Near-room temperature single-domain epitaxy of reactively sputtered ZnO films

• Published in: Journal of physics. D, Applied physics Vol. 46; no. 23; pp. 235107 - 235113
• Main Authors: Chamorro, W, Horwat, D, Pigeat, P, Miska, P, Migot, S, Soldera, F, Boulet, P, Mücklich, F
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 13.06.2013; Institute of Physics
• Subjects: Condensed Matter; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Diffusion in solids; Epitaxy; Exact sciences and technology; Low temperature; Magnetron sputtering; Materials Science; Methods of deposition of films and coatings; film growth and epitaxy; Physics; Transport properties of condensed matter (nonelectronic); ZnO; Epitaxial layers; Transition element compounds; Interstitials; Binary compounds; Defects; Cathode sputtering; Compressive stress; Transmission electron microscopy; II-VI semiconductors; Ambient temperature; Zinc oxide; Atom scattering; Sputter deposition
• ISSN: 0022-3727; 1361-6463
• DOI: 10.1088/0022-3727/46/23/235107

Single-domain epitaxial ZnO films are grown near-room temperature (below 40 °C) on (0 0 0 1)-sapphire using reactive magnetron sputtering of a zinc target in the transition between the metallic and compound sputtering regimes. As the oxygen content in the reactive gas mixture is increased, the in-plane six-fold symmetry of hexagonal wurtzite ZnO, probed by -scan measurements, develops. Transmission electron microscopy analyses confirm that single-domain epitaxial layers are formed. This is accompanied by the incorporation of oxygen interstitial defects associated with oxygen over-stoichiometry and by compressive stresses. A model is proposed to explain the observed behaviour based on the transformation of the kinetic energy of fast oxygen particles into the mobility of the adatoms.