Abstract: In the treatment of semiconductor slices, in particular silicon slices, w aqueous solutions containing hydrofluoric acid, a contamination of the slice surface with particles which interfere with the subsequent processes has been observed. This increase in particles can be markedly decreased by additionally adding to the solutions, organic ring molecules capable of forming inclusion compounds, such as, for instance, cyclodextrins, and/or acids with pKa below 3.14 which are incapable of oxidizing the semiconductor material. The actual treatment can be carried out in the usual way, for example, in immersion baths.