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Title: Measuring the depth profiles of strain/composition in AlGaN-graded layer by high-resolution x-ray diffraction

Here, we demonstrate X-ray fitting through kinematical simulations of the intensity profiles of symmetric reflections for epitaxial compositionally graded layers of AlGaN grown by molecular beam epitaxy pseudomorphically on [0001]-oriented GaN substrates. These detailed simulations depict obvious differences between changes in thickness, maximum concentration, and concentration profile of the graded layers. Through comparison of these simulations with as-grown samples, we can reliably determine these parameters, most important of which are the profiles of the concentration and strain which determine much of the electrical properties of the film. In addition to learning about these parameters for the characterization of thin film properties, these fitting techniques create opportunities to calibrate growth rates and control composition profiles of AlGaN layers with a single growth rather than multiple growths as has been done traditionally.
Authors:
 [1] ;  [2] ; ; ;  [3] ; ; ; ;  [1]
  1. Institute for Nanoscience and Engineering, University of Arkansas, W. Dickson 731, Fayetteville, Arkansas 72701 (United States)
  2. (Ukraine)
  3. V.Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine, Pr. Nauky 45, Kyiv 03028 (Ukraine)
Publication Date:
OSTI Identifier:
22402781
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 116; Journal Issue: 22; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; DEPTH; ELECTRICAL PROPERTIES; GALLIUM NITRIDES; LAYERS; MOLECULAR BEAM EPITAXY; RESOLUTION; SIMULATION; STRAINS; SUBSTRATES; SYMMETRY; THICKNESS; THIN FILMS; X RADIATION; X-RAY DIFFRACTION