Method for fabricating phase change memory

Abstract

A phase change memory includes an insulating layer on a substrate, an electrode layer having one pole and an electrode layer having another pole within the insulating layer, an opening portion whose lower portion on an upper portion of the insulating layer is substantially square or substantially rectangular, a phase change portion formed substantially parallel to a surface of the substrate along the respective sides of the lower portion of the opening portion, and two connection electrodes having a pole and connected to the phase change portion at two opposing corners of the lower portion of the opening portion connecting a diode portion connected to the electrode layer having one pole and the phase change portion, and two connection electrodes having another pole and connected to the phase change portion at the other two opposing corners connecting the phase change portion and the electrode layer having another pole.

1 - 15 . (canceled) 
     
     
         16 . A method for fabricating a phase change memory, comprising:
 forming an opening portion having a substantially square or substantially rectangular shape on an insulating layer;   forming a phase change film in the opening portion on the insulating layer; and   etching back the phase change film and forming a phase change portion along the sides of a lower surface of the opening portion,   wherein two electrodes having one pole and two electrodes having another pole are exposed at four corners of the opening portion, and   the phase change portion is connected to the electrodes having one pole and the electrodes having another pole at the four corners of the opening portion.   
     
     
         17 . The method of  claim 16 , wherein the phase change film is formed through sputtering. 
     
     
         18 . The method of  claim 16 , wherein etching back the phase change film is performed through dry etching. 
     
     
         19 . A method for fabricating a phase change memory, comprising:
 forming an electrode layer having one pole and a diode layer on an insulating layer formed on a substrate;   forming an insulating layer covering the electrode layer having one pole and forming an electrode layer having another pole on the insulating layer covering the electrode layer having one pole;   forming an insulating layer covering the electrode layer having another pole, forming a connection electrode having one pole and connected to the diode layer, and forming a connection electrode having another pole and connected to the electrode layer having another pole;   forming an insulating layer with an opening portion formed to have a substantially square or substantially rectangular shape;   forming a phase change film on a surface where the opening portion is formed; and   etching back the phase change film and forming a phase change portion along the sides of a lower surface of the opening portion,   wherein the phase change portion is connected to a part of the connection electrode having one pole and a part of the connection electrode having another pole at four corners of the lower surface of the opening portion.   
     
     
         20 . The method of  claim 18 , further comprising, after forming a connection electrode having one pole and a connection electrode having another pole:
 etching back the connection electrode having one pole and the connection electrode having another pole;   forming a film to be a conductive portion, after etching back;   forming an insulating layer on the film to be a conductive portion; and   polishing the insulating layer and the film to be the conductive portion,   wherein a part of the connection electrode having one pole and a part of the connection electrode having another pole are formed to respectively have a hollow prism shape by the conductive portion.   
     
     
         21 . The method of  claim 18 , wherein the phase change film is formed through sputtering. 
     
     
         22 . The method of  claim 18 , wherein etching back the phase change film is performed through dry etching. 
     
     
         23 . The method of  claim 22 , wherein the phase change film is formed through sputtering. 
     
     
         24 . The method of  claim 22 , wherein etching back the phase change film is performed through dry etching.