Growth of high-quality In-rich InGaN alloys by RF–MBE for the fabrication of InN-based quantum well structures

• Published in: Journal of crystal growth 2006-03, Vol.288 (2), p.283-288
• Main Authors: Naoi, Hiroyuki, Kurouchi, Masahito, Muto, Daisuke, Araki, Tsutomu, Miyajima, Takao, Nanishi, Yasushi
• Format: Article
• Language: English
• Subjects: A1. Photoluminescence; A1. Quantum well; A1. X-ray diffraction; A3. RF–MBE; B2. In-rich In xGa 1−xN; B2. InN; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Iii-v semiconductors; Materials science; Nanoscale materials and structures: fabrication and characterization; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Photoluminescence; Physics; Quantum wells
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2005.12.008

This paper describes studies performed for improving the quality of In-rich In x Ga 1− x N alloys. The crystalline quality and surface morphology of In-rich In x Ga 1− x N films was improved by using InN templates as underlying layers. It was also found that the crystalline quality of In-rich In x Ga 1− x N was strongly correlated with that of the underlying InN templates. High-quality InN templates with the (0 0 0 2) X-ray rocking curves (XRCs) as narrow as 1 arcmin, have recently been achieved by optimizing the nitridation conditions of (0 0 0 1) sapphire substrates (300 °C, 2 h). These InN templates have provided further improvement of the crystalline quality of In 0.8Ga 0.2N films. The (0 0 0 2) XRCs for these In 0.8Ga 0.2N films were approximately 18 arcmin (full-width at half-maximum), dramatically narrower than the 36 arcmin obtained with a previous substrate-nitridation process (550 °C, 1 h). By employing these high-quality In 0.8Ga 0.2N layers as not only growth templates but also bottom barrier layers, an InN/In 0.8Ga 0.2N multiple quantum well (MQW) structure and single-quantum well (SQW) structures with different well widths were fabricated. The MQW structure showed clear 1st and 2nd satellite peaks of X-ray diffraction. The SQW structures exhibited photoluminescence emission from their well layers.