Evidence for H2 at high pressure in the silicon nanocavities after dipping in HF solution

The immersion in HF solutions of silicon containing nanocavities (produced by the annealing at high temperature, 950 °C, of silicon implanted with helium at high fluence, 2 × 1016 cm−2) results in the injection of hydrogen in an infrared-mute state (most likely H2) into the nanocavities. The pressure achieved in the cavities is sufficiently high to stabilize the hydrogen coverage of the inner surfaces at temperatures exceeding by 200 °C the one of complete desorption from the outer surface.