IR Studies on VON, CIOI and CICS Defects in Ge-Doped Cz-Si

Abstract

This paper reports experimental results on the production and annealing of oxygen-vacancy related (VOn, 1<n<5) and carbon-related (CiOi, CiOiI, and CiCs) defects in Ge-doped Czochralski-grown silicon (Cz-Si) materials containing carbon. The samples were irradiated by 2 MeV fast electrons and the behavior of radiation-produced defects is studied by means of infrared (IR) spectroscopy, monitoring the relevant bands in spectra. Regarding the VOnfamily, it was found that the presence of Ge affects the annealing temperature of VO defects as well as their fraction that is converted to VO2defects. Both effects are discussed in relation with an impact of Ge on the concentration of self-interstitials that take part in the annealing of VO defects via two reaction paths VO + I → Oiand VO + Oi→ VO2. Furthermore, two bands at 1037 and 1051 cm-1are attributed to the VO5defect, although three other bands at 762, 967 and 1005 cm-1are believed to be associated with VnOmclusters containing carbon, most likely having a VOnCsstructure. Regarding carbon-related complexes, it has been established that the annealing of the 862 cm-1band belonging to the CiOidefect is accompanied by the emergence of the 1048 cm-1band previously assigned to the CsO2icenter. The evolution of the CiCsand the CiOiI bands is monitored and the identification of bands at 947, 967 and 1020 cm-1making their appearance in IR spectra over the temperature range where CiCsand CiOiI defects are annealed out is discussed.