Resistive random access memory device and fabrication method thereof

A resistive random access memory device, comprising:

• a substrate;
• a dielectric layer disposed on the substrate;
• a conductive via disposed in the dielectric layer;
• a metal nitride layer disposed on the conductive via, wherein the metal nitride has a gradient nitrogen concentration along a thickness direction of the metal nitride layer;
• a resistive switching layer disposed on the metal nitride layer;
• and
• a metal oxynitride layer disposed on the resistive switching layer, wherein the metal oxynitride layer has a gradient nitrogen concentration along a thickness direction of the metal oxynitride layer, wherein the metal oxynitride layer comprises a nitrogen-rich TiOxNy layer, wherein x is smaller than 0.5 and y is greater than 0.5.

A method for forming a resistive random access memory device, comprising:

• providing a substrate;
• forming a dielectric layer on the substrate;
• forming a conductive via in the dielectric layer;
• forming a metal nitride layer on the conductive via, wherein the metal nitride has a gradient nitrogen concentration along a thickness direction of the metal nitride layer;
• forming a resistive switching layer on the metal nitride layer;
• and
• forming a metal oxynitride layer on the resistive switching layer, wherein the metal oxynitride layer has a gradient nitrogen concentration along a thickness direction of the metal oxynitride layer, wherein the metal oxynitride layer comprises an oxygen-rich TiOxNy layer adjacent to the resistive switching layer, wherein x is greater than 0.5 and y is smaller than 0.5.

A method for forming a resistive random access memory device, comprising:

• providing a substrate;
• forming a dielectric layer on the substrate;
• forming a conductive via in the dielectric layer;
• forming a metal nitride layer on the conductive via, wherein the metal nitride has a gradient nitrogen concentration along a thickness direction of the metal nitride layer;
• forming a resistive switching layer on the metal nitride layer;
• and
• forming a metal oxynitride layer on the resistive switching layer, wherein the metal oxynitride layer has a gradient nitrogen concentration along a thickness direction of the metal oxynitride layer, wherein the metal oxynitride layer comprises a nitrogen-rich TiOxNy layer, wherein x is between smaller than 0.5 and y is greater than 0.5.