Investigations on the dissolution behavior of silicon in aqueous HF-HClO(4)-mixtures

Wet chemical etching processes are an essential part of silicon treatment in the photovoltaic and semiconductor industry. A commonly used system is HF-HNO(3). In order to avoid NO (x) -formation, silicon can also be etched with HF-(HCl)-Cl(2)-mixtures. Thorough investigations into perchloric acid indicate that even Si-H terminated surfaces are inert against this very strong oxidizing agent.