Wet etching of substrate involves arranging on the substrate a passivating substance comprising active substance reacting with component contained in etchant to form etch protecting compound

A substrate is wet etched by arranging a passivating substance on the substrate (1) to define a pattern. The passivating substance comprises an active substance reacting with a component contained in the etchant (4) to form an etch-protecting component. Wet etching of a substrate involves applying an etchant for etching the substrate in a given pattern. A passivating substance is arranged on the substrate to define the pattern. It forms an etch-protecting compound, which defines the pattern during etching. It comprises an active substance reacting with a component, which during etching is contained in the etchant solution, to form the etch-protecting compound. The active substance comprises ions that are soluble in the etchant and which form a compound, which is at least difficult to dissolve in the solution, with the component.