Patent ID: 7964498

Claim:
A method of manufacturing a phase-change memory device, the method comprising: forming a switching device in a semiconductor substrate; forming an interlayer dielectric layer on the semiconductor substrate; forming a bottom electrode contact hole in the interlayer dielectric layer, wherein a lower portion of the bottom electrode contact has a diameter larger than a diameter of an upper portion of the bottom electrode contact; forming a bottom electrode contact in the bottom electrode contact hole; and forming a phase-change layer on the interlayer dielectric layer, wherein forming the bottom electrode contact hole includes: forming a buffer layer on the interlayer dielectric layer; forming a preliminary hole by etching the buffer layer until a predetermined portion of the interlayer dielectric layer, over the switching device, is exposed; forming a blocking layer both on the buffer layer and on a surface of the preliminary hole; removing the blocking layer such that the predetermined portion of the interlayer dielectric layer, over the switching device, is exposed; and isotropically etching the exposed interlayer dielectric layer by using a remaining blocking layer as an etching mask.