Investigation of the Angle of Sliding a Drop of Water from the Surface of the SI (111)

Abstract

Silicon is the main raw material for micro- and nanoelectronics. Achievements in these areas are based to a sufficient extent on knowledge of the processes occurring on the surface. Therefore, the study of these processes on a silicon surface is topical today. In this work, the dependences of the angles of water runoff from the silicon surface on the modes of their preparation are experimentally studied. The objects of study were Si single-crystal silicon wafers with (111) surface orientation. An aqueous solution of hydrofluoric acid was used to clean the surface from contamination and natural oxide. To assess the efficiency of cleaning and the state of the studied solid surfaces, the dynamic wetting angle was measured. Distilled water was used as a wetting liquid. It has been found that plates for which ethanol is used in the preparation procedure are better wetted with water. The obtained experimental data are confirmed by the Auger analysis — the plates treated with ethanol contain a smaller amount of carbon-containing impurities. The obtained surface topograms also indicate the effect of surface chemical treatment on its roughness.