Evidence of lattice tilt and slip in m-plane InGaN/GaN heterostructure

Using high-resolution microbeam x-ray diffraction and cross-section transmission electron microscopy, we investigated in-plane anisotropy resulting from epilayer lattice tilts in heteroepitaxial InGaN on a m-plane GaN substrate. The in-plane structure consists of two lattice tilts along the [11 (2) over bar0] direction corresponding to (10 (1) over bar0) and (0 (1) over bar 10) slip planes inclined at roughly 60 degrees from the m-plane. Based on the Peierls-Nabarro model, we explain this structure by proposing a slip system via the {10 (1) over bar0} prism plane with < 11 (2) over bar0 >-type slip directions. (C) 2011 American Institute of Physics. [doi:10.1063/1.3644978]