Crystal tilting in the epitaxial laterally overgrown GaN films on sapphire substrate by hydride vapor phase epitaxy

Crystal tilts in the lateral overgrowth of GaN over SiO₂ mask on Sapphire Substrate by HVPE away from the opening region are demonstrated and characterized by scanning electron (SEM) and high resolve x-ray diffraction (HRXRD). The tilts and stripe morphologies are directly related to the mask width and "fill factors" (ratio of stripe opening width to stripe period). It is found that the growth condition, such as the introduction HCl, C₃H₈/H₂ and the growth rate also have a significant effect on the wing tilt. The mechanisms of these factors affecting the wing tilts and stripe morphologies are discussed respectively.