Double correlation deep level transient spectroscopy (DDLTS) is used to study the deep centers in oxygen‐implanted and (oxygen + silicon) co‐implanted LEC n‐GaAs samples in the range of 260 to 450 K. Two deep centers are detected and characterized. One of them is related to the presence of oxygen and is annihilated in the case of silicon co‐implantation. The behavior of these defects and their concentration variations with the implantation parameters and annealing treatments are reported. Possible structures of these deep centers are discussed.