We investigated annealing effects on the bipolar resistive switching characteristics and mechanism of the thin FeOx transition layer in a Ti/TiN/SiO2/FeOx/FePt structure by depositing a plasma-enhanced tetraethyl orthosilicate oxide onto the Fe-contented electrode. The electrical results show that the values of operation voltage, variation of electrical parameters and retention properties could be improved with the increasing thermal treatment budget. Tunneling electron microscope, X-ray diffraction, Auger electron spectroscopy and X-ray photon-emission spectra depth profiles were examined for cross-section image, crystallinity and composition analyses of the transition layer. In order to investigate the resistive switching mechanism and characterizations in Ti/TiN/SiO2/FeOx/FePt structure, the electrical parameters were extracted during set and reset process. The retention property at room temperature and 85 C was improved after the thermal treatment and maintains both resistance states over 6 x 10(4) s implies promising potential for future memory application. (C) 2011 Elsevier B.V. All rights reserved.