Morphology and origin of V-defects in semipolar (11–22) InGaN

V-shaped pits (V-defects) were observed in semipolar (112̄2)-oriented InGaN/GaN layers grown by plasma-assisted molecular beam epitaxy (PA-MBE). The pit morphology was that of inverted rhombic or trigonal pyramids aligned along the in-plane [11̄00] direction. Pit facet orientations were identified. The surface pits were found to be connected at their apex to mixed type a+c threading dislocations with large screw components. Such dislocations exhibited [112̄0] average line directions with zig-zag 〈101̄0〉 local lines, and they also induced V-defects at the InGaN/GaN interface.

► V-shaped pits (V-defects) were observed on the surface of (112̄2) InGaN grown by plasma-assisted MBE.
► The pit morphology was that of inverted rhombic or trigonal pyramids aligned along the in-plane [11̄00] direction.
► V-defects were associated with mixed type a+c threading dislocations with lines along [112̄0] on average.
► The same threading dislocations also induced V-defects at the InGaN/GaN interface.