HYDRIDE VAPOR PHASE EPITAXY OF GaN ON NdGaO3 SUBSTRATE AND REALIZATION OF FREESTANDING GaN WAFERS WITH 2-INCH SCALE

GaN thick film is grown on NdGaO3 substrate using hydride VPE. To avoid decomposition of NdGaO3 substrate by NH3, a low-temperature grown GaN protective layer is adopted. Using NdGaO3 substrate and a low-temperature GaN protective layer simultaneously, 2-in.-scale GaN wafers are realized. The photoluminescence (PL) spectrum indicates strong band-edge emission without deep-level related emission. Both plan-view TEM and cathode luminescence images suggest that the dislocation density of freestanding GaN wafers is expected to be as low as 106 cm-2. 6 refs.