Annealing behavior of carbon-oxygen complexes in silicon crystals observed by low-temperature infrared absorption

A low-temperature infrared-absorption study has been performed to investigate the annealing behavior of the carbon-oxygen complexes causing the peaks at 1104 cm−1 (C-OA complex) and 1108 cm−1 (C-OD complex). Upon annealing, the concentrations of the C-OA and C-OD complexes quickly reach the quasithermal-equilibrium values described by the mass-action law. The obtained formulas of this mass-action law indicate that both of these two complexes involve a carbon atom and an oxygen atom. For the annealing temperatures higher than 800 °C, the quasithermal-equilibrium concentration of the C-OA complex increases with increasing temperature. A hypothetical explanation is proposed for this unusual temperature dependence.