Phase-changeable memory devices including an adiabatic layer and methods of forming the same

A method of manufacturing a phase-changeable memory device, the method comprising:

• forming a lower electrode electrically connected to an impurity region of a transistor on the substrate;
• forming a programming layer including a first phase-changeable material on the lower electrode;
• forming an adiabatic layer including a material having a lower thermal conductivity than the first phase-changeable material on the programming layer pattern;
• forming a conductive layer on the adiabatic layer;
• and
• partially etching the conductive layer, the adiabatic layer and the programming layer to form an upper electrode, an adiabatic layer pattern and a programming layer pattern.

A method of manufacturing a phase-changeable memory device, the method comprising:

• forming a transistor including a gate structure and first and second impurity regions on a substrate;
• forming a wiring line electrically connected to the first impurity region on the substrate;
• forming a lower electrode electrically connected to the second impurity region on the substrate;
• forming a preliminary adiabatic layer structure that includes a first adiabatic layer including a first phase-changeable material and a second adiabatic layer including a different second phase-changeable material, the first and second adiabatic layers being alternately and repeatedly stacked;
• forming a conductive layer on the preliminary adiabatic layer structure;
• partially etching the conductive layer and the first and second adiabatic layers to form an adiabatic layer structure on the lower electrode;
• heating a lower portion of the adiabatic layer structure that makes contact with the lower electrode to form a programming layer pattern including a different third phase-changeable material formed from heating of a material in the lower portion of the adiabatic layer structure;
• and
• forming an upper electrode on the adiabatic layer structure.