Quality Improvement of GaN on Si Substrate for Ultraviolet Photodetector Application

摘要: GaN is grown on an Si substrate using metal-organic vapor-phase epitaxy. Compared with the full width at half maximum values from X-ray diffraction patterns and photoluminescence spectra of conventional substrate, those insertion various-temperature AlN nucleation layers Al0.3Ga0.7N/GaN superlattice intermediate are reduced by 34.9% 25.6%, respectively. In addition, Raman show that residual stress epilayers decreased 0.35 GPa. The c-lattice parameter epilayer 5.1844 Å, which close to unstrained layer. Ultraviolet metal-semiconductor-metal photodetectors fabricated almost-crack-free surface. dark current a photodetector 2.4 ×10-11 A 9 V applied bias, one order magnitude smaller than sapphire substrate. quantum efficiency value ~ 97% incident light wavelength 360 nm bias.