We report on the unipolar resistive switching (RS) phenomenon in yttrium oxide (Y2O3) metal-insulator-metal structures. The RS behavior for Y2O3 shows a superior ON/OFF resistance ratio of greater than 106 and good memory retention reliability performance of at least 10(6) seconds at room temperature. By adding a thin yttrium (Y) layer to form a Y-Y2O3 bilayer structure, a reduction in the RESET current by two orders of magnitude is achieved, which is advantageous in reducing the total switching energy consumption for resistive random access memory application. (C) 2011 The Electrochemical Society. [DOI: 10.1149/2.008203esl] All rights reserved.