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.