Wurtzite GaN Surface Structures Studied by Scanning Tunneling Microscopy and Reflection High Energy Electron Diffraction
نویسندگان
چکیده
We report studies of the surface reconstructions for both the Ga-face and the N-face of wurtzite GaN films grown using molecular beam epitaxy. Nface reconstructions are primarily adatom-on-adlayer structures which can be formed by room temperature sub-monolayer Ga deposition. These structures undergo reversible order-disorder phase transitions to 1×1 in the temperature range of 200–300 C. Ga-face reconstructions, on the other hand, require annealing to high temperatures (600-700 C) in order to form, and in most cases they are stable at those temperatures. The film polarity is found to be determined by the initial nucleation stage of the film growth.
منابع مشابه
GaN(0001) Surface Structures Studied Using Scanning Tunneling Microscopy and First-Principles Total Energy Calculations
Surface reconstructions occurring on the (0001) surface of wurtzite GaN are studied using scanning tunneling microscopy, electron diffraction, and Auger electron spectroscopy. The family of reconstructions found on this face includes 2×2, 5×5, 6×4, and “1×1”, in order of increasing surface Ga/ N ratio. Detailed experimental results are presented for each of these reconstructions. First-principl...
متن کاملReconstructions of GaN and InGaN surfaces
The reconstruction and growth kinetics of gallium nitride (0001) and (000 ) surfaces are studied using scanning tunneling microscopy, reflection high-energy electron diffraction, and low-energy electron diffraction. Results for bare GaN surfaces are summarized, with particular attention paid to the “pseudo-1×1” reconstruction of the (0001) face. Changes in the surface structure and kinetic proc...
متن کاملReconstructions of the GaN(000 ) Surface
Reconstructions of the GaN(000 ) surface are studied for the first time. Using scanning tunneling microscopy and reflection high-energy electron diffraction, four primary structures are observed: 1×1, 3×3, 6×6, and c(6×12). On the basis of first-principles calculations, the 1×1 structure is shown to consist of a Ga monolayer bonded to a N-terminated GaN bilayer. From a combination of experiment...
متن کاملReconstructions of GaN„0001... and „0001̄... surfaces: Ga-rich metallic structures
Reconstructions of GaN~0001! and ~0001̄! surfaces are studied by scanning tunneling microscopy and spectroscopy, by electron diffraction, by Auger electron spectroscopy, and using first-principles theory. Attention is focused on Ga-rich reconstructions for each surface, which are found to have a metallic character involving significant overlap between Ga valence electrons. The electron counting ...
متن کاملReconstructions of GaN(0001) and (000 ) Surfaces: Ga-rich Metallic Structures
Reconstructions of GaN(0001) and (000 ) surfaces are studied by scanning tunneling microscopy and spectroscopy, by electron diffraction, by auger electron spectroscopy, and using first-principles theory. Attention is focused on Ga-rich reconstructions for each surface, which are found to have metallic character involving significant overlap between Ga valence electrons. The electron counting ru...
متن کامل