Method of manufacturing magnetic random access memory (MRAM)

Abstract

A magnetic random access memory (MRAM), and a method of manufacturing the same, includes a switching device and a magnetic tunneling junction (MTJ) cell connected to the switching device, wherein the MTJ cell includes a pinned film having a metal film and a magnetic film, the magnetic film enclosing the metal film.

1 - 5 . (canceled)  
   
   
       6 . A method of manufacturing a magnetic random access memory (MRAM), comprising: 
 forming a switching device in a substrate;    forming an interlayer dielectric on the substrate to cover the switching device;    forming a stack structure on a predetermined region of the interlayer dielectric, the stack structure including a lower electrode, a buffering film, a pinning film, a first magnetic film, a metal film, a second magnetic film, a tunneling film, a free magnetic film, and a capping film, and the stack structure being connected to the switching device; and    contacting the first magnetic film to the second magnetic film in the stack structure.    
   
   
       7 . The method as claimed in  claim 6 , wherein forming the stack structure comprises sequentially stacking the lower electrode, the buffering film, the pinning film, the first magnetic film, the metal film, the second magnetic film, the tunneling film, the free magnetic film, and the capping film.  
   
   
       8 . The method as claimed in  claim 7 , wherein forming the stack structure further comprises: 
 forming a contact hole in the interlayer dielectric to expose the switching device;    filling the contact hole with a conductive plug;    sequentially forming the lower electrode to cover the conductive plug, the buffering film, the pinning film, the first magnetic film, the metal film, the second magnetic film, the tunneling film, the free magnetic film, and the capping film on the interlayer dielectric;    forming a photoresist pattern on the capping film to define the predetermined region of the interlayer dielectric;    etching the films stacked on the interlayer dielectric using the photoresist pattern as an etch mask; and    removing the photoresist pattern.    
   
   
       9 . The method as claimed in  claim 7 , wherein contacting the first magnetic film to the second magnetic film is performed before stacking the tunneling film, the free magnetic film, and the capping film.  
   
   
       10 . The method as claimed in  claim 6 , wherein contacting the first magnetic film to the second magnetic film comprises removing an outer portion of the metal film.  
   
   
       11 . The method as claimed in  claim 6 , wherein the first magnetic film and the second magnetic film are formed to different thicknesses.  
   
   
       12 . The method as claimed in  claim 10 , wherein removing the outer portion of the metal film comprises etching using an etchant having a high etch selectivity with respect to the metal film.  
   
   
       13 . The method as claimed in  claim 6 , wherein forming the stack structure comprises sequentially stacking the lower electrode, the buffering film, the free magnetic film, the tunneling film, the first magnetic film, the metal film, the second magnetic film, the pinning film, and the capping film.  
   
   
       14 . The method as claimed in  claim 13 , wherein forming the stack structure further comprises: 
 forming a contact hole in the interlayer dielectric to expose the switching device;    filling the contact hole with a conductive plug;    sequentially forming the lower electrode to cover the conductive plug, the buffering film, the free magnetic film, the tunneling film, the first magnetic film, the metal film, the second magnetic film, the pinning film, and the capping film on the interlayer dielectric;    forming a photoresist pattern on the capping film to define the predetermined region of the interlayer dielectric;    etching the films stacked on the interlayer dielectric using the photoresist pattern as an etch mask; and    removing the photoresist pattern.    
   
   
       15 . The method as claimed in  claim 13 , wherein contacting the first magnetic film to the second magnetic film is performed before stacking the pinning film and the capping film.  
   
   
       16 . The method as claimed in  claim 6 , wherein the buffering film is an amorphous film.  
   
   
       17 . The method as claimed in  claim 6 , wherein the pinning film is a semi-ferromagnetic film.  
   
   
       18 . The method as claimed in  claim 6 , wherein each of the first and second magnetic films is a semi-ferromagnetic film.  
   
   
       19 . The method as claimed in  claim 6 , wherein each of the first and second magnetic films is a cobalt iron (CoFe) film.  
   
   
       20 . The method as claimed in  claim 6 , wherein the metal film is ruthenium (Ru) or another metal.  
   
   
       21 . A method of manufacturing magnetic random access memory (MRAM), comprising: 
 forming a switching device; and    forming a magnetic tunneling junction (MTJ) cell connected to the switching device, wherein forming the MTJ cell includes:    forming a pinned film having a single metal film and a magnetic film, the magnetic film enclosing the metal film;    forming a tunneling film; and    forming a free magnetic film, wherein:    the tunneling film is disposed between the free magnetic film and the pinned film, and    the metal film extends laterally within the magnetic film and has a width that is less than that of the magnetic film.    
   
   
       22 . The method as claimed in  claim 21 , further comprising forming an interlayer dielectric covering the switching device, wherein the switching device is connected to the MTJ cell by a conductive plug that passes through the interlayer dielectric.  
   
   
       23 . The method as claimed in  claim 22 , wherein the first and second magnetic films contact each other only at sides of the pinned film.  
   
   
       24 . A method of manufacturing magnetic random access memory (MRAM), comprising: 
 forming a switching device; and    forming a magnetic tunneling junction (MTJ) cell connected to the switching device, forming the MTJ cell including:    forming a pinned film having a single metal film and a magnetic film, the magnetic film enclosing the metal film such that exactly one closed loop surrounding the metal film can be formed in the magnetic film by a magnetic field generated in the magnetic film;    forming a tunneling film; and    forming a free magnetic film, wherein the tunneling film is disposed between the free magnetic film and the pinned film.    
   
   
       25 . The method as claimed in  claim 24 , wherein forming the free magnetic film includes: 
 forming a first magnetic film; and    forming a second magnetic film, wherein:    an outer portion of the first magnetic film contacts an outer portion of the second magnetic film, and    the closed loop surrounding the metal film extends between the tunneling film and the metal film, within the first magnetic film.    
   
   
       26 . The MRAM as claimed in  claim 24 , wherein the free magnetic film is a single material.