Fabrication of p-type porous silicon using double tank electrochemical cell with halogen and LED light sources

Abstract

Porous silicon has attracted much attention as the substrates for optical and biomedical applications due to its several characteristics such as three dimensional or regular porous structures with high surface area to volume ratio. Conventional fabrication method of porous silicon requires electrolytic cells with continuous stirring as well as metal deposition at the back side of a substrate for electrical contact. Although there exists double tank electrochemical cell as an alternative fabrication method, researches about using double tank cell and relevant experimental data have not been performed widely. In this work, we investigated the fabrication of n- and p-type porous silicon substrates at different current densities and etching times using double tank electrochemical cell. The irregular growth of pores in n-type porous silicon was confirmed with using double tank cell. In addition, we investigated the differences in forming porous structures in p-type porous silicon with respect to two different illumination source, halogen and LED light. We confirmed that double tank electrochemical cell enables the simple and convenient fabrication of porous silicon substrates.