Method of forming a contact and method of manufacturing a phase change memory device using the same

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

• forming, on a substrate, an insulating layer pattern including a plurality of first contact holes exposing portions of the substrate, the insulating layer pattern having first and second sidewalls delimiting the first contact holes, the first sidewalls extending in a first direction and the second sidewalls extending in a second direction perpendicular to the first direction;
• forming vertical cell diodes in lower portions of the first contact holes, respectively, such that upper portions of the second sidewalls project above upper surfaces of the vertical cell diodes;
• removing the upper portions of the second sidewalls which project above the upper surfaces of the vertical cell diodes;
• forming, on the upper surfaces of the vertical cell diodes and side surfaces of the first sidewalls, isolation spacers that expose central portions of the upper surfaces of the vertical cell diodes;
• and
• etching the vertical cell diodes using the isolation spacers as a first etching mask to divide each of the vertical cell diodes into two vertical cell diodes.

A method of manufacturing a semiconductor device, comprising:

• forming an insulating layer on a substrate,
• using photolithographic and etching processes to form quadrangular contact holes through the insulating layer and thereby form an insulating layer pattern;
• forming initial patterns of semiconductor material in lower portions of the contact holes, respectively, wherein surfaces that delimit upper portions of the contact holes are left exposed;
• forming an isolation layer pattern on the insulating layer pattern and initial patterns of semiconductor material;
• and
• using the isolation layer pattern as a first etching mask to divide each the initial patterns of semiconductor material into a plurality of semiconductor patterns.