N incorporation and optical properties of GaAsN epilayers on (3 1 1)A/B GaAs substrates

• Published in: Journal of physics. D, Applied physics Vol. 44; no. 1; p. 015402
• Main Authors: Han, Xiuxun, Suzuki, Hidetoshi, Lee, Jong-Han, Kojima, Nobuaki, Ohshita, Yoshio, Yamaguchi, Masafumi
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 12.01.2011; Institute of Physics
• Subjects: Annealing; Beams (radiation); Chemical vapor deposition (including plasma-enhanced cvd, mocvd, etc.); Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Emission; Epitaxial growth; Exact sciences and technology; Gallium arsenide; Gallium arsenides; Iii-v semiconductors; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of specific thin films; Orientation; Physics; Polarity; Integrated intensity; Gallium arsenides; Annealing; Epitaxial layers; Impurity density; Crystal orientation; Photoluminescence; XRD; Fabrication property relation; CVD; Dangling bonds; Atomic arrangement; Polarity; Nitrogen additions; Deep level
• ISSN: 0022-3727; 1361-6463
• DOI: 10.1088/0022-3727/44/1/015402

We compared the N incorporation and optical emission in GaAsN epilayers grown on (3 1 1)A/B and (1 0 0) GaAs substrates using a chemical beam expitaxy system. Over the growth-temperature range 420 –460 °C, N composition was enhanced 2–3 times for the epitaxial growth following [3 1 1]B orientation, but reduced in the [3 1 1]A direction. Both (3 1 1) A and B substrates are effective to weaken the photoluminescence emission from the deep levels as compared with the (1 0 0) plane. The deep-level emission can be further suppressed for all substrates by increasing the growth temperature and/or performing postgrowth annealing. However, in contrast to the continuous increase in total emission intensities of (3 1 1)B sample, a decreasing tendency was recorded for (3 1 1)A with the rise in growth temperature. The optimum growth temperature and annealing conditions for better crystal quality were found to depend on the growth orientation and surface polarity. These results present a potential approach to improving the N incorporation efficiency in Ga(In)AsN materials through adopting high-index substrates such as (3 1 1)B.