Variable resistive memory device and method of fabricating the same
View Patent ↗Provided are a variable resistive memory device and a method of fabricating the same. The variable resistive memory device includes an interlayer insulating film having an opening therein, the opening exposing a surface of a first electrode which is disposed at a bottom of the opening. A variable resistive layer is formed in the opening and a second electrode is formed on the variable resistive layer. The variable resistive layer has a sidewall that is separated from an inner side surface of the opening to define a gap between the sidewall of the variable resistive layer and the inner side surface of the opening.
1. A method of fabricating a variable resistive memory device, the method comprising:
forming an interlayer insulating film, the interlayer insulating film having an opening therein, the opening exposing a surface of a first electrode which is disposed at a bottom of the opening;
forming a sacrificial film on an inner side surface of the opening, the sacrificial film defining a groove through which a surface of the first electrode is exposed;
filling the groove with a variable resistive material;
forming a variable resistive layer by removing the variable resistive material film to expose the sacrificial film;
removing the sacrificial film to form a gap between the inner side surface of the opening and a sidewall of the variable resistive layer; and
forming a second electrode on the variable resistive layer.
2. The method of claim 1 , wherein the forming of the sacrificial film comprises:
filling the opening with a sacrificial layer; and
anisotropically etching the sacrificial layer to form the sacrificial film having a spacer shape on the inner side surface of the opening.
3. The method of claim 1 , wherein the forming of the sacrificial film comprises:
conformally forming, to a uniform thickness, a sacrificial layer on the inner side surface of the opening and on the exposed surface of the first electrode; and
etching the sacrificial layer to form the sacrificial having a liner shape on the inner side surface of the opening.
4. The method of claim 1 , wherein the removing the sacrificial film further comprises:
removing the sacrificial film by wet etching.
5. The method of claim 1 , wherein the removing the variable resistive material further comprises:
removing the variable resistive material film by planarization or etchback.
6. The method of claim 1 , wherein the sacrificial has a higher etch rate than that of the interlayer insulating film.
7. The method of claim 1 , wherein the interlayer insulating film comprises a silicon oxide film, and the sacrificial film comprises a silicon nitride film, a silicon oxynitride film, or a combination thereof.
8. The method of claim 1 , wherein the first electrode is formed at the bottom of the opening.
9. The method of claim 1 , wherein the forming of a second electrode comprises:
forming the second electrode using physical vapor deposition.
10. The method of claim 1 , wherein the second electrode is patterned to extend over an outer surface of the interlayer insulating film to cover the gap.
11. The method of claim 1 , further comprising:
filling the gap with oxygen, nitrogen, an inert gas, or a mixture thereof.
12. The method of claim 1 , further comprising:
evacuating the gap.
13. The method of claim 1 , wherein the variable resistive layer comprises a phase-change material layer.
14. The method of claim 13 , wherein the phase-change material layer comprises a chalcogenide material.