TY - JFULL AU - Abbas Nasir and Xiong Zhang and Sohail Ahmad and Yiping Cui PY - 2021/6/ TI - Growth of Non-Polar a-Plane AlGaN Epilayer with High Crystalline Quality and Smooth Surface Morphology T2 - International Journal of Materials and Metallurgical Engineering SP - 112 EP - 116 VL - 15 SN - 1307-6892 UR - https://publications.waset.org/pdf/10012024 PU - World Academy of Science, Engineering and Technology NX - Open Science Index 173, 2021 N2 - Non-polar a-plane AlGaN epilayers of high structural quality have been grown on r-sapphire substrate by using metalorganic chemical vapor deposition (MOCVD). A graded non-polar AlGaN buffer layer with variable aluminium concentration was used to improve the structural quality of the non-polar a-plane AlGaN epilayer. The characterisations were carried out by high-resolution X-ray diffraction (HR-XRD), atomic force microscopy (AFM) and Hall effect measurement. The XRD and AFM results demonstrate that the Al-composition-graded non-polar AlGaN buffer layer significantly improved the crystalline quality and the surface morphology of the top layer. A low root mean square roughness 1.52 nm is obtained from AFM, and relatively low background carrier concentration down to 3.9×  cm-3 is obtained from Hall effect measurement. ER -