Different behavior in the deposition of platinum from HF solutions on n- and p-type (100) Si substrates

Platinum electroless deposition on silicon from HF solutions was studied by scanning electron microscopy and transmission electron microscopy, focusing the interest on the different evolution of the deposit on n- and p-doped samples. In both cases the final result was that a complete platinum layer was eventually formed, but the process was hindered on n(+) substrates which exhibited an induction period and displayed a more local behavior compared to p substrates. The results are discussed in terms of a global electrochemical process in which silicon is oxidized and platinum reduces injecting holes to the silicon valence band.