High-resolution dislocation imaging and micro-structural analysis of HVPE-βGa2O3 films using monochromatic synchrotron topography

Threading and basal dislocations were observed and their Burgers vectors ((b) over right arrow) were analyzed in 20 mu m thick halide vapor phase homoepitaxially grown beta-gallium oxide (beta-Ga2O3) films using 15 keV monochromatic synchrotron X-ray topography with symmetric reflection (004) and two asymmetric reflections (205) and (115) in back-reflection and grazing incidence angle geometries, respectively. In a 1 x 1.5 cm(2) sample, threading screw dislocations with (b) over right arrow = < 001 > were observed with a density of 30 cm(-2), whereas a single threading edge dislocation with (b) over right arrow = < 100 > was observed. Basal dislocations with (b) over right arrow = 1/2 < 112 > were observed with a density of similar to 20 cm(-2), and a single basal dislocation with (b) over right arrow = < 010 > was observed. Rocking curve mapping of the three reflections was also performed on the entire sample with the same setup and a high resolution x-ray camera to obtain the full width at half maximum (FWHM), strain, and curvature maps in two almost orthogonal directions. The epilayer demonstrated excellent crystalline quality with a median FWHM of 8.2 arc sec in the (004) reflection and a very low median strain of similar to vertical bar 8 x 10(-5)vertical bar obtained from both sample directions. The median radius of curvature was similar to-100 m along the [100] direction and similar to 280 m along the [010] sample axis, indicating very low lattice plane curvature that enables high manufacturability and reliability of devices. (C) 2018 Author(s).