF structures from BPDs, which involves the bending of the dislocation line. The investigation also indicated that there are only 36 classifications in terms of the final extended shape of 1SSF, clarifying the correspondence between the equivalent Burgers vectors on the positive and negative sides.