Influence of buffer layers on the microstructure of MOVPE grown a-plane InN

• Published in: Journal of crystal growth 2011-01, Vol.315 (1), p.233-237
• Main Authors: Laskar, Masihhur R., Ganguli, Tapas, Kadir, Abdul, Hatui, Nirupam, Rahman, A.A., Shah, A.P., Gokhale, M.R., Bhattacharya, Arnab
• Format: Article
• Language: English
• Subjects: A1. High resolution X-ray diffraction; A3. Metalorganic vapor phase epitaxy; Aluminum nitride; Anisotropy; B1. Non-polar; B2. Semiconducting III–V materials; Buffer layers; Camber; Carrier density; Chemical vapor deposition (including plasma-enhanced cvd, mocvd, etc.); Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Density; Exact sciences and technology; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Microstructure; Other semiconductors; Physics; Specific materials; Structure and morphology; thickness; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology; Tilt; Vapor phase epitaxy; growth from vapor phase
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2010.08.019

We report a comparative study of the microstructure of a-plane ( 1 1 2 ¯ 0 ) InN epilayers grown on different buffer layers via metalorganic vapour phase epitaxy. Under optimized growth conditions, the crystalline quality of the InN epilayer is found to be best on an AlN buffer layer compared to that on GaN buffer layers or InN nucleation layers. All a-plane InN epilayers show an anisotropy in the in-plane mosaicity with the in-plane tilt value being different along the c- and m-directions. We also observe a Nagai-like tilt in all the epilayers. The magnitude and nature of this anisotropy and the Nagai-like tilt is also strongly influenced by the buffer layer. Our investigations show that InN grown on an AlN buffer has smaller in-plane tilt, basal plane stacking fault density, and background carrier concentration resulting in a higher mobility and a low band gap energy of ∼ 0.70 eV .