Localized porous silicon structures obtained by using shadow mask-assisted patternable illumination

In this work, localized porous silicon structures were fabricated using patterned illumination by shadow masks. For comparative analysis, selective formation of porous silicon structures was performed using metal (chromium) and insulating (SU-8 photoresist) masking layers. Various porous structures were fabricated and the types of silicon substrates and configurations of masking layers were investigated. Localized porous structures were successfully fabricated on n-type silicon substrates using a double-tank electrochemical cell and a patterned shadow mask. The developed fabrication method requires no deposition or pre-patterning of the masking layers. Thus, the fabrication of localized porous structures is simpler and faster than that based on conventional methods.