High crystal quality of vertical Bridgman and edge-defined film-fed growth β-Ga2O3 bulk crystals investigated using high-resolution X-ray diffraction and synchrotron X-ray topography

Abstract

High crystal quality of vertical Bridgman (VB)-grown (001) β-Ga2O3 single-crystal was confirmed in comparison with edge-defined film-fed growth (EFG)-grown (001) β-Ga2O3 single-crystal. The FWHMs of VB were lower than FWHMs of EFG from X-ray diffraction rocking curve analysis. VB and EFG crystal curvatures were measured as 232.24 m and 45.83 m, respectively. By using transmission and reflection geometry in synchrotron X-ray topography, we unambiguously determined the Burgers vector ( b ) = [010] and [001]. For the VB crystal, screw dislocations with b = [010] and dislocation direction ( t ) = [010] were observed. For the EFG crystal, edge dislocations with b = [001] and t = [010] were observed. In addition, wandering dislocations on the (001) plane with b = [010] for EFG and b = [001] for both EFG and VB were observed. These phenomena indicate that the wandering dislocations were formed by a slip motion on the (001) slip plane.