MeV heavy ion irradiation of hydrogenated plasma-deposited silicon nitride induces formation of the volatile molecules H2 and N2 inside the material. This type of nitride appeared permeable for these molecules and they effuse at relatively low temperature. These effusing molecules were used to study the low temperature permeation in a 100nm hydrogenated amorphous Si layer, deposited onto the nitride. Upon irradiation of the double layer stack with 43.3MeV Ag ions, appearance of D2 and N2 from the bottom deuterated silicon nitride layer in the vacuum does not take place up to an ion fluence of 3 x 1012/cm2. This showed that the 100 nm plasma-deposited hydrogenated amorphous Si top layer was initially not permeable to D2 and N2 molecules.

Study of the Permeability of Thin Films of a-Si:H using MeV Ion Beams. A.M.Brockhoff, W.M.Arnoldbik, F.H.P.M.Habraken: Nuclear Instruments and Methods in Physics Research B, 2002, 190[1-4], 226-30