Electron traps in Czochralski–grown n-type (100) silicon with and without donor annihilation annealing have been studied by deep–level transient spectroscopy. A total of eight electron traps are observed in the concentration range 1010 –1011 cm −3. It is thought that these are grown–in defects during crystal growth cooling period including donor annihilation annealing. It is suggested that two electron traps labelled A2 (Ec–0.34 eV) and A3 (Ec–0.38 eV) of these traps are correlated with oxygen–related defects. It is shown that traps A2 and A3 are formed around 400 ° C and disappear around 500–600 ° C.