X-ray diffraction and Raman characterization of β-Ga2O3 single crystal grown by edge-defined film-fed growth method

The crystallinity and wafer uniformity of ((2) over bar 01) and (010) oriented beta-Ga2O3 substrates grown by edge-defined film-fed growth (EFG) were investigated by laboratory X-ray diffraction (XRD), synchrotron XRD, polarized Raman spectroscopy, and Raman mapping. XRD results indicated that the EFG substrates had superior crystallinity and high uniformity. Position-dependent XRD omega-rocking curves recorded across a 50.8-mm-diameter substrate had small standard deviations of delta(F) = 1.6% for the full width at half maximum and delta(P) = 2.8% for the peak intensity. The radius of curvature was measured to be 37.7 m for the ((2) over bar 01) substrate and 16.4 m for the (010) substrate. The results of synchrotron XRD with various beam sizes suggested that the curving of crystal planes was mainly along the [010] growth direction rather than along the [102] direction. Raman spectra showed that Sn doping up to 3.3 x 10(18)cm(-3) did not give rise to a notable Raman peak shift. The strain distribution evaluated by Raman mapping implied the high uniformity of both ((2) over bar 01) and (010) substrates. From these results, it was concluded that beta-Ga2O3 ingots grown by EFG have high crystallinity and can be treated as three-dimensionally uniform bulk crystals in the cases of both undoped and Sn-doped growth. Published under license by AIP Publishing.