Method of manufacturing a spin-valve giant magnetoresistive head

Abstract

Multiple thin films of spin-valve GMR sensor are formed in a trapezoidal cross-sectional shape by laminating an antiferromagnetic layer, a pinned magnetic layer, a nonmagnetic conductive layer, a free magnetic layer and a nonmagnetic protective layer on a lower insulated gap layer. The amount of etching of the lower insulated gap layer produced in the process of patterning the spin-valve giant magnetoresistive layers into the multiple thin films of spin-valve GMR sensor is 10 nm or less. Further, the angle θ which the tangent line of each side face of the multiple thin films to the middle line of the free magnetic layer in its thickness direction forms with respect to the middle line of the free magnetic layer becomes 45 degrees or more. This structure makes it possible to provide such a spin-valve giant magnetoresistive head that it meets the requirements for securing constant breakdown voltage and preventing instability of MR output voltage waveform.

1 . A method of manufacturing a spin-valve giant magnetoresistive head comprising the steps of: 
 forming a lower shield layer above a substrate;    forming a lower insulated gap layer above said lower shield layer;    forming multiple thin films above said lower insulated gap layer, said multiple thin films includes an antiferromagnetic layer, a pinned magnetic layer, a nonmagnetic conductive spacer, a free magnetic layer and a nonmagnetic protective layer;    forming an organic film exhibiting a thickness within the range of 0.01 to 0.05 μm above said multiple thin films;    forming an inorganic film exhibiting a thickness within the range of 0.1 to 0.30 μm;    forming a desired resist mask pattern with a resist film exhibiting a thickness within the range of 0.1 to 0.35 μm;    etching uncovered portions of said inorganic film under said resist mask pattern to form a desired pattern of said inorganic film; using the desired pattern of said inorganic film as a mask to etch uncovered portions of said multiple thin films under openings of the desired pattern of said inorganic film to pattern said multiple thin films into multiple thin films of GMR sensor;    forming magnetic-domain control layers and conductive layers at both ends of said multiple thin films of GMR sensor; and    removing said resist mask pattern to lift off said magnetic-domain control layers and said conductive layers.    
   
   
       2 . A method of manufacturing a spin-valve giant magnetoresistive head comprising the steps of: 
 forming a lower shield layer above a substrate;    forming a lower insulated gap layer above said lower shield layer;    forming multiple thin films above said lower insulated gap layer, said multiple thin films includes an antiferromagnetic layer, a pinned magnetic layer, a nonmagnetic conductive spacer, a free magnetic layer and a nonmagnetic protective layer;    forming a desired resist mask pattern above said multiple thin films with a resist film exhibiting a thickness within the range of 0.1 to 0.35 μm;    making said resist mask pattern in such an undercut shape that each lower part up to 0.05 μm in height from the bottommost face of said resist film intrudes 0.05 to 0.15 μm inwardly;    etching uncovered portions of said multiple thin films under openings of said resist mask pattern to pattern said multiple thin films into multiple thin films of GMR sensor;    forming magnetic-domain control layers and conductive layers at both ends of said multiple thin films of GMR sensor; and    removing said resist mask pattern to lift off said magnetic-domain control layers and said conductive layers.    
   
   
       3 . The method according to  claim 1 , wherein said resist film has the property of permitting resist patterning using light with an exposure wavelength of 365 nm.  
   
   
       4 . The method according to  claim 1 , wherein said resist film has the property of permitting resist patterning using light with an exposure wavelength of 248 nm.  
   
   
       5 . The method according to  claim 1 , wherein said resist film has the property of permitting resist patterning using light with an exposure wavelength of 193 nm.  
   
   
       6 . The method according to  claim 1 , wherein said resist film has the property of permitting resist patterning using an electron beam.  
   
   
       7 . The method according to  claim 1 , wherein said resist film has the property of permitting resist patterning using light with an exposure wavelength of 365 nm and an electron beam in combination.  
   
   
       8 . The method according to  claim 1 , wherein said resist film has the property of permitting resist patterning using light with an exposure wavelength of 248 nm and an electron beam in combination.  
   
   
       9 . The method according to  claim 1 , wherein said resist film has the property of permitting resist patterning using light with an exposure wavelength of 365 nm, the resist mask pattern having a trapezoidal cross-sectional shape with an angle of three degrees or more which each side face of said resist film forms with respect to the vertical direction.  
   
   
       10 . The method according to  claim 1 , wherein said resist film has the property of permitting resist patterning using light with an exposure wavelength of 248 nm, the resist mask pattern having a trapezoidal cross-sectional shape with an angle of three degrees or more which each side face of said resist film forms with respect to the vertical direction.  
   
   
       11 . The method according to  claim 1 , wherein said resist film has the property of permitting resist patterning using an electron beam, the resist mask pattern having a trapezoidal cross-sectional shape with an angle of three degrees or more which each side face of said resist film forms with respect to the vertical direction.  
   
   
       12 . The method according to  claim 1 , wherein an end point detector equipment controls the amount of etching during etching of said multiple thin films.  
   
   
       13 . A method of manufacturing a spin-valve giant magnetoresistive head comprising the steps of: 
 forming multiple thin films of a GMR sensor including at least a lower shield layer, a lower insulated gap layer, an antiferromagnetic layer, a pinned magnetic layer formed on a border of the antiferromagnetic layer so that a magnetic orientation thereof is aligned in a fixed direction, a free magnetic layer, and a non-magnetic conductive spacer which achieves magnetic insulation between the pinned magnetic layer and the free magnetic layer;    forming at both ends of the multiple thin films of the GMR sensor, magnetic-domain control layers operative to make the magnetic orientation of the free magnetic layer uniform, and conductive layers operative to supply current to the multiple thin films of the GMR sensor; and forming above the multiple thin films of the GMR sensor, an upper insulated gap layer and an upper magnetic shield layer;    wherein the antiferromagnetic layer which is part of multiple thin films of GMR sensor is formed in at least one of a one layer and a two layer structure;    wherein a read gap length indicative of a distance from the top of the lower shield layer and the bottom of the upper shield layer between which the multiple thin films of the GMR sensor are sandwiched is at least one of no greater than 0.1 μm and no greater than 0.12 μm; and    wherein the angle which the tangent line of each side end face of the multiple thin films of the GMR sensor to the middle line of the free magnetic layer in a thickness direction thereof forms with respect to the middle line of the free magnetic layer is at least 45 degrees.