Abstract

A new approach for manufacturing of porous and amorphous silicon is presented. The electrochemistry and the rare behaviour of Si were examined with cathodic etching conditions under coulostatic pulse polarization in aqueous buffer solutions. Compared to the usual situation of the etching process here the pores were made by pulse polarizing the silicon electrodes cathodically in aqueous alkaline solution instead of typical anodic etching with highly acidic conditions of hydrofluoric acid combined with aqueous or organic solvents. According to this research, some interesting results were noticed. Therefore, it seems obvious that there is still the possibility to find new ways of forming pores and porous silicon with peculiar features and with possible interest of applications. The porous silicon manufacturing process also has an effect on the types of the pores formed. In the paper a new way of formation of porous silicon is described. The features, structures and manufacturing processes of the pores are analysed and possible reaction mechanism of the pore formation is proposed. In addition, the Si-electrolyte contact itself has an interesting science and technology features. Presented manufacturing process can be abused for instance in sensor platform applications.

Keywords: Amorphous silicon, cathodic pulse-polarization of silicon, damage defects in silicon, microcrystalline silicon, porous silicon.

Graphical Abstract