Methods of manufacturing a phase change memory device including a heat sink

1. A method of manufacturing a phase change memory device, the method comprising:

forming a lower electrode on a substrate, including:

forming a lower electrode layer pattern; and

forming a first recess in the lower electrode layer pattern;

forming a heat sink in the first recess adjacent to and spaced apart from the lower electrode, wherein forming the heat sink includes:

forming a first insulation layer on the substrate to cover the lower electrode;

forming a metal layer on the first insulation layer to sufficiently fill the first recess space adjacent the lower electrode; and

removing an upper portion of the metal layer to a level lower than the top surface of the lower electrode;

forming a phase change material layer pattern on the lower electrode; and

forming an upper electrode on the phase change material layer pattern;

wherein forming the heat sink includes forming the heat sink having a top surface lower than a top surface of the upper electrode.

2. The method of claim 1 , further comprising

forming a first insulation layer on the substrate to cover the lower electrode;

forming the heat sink on a portion of the first insulation layer;

forming a second insulation layer on the first insulation layer to cover the heat sink;

removing upper portions of the first and second insulation layers to expose the lower electrode;

removing an upper portion of the exposed lower electrode to form a second recess; and

forming the phase change material layer pattern to fill the second recess.

3. The method of claim 1 , wherein:

forming the lower electrode includes forming a plurality of lower electrodes in both first and second directions to form a lower electrode array;

forming the upper electrode includes forming a plurality of upper electrodes in the second direction, each upper electrode extending in the first direction; and

forming the heat sink includes forming a plurality of heat sinks between structures arranged in the first direction, each structure including a corresponding lower electrode and a corresponding phase change material layer pattern disposed in the second direction, and each heat sink extending in the second direction.

4. The method of claim 3 , further comprising:

prior to forming the lower electrodes, forming a plurality of word lines electrically connected to the plurality of lower electrodes, the word lines being formed in the first direction, and each word line extending in the second direction; and

after forming the upper electrodes, forming bit lines electrically connected to the upper electrodes, respectively, each bit line extending in the first direction.

5. The method of claim 1 , wherein forming the heat sink includes:

removing an upper portion of the metal layer to form the heat sink filling a lower portion of the first recess.

6. The method of claim 1 , wherein forming the phase change material layer pattern on the lower electrode comprises, after removing the upper portion of the metal layer to form the heat sink:

forming a second insulation layer on the first insulation layer to cover the heat sink;

removing upper portions of the first and second insulation layers to expose the lower electrode;

removing an upper portion of the exposed lower electrode to form a second recess; and

forming the phase change material layer pattern to fill the second recess.

7. A method of manufacturing a phase change memory device, the method comprising:

forming a first metal layer on a substrate;

patterning the first metal layer to form lower electrodes with first recesses between the lower electrodes;

forming a first insulating layer on the lower electrodes;

forming a second metal layer on the first insulating layer in the first recesses;

removing an upper portion of the second metal layer to form a heat sink;

forming a second insulating layer on the first insulating layer and the heat sink;

removing at least a portion of the first and second insulating layers to expose the lower electrode;

removing an upper portion of the lower electrodes to form second recesses; and

forming a phase change material in the second recesses.