Methods for forming phase-change memory devices

A method for fabricating a phase-change memory device comprising:

• forming a first insulation layer having a first opening therein on an integrated circuit substrate;
• forming a first electrode on the first insulation layer, the first electrode having a vertical part including a recess in an upper portion thereof in the first opening;
• and
• forming a phase-change material layer on the first electrode and extending into the recess, wherein:
• forming a first insulation layer includes patterning the first insulation layer to form the first opening, the first opening including a top opening defined by a sloped upper sidewall part and a bottom opening defined by a substantially vertical bottom sidewall part;
• forming a first electrode includes forming a conformal first electrode layer along the first insulation layer and the first opening to have a recessed slope part in the first opening;
• forming a phase-change material layer comprises:
• forming a second insulation layer on the first electrode layer;
• patterning the second insulation layer to have a second opening exposing the recessed slope part of the first electrode layer;
• and
• forming a phase-change material layer on the second insulation layer to fill the second opening, the method further comprising:
• forming a second electrode layer on the phase-change material layer;
• and
• sequentially patterning the second electrode layer, the phase-change material layer, the second insulation layer and the first electrode layer.

A method for fabricating a phase-change memory device, comprising:

• forming a first insulation layer on a semiconductor substrate;
• patterning the first insulation layer to form a temporary opening;
• forming an insulation layer spacer on a sidewall of the temporary opening, the insulation layer spacer defining a first opening comprised of a top opening defined by a sloped-top lateral part and a bottom opening defined by a vertical-bottom-lateral part;
• forming a first electrode layer along the first opening and the first insulation layer to have a recessed slope part in the first opening;
• forming a second insulation layer on the first electrode layer;
• patterning the second insulation layer to have a second opening exposing the recessed slope part of the first electrode layer;
• forming a phase-change material layer in the second opening and on the second insulation layer;
• forming a second electrode layer on the phase-change material layer;
• and
• sequentially patterning the second electrode layer, the phase-change material layer, the second insulation layer and the first electrode layer.