Study of the properties of the surface of gallium arsenide by scanning atomic force microscopy
| Autor: | N. A. Torkhov, V. A. Novikov, I. V. Ivonin, V. G. Bozhkov |
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| Rok vydání: | 2008 |
| Předmět: |
Surface (mathematics)
Aqueous solution Chemistry Analytical chemistry Surface finish Condensed Matter Physics Molecular physics Atomic and Molecular Physics and Optics Electronic Optical and Magnetic Materials Gallium arsenide chemistry.chemical_compound symbols.namesake Gaussian function symbols Substructure Contact area Order of magnitude |
| Zdroj: | Semiconductors. 42:531-539 |
| ISSN: | 1090-6479 1063-7826 |
| Popis: | Using the method of atomic force microscopy, complex studies of the profile, potential distribution φ(x,y), and distributions of the phase contrast of the surface of n-GaAs subjected to various types of chemical treatment are carried out. The distribution of the potential and phase contrast at a microlevel, in general, correlates with the profile character. The surface treated in the solution H2SO4: H2O = 1: 10 is characterized by a high degree of nonuniformity with an average roughness of the main profile Δh≈ 10 nm. A considerable part of the surface is covered by hills 20–60 nm in height and 100–500 nm in diameter forming a specific substructure, which correspond to potential jumps as large as 50–60 mV against a general background of 0.77–0.80 V. At a nanolevel, correlation between the profile and phase contrast is clearly pronounced, but no correlation is found between the profile and potential distribution. Treatment of the surface of n-GaAs in a concentrated aqueous NH4OH solution leads to a decrease in the value of φ(x,y) by ∼0.2 V, and in its roughness by more than an order of magnitude (∼0.75 nm). The distribution of the profile and phase contrast over the surface is close to the ideal Gaussian distribution for relatively small areas of the surface (200 × 200 nm2). As the area increases, deviation from the Gaussian distribution becomes substantial because of smooth variation in the potential over the contact area. Conservation of the Gaussian character of the surface profile and a simultaneous rise in the average level of the roughness with an increase in the analyzed area indicates the fractal mechanism of formation of the surface profile. |
| Databáze: | OpenAIRE |
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