Shielded hydrogen passivation: a potential in‐line passivation process

Shielded hydrogen passivation (SHP) is a recently developed technique for introducing atomic hydrogen into materials and it offers significant advantages over the other hydrogenation techniques. Hydrogen de‐activation of boron followed by electrochemical CV profiling was used to demonstrate that substantial quantities of atomic hydrogen can permeate though palladium/silver alloy foils which are 10 µm thick. It is thought that such thickness will be sufficient to withstand pressures of up to 1 atmosphere allowing passivation in an in‐line process. Further, it is shown that poisoning of the foil by using sulphur increases the flux of atomic hydrogen released. SHP delivers extremely good passivation of SiO2‐Si interfaces, as demonstrated by using thermally oxidised 1 Ω‐cm, n‐type silicon where the lifetime, at 1015 cm−3 injection level, was found to increase from 12 to 1.05 ms after SHP processing. Upon application of corona charge, the lifetime further increased to 6.3 ms, equivalent to SRV ≤ 0.17 cm s−1