Manufacturing method of magnetic tunneling junction device

Abstract

A method of manufacturing a magnetic tunneling junction device, includes: forming a magnetic pinned layer over a substrate; forming an insulating film over the magnetic pinned layer; forming a recess in the insulating film, the recess reaching a bottom of the insulating film; forming a tunneling insulating film over a bottom and side walls of the recess and over the insulating film; forming a magnetic free layer over the tunneling insulating film; forming an upper electrode conductive film on the magnetic free layer; and oxidizing a portion of the magnetic free layer along the side walls of the recess.

What is claimed is: 
     
         1 . A method of manufacturing a magnetic tunneling junction device, comprising:
 forming a magnetic pinned layer over a substrate;   forming an insulating film over the magnetic pinned layer;   forming a recess in the insulating film, the recess reaching a bottom of the insulating film;   forming a tunneling insulating film over a bottom and side walls of the recess and over the insulating film;   forming a magnetic free layer over the tunneling insulating film;   forming an upper electrode conductive film on the magnetic free layer; and   oxidizing a portion of the magnetic free layer along the side walls of the recess.   
     
     
         2 . The method of manufacturing the magnetic tunneling junction device according to  claim 1 , wherein:
 an interlayer insulating film and a conductive plug buried in the interlayer insulating film are exposed on an upper surface of the substrate;   the magnetic pinned layer is formed in such a manner that the magnetic pinned layer is in electrically contact with the conductive plug;   the recess is formed in such a manner that the recess is not overlapped with the conductive plug; and   after oxidizing the portion of the magnetic free layer, further comprising pattering each layer from the magnetic pinned layer to the upper electrode conductive film to leave each layer from the magnetic pinned layer to the upper electrode conductive film in an area overlapped with both the conductive plug and the recess.   
     
     
         3 . The method of manufacturing the magnetic tunneling junction device according to  claim 1 , wherein:
 the upper electrode conductive film is formed under a condition that a thickness of a portion of the upper electrode conductive film along side walls of the recess is thinner than a thickness of the upper electrode conductive film on a bottom of the recess and on an upper surface of the insulating film; and   in oxidizing the portion of the magnetic free layer, heat treatment in an oxidizing atmosphere is performed under a condition that a portion of the magnetic free layer along the side walls of the recess is oxidized via a relatively thin portion of the upper electrode conductive film along the side walls of the recess and that the magnetic free layer under a relatively thick portion of the upper electrode conductive film along a bottom of the recess.   
     
     
         4 . The method of manufacturing the magnetic tunneling junction device according to  claim 3 , wherein the upper electrode conductive film is made of conductive material maintaining conductivity even after oxidization. 
     
     
         5 . The method of manufacturing the magnetic tunneling junction device according to  claim 1 , wherein:
 the insulating film is formed under a condition that moisture is contained in the insulating film; and   in oxidizing the portion of the magnetic free layer, the magnetic free layer is oxidized by moisture contained in the insulating film via the tunnel insulating film.   
     
     
         6 . The method of manufacturing the magnetic tunneling junction device according to  claim 1 , wherein the magnetic free layer is made of material becoming non-magnetic through oxidization.