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Title: Optimization of ion-atomic beam source for deposition of GaN ultrathin films

We describe the optimization and application of an ion-atomic beam source for ion-beam-assisted deposition of ultrathin films in ultrahigh vacuum. The device combines an effusion cell and electron-impact ion beam source to produce ultra-low energy (20–200 eV) ion beams and thermal atomic beams simultaneously. The source was equipped with a focusing system of electrostatic electrodes increasing the maximum nitrogen ion current density in the beam of a diameter of ≈15 mm by one order of magnitude (j ≈ 1000 nA/cm{sup 2}). Hence, a successful growth of GaN ultrathin films on Si(111) 7 × 7 substrate surfaces at reasonable times and temperatures significantly lower (RT, 300 °C) than in conventional metalorganic chemical vapor deposition technologies (≈1000 °C) was achieved. The chemical composition of these films was characterized in situ by X-ray Photoelectron Spectroscopy and morphology ex situ using Scanning Electron Microscopy. It has been shown that the morphology of GaN layers strongly depends on the relative Ga-N bond concentration in the layers.
Authors:
; ; ; ; ;  [1] ;  [2] ;  [1]
  1. Institute of Physical Engineering, Brno University of Technology, Technická 2, 616 69 Brno (Czech Republic)
  2. (Czech Republic)
Publication Date:
OSTI Identifier:
22314654
Resource Type:
Journal Article
Resource Relation:
Journal Name: Review of Scientific Instruments; Journal Volume: 85; Journal Issue: 8; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; ATOMIC BEAM SOURCES; ATOMIC BEAMS; CHEMICAL COMPOSITION; CHEMICAL VAPOR DEPOSITION; CONCENTRATION RATIO; CRYSTAL GROWTH; CURRENT DENSITY; ELECTRODES; EV RANGE; GALLIUM NITRIDES; ION BEAMS; MORPHOLOGY; NITROGEN IONS; OPTIMIZATION; PRESSURE RANGE NANO PA; SCANNING ELECTRON MICROSCOPY; SILICON; SUBSTRATES; THIN FILMS; X-RAY PHOTOELECTRON SPECTROSCOPY