Divacancy-oxygen and trivacancy-oxygen complexes in silicon:Local Vibrational Mode studies

摘要

Fourier transform infrared absorption spectroscopy was used to study the evolution ofmultivacancy-oxygen-related defects in the temperature range 200-300 °C in Czochralski-grown Sisamples irradiated with MeV electrons or neutrons. A clear correlation between disappearance ofthe divacancy (V_2) related absorption band at 2767 cm~(-1)and appearance of two bandspositioned at 833.4 and 842.4 cm~(-1)at 20 K (825.7 and 839.1 cm~(-1)room temperature) has beenfound. Both these two emerging bands have previously been assigned to a divacancy-oxygen defectformed via interaction of mobile V_2with interstitial oxygen (O_i) atoms. The present study shows,however, that the two bands arise from different defects since the ratio of their intensities dependson the type of irradiation. The 842.4 cm~(-1)band is much more pronounced in neutron irradiatedsamples and we argue that it is related to a trivacancy-oxygen defect (V_3O) formed via interactionof mobile V_3with O_i atoms or/and interaction of mobileV