An impurity-related bistable defect in thermally processed silicon

Abstract

A process-induced metastable defect in n-type silicon is reported. The defect is found close to the wafer surface after combination of ambient gas-flow annealing at ≊900 °C depending on subsequent cleaning procedure. The defect gives rise to a band-gap level Ec−Et=0.25 eV observed by deep-level transient spectroscopy after reverse-bias cooling of the sample. Both annealing and generation of the defect proceed by 1st order processes. The activation enthalpies (ΔE) and pre-exponential factors (v) have been determined from Arrhenius analyses; the results are ΔE=0.63 eV and ν=1⋅1012 s−1 for annealing, and ΔE=0.65 eV and ν=6⋅1014 s−1 for generation.