Memory device and method for manufacturing the same

Abstract

A memory device according to one embodiment includes a resistance change film, an insulating film provided on the resistance change film, a first wiring provided on the insulating film and being not in contact with the resistance change film, and a high resistance film having a higher resistivity than the first wiring. The high resistance film is provided on a side surface of a stacked body including the insulating film and the first wiring, and the high resistance film is electrically connected between the first wiring and the resistance change film.

What is claimed is: 
     
         1 . A memory device comprising:
 a resistance change film;   an insulating film provided on the resistance change film;   a first wiring provided on the insulating film and being not in contact with the resistance change film; and   a high resistance film having a higher resistivity than the first wiring, provided on a side surface of a stacked body including the insulating film and the first wiring, and electrically connected between the first wiring and the resistance change film.   
     
     
         2 . The device according to  claim 1 , wherein width of the stacked body is narrower than width of the resistance change film. 
     
     
         3 . The device according to  claim 2 , further comprising:
 an electrode having a lower resistivity than the high resistance film and placed between the resistance change film and the high resistance film.   
     
     
         4 . The device according to  claim 3 , wherein
 the width of the stacked body is narrower than width of the electrode, and   a lower end of the high resistance film is in contact with the electrode.   
     
     
         5 . The device according to  claim 1 , further comprising:
 a second wiring extending in a direction crossing a direction in that the first wiring extends, provided below the resistance change film, and connected to the resistance change film.   
     
     
         6 . The device according to  claim 1 , wherein the high resistance film contains tantalum, silicon, and nitrogen. 
     
     
         7 . The device according to  claim 1 , wherein the resistance change film includes:
 a resistance change layer having a higher resistivity than the first wiring; and   a metal layer in contact with the resistance change layer.   
     
     
         8 . The device according to  claim 7 , wherein
 the resistance change layer contains silicon, and   the metal layer contains one or more metals selected from the group consisting of silver, cobalt, nickel, and copper.   
     
     
         9 . A memory device comprising:
 a plurality of first wiring layers each including a plurality of first wirings extending in a first direction;   a plurality of second wiring layers each including a plurality of second wirings extending in a second direction crossing the first direction;   a first insulating film provided on an upper surface of each of the second wirings;   a second insulating film provided on a lower surface of each of the second wirings;   a high resistance film having a higher resistivity than the first wiring and the second wiring, provided on a side surface of a stacked body including the second insulating film, the second wiring, and the first insulating film, and connected to the second wiring; and   a resistance change film electrically connected between each of the first wirings and the high resistance film and being not in contact with the second wirings,   the first wiring layers and the second wiring layers being stacked alternately.   
     
     
         10 . The device according to  claim 9 , wherein length in the first direction of the stacked body is shorter than length in the first direction of the resistance change film. 
     
     
         11 . The device according to  claim 10 , further comprising:
 an electrode having a lower resistivity than the high resistance film and placed between the resistance change film and the high resistance film.   
     
     
         12 . The device according to  claim 11 , wherein
 width of the stacked body is narrower than width of the electrode, and   an end surface of the high resistance film is in contact with the electrode.   
     
     
         13 . The device according to  claim 9 , wherein the high resistance film contains tantalum, silicon, and nitrogen. 
     
     
         14 . The device according to  claim 9 , wherein the resistance change film includes:
 a resistance change layer having a higher resistivity than the first wiring; and   a metal layer in contact with the resistance change layer.   
     
     
         15 . The device according to  claim 14 , wherein
 the resistance change layer contains silicon, and   the metal layer contains one or more metals selected from the group consisting of silver, cobalt, nickel, and copper.   
     
     
         16 . A method for manufacturing a memory device, comprising:
 forming a resistance change film on a first wiring film;   processing the resistance change film into a strip extending in a first direction and processing the first wiring film into a plurality of first wirings extending in the first direction by selectively removing the resistance change film and the first wiring film;   forming an insulating film and a second wiring film in this order;   processing the second wiring film into a plurality of second wirings extending in a second direction crossing the first direction, processing the insulating film into a strip extending in the second direction, and dividing the resistance change film along the first direction by selectively removing the second wiring film, the insulating film, and the resistance change film;   reducing width of a stacked body including the insulating film and the second wiring; and   forming a high resistance film on a side surface of the stacked body, the high resistance film having a higher resistivity than the first wiring film and the second wiring film and being electrically connected to the resistance change film.   
     
     
         17 . The method according to  claim 16 , wherein the forming the high resistance film includes:
 depositing the high resistance film so as to cover the stacked body; and   removing a portion of the high resistance film located on an upper surface of the stacked body and leaving a portion of the high resistance film located on a side surface of the stacked body by etching the high resistance film.   
     
     
         18 . The method according to  claim 16 , wherein the reducing the width of the stacked body includes performing isotropic etching on the insulating film and the second wiring. 
     
     
         19 . The method according to  claim 16 , wherein the dividing includes performing anisotropic etching on the second wiring film, the insulating film, and the resistance change film. 
     
     
         20 . The method according to  claim 16 , further comprising:
 forming an electrode film on the resistance change film,   wherein in the processing into the plurality of first wirings, the electrode film is also processed into a strip extending in the first direction,   in the dividing, the electrode film is processed into a plurality of electrodes arranged along both the first direction and the second direction, and   in the forming the high resistance film, the high resistance film is brought into contact with the electrode.