Single crystal gallium oxide (Ga2O3) has been an emerging material for power semiconductor applications. However, the defect distribution of Ga2O3 substrates needs to be carefully characterized to improve crystal quality during crystal growth. We analyzed the type and the distribution of defects on commercial (-201) Ga2O3 substrates to get a basic standard prior to growing Ga2O3 crystals. Etch pit technique was employed to expose the type of defects on the Ga2O3 substrates. Synchrotron white beam X-ray topography was also utilized to observe the defect distribution by a nondestructive manner. We expect that the observation of defect distribution with three-dimensional geometry will also be useful for other crystal planes of Ga2O3 single crystals.
