Fast electroless fabrication of uniform mesoporous silicon layers

We present a new route for the fabrication of mesoporous silicon using Pt nanoparticle-assisted chemical etching. In contrast to stain etching, the mesoporous silicon films show good uniformity. The porosity and thickness can be tuned well via adjusting the HF and H2O2 concentration. Etching rates of more than 1.7 μm/min have been obtained under optimized conditions. The charge transfer through the Pt–Si nano-Schottky contact was simulated to qualitatively explain the observed phenomenon. Our approach will allow a much simpler and cheaper route to fabricate mesoporous silicon layers compared to electrochemical etching as used in the area of surface micromachining and layer transfer techniques.