Published online by Cambridge University Press: 25 February 2011
Radiation-induced defects (RD) in Si.:Al have been investigated by means of infrared absorption (IRA) and photoluminescence (PL) methods. It has been found that the main Al containing RD in electron-irradiated Si is an interstitial Al atom (Al1). In the process of annealing at about 225 °C the production of Al1-Al1 pairs takes place. The activatin energy of this RD production is 0.95 eV, which corresponds to Al1 migration energy along hexagonal interstitials. Al1 is shown to be a two - charge donor with the energy level E(+/++) = Ev + 0.20 eV. Besides the above mentioned defect as well as acceptor type defect with Ev + 0.21 eV level a number of other defects has been revealed in neutron-irradiated Si:Al. These centers give rise to a great number of IRA and PL lines in the spectral range from 0.1 to 1.2 eV. The classification of the observed defects has been done on the basis of the annealing results and uniaxial stress measurements.