Fig. 1.

The apparatus, with which both the anodic etching and Pt electrodeposition are performed, is made of a Teflon cell with two separate parts. The bottom consists of a Cu disc, which makes contact with the bottom side of the Si sample. Si is pressed against this disc by the screws that push the top Teflon part down to the bottom. An O-ring is placed on the Si sample and the pressure by the top Teflon part prevents the etching solution from leaking outside. The solution is poured inside a funnel in the top cell and makes contact with the Si bordered by the O-ring. The funnel is large enough to allow ultraviolet light to reach Si from the top. Etching is performed while the whole set up is suspended in an ultrasonic bath. Immediately after etching, the solution is washed out and a new solution for the electrodeposition of Pt is poured in. The electrodeposition is performed in the same cell.