Crystalline perfection of GaN and AlN epitaxial layers and the main features of structural transformation of crystalline defects

Nikolai Faleev, Christiana Honsberg, Omkar Jani, Ian Ferguson

Research output: Contribution to journalArticlepeer-review

14 Scopus citations

Abstract

We report on high-resolution X-ray diffraction studies of crystalline perfection and relaxation of elastic strain in GaN and AlN layers grown on SiC and sapphire substrates. Thin (300-500 nm) GaN layers are grown with a threading screw dislocation density of about 1-2×107 cm-2. A density of 1.75-8.5×105 cm-2, the lowest value ever reported for III-nitride epitaxial layers, is observed in thin (200-300 nm) AlN layers. In both cases, low density is observed in a surface layer formed over the defective nucleation layer. A model of spatial distribution of crystalline defects, based on generation of point defects on the growth surface, diffusion and further structural transformation under the action of volumetric elastic strain accounts for these observations. Perfect thin layers may be used as templates for epitaxial growth of perfect layers of other compositions, for example, GaN or InGaN layers for photovoltaic applications.

Original languageEnglish (US)
Pages (from-to)246-250
Number of pages5
JournalJournal of Crystal Growth
Volume300
Issue number1
DOIs
StatePublished - Mar 1 2007
Externally publishedYes

Keywords

  • A1. Characterization
  • A1. Defects
  • A1. High-resolution X-ray diffraction
  • B1. Nitrides

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Inorganic Chemistry
  • Materials Chemistry

Fingerprint Dive into the research topics of 'Crystalline perfection of GaN and AlN epitaxial layers and the main features of structural transformation of crystalline defects'. Together they form a unique fingerprint.

Cite this