Modification of Electronic Structure of n-GaN(0001) Surface by N+-Ion Bombardment
M. Grodzicki, P. Mazur and A. Ciszewski
Institute of Experimental Physics, University of Wrocław, pl. M. Borna 9, Wrocław, Poland
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The electronic structure of n-type GaN(0001) surface and its modification by N+ ion bombardment are presented in this report. The studies were carried out in situ in ultrahigh vacuum by ultraviolet photoelectron spectroscopy, X-ray photoelectron spectroscopy, and low-energy electron diffraction. Low-energy N+ ion bombardment, which was done using an ion gun at an energy of 200 eV, leads to nitriding of the surface. The process changes the surface stoichiometry and, consequently, provides formation of a disordered altered GaN layer. The calculated electron affinity of the clean n-GaN surface of 3.4 eV and band bending of 0.2 eV became changed after bombardment to 2.9 eV and 0.8 eV, respectively. The obtained difference in valence band maximum between the clean sample and the bombarded one was 0.6 eV.

DOI: 10.12693/APhysPolA.132.351
PACS numbers: 68.47.Fg, 73.30.+y, 82.80.Pv