Hydride Vapor Phase Epitaxy 법에 의한 GaN 성장에 관한 연구

Abstract

In this study, the optical properties of thick GaN films grown on sapphire substrates using the HVPE (hydride vapor phase epitaxy) method were investigated by photoluminescence (PL) measurement at 300 K and 77 K. GaN was grown at different growth temperature from 900 ℃ to 1090 ℃ for obtaining high quality GaN. At the results of PL spectrum, bound exciton peak at 357.5 nm(3.46 eV) with FWHM(full width at half maximum) of 17.7 meV and DAP(donor-accepter pair)peak at 376.5 nm(3.29 eV) was observed at 77 K. A peak was appeared at 80.5 meV below the bound exciton peak. This peak might originate from the impurity-related peak formed by diffusion of Oxygen impurities from sapphire substrates. Therefore, we suggest that optimized growth temperature to obtain high quality GaN crystal was 1050 ℃.