Phase-change memory device and method of fabricating the same

1. A method of fabricating a phase-change memory device, comprising:

forming a phase-change area having a hole type exposing a lower electrode formed on a semiconductor substrate;

uniformly forming a first material-rich first phase-change layer comprised of a hetero compound of the first material and a second material only on sidewalls and bottom of the phase-change area; and

forming a second phase-change layer on a surface of the first phase-change layer to fill the phase-change area.

2. The method of claim 1 , wherein the forming of the phase-change area includes:

forming an interlayer insulating layer on the semiconductor substrate with the lower electrode; and

forming the phase-change area in the interlayer insulating layer by etching a portion of the interlayer insulating layer to expose an upper portion of the lower electrode.

3. The method of claim 1 , wherein the first phase-change layer is formed by an atomic layer deposition (ALD) method.

4. The method of claim 3 , wherein the forming of the first phase-change layer includes:

supplying a first material to be deposited in a type of an atomic layer;

purging a resultant structure of the semiconductor substrate;

supplying a second material to be deposited in a type of an atomic layer; and

purging a resultant structure of the semiconductor substrate.

5. The method of claim 4 , wherein the supplying of the first material is performed relatively longer than the supplying of the second material.

6. The method of claim 5 , wherein a metal organic precursor is used as the first material.

7. The method of claim 6 , wherein an antimony precursor including a nitrogen ligand is used as the first material.

8. The method of claim 1 , wherein the second phase-change layer is formed by an atomic layer deposition (ALD) method or a chemical vapor deposition (CVD) method.

9. The method of claim 8 , wherein the second phase-change layer is formed using sources including third to fifth materials, respectively.

10. The method of claim 8 , wherein the second phase-change layer is formed using a mixed source including third and fourth materials and a source including a fifth material.

11. The method of 8 , wherein the second phase-change layer is formed using a mixed source of third to fifth materials.

12. The method of claim 1 , further comprising performing a pre-treatment process to improve adhesion characteristics of the first and second phase-change layers, before the forming of the first phase-change layer.

13. The method of claim 12 , wherein the pre-treatment process includes a furnace process, a rapid thermal annealing (RTA) process, an ultraviolet (UV) bake process and a chamber annealing process.

14. The method of claim 1 , further comprising performing a post-treatment process, after the forming of the second phase-change layer.

15. The method of claim 14 , wherein the post-treatment process includes a rapid thermal annealing (RTA) process, an ultraviolet (UV) bake process, a chamber annealing process and a plasma treatment.

16. The method of claim 1 , wherein at least one of the first and second phase-change layers includes a dopant.