Factors determining hydrophobicity silicon-based materials

The article describes the possibilities of preparation of differently textured silicon (Si) based surfaces, providing a material with high hydrophobicity. Structured surfaces with different degrees of roughness were prepared via non-isotropic etching method. The organosilane monolayer was deposited on the prepared samples with different surface profiles and the surfaces were subsequently characterized with goniometric methods (sessile drop measurement), atomic force microscopy (AFM) and scanning electron microscopy (SEM). It was found, that the choice of the appropriate etching process conditions can lead to surfaces with a different height and symmetry of the etched relief, which together with the type of used organosilane defines the surface hydrophobicity. Furthermore, it was found that the highest hydrophobicity was achieved in organosilane modified homogeneous surfaces with the pyramidal structure and the roughness of about 5 μm