Patent ID: 7745341

Claim:
A method of manufacturing a phase-change semiconductor device, comprising: forming a metal layer pattern on a substrate, the metal layer pattern including an opening that exposes a portion of the substrate; forming an etch stop layer on the metal layer pattern, a sidewall of the opening and the exposed portion of the substrate, the etch stop layer formed with a thickness less than an upper thickness threshold; forming an oxide layer pattern on the etch stop layer to at least partially fill the opening; forming an insulation layer on the etch stop layer and the oxide layer pattern; forming a contact hole through the insulation layer and the etch stop layer to expose a portion of the metal layer pattern; forming a contact electrode to fill the contact hole, the contact electrode being electrically connected to the metal layer pattern; forming a phase-change layer on the insulation layer and the contact electrode; forming an upper electrode layer on the phase-change layer; and partially etching the upper electrode layer and the phase-change layer to form a phase-change layer pattern and an upper electrode.