Method of manufacturing a variable resistance structure and method of manufacturing a phase-change memory device using the same

A method of manufacturing a phase-change memory device comprising:

• forming a first contact region and a second contact region on a semiconductor substrate;
• forming a first insulating interlayer on the semiconductor substrate;
• forming a first contact hole and a second contact hole through the first insulating interlayer to expose the first and the second contact regions;
• forming a first conductive layer on the first insulating interlayer to fill up the first and the second contact holes;
• forming a first protection layer pattern and a lower wiring protection pattern on the first conductive layer;
• partially etching the first conductive layer using to the first protection layer pattern and the lower wiring protection as etching masks to form a first contact and a second contact and to form a first electrode and a lower wiring, wherein the first and the second contacts make contact with the first and the second contact regions, and the first electrode and the lower wiring are formed on the first and the second contacts, respectively;
• forming a second insulating interlayer on the first insulating interlayer to cover the first protection layer pattern and the lower wiring protection pattern;
• planarizing the second insulating interlayer using the first protection layer pattern and the lower wiring protection pattern as polishing stop layers until the first protection layer pattern and the lower wiring protection pattern are exposed;
• forming a second protection layer on the first protection layer pattern and the lower wiring protection pattern;
• forming an opening exposing the first electrode through the second protection layer and the first protection layer pattern;
• forming a phase-change material layer pattern on the first electrode to fill up the opening;
• and
• forming a second electrode on the phase-change material layer pattern and the second protection layer.