Properties of ZnO(0001) layers grown by metalorganic chemical vapor deposition on GaN(0001) templates

• Published in: Physica status solidi. C Vol. 5; no. 6; pp. 1733 - 1735
• Main Authors: Ive, T., Ben-Yaacov, T., Asamizu, H., Van de Walle, C. G., Mishra, U., DenBaars, S. P., Speck, J. S.
• Format: Journal Article
• Language: English
• Published: Berlin WILEY-VCH Verlag 01.05.2008; WILEY‐VCH Verlag
• Subjects: 61.05.cp; 68.30.Ps; 68.55.−a
• ISSN: 1862-6351; 1610-1634; 1610-1642
• DOI: 10.1002/pssc.200778612

We studied the properties of ZnO(0001) layers grown by metalorganic chemical vapor deposition on GaN(0001) templates. A two‐step growth procedure was used where a buffer layer was first deposited at 400 °C before the temperature was increased to 900 °C for the deposition of the epitaxial layer. Atomic force microscopy revealed locally straight steps on a 20 × 20 mm2 scan area. This indicates a step‐flow growth mode. The root‐mean‐square roughness was 2.6 nm. The surface exhibited hexagonal pits. The pit density was 7.5 × 105–2.1 × 108 cm–2. The full width at half maximums of w‐scans for the symmetric (0002) and the skew‐symmetric (20$ \bar 2 $1) reflections were 0.091° and 0.159°, respectively. The ZnO films were fully relaxed as revealed by reciprocal space maps for the (10$ \bar 1 $5) reflection. Gallium doped n‐type ZnO layers were deposited on (In,Ga)N light emitting diodes as transparent contacts. The electron concentration was 9.4 × 1019 cm–3 and the sheet resistance 45 W/sq. The resistivity and the mobility was 1.5 × 10–3 Wcm and 43 cm2/(Vs), respectively. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)