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 [112¯0] direction corresponding to (101¯0) and (01¯10) slip planes inclined at roughly 60° from the m-plane. Based on the Peierls-Nabarro model, we explain this structure by proposing a slip system via the {101¯0} prism plane with 〈112¯0〉-type slip directions.