Interstitial carbon-substitutional tin center in silicon (?)

Abstract

Electron-irradiated n-type silicon doped with carbon and tin has been studied by infrared absorption spectroscopy. In addition to the well known signals of interstitial carbon, C i, and the dicarbon center, C s–C i, three new lines at 873.5, 1025, and 6875 cm −1 are observed in the spectra. The 873.5 and 1025 cm −1 lines are located in a region characteristic of the local vibrational modes of interstitial carbon in silicon. Similarly, the frequency of the 6875 cm −1 line is very close to the electronic transition of C i at 6903 cm −1 . Based on the annealing kinetics of these lines as well as those belonging to C i and C s–C i, we tentatively identify the center responsible for the 873.5, 1025, and 6875 cm −1 lines as interstitial carbon perturbed by tin, which is located at one of the neighboring substitutional lattice sites.