Copper deposition in microporous silicon using supercritical fluid

•Cu deposition into the microporous Si (PS) was performed by using supercritical CO2 fluid.•Continuous filling of the PS pores with Cu was achieved down to a depth of about 0.5 μm.•Improved current–potential curves were confirmed for copper deposited PS layer.

Microporous silicon has been formed by anodization of p-type silicon. The pores with diameter less than 2 nm were filled with copper by using supercritical carbon dioxide fluid. The copper-filled layers were investigated with the field emission scanning electron microscopy, X-ray diffractometry, and energy-dispersive X-ray spectroscopy. Structural characterizations indicated that copper was continuously deposited into porous silicon down to a depth of about 0.5 μm. Electrical measurement confirmed this result. Copper-deposited layers exhibited much improved current density–potential curves.