Polarity characterization by anomalous x-ray dispersion of ZnO films and GaN lateral polar structures

Christopher T. Shelton, Edward Sachet, Elizabeth A. Paisley, Marc P. Hoffmann, Joseph Rajan, Ramón Collazo, Zlatko Sitar, Jon Paul Maria

Research output: Contribution to journalArticlepeer-review

6 Scopus citations

Abstract

We demonstrate the use of anomalous x-ray scattering of constituent cations at their absorption edge, in a conventional Bragg-Brentano diffractometer, to measure absolutely and quantitatively the polar orientation and polarity fraction of unipolar and mixed polar wurtzitic crystals. In one set of experiments, the gradual transition between c+ and c- polarity of epitaxial ZnO films on sapphire as a function of MgO buffer layer thickness is monitored quantitatively, while in a second experiment, we map the polarity of a lateral polar homojunction in GaN. The dispersion measurements are compared with piezoforce microscopy images, and we demonstrate how x-ray dispersion and scanning probe methods can provide complementary information that can discriminate between polarity fractions at a material surface and polarity fractions averaged over the film bulk.

Original languageEnglish (US)
Article number044912
JournalJournal of Applied Physics
Volume115
Issue number4
DOIs
StatePublished - Jan 28 2014

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)

Fingerprint Dive into the research topics of 'Polarity characterization by anomalous x-ray dispersion of ZnO films and GaN lateral polar structures'. Together they form a unique fingerprint.

Cite this