The effect of trichloroethylene (TCE) addition on electron traps in was observed using the avalanche injection method. Avalanche injection of hot electrons not only shifts the flatband voltage due to the charging of electron traps, but also creates a large number of interface states. To determine the energetic distribution of electron traps, thermal detrapping was used and the etch‐back technique was used for the determination of the spatial location of these traps. The addition of TCE introduces shallow traps near the conduction bandedge of silicon dioxide and reduces deep traps. The deep traps are uniformly distributed in the oxide and seem to be introduced by sodium in the oxide. The shallow traps have centroids far away from the interface (700Å for a 3000Å thick oxide). An oxygen dangling bond seems to be a possible defect that gives rise to these shallow electron traps.