High Quality GaN Display Films Growth on Pre-treated Sapphire Substrate

摘要

Etch pits on sapphire substrate surface are formed after surface treating. GaN films have been grown by LP-MOCVD on the sapphire substrate, which a half of it is pretreated by chemical etch. The crystal quality and optical quality of GaN films are analyzed by high-resolution double crystal X-ray rocking curve (XRC) and optical transmission measurement. These results indicate that the crystal quality of GaN determined by transmission measurement is in agreement with that determined by XRC, that the (0002) plane and (10-12) plane full-width at half-maximum by XRC of GaN films grown on pre-treated sapphire substrate are as low as 208.80 arcsec and 320.76 acrsec, respectively. The transmission spectrum of GaN is studied to assess the crystal and optical quality. The epilayer grown on pre-treated sapphire substrate exhibits excellent optical quality, in which the yellow luminescence (YL) is nearly invisible in the photoluminescence (PL) spectrum. The epilayer grown on the pre-treated sapphire substrate exhibits superior optical properties and crystal properties, in which the higher transmission ratio and the greater modulation depth can be shown in the transmission spectrum.