Hydrogen injection and retention in nanocavities of single-crystalline silicon

The control of the chemical state of the inner surfaces of nanocavities (NCs) produced by the annealing of helium-implanted silicon has influence on lifetime control, gettering and wafer bonding. In this work it is demonstrated that the etching in HFaq of (1 0 0) silicon containing a buried array of NCs produces a giant injection of hydrogen with the consequent passivation of the inner surfaces, mainly via the formation of silicon monohydride at (1 1 1) faces and monohydride dimers at 2 × 1 reconstructed (1 0 0) faces. These terminations are very stable and survive heat treatments at 700 °C.