Resistance memory element and method of manufacturing the same

Abstract

A resistance memory element having a pair of electrodes and an insulating film sandwiched between a pair of electrodes includes a plurality of cylindrical electrodes of a cylindrical structure of carbon formed in a region of at least one of the pair of electrodes, which is in contact with the insulating film. Thus, the position of the filament-shaped current path which contributes to the resistance states of the resistance memory element can be controlled by the positions and the density of the cylindrical electrodes.

1 . A resistance memory element comprising:
 a pair of electrodes, and an insulating film sandwiched between the pair of electrodes, wherein   at least one of the pair of electrodes has a plurality of cylindrical electrodes of a cylindrical structure of carbon in a region thereof, which is in contact with the insulating film.   
     
     
         2 . The resistance memory element according to  claim 1 , wherein
 the cylindrical structure is a carbon nanotube.   
     
     
         3 . The resistance memory element according to  claim 1 , wherein
 the insulating film is formed of a resistance memory material whose high resistance state and low resistance state are switched by application of a voltage.   
     
     
         4 . The resistance memory element according to  claim 3 , wherein
 the resistance memory material is titanium oxide, nickel oxide, Pr 1-x Ca x MnO 3  or La 1-x Ca x MnO 3 .   
     
     
         5 . A semiconductor memory device comprising:
 a memory cell transistor; and   a resistance memory element including:
 a pair of electrodes one of which is connected to the memory cell transistor; 
 an insulating film sandwiched between the pair of electrodes, wherein 
 at least one of the pair of electrodes has a plurality of cylindrical electrodes of a cylindrical structure of carbon in a region thereof, which is in contact with the insulating film. 
   
     
     
         6 . The semiconductor device according to  claim 5 , wherein
 the cylindrical structure is a carbon nanotube.   
     
     
         7 . The semiconductor device according to  claim 5 , wherein
 the insulating film is formed of a resistance memory material whose high resistance state and low resistance state are switched by application of a voltage.   
     
     
         8 . The semiconductor device according to  claim 7 , wherein
 the resistance memory material is titanium oxide, nickel oxide, Pr 1-x Ca x MnO 3  or La 1-x Ca x MnO 3 .