C. Girardeaux, et al.
J. Phys. IV France 132 (2006) 263-267
Wet chemical nitridation of GaAs(001) surfaceV.L. Berkovits1, A.N. Karpenko1, L. Masson2 and V.P. Ulin1
1 A. F. Ioffe Physico-Technical Institute, 194021 Saint Petersburg, Russia
2 CRMCN-UPR CNRS 7251, Campus de Luminy, Case 901, 13288 Marseille Cedex 09, France
Auger Electron Spectroscopy and Scanning Tunnelling Microscopy were used to study the chemical and structural properties of the GaAs(001) surface after wet chemical nitridation by hydrazine-sulfide solutions. AES results show that the as-nitrided surface is covered by a thin film formed by a layer of nitrogen atoms strongly bonded with the substrate, and by a layer of residual impurities above it. The residual layer consists of oxygen- and sulfur-containing compounds, which are removed by annealing at near 450 and 520C respectively. The STM relief of the annealed surface is smooth with the rms roughness of the order of 0.4 nm. It is formed by numerous grain-like features of average lateral size near 5 nm and of 0.5 nm of height. Possible origin of the features is discussed.
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