Smooth surface morphology and low dislocation density of p-GaN using indium-assisted growth

• Published in: Applied physics. A, Materials science & processing Vol. 116; no. 4; pp. 1561 - 1566
• Main Authors: Zhang, Kexiong, Liang, Hongwei, Shen, Rensheng, Song, Shiwei, Wang, Dongsheng, Liu, Yang, Xia, Xiaochuan, Yang, Dechao, Luo, Yingmin, Du, Guotong
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.09.2014
• Subjects: Characterization and Evaluation of Materials; Condensed Matter Physics; Machines; Manufacturing; Nanotechnology; Optical and Electronic Materials; Physics; Physics and Astronomy; Processes; Surfaces and Interfaces; Thin Films; Metal Adatoms; Hole Concentration; Flow Rate Ratio; Root Mean Square Roughness; Smooth Surface Morphology
• ISSN: 0947-8396; 1432-0630
• DOI: 10.1007/s00339-014-8384-5

Mg-doped, 1-μm-thick, p-type GaN films were grown by metal-organic chemical vapor deposition using indium-assisted method. The influence of flow rate ratio of indium to magnesium (In/Mg ratio) on the quality of p-GaN thin films was investigated by atomic force microscope, X-ray diffraction, Hall measurement and secondary ion mass spectroscopy. The surface roughness, crystalline quality and hole concentrations of p-GaN present a different variation tendency below and above 0.183 In/Mg ratio. The evolution process of indium-adlayer model considering adsorption, desorption and the transformation of indium mono-adlayer was proposed to explain the above phenomenon. Indium-assisted growth method can improve surface smoothness and crystalline quality of p-GaN effectively without affecting its electrical properties.