Annealing kinetics of the di-carbon radiation-damage centre in edge-defined film-fed growth silicon

Abstract

A systematic study of the isothermal annealing effect on the thermal destruction of the G centre was carried out at various annealing temperatures between 180°C and 240°C for e−-irradiated EFG Si samples with various radiation doses between 5×1016 and 8×1017 cm−2. We show that the thermal decay of the concentration of the G centre (monitored by the 969 meV ‘G’ zero-phonon line absorption) can be explained by the combination of two independent processes through the break-up of the G centres and the capture of migrating defects. By analysing the rates of changes of [G],[Ci] (interstitial carbon atoms), and [T] (migrating defects), the two exponential decay behaviour of the G centres during annealing was modelled successfully. With this decay model, it was shown that the time constant of the slow decay process has the temperature dependence with the two exponential factors of the break-up energy of the G centre (1.934 eV) and the migration energy of carbon atom (0.890 eV). For the fast decay process, the temperature dependence of the time constant was fitted with a single exponential curve and the migration energy of the defect was obtained as Emd=0.879 eV.