Dislocation density reduction in (1011) GaN at a high temperature using tri-halide vapor phase epitaxy

摘要

The dependence of growth temperature for the epitaxial films grown by tri-halide vapor phase epitaxy (THVPE) on thecrystal characteristics, such as the surface morphology, the full width at half maximum (FWHM), the threadingdislocation density (TDD), the impurity concentration, and the photoluminescence (PL) was investigated. The epitaxialfilms grown at relatively high growth temperature of 1300–1350 °C showed that the crystal quality, such as FWHM andTDD retained that for the used substrate. The near-band-edge emission for PL for 1300–1350 °C growth showed lagerintensities due to low nonradiative recombination center (NRC). Moreover, the epitaxial growth on the supercriticalacidic ammonia technology (SCAAT?) substrate was demonstrated. The TDD was as low as 2 × 10~4 cm~(-2), whichindicated that the epilayer grown by THVPE retained the superior crystal quality of SCAATTM.