Patent ID: 8901527

Claim:
A resistive random-access memory (RRAM) structure, comprising: a bottom electrode; a top electrode; and a tri-layer resistive stack having a first surface and a second surface which are parallel with each other and sandwiched between the bottom electrode and the top electrode, wherein the tri-layer resistive stack comprises a dielectric middle layer, a dielectric screen layer between the dielectric middle layer and the top electrode, and a dielectric barrier layer between the dielectric middle layer and the bottom electrode, wherein said first surface is in direct contact with said top electrode and said second surface is in direct contact with said bottom electrode so that the dielectric barrier layer is disposed between the top electrode and the bottom electrode, and said dielectric middle layer further comprises oxygen ions or nitrogen ions from a treatment on the tri-layer resistive stack after the tri-layer resistive stack is formed, said dielectric screen layer and said dielectric barrier layer respectively block the diffusion of said oxygen ions or nitrogen ions to said top electrode and said bottom electrode.