Phase change memory device and fabrication method thereof
A phase change memory device is provided in which the area of contact between phase change material and heater electrode is reduced to suppress current required for heating and a phase change region is formed directly on a contact to raise the degree of integration. The device comprises a heater electrode in which the lower part thereof is surrounded by a side wall of a first insulating material and the upper part thereof protruding from the side wall has a sharp configuration covered by a second insulating material except for a part of the tip end thereof, and the exposed tip end is coupled to the phase change material layer.
1. A phase change memory device comprising:
a phase change material layer;
a heater electrode having a lower part and an upper part, and the lower part surrounded by a first insulating layer and the upper part protruding the first insulating layer and having a sharp configuration and a tip end coupled to the phase change material layer.
2. The phase change memory device according to claim 1 , further comprising a second insulating layer covering the upper part without the tip end.
3. The phase change memory device according to claim 2 , wherein the second insulating layer is formed on a whole upper surface of the first insulating layer.
4. The phase change memory device according to claim 1 , further comprising a contact plug coupled between a bottom of the heater electrode and an active switching device and an upper electrode in contact with an upper surface of the phase change material layer.
5. The phase change memory device according to claim 4 , wherein the heater electrode includes a material having a higher resistance than that of the contact plug.
6. The phase change memory device according to claim 4 , wherein the active switching device is a transistor, the contact plug is connected to one of a source region and drain region of the transistor, and the other region of a source region and drain region of the transistor is connected to a wiring layer supplied ground potential.
7. The phase change memory device according to claim 1 , further comprising a third insulating layer covering a side surface of the first insulating layer and a side surface of the second insulating layer.
8. The phase change memory device according to claim 7 , wherein the third insulating layer has a height higher than that of the first insulating layer and the second insulating layer has an upper surface, and a level of the upper surface of the second insulating layer is lower than that of the third insulating layer.
9. The phase change memory device according to claim 7 , wherein the third insulating layer has a height higher than that of the first insulating layer and the second insulating layer has an upper surface, and a level of the upper surface of the second insulating layer is substantially equal to that of the third insulating layer.