LAUSR

Abstract The non-polar a-plane Mg-delta-doped p-AlGaN epi-layers with excellent electrical conduction were achieved on r-plane sapphire substrates via metal organic chemical vapor deposition technology. The impacts of Ⅴ/Ⅲ ratio and Cp2Mg flow rate on the properties of the non-polar p-AlGaN epi-layers were investigated with scanning electron microscopy, high-resolution X-ray diffraction, Raman spectroscopy, and Hall effect measurement. It was discovered that the crystalline quality and the electrical conductivity were extremely relied upon the Ⅴ/Ⅲ ratio and Mg-doping level. Actually, a hole concentration of 3.7 × 1017 cm−3 and an electrical resistivity of 2.6 Ω ⋅ cm were obtained for non-polar p-Al0.12Ga0.88N epi-layer by carefully optimizing the Ⅴ/Ⅲ ratio and Cp2Mg flow rate during the epitaxial procedure. In addition, the results revealed that improvement on electrical conductivity was ascribed to the evident repression of self-compensation effect generated by decreasing in the densities of the nitrogen vacancy (VN) as well as the VN-related complexes and the Mg-related defects via the employment of the proper Ⅴ/Ⅲ ratio and the Mg-doping concentration.