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Title: Change in equilibrium position of misfit dislocations at the GaN/sapphire interface by Si-ion implantation into sapphire. II. Electron energy loss spectroscopic study

In Part I, we have shown that the addition of Si into sapphire by ion implantationmakes the sapphire substrate elastically softer than for the undoped sapphire. The more compliant layer of the Si-implanted sapphire substrate can absorb the misfit stress at the GaN/sapphire interface, which produces a lower threading-dislocation density in the GaN overlayer. Here in Part II, based on experimental results by electron energy loss spectroscopy and a first-principle molecular orbital calculation in the literature, we suggest that the softening effect of Si results from a reduction of ionic bonding strength in sapphire (α-Al{sub 2}O{sub 3}) with the substitution of Si for Al.
Authors:
;  [1] ;  [2]
  1. Department of Materials Science and Engineering and Research Institute of Advanced Materials (RIAM), Seoul National University, Seoul 151-744 (Korea, Republic of)
  2. Korea Basic Science Institute, Daejeon 305-806 (Korea, Republic of)
Publication Date:
OSTI Identifier:
22492278
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Advances; Journal Volume: 5; Journal Issue: 7; Other Information: (c) 2015 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ALUMINIUM OXIDES; DISLOCATIONS; ELECTRONS; ENERGY LOSSES; ENERGY-LOSS SPECTROSCOPY; GALLIUM NITRIDES; INTERFACES; ION IMPLANTATION; LAYERS; MOLECULAR ORBITAL METHOD; SAPPHIRE; SILICON; SILICON IONS; STRESSES; SUBSTRATES