High temperature millisecond annealing of arsenic implanted silicon

Abstract

High-temperature, short-time annealing techniques have been used to study the electrical activation of amorphous layers produced by ion implantation of As+ into Si. Chemical and electrical characterisation of partially and fully regrown layers indicates that full activation does not coincide with solid-phase epitaxial (SPE) regrowth or complete As substitutionality. Although As atoms are incorporated onto substitutional sites during SPE regrowth in concentrations exceeding equilibrium electrical solubility, additional annealing causes further increases in substitutionality within the regrown material. Short annealing timescales have revealed electrically inactive As tails in the damaged but crystalline material beyond the as-implanted amorphous/crystalline interface, correlated with excess point defects (Si interstitials), and electrical activation within amorphous material. Accurate modelling of As activation and diffusion on rapid thermal annealing timescales will require incorporation of such point defect evolution processes into the physical models of simulation codes. © 1990.