Characterization of AlGaN layer with high Al content grown by mixed-source HVPE

摘要

Using mixed-source hydride vapor-phase epitaxy (HVPE), an AlGaN layer with high Al content on GaN/Al_2O_3 substrate is obtained. The AlGaN layer grown by mixed-source HVPE is characterized by X-ray diffraction (XRD) measurements and cathodoluminescence (CL) spectra. In the mixed-source HVPE technique, the AlGaN material is compounded from the chemical reaction between NH_3 and an aluminum-gallium chloride formed using HCl that is flowed over metallic Ga mixed with Al. The XRD measurements indicate that single-crystal hexagonal AlGaN with high Al content had been grown. The CL spectra at 4 K show that the distribution of the Al on the AlGaN surface for very high Al content (x = 0.8 in Al_xGa_(1-x)) is not uniform.