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Title: Chemical composition and thermal stability of GaAs oxides grown by AFM anodic oxidation for site-controlled growth of InAs quantum dots

We have fabricated GaAs oxides by using atomic force microscope (AFM)-assisted anodic oxidation at various bias voltages, V{sub ox}, and studied their chemical compositions and thermal stabilities. The oxides grown at bias voltages less than 30 V desorbed after standard thermal cleaning in molecular beam epitaxy, while the oxide patterns fabricated at V{sub ox}{>=}40 V survived on the surface. We have further investigated the chemical composition of the oxides by X-ray photoemission spectroscopy. It has been found that the AFM oxides grown at V{sub ox}{approx}10 V predominantly consist of Ga{sub 2}O and GaO, whereas those grown at V{sub ox}{approx}50 V contain a Ga{sub 2}O{sub 3}-component. This result indicates that the better thermal stability of AFM oxides grown at V{sub ox}{>=}40 V can be attributed to the formation of Ga{sub 2}O{sub 3}. We grew a GaAs buffer layer on the oxide nanomasks and obtained nanoholes. After supplying InAs, selective dot nucleation took place in the nanoholes, resulting in successful formation of site-controlled QDs.
Authors:
; ; ; ;  [1] ;  [1] ;  [2] ;  [2]
  1. Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505 (Japan)
  2. (Japan)
Publication Date:
OSTI Identifier:
21612388
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1399; Journal Issue: 1; Conference: 30. international conference on the physics of semiconductors, Seoul (Korea, Republic of), 25-30 Jul 2010; Other Information: DOI: 10.1063/1.3666343; (c) 2011 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 77 NANOSCIENCE AND NANOTECHNOLOGY; ATOMIC FORCE MICROSCOPY; CHEMICAL COMPOSITION; CRYSTAL GROWTH; EMISSION SPECTROSCOPY; GALLIUM ARSENIDES; GALLIUM OXIDES; INDIUM ARSENIDES; LAYERS; MOLECULAR BEAM EPITAXY; NUCLEATION; OXIDATION; PHASE STABILITY; PHOTOEMISSION; QUANTUM DOTS; SURFACES ARSENIC COMPOUNDS; ARSENIDES; CHALCOGENIDES; CHEMICAL REACTIONS; CRYSTAL GROWTH METHODS; EMISSION; EPITAXY; GALLIUM COMPOUNDS; INDIUM COMPOUNDS; MICROSCOPY; NANOSTRUCTURES; OXIDES; OXYGEN COMPOUNDS; PNICTIDES; SECONDARY EMISSION; SPECTROSCOPY; STABILITY