Formation and structural studies of integrated membranes based on channel silicon

Abstract

A method for obtaining structures for integrated membranes based on channel silicon is proposed. In this work features of the formation of through channels in electronic silicon are considered depending on the composition of the electrolyte, the concentration of charge carriers and anode etching regimes. It is shown that porous structures in the form of «bottlenecks» are formed under the used regimes. It has been established that in the electrolyte based on HF: C3 H7 OH, to obtain porous layers with a thickness of more than 100 μm, it is necessary to interrupt the anodic etching process, which is due to the feature of pore formation. For the electrolyte based on HF: (CH3 )2CO, the duration of etching may be longer, which is associated with a higher solubility of hydrogen in acetone than isopropanol. The average pore diameter in this electrolyte grows more slowly with depth compared to the use of the HF: C3 H7 OH electrolyte. This effect can be explained by facilitating diffusion in the structures of not only hydrogen but also fluoride ions.

Keywords

• porous silicon
• scanning electron microscopy
• membranes