Photoluminescence studies of defects in annealed Czochralski silicon

Abstract

Photoluminescence spectroscopy (PL) is becoming a standard technique for characterizing defects and impurities in high-purity semiconductors. Further information can be obtained by combining high-resolution continuous-wave PL with time-resolved measurements and excitation spectroscopy. It is well known that low-temperature annealing, near 450 °C, produces a wide variety of electrically active defects in Czochralski-grown Si containing high concentrations of O, including the well-known thermal donors. The nature of these heat-treatment centers strongly depends on the annealing time, the prior thermal history of the sample, and the concentration of O (and C) in the starting material. We present the results of extensive photoluminescence studies on such annealed Si samples. Both thermal-donor bound excitons and two isoelectronic centers are discussed.