A method for constructing a phase change memory device includes forming a first dielectric layer on a substrate; forming a first conductive component in the first dielectric layer; forming a second dielectric layer over the first conductive component in the first dielectric layer; forming a conductive crown in the second dielectric layer, the conductive crown being in contact and alignment with the conductive component; depositing a third dielectric layer in the conductive crown; and forming a trench filled with chalcogenic materials having an amorphous phase and a crystalline phase programmable by controlling a temperature thereof to represent logic states, wherein the trench extends across the conductive crown, such that the trench is free from a rounded end portion caused by lithography during fabrication of the phase change memory device.