High fluence deuteron bombardmemnt of silicon

Abstract

A study has been made of d⁺ ion implantation in Si(111) at 100 K and 300 K. Deuterium depth profiles as a function of fluence were obtained using a method based on observing the energy spectra of the tritons and protons from the D(d, p)T reaction induced with a deuteron beam. Profiles at 300 K show two distinct regions in the target. For a fluence of 4 × 10¹⁵ d⁺/cm² the surface region which extends over the first half of the deuteron range contains little deuterium (∼ 0.3 atomic %) while a relatively large amount (∼ 5 at. %) is retained in a buried layer. Typical scanning electron micrographs taken following implantation are presented. They show the deeper layers to be highly damaged. In striking contrast, the surface region shows little observable damage even for doses exceeding 10¹⁹d⁺/cm². Deuterium diffusion coefficients are estimated for silicon under irradiation conditions.