This work presents the co-integration of resistive random access memory crossbars within a 180 nm Read-Write CMOS chip.-based ReRAMs have been fabricated and characterized with materials and process steps compatible with the CMOS Back-End-of-the-Line. Two different strategies, consisting in insertion of an tunnel barrier layer and the design of a dedicated CMOS read circuit, have been developed in order to increase the cell high-to-low resistance ratio of a factor of 1000 and to reduce the sneak-path current effects by one order of magnitude. The ReRAM cells have been integrated directly on a standard CMOS foundry chip, enabling low cost ReRAM-CMOS integration. The integrated memories show a set and reset voltages of and 1.3 V, respectively. The measured operating voltages are compatible for low-voltage applications.Index Terms-Heterogeneous integration, passive crossbar array, post-processing, read-write circuit, resistive ramdom access memories (ReRAMs).