Lateral Epitaxial Overgrowth of High-Quality Thick GaN Film by Hydride Vapor Phase Epitaxy

High-quality thick GaN film of 320 ¿m thickness was grown on low-temperature HVPE-GaN/c-Al₂O₃ template by hydride vapor phase epitaxy (HVPE) after radio frequency (RF) magnetron sputtering (MS) ZnO buffer layer was deposited on the template. The void areas in the interface between three-dimension island of ZnO buffer and thick GaN film helpful to the formation of lateral epitaxial overgrowth (LEO) of GaN layer when V/III rate of HVPE is adjusted. The crystal properties of thick GaN film were detected by double crystal X-ray diffraction (DCXRD), atomic force microscopy (AFM) and scanning electron microscope (SEM). As a result, the full width at half maximum (FWHM) of GaN(0002) double crystal x-ray diffraction rocking curve is 336.15 arcsec and the threading dislocation density (TDD) estimates about 10⁷ cm^-2, which indicated that the quality of crystal is as high as suitable for free-Standing GaN substrate.