Influence of MBE growth modes and conditions on spontaneous formation of metallic In nanoparticles and electrical properties of InN matrix

• Published in: Journal of crystal growth Vol. 478; pp. 216 - 219
• Main Authors: Komissarova, T.A., Wang, P., Paturi, P., Wang, X., Ivanov, S.V.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15-11-2017; Elsevier BV
• Subjects: A3. Growth modes; A3. Molecular beam epitaxy; B1. Nitrides; B2. In nanoparticles; B2. Semiconducting indium compounds; Conductivity; Electrical properties; Electrical resistivity; Epitaxial growth; Inclusions; Indium; Influence; Molecular beam epitaxy; Nanoparticles; Reduction (metal working); Studies; Thermal decomposition; Transport properties; B2. Semiconducting indium compounds; A3. Molecular beam epitaxy; A3. Growth modes; B1. Nitrides; B2. In nanoparticles
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2017.09.010

•Effect of In nanoparticles on electrical properties of InN MBE layers depends on growth modes.•Three-step growth comprising MBE, MEE, and DERI modes minimizes the metallic In amount.•In nanoparticles dominate the InN transport parameters even at minimum In amount of 3.8%.
Influence of the molecular beam epitaxy (MBE) growth conditions on the electrical properties of the InN epilayers in terms of minimization of the effect of spontaneously formed In nanoparticles was studied. A three-step growth sequence was used, including direct MBE growth of an InN nucleation layer, migration enhanced epitaxy (MEE) of an InN buffer layer, and In-rich MBE growth of the main InN layer, utilizing the droplet elimination by radical-beam irradiation (DERI) technique. The three-step growth regime was found to lead to decreasing the relative amount of In nanoparticles to 4.8% and 3.8% in In-rich and near-stoichiometric conditions, respectively, whereas the transport properties are better for the In-rich growth. Further reduction of the metallic indium inclusions in the InN films, while keeping simultaneously satisfactory transport parameters, is hardly possible due to fundamental processes of InN thermal decomposition and formation of the nitrogen vacancy conglomerates in the InN matrix. The In inclusions are shown to dominate the electrical conductivity of the InN films even at their minimum amount.