Origin of Double-Rhombic Single Shockley Stacking Faults in 4H-SiC Epitaxial Layers

Effect of basal plane dislocation structures on single Shockley-type stacking fault expansion rate in 4H-SiC

“…A 1SSF originating from a half loop array (HLA) [39][40][41][42][43][44][45][46] formed a double rhombic stacking fault (DRSF). 26,27,45) After colliding with the neighboring DRSF, the part of the expanding front that could be a 90°Si-core PD disappeared at 120 s. 27) We therefore measured the distance of the expanding front before and after the rapid movement of the 90°Si(g) PD, which is the diagonal distance of the diamond as shown in Fig. 2(b).…”

“…11,19) In other words, differences in the combinations of PDs change the 1SSF shape as they expand, resulting in triangles, 8,20) trapezoids,8, 21,22) parallelograms, 21,22) bars with and without a triangle, 11,21,23) and double rhombuses. [24][25][26][27] The Burgers vectors and line directions of the PDs in various 1SSF shapes have been characterized using photoluminescence (PL) and transmission electron microscopy (TEM) analyses, and the results can explain the expanded 1SSF shapes by the combinations of the Burgers vector and line direction of the BPD at the origin. [21][22][23][26][27][28][29][30][31][32][33] 1SSF shapes are understood by the different expansion rates of leading PDs of 30°or 90°Si(g); namely, 90°S i(g) PDs expand faster than 30°Si(g) PDs.…”

“…[24][25][26][27] The Burgers vectors and line directions of the PDs in various 1SSF shapes have been characterized using photoluminescence (PL) and transmission electron microscopy (TEM) analyses, and the results can explain the expanded 1SSF shapes by the combinations of the Burgers vector and line direction of the BPD at the origin. [21][22][23][26][27][28][29][30][31][32][33] 1SSF shapes are understood by the different expansion rates of leading PDs of 30°or 90°Si(g); namely, 90°S i(g) PDs expand faster than 30°Si(g) PDs. 34,35) Only a few experiments on the expansion rates of 1SSFs have been reported, and these were conducted by electroluminescence (EL) or UV illumination.…”

Partial dislocation structures at expansion terminating areas of bar-shaped single Shockley-type stacking faults and basal plane dislocations at the origin in 4H-SiC

“…34,35) If the BPD had been a 60°perfect dislocation, it would have expanded as a doublerhombic 1SSF. 26) The BPD at the origin might have converted into a TED in the epilayer. Note that care is required because the expanding shapes of 1SSFs differ depending on the places where the BPDs at the origin were located, namely, near the substrate/epilayer side or the surface side, even for the same combination of b BPD and the line direction, ξ.…”

“…25) The difference in expansion shapes of the 1SSFs was explained by the different characters of the BPDs at the origin, such as a perfect screw dislocation with Burgers vector (b BPD ) = (1/3) [11 20] to a triangular 1SSF and a 60°perfect dislocation with b BPD = (1/3)[ 2110] or (1/3)[1 210] to an inclined double-rhombic 1SSF. 26) The threshold current density for expansion and the expansion rate have also been reported to be dependent of the 1SSF shapes. 17,27) From the viewpoint of the electrical properties of power devices, a correlation between 1SSFs and blocking voltage degradation has been reported.…”