The implementation at the sub-100nm scale of ion cleaving required ion beams of some 5keV/amu or less. The blistering efficiency in 5keV H-ion implanted and annealed Si was found to peak and vanish in a narrow range of ion fluence of (1.5–3.5) x 1016H/cm2. In order to understand this effect, the defect profiles in 5keV H-irradiated Si were studied by Rutherford back-scattering/channelling, while the Si-H bonding configurations during annealing were investigated by Raman scattering spectroscopy. Three types of defects play major roles: the so-called broad-band monohydride multivacancy complexes, the fully or partially passivated monovacancy VHn, and H-terminated internal surfaces Si(100):H. Blister absence at high fluence was characterized by the persistence up to 550C of the Si(100):H structures, which were blister embryos that failed to coalesce and grow. Radiation-induced stresses and fracture toughening may play roles in inhibiting cleavage at high fluence; however, widening towards the surface of the zone of high H and defect concentration was the likely major factor.

The Fluence Effect in Hydrogen-Ion Cleaving of Silicon at the Sub-100nm Scale. O.Moutanabbir, B.Terreault, M.Chicoine, F.Schiettekatte: Applied Physics A, 2005, 80[7], 1455-62