Annealing Kinetics of the Interstitial Carbon–Dioxygen Complex in Silicon

The interstitial carbon-interstitial dioxygen complex (CiO2i) has a deep state close to the mid bandgap of Si and can be an efficient recombination center. In this work, the annealing kinetics of CiO2i in p-type, boron doped, Czochralski grown (Cz) silicon are studied. Two sets of samples are irradiated at room temperature (RT) with 1.8 MeV protons to doses of 1 x 10(13) cm(-2) (set A) and 5 x 10(13) cm(-2) (set B). After irradiation, the samples of both sets are pre-annealed at 400 degrees C for 30 h in order to anneal out the well-known interstitial carbon-interstitial oxygen (CiOi) complex and to form the CiO2i complex. The annealing of CiOi and formation of CiO2i is monitored by deep level transient spectroscopy (DLTS) via observation of the corresponding electronic levels at 0.36 eV and 0.39 eV above the valence band edge (E-V), respectively. The samples are then subjected to isothermal annealing treatments in the temperature range 450-550 degrees C. The annealing of CiO2i follows a first order kinetics, exhibiting an activation energy of 2.55 eV, and a pre-exponential factor in the range (2-30) x 10(12) s(-1). The kinetics and the deduced parameters suggest that CiO2i anneals out by dissociation rather than diffusion mechanism.