Effects of Ⅴ/Ⅲ ratio and Cp2Mg flow rate on characteristics of non-polar a-plane Mg-delta-doped p-AlGaN epi-layer. (September 2020)

• Record Type: Journal Article
• Authors: Fan, Aijie; Zhang, Xiong; Chen, Shuai; Li, Cheng; Lu, Liang; Zhuang, Zhe; Lyu, Jiadong; Hu, Guohua; Cui, Yiping
• Is Part Of: Superlattices and microstructures. Volume 145(2020)
• Publication Date: 2020-09
• Subjects: Non-polar a-plane p-AlGaN -- V/III ratio -- Electrical resistivity -- Hole concentration -- Mg-delta-doping; Superlattices as materials -- Periodicals; Microstructure -- Periodicals; Semiconductors -- Periodicals; Superréseaux -- Périodiques; Microstructure (Physique) -- Périodiques; Semiconducteurs -- Périodiques; 621.38152
• DOI: 10.1016/j.spmi.2020.106632
• Languages: English
• ISSNs: 0749-6036

Abstract

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 Cp2 Mg 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 × 10 17 cm − 3 and an electrical resistivity of 2.6 Ω ⋅ cm were obtained for non-polar p-Al0.12 Ga0.88 N epi-layer by carefully optimizing the Ⅴ/Ⅲ ratio and Cp2 Mg 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. Highlights: The non-polar a -plane Mg-delta-doped Al0.12 Ga0.88 N epi-layers were grown by metal organic chemical vapor deposition technology. A hole concentration of 3.7 × 10 17 cm −3, a hole mobility of 3.5 cm 2 · V −1 · s −1, and an electrical resistivity of 2.6 Ω · cm of non-polar a -plane p-Al0.12 Ga0.88 N epi-layer was achieved at the carefully optimized Ⅴ/Ⅲ ratio and the Cp2 Mg flow rate. The XRD, Raman spectra, and Hall effect measurement results revealed that the effective suppression of the defects-related self-compensation effect owing to the optimization of the Ⅴ/Ⅲ ratio and Cp2 Mg flow of the non-polar a -plane p-Al0.12 Ga0.88 N epi-layers.