Semiconductor memory

Abstract

Manufacturing processes for phase change memory have suffered from the problem of chalcogenide material being susceptible to delamination, since this material exhibits low adhesion to high melting point metals and silicon oxide films. Furthermore, chalcogenide material has low thermal stability and hence tends to sublime during the manufacturing process of phase change memory. According to the present invention, conductive or insulative adhesive layers are formed over and under the chalcogenide material layer to enhance its delamination strength. Further, a protective film made up of a nitride film is formed on the sidewalls of the chalcogenide material layer to prevent sublimation of the chalcogenide material layer.

1 - 23 . (canceled) 
     
     
         24 . A semiconductor device comprising:
 a semiconductor substrate;   an interlayer insulating film formed over the semiconductor substrate;   a plug formed in the interlayer insulating film;   a contact film formed on the plug;   a chalcogenide material film formed on the contact film; and   an upper electrode formed on the chalcogenide material film,   wherein the contact film is a conductive material.   
     
     
         25 . The semiconductor device according to  claim 24 , wherein the conductive material is different from a material of the plug and the chalcogenide material film. 
     
     
         26 . The semiconductor device according to  claim 24 , the semiconductor device further comprising:
 a transistor formed over the semiconductor substrate,   wherein the transistor has a semiconductor region, and   the plug is electrically connected to the semiconductor region.   
     
     
         27 . The semiconductor device according to  claim 24 , wherein the conductive material includes one or more type of elements selected from a group consisting of Ti, Zr, Hf, and Al. 
     
     
         28 . The semiconductor device according to  claim 24 , wherein the chalcogenide material film includes Ge, Sb and Te. 
     
     
         29 . The semiconductor device according to  claim 24 , wherein the chalcogenide material film can change between a crystalline state and an amorphous state so as to store data therein. 
     
     
         30 . A semiconductor device comprising:
 a semiconductor substrate;   an interlayer insulating film formed over the semiconductor substrate;   a plug formed in the interlayer insulating film;   a contact film formed on the plug;   a chalcogenide material film formed on the contact film; and   an upper electrode formed on the chalcogenide material film,   wherein the plug includes a tungsten film,   the contact film includes Ti, Si, and N, and   the chalcogenide material film includes Ge, Sb and Te.   
     
     
         31 . The semiconductor device according to  claim 30 , the semiconductor device further comprising:
 a transistor formed over the semiconductor substrate,   wherein the transistor has a semiconductor region, and   the plug is electrically connected to the semiconductor region.   
     
     
         32 . The semiconductor device according to  claim 30 , wherein the chalcogenide material film can change between a crystalline state and an amorphous state so as to store data therein.