Resistive memory device, method of fabricating the same, and memory apparatus and data processing system having the same
A resistive memory device capable of implementing a multi-level cell, a method of fabricating the same, and a memory apparatus and data processing system including the same are provided. The resistive memory device includes a lower electrode, a first phase-change material layer formed over the lower electrode, a second phase-change material layer formed to surround an outer sidewall of the first phase-change material layer, and an upper electrode formed over the first phase-change material layer and the second phase-change material layer.
1. A resistive memory device, comprising:
a lower electrode;
a first phase-change material layer formed over the lower electrode;
a second phase-change material layer formed to surround an outer sidewall of the first phase-change material layer; and
an upper electrode formed over the first phase-change material layer and the second phase-change material layer,
wherein the second phase-change material layer is configured to have lower resistance than the first phase-change material.
2. The resistive memory device of claim 1 , wherein the first phase-change material layer includes a material having a higher melting point than the second phase-change material layer.
3. The resistive memory device of claim 1 , wherein the first phase-change material layer includes a germanium-tellurium (Ge—Te) compound.
4. The resistive memory device of claim 3 , wherein the second phase-change material layer includes a germanium-antimony-tellurium (Ge—Sb—Te) compound.
5. The resistive memory device of claim 1 , wherein the first phase-change material layer has a cylindrical shape.