Nonvolatile memory device and fabrication method thereof
View Patent ↗A nonvolatile memory device and its fabrication method of the present invention may ensure a margin of the threshold drive voltage during a design process of the device by forming a resistance layer determining phase of ReRAM along an upper edge of a lower electrode, and improve operating characteristics of the device
1. A fabrication method of a nonvolatile memory device, comprising:
forming a first interlayer insulating film including a first electrode over a part of a semiconductor substrate;
forming a second interlayer insulating film including a contact hole exposing the first electrode over a part of the first interlayer insulating film;
forming a first resistance layer on sidewalls of the contact hole;
forming a second resistance layer filling up an inside of the first resistance layer;
forming a second electrode over the first and second resistance layers; and
forming a third interlayer insulating film with a contact plug overlapping with the first electrode over a part of the second electrode.
2. The method of claim 1 , wherein the first electrode and the second electrode are comprise platinum group elements.
3. The method of claim 2 , wherein the platinum group elements are selected from the group consisting of platinum (Pt), iridium (Ir), and metallurgical equivalents thereof.
4. The method of claim 1 , wherein the first resistance layer comprises an oxide containing niobium (Nb).
5. The method of claim 4 , wherein the oxide containing Nb principally comprises NbO 2 or Nb 2 O 5 .
6. The method of claim 1 , comprising forming the first resistance layer by a chemical vapor deposition (CVD) process.
7. The method of claim 1 , wherein the second resistance layer comprises a material having a threshold drive voltage for switching phase higher than a threshold drive voltage for switching phase of the first resistance layer.
8. The method of claim 1 , wherein the second resistance layer comprises an oxide containing aluminum (Al).
9. The method of claim 8 , wherein the oxide containing Al principally comprises Al 2 O 3 .
10. The method of claim 1 , comprising forming the second resistance layer by a chemical vapor deposition (CVD) process.