Method for chemically treating a substrate

A method for chemically treating a disc-shaped substrate having a bottom surface, a top surface and side surfaces by contacting a process medium that is fluid-chemically active with at least the bottom surface of the substrate. The substrate is moved relative to the process medium while forming a triple line between the substrate, the substrate medium and the atmosphere surrounding the substrate and medium. In order to chemically remove errors, particularly in the side surfaces, relative motion should be carried out while avoiding a contacting of the process medium with the top surface of the substrate, where the triple line is formed at a desired height of the side surface facing away from the process medium flow side in relation to the relative motion between the substrate and the process medium.