The purpose of this paper is to report the results of a transmission‐electron‐microscopy (TEM) characterization of structural defects observed in a Czochralski‐grown silicon crystal after a two‐step anneal, i.e., 3 h at 700 °C and 1 h at 1000 °C. Six types of defects were identified, i.e., extrinsic stacking faults, microprecipitates on or near the plane of the stacking fault, particles, generator‐dislocation loops, small strain centers, and a ’’new’’ precipitate structure, whose characterization is emphasized in this study. It was concluded that the new defect structure places the surrounding matrix in a compressive condition, i.e., it is of interstitial type. The possibility of carbon or oxygen being responsible for this precipitate structure was discussed. It was suggested that future electron energy‐loss spectroscopy work should, in principle, distinguish between an oxide and a carbide.