Patent ID: 8513051

Claim:
A method of manufacturing a phase-changeable memory device, the method comprising: forming a lower electrode on a substrate; forming a first phase-changeable material layer on the lower electrode, wherein the first phase-changeable material layer comprises Ge 2 Sb 2 Te 5 ; forming a second phase-changeable material layer directly on the first phase-changeable material layer, the second phase-changeable material layer having a melting point higher than that of the first phase-changeable material layer; forming a conductive layer on the second phase-changeable material layer; and partially etching the conductive layer, the second phase-changeable material layer and the first phase-changeable layer to form an upper electrode, a second phase-changeable material layer pattern and a first phase-changeable material layer pattern, wherein forming the second phase-changeable material layer comprises: forming a first layer including a first chalcogenide that has a melting point higher than that of the first phase-changeable material layer, the first layer comprising GeTe; and forming a second layer on the first layer, the second layer including a second chalcogenide that has a thermal conductivity lower than that of the first phase-changeable material layer, wherein the second layer comprises Sb 2 Te 3 .