Role of high nitrogen flux in InAlN growth by plasma-assisted molecular beam epitaxy

• Published in: Journal of crystal growth 2020-08, Vol.544, p.125720, Article 125720
• Main Authors: Sawicka, Marta, Fiuczek, Natalia, Wolny, Paweł, Feduniewicz-Żmuda, Anna, Siekacz, Marcin, Kryśko, Marcin, Nowakowski-Szkudlarek, Krzesimir, Smalc-Koziorowska, Julita, Kret, Sławomir, Gačević, Žarko, Calleja, Enrique, Skierbiszewski, Czesław
• Format: Article
• Language: English
• Subjects: A1. Atomic force microscopy; A1. Reflection high energy electron diffraction; A3. Molecular beam epitaxy; B1. Nitrides; B2. Semiconducting III-V materials; Epitaxial growth; Flux; Indium; Inhomogeneity; Lattice matching; Molecular beam epitaxy; Morphology; Nitrogen
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/j.jcrysgro.2020.125720

•High N-flux stabilizes In-N bonds in InAlN.•InAlN lattice-matched to GaN was grown at 605 °C by MBE.•InAlN indium content diagram is shown as a function of growth temperature and N-flux.•Honeycomb microstructure is observed for InAlN grown with low and high N-flux.•Increase of average cell size is observed for increased N-flux and growth temperature. We study the impact of increased active nitrogen flux (N-flux) on the indium content and structural properties of InAlN layers grown by plasma-assisted molecular beam epitaxy. It is shown that high N-flux can stabilize In-N bonds, so that In0.18Al0.82N is grown at 605 °C, which is the highest reported temperature so far for the composition lattice-matched (LM) to GaN. Adiagram of InAlN indium content is shown as a function of growth temperature and N-flux. The InAlN layers grown using low and high N-flux had grainy surface morphology typical for N-rich conditions. Inhomogeneity in indium distribution on nanometer scale, i.e. typical honeycomb microstructure, is found for InAlN layers grown using both: low and high N-flux. An increase of average cell size is observed for LM-InAlN when the N-flux and growth temperature are increased.