Pore filling of macropores prepared in p‐type silicon by copper deposition

Copper deposition into ordered macroporous silicon prepared in p-type substrates was investigated by immersion plating and electrochemical deposition in an aqueous solution containing Cu 2+ ions. When the sample was immersed in 0.1 M CuSO 4 solution at the open circuit potential, Cu crystallites are clearly observed at the top surface and inside the pores. The deposition of Cu oxidizes the substrate simultaneously to SiO 2 . On the other hand, the potentiostatic deposition in the dark revealed that Cu deposits preferentially at the pore bottom and propagates towards the top surface. Furthermore, when the substrate was illuminated under cathodic potential, the Cu deposition was enhanced mainly at the top-surface and around the pore walls. The different deposition behavior was compared and discussed.