A method for making an RRAM resistive structure includes, step 1, forming a via structure, which includes depositing an ultra-low dielectric constant material layer on a substrate, depositing a copper layer on the ultra-low dielectric constant material layer, depositing a carbon-containing silicon nitride layer, and patterning a via in the carbon-containing silicon nitride layer. step 2, filling the via structure with a TaN layer, followed by planarizing a surface of the via structure without dishing; step 3, forming a first TiN layer on the TaN-filled via structure; and step 4, forming an RRAM resistive structure stack having layers of TaOx, Ta2O5, Ta, and a second TiN from bottom to top on the first TiN layer, and step 5, patterning the RRAM resistive structure stack the first TiN layer over the TaN-filled via structure to form the RRAM resistive structure.