Improvement of GaN layer quality by using the bulk-GaN buffer structure grown by metalorganic chemical vapor deposition

摘要: In this article, we propose a new buffer structure to obtain the high quality GaN epitaxial layers grown on sapphire substrates by separate-flow reactor of metalorganic chemical vapor deposition (MOCVD). This consists 200–300 A nucleation layer/6 μm GaN-bulk layer. The bulk-GaN have also been prepared MOCVD. layer exhibits full width at half maximum (FWHM) double-crystal x-ray diffraction 170 arcsec, FWHM 300 K photoluminescence 56 meV, an electron mobility 400 cm2/V s and 815 140 K, concentration 3.6×1017 cm−3 K. growth with has wide window different nucleation-layer thicknesses. good can be obtained using structure.