Study of radiation damage restoration and antimony ions redistribution in Si(1 0 0) and Si(1 1 1) crystals

Abstract

In this work, we study the radiation damage restoration and antimony ions redistribution into 〈1 0 0〉 and 〈1 1 1〉 oriented silicon substrates. The samples are implanted with antimony to a dose of 5×10 14 Sb + cm −2 at 60 keV energy, then annealed under oxygen atmosphere at 900°C, 30 min. The thin layer of SiO 2 (which is formed on Si surface by dry oxidation and expected to prevent any loss of Sb + dopant during Si recovery) is removed by a 10% HF solution. The specimens are analyzed by H + Rutherford Backscattering Spectrometry (RBS) operating at 0.3 MeV energy in both random and channelling modes. The values of the projected range, R p, the standard deviation, Δ R p, and the dose of antimony ions, which are estimated with a simple program, are in agreement with tabulated ones. It is also shown that the surface damage restoration is better for Si(1 0 0) samples than for Si(1 1 1) ones, in other words, the radiation damage is more significant in Si(1 1 1) substrates. Moreover, for both Si(1 0 0) and Si(1 1 1), it has been noticed that an important quantity of implanted antimony is localized in substitutional silicon sites. This fact is more pronounced in Si(1 0 0). On the other hand, it has been found, for Si(1 0 0) substrates only, that antimony ions are redistributed into the silicon lattice following a Gaussian law.