Methods of forming a semiconductor memory device

A method of forming a semiconductor memory device comprising:

• forming a patterned metal structure having an outer surface over a substrate;
• blanket depositing a chalcogenide material on said patterned metal structure outer surface;
• diffusing a portion of said patterned metal outwardly into a portion of said chalcogenide material;
• and
• etching a portion of said chalcogenide material into which said patterned metal has not been diffused.

A method of forming a semiconductor memory device, said method comprising:

• forming a first electrode over a semiconductor substrate;
• forming a metal layer over said first electrode;
• forming a layer comprising a chalcogenide material over said first electrode and said metal layer;
• irradiating said metal layer to diffuse at least a portion of metal ions from said metal layer into portions of said chalcogenide layer, wherein said chalcogenide layer comprises a first region with metal ions diffused therein and a second region without a substantial amount of metal ions diffused therein;
• removing said second region of said chalcogenide layer, wherein said first region of said chalcogenide layer remains;
• and
• forming a second electrode over at least a portion of said remaining first region of said chalcogenide layer.

A method of forming a semiconductor memory device comprising:

• forming a first metal layer over a semiconductor substrate;
• forming a second metal layer over said first metal layer;
• forming a chalcogenide layer over said first and second metal layers;
• diffusing a portion of said second metal layer into a portion of said chalcogenide material to form a first and second region, wherein said first region comprises metal ions from said second metal layer;
• and
• removing said second region from said chalcogenide material.