The behaviour of deuterium incorporated into the buried oxide of SIMOX

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The buried oxide (BOX) layer of SIMOX samples was implanted with 20–30 keV D + ion implantation at doses from 10 14 to 10 16 cm −2 . Other samples were exposed to pure deuterium gas (0–1 MPa) at temperatures in the range 800–1100 K. Thermal desorption spectrometry (TDS) revealed two main trapping sites for deuterium in the buried oxide. The first releases deuterium at ∼900 K (activation energy ∼2.5 eV) and the second at ∼1250 K (activation energy ∼3.4 eV). They are attributed to dissociation of Si–D and Si–OD groups, respectively. The first peak is dominant in the implanted samples while the second is the dominant one for samples exposed to deuterium gas. The formation of the Si–OD groups is a temperature-activated process. The trapping of deuterium in the implanted samples is related to implantation-induced vacancy-like defects that are detected by means of positron beam analysis (PBA). Annealing at 900 K leads to a complete defect recovery. Deuterium profiling by SIMS confirms the trapping in the defects.