Abstract:
A current perpendicular to plane magneto-resistance effect element includes: a magneto-resistance effect film comprised of a fixed magnetization layer, a free magnetization layer, and a complex spacer layer including an insulating layer and current paths formed through the insulating layer; a biasing mechanism for stabilizing the free magnetization layer; a shielding mechanism for ensuring a reproducing resolution of the magneto-resistance effect element; and a pair of electrodes for flowing a current perpendicular to a film surface of the magneto-resistance effect element; wherein a resistance area product (RA:Ω×μm 2 ) is set to 0.00062×√{square root over ((GAP))}×TW+0.06 when a track width of the magneto-resistance effect element is defined as TW (nm) and a gap length of the magneto-resistance effect element is defined as GAP (nm).

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2007-085440, filed on Mar. 28, 2007; the entire contents of which are incorporated herein by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a magneto-resistance effect element which is configured such that a current is flowed in the direction perpendicular to the film surface thereof. The present invention also relates to a magnetic head and a magnetic recording/reproducing device which utilize the magneto-resistance effect element according to the present invention. 
         [0004]    2. Description of the Related Art 
         [0005]    As of now, a spin valve film (SV film) is widely available as a reproducing head for a hard disk drive (HDD). In this case, the reproduction is realized by utilizing Giant Magneto-resistive Effect (GMR) of the SV film and the biasing current is flowed parallel to the film surface of the SV film so as to constitute the SV film as a CIP (Current In-plane)-GMR film. The CIP-GMR film is made of a three-layered structure of a fixed magnetization layer of which the magnetization is fixed in one direction as reference, a free magnetization layer of which the magnetization is changed in accordance with an external magnetic field and a spacer layer disposed between the fixed magnetization layer and the free magnetization layer. 
         [0006]    The free magnetization layer and the fixed magnetization layer are made of magnetic material such as Co, Ni, Fe and the spacer layer is made of non-magnetic conductor such as Cu, Ag, Au. Recently, there production is realized by utilizing Tunneling Magneto-resistive Effect (TMR) of the SV film and the biasing current is flowed perpendicular to the film surface of the SV film so as to constitute the SV film as a CPP (Current Perpendicular to plane)-TMR film. The CPP-TMR film is being mass-manufactured. Moreover, attention is paid to a CPP-GMR film in view of high density recording (Reference 1). 
         [0007]    [Reference 1] IEEE Trans. Magn., Vol. 38, pp. 2277-, 2002 
         [0008]    As described in Reference 1, it is required that the CPP-GMR film has an MR ratio (Magneto Resistive Ratio=resistance variation resistance) of at least about 3% in the HDD. In view of the enhancement of S/N, it is desired that CPP-GMR film has the MR ratio of 7% about twice as large as the required one of 3%. In the conventional CPP film, however, the MR ratio is within a range of 0.5 to 1.0% not to satisfy the above-described requirement. In this point of view, metal holes are formed in the spacer layer of the SV film to form the current-confined structure in the spacer layer in order to develop the MR ratio, that is, the S/N (Reference 2). 
         [0009]    [Reference 2] JP-A 2006-54257 (KOKAI) 
         [0010]    In Reference 2, the reproducing head has an MR ratio of 7.5% and a resistance area product (RA) of 0.6 Ωμm 2 . Then, the MR ratio is collated with the RA. The size of the reproducing head in the track direction is 70 nm, and the size of the reproducing head in the height direction is 70 nm, and the gap length of the reproducing head is 55 nm. 
         [0011]    If the reproducing head is employed by means of vertical recording under the biasing voltage of 120 mV, the output of the reproducing head becomes 1.6 mVpp within a lower frequency range and the S/N of the reproducing head becomes high. As shown in  FIG. 1 , however, the output voltage of the reproducing head is fluctuated randomly with time. In the case that the reproducing head is installed in the HDD, the AGC (Auto Gain Control) of the HDD may not operate if the output of the reproducing head is often fluctuated at a range of 10%. In this point of view, it is required that the standard deviation in output fluctuation of the reproducing head is reduced within a range of 5% or less. 
       BRIEF SUMMARY OF THE INVENTION 
       [0012]    An aspect of the present invention relates to a current perpendicular to plane magneto-resistance effect element (first reproducing element), including: a magneto-resistance effect film comprised of a fixed magnetization layer of which a magnetization is fixed in one direction, a free magnetization layer of which a magnetization is changed in accordance with an external magnetic field, and a complex spacer layer including an insulating layer and current paths formed through the insulating layer; a biasing mechanism for stabilizing the free magnetization layer; a shielding mechanism for ensuring a reproducing resolution of the magneto-resistance effect element; and a pair of electrodes for flowing a current perpendicular to a film surface of the magneto-resistance effect element; wherein a resistance area product (RA:Ω×μm 2 ) is set to 0.00062×√{square root over ((GAP))}×TW+0.06 when a track width of the magneto-resistance effect element is defined as TW (nm) and a gap length of the magneto-resistance effect element is defined as GAP (nm). 
         [0013]    Another aspect of the present invention relates to a current perpendicular to plane magneto-resistance effect element (second reproducing element), including: a magneto-resistance effect film comprised of a fixed magnetization layer of which a magnetization is fixed in one direction, a free magnetization layer of which a magnetization is changed in accordance with an external magnetic field, and a complex spacer layer including an insulating layer and current paths formed through the insulating layer; a biasing mechanism for stabilizing the free magnetization layer; a shielding mechanism for ensuring a reproducing resolution of the magneto-resistance effect element; and a pair of electrodes for flowing a current perpendicular to a film surface of the magneto-resistance effect element; wherein a resistance area product (RA:Ω×μm 2 ) is set to 0.14×TW(nm)×√{square root over ((kBPI)+0.06)} when a track width of the magneto-resistance effect element is defined as TW (nm) and a gap length of the magneto-resistance effect element is defined as GAP (nm). 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0014]      FIG. 1  is a graph showing the output fluctuation of a conventional CPP reproducing element. 
           [0015]      FIG. 2  is an explanatory view showing the area around a GMR element to be employed in a HDD. 
           [0016]      FIG. 3  is an also explanatory view showing the area around a GMR element to be employed in a HDD. 
           [0017]      FIG. 4  is a graph showing the relation between the RA and the output fluctuation. 
           [0018]      FIG. 5  is a graph showing the relation between the track width and the output fluctuation. 
           [0019]      FIG. 6  is a graph showing the relation between the gap and the output fluctuation. 
           [0020]      FIG. 7  is a perspective view showing a CPP magneto-resistance effect element according to an embodiment. 
           [0021]      FIG. 8  is a schematic view illustrating a film forming apparatus for manufacturing the magneto-resistance effect element 
           [0022]      FIG. 9  is a graph showing the output fluctuation of the CPP magneto-resistance effect element in Example. 
           [0023]      FIG. 10  is another graph showing the output fluctuation of the CPP magneto-resistance effect element in Examples. 
           [0024]      FIG. 11  is still another graph showing the output fluctuation of the CPP magneto-resistance effect element in Examples. 
           [0025]      FIG. 12  is a graph showing the output fluctuation of the CPP magneto-resistance effect element in Comparative Example. 
           [0026]      FIG. 13  is a perspective view illustrating an essential part of a magnetic recording/reproducing device according to the present invention. 
           [0027]      FIG. 14  is an enlarged perspective view illustrating the magnetic head assembly of the magnetic recording/reproducing device as viewed from a magnetic recording disk. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0028]    Hereinafter, the present invention will be described in detail with reference to the drawings. 
         [0029]    The area around a GMR element to be employed in a HDD will be described. In this case, the GMR element is configured rectangular so that one surface of the GMR element is exposed to the air bearing surface (ABS) of a magnetic recording medium (refer to  FIG. 2 ). The (physical) length of one side of the surface exposing to the ABS is called as a “track width (TW)”. The length of another surface of the GMR element perpendicular to the ABS is called as a “throat height (SW)”. The size of the GMR element at the top thereof is different from the size of the GMR element at the bottom thereof dependent on the manufacturing method so that the throat height (SW) are defined referring to the boundary between the fixed magnetization layer and the spacer layer which affects the reproducing width largely. 
         [0030]    Then, the GMR element includes magnetic shields and the distance between the magnetic shields is called as a “gap length (GAP)” (refer to  FIG. 3 ). With the magnetic head, the RA (Ω×μm 2 ) is defined by the reproducing resistance R and the element area A (TW×SH). In order to mitigate the above-described problems, the output fluctuation was estimated for a CCP-CPP-GMR element which can exhibit a reproducing output of 1.5 mV or more at the biasing voltage of 120 mV by changing the GAP, TW, SH and RA and using a vertical magnetic recording medium. As a result, it was turned out that the output fluctuation depends largely on the GAP, TW and RA. 
         [0031]    Concretely, the output fluctuation is in proportion to the half power of “RA-0.06 (Ω×μm 2 )” (refer to the approximate curve ( 1 ) in  FIG. 4 ). Then, the output fluctuation is in inverse proportion to the half power of “TW” (refer to  FIG. 5 ). Then, the output fluctuation is in inverse proportion to the quarter power of “GAP” (refer to  FIG. 6 ). In this point of view, the output fluctuation can be represented by the following equation: 
         [0000]    
       
         
           
             
               
                 
                   
                     Output 
                      
                     
                         
                     
                      
                     fluctuation 
                   
                   ∝ 
                   
                     
                       
                         RA 
                         - 
                         0.06 
                       
                       
                         TW 
                         × 
                         
                           GAP 
                         
                       
                     
                   
                 
               
               
                 
                   ( 
                   1 
                   ) 
                 
               
             
           
         
       
     
         [0032]    Then, the averaged output fluctuation shown in  FIG. 4  +1σ can be represented by the following equation: 
         [0000]      Averaged output fluctuation+1σ(%)=7.25×√{square root over ( RA (Ω·μm 2 )−0.06)}  (2) 
         [0000]    (refer to the approximate curve ( 2 ) in  FIG. 4 ). In this case, least squares method is also employed. Since the averaged GAP is 60 nm and the averaged TW is 99 nm, the equation (2) can be rewritten as the equation (3) using the equation (1). 
         [0000]    
       
         
           
             
               
                 
                   
                     
                       Averaged 
                        
                       
                           
                       
                        
                       output 
                        
                       
                           
                       
                        
                       fluctuation 
                     
                     + 
                     
                       1 
                        
                       
                         σ 
                          
                         
                           ( 
                           % 
                           ) 
                         
                       
                     
                   
                   = 
                   
                     7.25 
                     × 
                     
                       
                         99 
                          
                         
                           ( 
                           nm 
                           ) 
                         
                         × 
                         
                           
                             60 
                              
                             
                               ( 
                               nm 
                               ) 
                             
                           
                         
                       
                     
                     × 
                     
                       
                         
                           
                             RA 
                              
                             
                               ( 
                               
                                 Ω 
                                 · 
                                 
                                   µm 
                                   2 
                                 
                               
                               ) 
                             
                           
                           - 
                           0.06 
                         
                         
                           
                             TW 
                              
                             
                               ( 
                               nm 
                               ) 
                             
                           
                           × 
                           
                             
                               GAP 
                                
                               
                                 ( 
                                 nm 
                                 ) 
                               
                             
                           
                         
                       
                     
                   
                 
               
               
                 
                   ( 
                   3 
                   ) 
                 
               
             
           
         
       
     
         [0033]    In order to set the output fluctuation of the magnetic head with the TW and GAP which are determined on the recording density within a range of 5%, in view of σ, the equation (3) satisfies the above-described range. Therefore, the equation (3) can be rewritten as the equation (4). In this case, the character “α” means the constant including the output fluctuation of 5% and is set to 0.00062. The unit of the RA is “Ω·μm 2 ”, and the unit of the TW and GAP is “nm” (first reproducing element). 
         [0000]        RA≦α×TW× √{square root over (( GAP )+0.06)} 
         [0000]        RA≦ 0.00062×√{square root over (( GAP ))}×TW+0.06  (4) 
         [0034]    When the magnetic head is employed for the HDD, the GAP can be used twice as large as the minimum bit length. Therefore, the relation of GAP (nm)=2.54×10 7 ÷(kBPI×10 3 )×2 is substituted in the equation (2), and thus, the following equation (5) can be obtained: 
         [0000]        RA≦ 0.14 ×TW (nm)×√{square root over (( kBPI )+0.06)}  (5) 
         [0000]    In this case, the output fluctuation can be suppressed within a range of 5% (second reproducing element).
 
According to the aspect of the present invention, even though the low RA, which can not be considered conventionally, is employed, the output fluctuation can be suppressed, particularly for the CCP-CPP-GMR element.
 
         [0035]      FIG. 7  is a perspective view illustrating a magneto-resistance effect element (CCP-CPP type element) according to an embodiment of the present invention. Some or all components throughout the drawings in the present application are schematically illustrated so that the illustrated thickness ratio for the components is different from the real thickness ratio for the components. 
         [0036]    The magneto-resistance effect element illustrated in  FIG. 7  includes a magneto-resistance effect element  10 , a top electrode  11  and a bottom electrode  20  which are disposed so as to sandwich the magneto-resistance effect element  10 . Herein, the illustrated stacking structure is formed on a base (not shown). 
         [0037]    The magneto-resistance effect element  10  includes an underlayer  12 , a pinning layer  13 , a pinned layer  14 , a bottom metallic layer  15 , a CCP-NOL layer  16  (an insulating layer  161  and a current confining path  162 ), a top metallic layer  17 , a free layer  18  and a cap layer  19  which are subsequently stacked and formed. The pinned layer  14 , the bottom metallic layer  15 , the CCP-NOL layer  16 , the top metallic layer  17  and the free layer  18  constitute a spin valve film which is configured such that the non-magnetic spacer layer is sandwiched between the two ferromagnetic layers. For clarifying the structural feature of the magneto-resistance effect element, the CCP-NOL layer  16  is represented under the condition that the CCP-NOL layer  16  is separated from the upper and lower layers (the bottom metallic layer  15  and the top metallic layer  17 ). 
         [0038]    The bottom electrode  11  and the top electrode  20  functions as a shielding mechanism so as to realize the reproducing performance. Not shown, a biasing mechanism such as hard magnetic layers is provided at both sides of the spin valve film so as to stabilize the free layer  18 . 
         [0039]    Then, the components of the magneto-resistance effect element will be described. The bottom electrode  11  functions as an electrode for flowing a current in the direction perpendicular to the spin valve film. In real, the current can be flowed through the spin valve film in the direction perpendicular to the film surface thereof by applying a voltage between the bottom electrode  11  and the top electrode  20 . The change in resistance of the spin valve film originated from the magneto-resistance effect can be detected by utilizing the current. In other words, the magnetization detection can be realized by the current flow. The bottom electrode  11  is made of a metallic layer with a relatively small electric resistance for flowing the current to the magneto-resistance effect element sufficiently. 
         [0040]    The underlayer  12  may be composed of a buffer layer  12   a  and a seed layer  12   b . The buffer layer  12   a  can be employed for the compensation of the surface roughness of the bottom electrode  11 . The seed layer  12   b  can be employed for controlling the crystalline orientation and the crystal grain size of the spin valve film to be formed on the underlayer  12 . 
         [0041]    The buffer layer  12   a  may be made of Ta, Ti, W, Zr, Hf, Cr or an alloy thereof. The seed layer  12   b  may be made of any material controllable for the crystalline orientation of (a) layer(s) to be formed thereon. For example, the seed layer  12   b  may be made preferably of a metallic layer with a fcc-structure (face-centered cubic structure), a hcp-structure (hexagonal close-packed structure) or a bcc-structure (body-centered cubic structure). Concretely, the seed layer  12   b  may be made of Ru with hcp-structure or NiFe with fcc-structure so that the crystalline orientation of the spin valve film to be formed thereon can be rendered an fcc (111) faced orientation. The crystalline orientation of the pinning layer  13  (e.g., made of PtMn) can be rendered an fct (111)-structure (face-centered tetragonal structure)-regulated orientation. 
         [0042]    The crystalline orientation for the spin valve film and the pinning layer  13  can be measured by means of X-ray diffraction. For example, the FWHMs (full width at half maximum) in X-ray rocking curve of the fcc (111) peak of the spin valve film, the fct (111) peak or the bcc (110) peak of the pinning layer  13  (PtMn) can be set within a range of 3.5 to 6 degrees, respectively under good crystallinity. The dispersion of the orientation relating to the spin valve film and the pinning layer can be recognized by means of diffraction spot using cross section TEM. 
         [0043]    The seed layer  12   b  may be made of a NiFe-based alloy (e.g., Ni X Fe 100-X : X=90 to 50%, preferably 75 to 85%) layer of a NiFe-based non-magnetic ((Ni X Fe 100-X ) 100-Y X Y : X=Cr, V, Nb, Hf, Zr, Mo)) layer. The crystalline orientation of the seed layer  12   b  of the NiFe-based alloy can be enhanced easily so that the FWHM in X-ray rocking curve can be rendered within a range of 3 to 5 degrees. 
         [0044]    The seed layer  12   b  functions not only as the enhancement of the crystalline orientation, but also as the control of the crystal grain size of the spin valve film. Concretely, the crystal grain size of the spin valve film can be controlled within a range of 5 to 40 nm so that the fluctuation in performance of the magneto-resistance effect element can be prevented, and thus, the higher MR ratio can be realized even though the magneto-resistance effect element is downsized. 
         [0045]    The crystal grain size of the spin valve film can be determined on the crystal grain size of the layer formed between the seed layer  12   b  and the spacer layer  16  by means of cross section TEM. In the case of a bottom type spin valve film where the pinning layer  14  is located below the spacer layer  16 , the crystal grain size of the spin valve film can be determined on the crystal grain size of the pinning layer  13  (antiferromagnetic layer) or the pinned layer  14  (fixed magnetization layer) to be formed on the seed layer  12   b.    
         [0046]    If the number of crystal grain per element area is decreased, the element characteristics may be fluctuated. In this point of view, it is not desired to enlarge the size of the crystal grain beyond a predetermined value. Particularly, with the CCP-CPP element with the current paths, it is not desired to enlarge the size of the crystal grain. On the other hand, too small grain size can not maintain the crystal orientation under good condition. In this point of view, it is desired that the crystal grain size is set within a range of 5 to 20 nm. 
         [0047]    The pinning layer  13  functions as applying the unidirectional anisotropy to the ferromagnetic layer to be the pinned layer  14  on the pinning layer  13  and fixing the magnetization of the pinned layer  14 . The pinning layer  13  may be made of an antiferromagnetic material such as PtMn, PdPtMn, IrMn, RuRhMn, FeMn, NiMn. In view of the use of the element as a high density recording head, the pinning layer  13  is preferably made of IrMn because the IrMn layer can apply the unidirectional anisotropy to the pinned layer  14  in comparison with the PtMn layer even though the thickness of the IrMn layer is smaller than the thickness of the PtMn layer. In this point of view, the use of the IrMn layer can reduce the gap width of the intended element for high density recording. 
         [0048]    The pinning layer  13  may be made of a hard magnetic layer instead of the antiferromagnetic layer. For example, the pinning layer  13  may be made of CoPt (Co=50 to 85%), (CoPt 100-X ) l00-Y Cr Y : X=50 to 85%, Y=0 to 40%) or FePt (Pt=40 to 60%). Since the hard magnetic layer has a smaller specific resistance, the Series resistance and the RA of the element can be reduced. 
         [0049]    The pinned layer (fixed magnetization layer)  14  is formed as a synthetic pinned layer composed of the bottom pinned layer  141  (e.g., Co 90 Fe 10 ), the magnetic coupling layer  142  (e.g., Ru) and the top pinned layer  143  (e.g., Fe 50 Co 50 /Cu×2/Fe 50 Co 50 ). The pinning layer  13  (e.g., IrMn layer) is coupled via magnetic exchange with the bottom pinned layer  141  formed on the pinning layer  13  so as to apply the unidirectional anisotropy to the bottom pinned layer  141 . The bottom pinned layer  141  and the top pinned layer  143  which are located under and above the magnetic coupling layer  142 , respectively, are strongly magnetically coupled with one another so that the direction of magnetization in the bottom pinned layer  141  becomes anti-paralleled to the direction of magnetization in the top pinned layer  143 . 
         [0050]    The bottom pinned layer  141  may be made of Co X Fe 100-X  alloy (X=0 to 100), Ni X Fe 100-X (X=0 to 100) or an alloy thereof containing a non magnetic element. The bottom pinned layer  141  may be also made of a single element such as Co, Fe, Ni or an alloy thereof. 
         [0051]    It is desired that the magnetic thickness (saturated magnetization Bs×thickness t (Bs·t)) of the bottom pinned layer  141  is set almost equal to the one of the top pinned layer  143 . Namely, it is desired that the magnetic thickness of the top pinned layer  143  corresponds to the magnetic thickness of the bottom pinned layer  141 . 
         [0052]    For example, the top pinned layer  143  of Fe 50 Co 50 /Cu×2/Fe 50 Co 50  is employed. The top pinned layer  143  composes the spin dependent scattering unit. The top pinned layer  143  is a magnetic layer directly contributing the MR effect so that it is important to control the sort of material and the thickness of the top pinned layer  143  so as to enhance the MR change ratio because the top pinned layer  143  is formed as a magnetic layer adjacent to the CCP-NOL layer  16  and contributes the spin dependent interface scattering. 
         [0053]    Then, the effect of the top pinned layer  143  made of Fe 50 CO 50  with bcc-structure will be described. In this case, since the top pinned layer  143  can exhibit the large spin dependent interface scattering effect, the magneto-resistance effect element can exhibit the large MR effect. As the FeCo alloy with bcc structure, Fe X Co 100-X  (X=30 to 100%) or Fe X Co 100-X  with additive can be exemplified. Particularly, the FeCo alloy represented by Fe 40 CO 60  through Fe 60 CO 40  is preferable. 
         [0054]    The top pinned layer  143  may be made of a Co 90 Fe 10  alloy with fcc-structure or a Co alloy with hcp-structure which used to be widely employed for a conventional magneto-resistance effect element, instead of the magnetic material with the bcc-structure. The top pinned layer  143  can be made of a single element such as Co, Fe, Ni or an alloy containing at least one of Co, Fe, Ni. In view of the large MR ratio of the top pinned layer  143 , the FeCo alloy with the bcc-structure, the Co alloy containing Co element of 50% or over and the Ni alloy containing Ni element of 50% or over are in turn preferable. 
         [0055]    In this embodiment, the top pinned layer  143  is made of the magnetic layers (FeCo layers) and the non magnetic layers (extremely thin Cu layers) which are alternately stacked respectively. In this case, the top pinned layer  143  can enhance the spin dependent scattering effect which is also called as a “spin dependent bulk scattering effect”, originated from the extremely thin Cu layers. 
         [0056]    The spin dependent bulk scattering effect is utilized in pairs for the spin dependent interface scattering effect. The spin dependent bulk scattering effect means the occurrence of an MR effect in a magnetic layer and the spin dependent interface scattering effect means the occurrence of an MR effect at an interface between a spacer layer and a magnetic layer. 
         [0057]    Hereinafter, the enhancement of the bulk scattering effect of the stacking structure of the magnetic layer and the non magnetic layer will be described. With the CCP-CPP element, since a current is confined in the vicinity of the current confining layer  16 , the resistance in the vicinity of the current confining layer  16  contributes the total resistance of the magneto-resistance effect element. Namely, the resistance at the interface between the current confining layer  16  and the magnetic layers (pinned layer  14  and the free layer  18 ) contributes largely to the resistance of the magneto-resistance effect element. That means the contribution of the spin dependent interface scattering effect becomes large and important in the CCP-CPP element and thus, the selection of magnetic material located at the interface for the current confining layer  16  is important in comparison with a conventional CPP element. In this point of view, the pinned layer  143  is made of the FeCo alloy with the bcc-structure exhibiting the large spin dependent interface scattering effect as described above. 
         [0058]    However, it may be that the spin dependent bulk scattering effect should be considered so as to develop the MR ratio. 
         [0059]    The non-magnetic layer sandwiched by the magnetic layers may be made of Hf, Zr, Ti instead of Cu. 
         [0060]    In the above embodiment, the top pinned layer  143  is constituted of the alternately stacking structure of FeCo layer and Cu layer, but may be made of an alloyed layer of FeCo and Cu. The composition of the resultant FeCoCu alloy may be set to ((Fe X Co 100-X ) 100-Y Cu Y : X=30 to 100% Cr, Y=3 to 15%), but set to another composition range. The third element to be added to the main composition of FeCo may be selected from Hf, Zr, Ti instead of Cu. 
         [0061]    The top pinned layer  143  may be also made of a single element such as Co, Fe, Ni or an alloy thereof. 
         [0062]    Then, the spacer layer will be concretely described. The bottom metallic layer  15  is employed for the formation of the current confining path  162  and thus, functions as a supplier for the current confining path  162 . It is not required that the metallic layer  15  remains as it is apparently after the formation of the current confining path  162 . In this point of view, the bottom metallic layer  15  functions broadly as a part of the spacer layer. The bottom metallic layer  15  functions as a stopper layer preventing the oxidization of the magnetic layer  143  which is located below the current confining layer  16  in the formation of the current confining layer  16 . 
         [0063]    The CCP-NOL layer  16  includes the insulating layer  161  and the current confining path  162 . The insulating layer  161  is made of oxide, nitride, oxynitride or the like. Concretely, the insulating layer  161  may be made of amorphous Al 2 O 3  or crystal MgO. The CCP-NOL layer  16  constitutes the current-confined layer of the present invention. 
         [0064]    Typically, the insulating layer  161  is made of Al 2 O 3 -based material, as occasion demands, containing an additive. As the additive, Ti, Hf, Mg, Zr, V, Mo, Si, Cr, Nb, Ta, W, B, C, V can be exemplified. The content of the additive may be set within a range of 0 to 50%. 
         [0065]    The insulating layer  161  may be made of Ti oxide, Hf oxide, Mg oxide, Zr oxide, Cr oxide, Ta oxide, Nb oxide, Mo oxide Si oxide or V oxide instead of the Al oxide such as Al 2 O 3 . In this case, the additive as described above may be contained in the above-exemplified one. The content of the additive may be set within a range of 0 to 50%. 
         [0066]    Instead of the oxide, the insulating layer  161  may be made of Al, Si, Hf, Ti, Mg, Zr, V, Mo, Nb, Ta, W, B, or C-based oxynitride or nitride only if the insulating layer  161  can exhibit the electric insulation. 
         [0067]    The current confining path  162  functions as a path to flow a current in the direction perpendicular to the film surface of the CCP-NOL layer  16  and then, confining the current. The current confining path  162  also functions as a conductor to flow the current in the direction perpendicular to the film surface of the insulating layer  161  and is made of a metal such as Cu. In other words, the spacer layer  16  exhibits the current-confined path structure (CCP structure) so as to enhance the MR ratio from the current confining effect. 
         [0068]    The current confining path  162  (CCP) may be made of Au, Ag, Ni, Co, Fe or an alloy containing at least one from the listed elements instead of Cu. In a preferred embodiment, the current confining path  162  is made of a Cu alloy. The current confining path  162  may be made of an alloy layer of CuNi, CuCo or CuFe. Herein, the content of Cu in the alloy is set preferably to 50% or over in view of the enhancement of the MR ratio and the reduction of the interlayer coupling field, Hin (interlayer coupling field) between the pinned layer  14  and the free layer  18 . 
         [0069]    The content in oxygen and nitrogen of the current confining path  162  is much smaller than (at least half as large as) the one of the insulating layer  161 . The current confining path  162  is generally crystallized. Since the resistance of the crystalline phase is smaller than the resistance of the non-crystalline phase, the current confining path  162  can easily conduct the inherent function. 
         [0070]    The top metallic layer  17  functions as a barrier layer protecting the oxidization of the free layer  18  to be formed thereon through the contact with the oxide of the current confining layer  16  so that the crystal quality of the free layer  18  cannot be deteriorated. When the insulating layer  161  is made of an amorphous material (e.g., Al 2 O 3 ), the crystal quality of a metallic layer to be formed on the layer  161  may be deteriorated, but when an extremely thin layer (e.g., Cu layer with a thickness of 1 nm or less) to develop the crystal quality of fcc-structure is provided, the crystal quality of the free layer  18  can be remarkably improved. 
         [0071]    The top metallic layer  17  may be not formed dependent on the sorts of material making the CCP-NOL layer  16  and the free layer  18 . Concretely, if the materials making the insulating layer  161  of the CCP-NOL  16  and the free layer  18  are appropriately selected, the crystallinity of the CCP-NOL layer  16  is not deteriorated and thus, the top metallic layer  17  can be removed. If the annealing for the CCP-NOL layer  16  is appropriately conducted, the top metallic layer  17  can be also removed. 
         [0072]    In view of the manufacturing margin, it is desired that the top metallic layer  17  is formed of e.g., a Cu layer with a thickness of 0.5 nm on the CCP-NOL layer  16 . 
         [0073]    The top metallic layer  17  may be made of Au or Ag instead of Cu. Then, it is desired that the top metallic layer  17  is made of the same material as the current confining path  162  of the CCP-NOL layer  16 . If the top metallic layer  17  is made of a different material from the current confining path  162 , the resistance at the interface between the top metallic layer  17  and the current confining path  162  is increased, but if the top metallic layer  17  is made of the same material from the current confining path  162 , the resistance at the interface between the top metallic layer  17  and the current confining path  162  is not increased. 
         [0074]    The free layer  18  is a ferromagnetic layer of which the direction of magnetization is varied commensurate with the external magnetic field. For example, the free layer  18  is made of a double-layered structure of Co 90 Fe 10 /Ni 83 Fe 17 . In order to realize the large MR ratio, it is desired to provide the CoFe alloy instead of the NiFe alloy. Then, in order to realize the large MR ratio, the selection of magnetic material of the free layer  18  in the vicinity of the spacer  16 , that is, at the interface therebetween is important. The free layer  18  may be made of a single CO 90 Fe 10  layer or a triple-layered structure of CoFe/NiFe/CoFe. 
         [0075]    Among CoFe alloys, the Co 90 Fe 10  layer is preferably employed in view of the stable soft magnetic property. Then, the free layer  18  is made of an alternately stacking structure of CoFe layers or Fe layers and extremely thin Cu layers. 
         [0076]    In the case that the CCP-NOL layer  16  is made of the Cu layer, it is desired that the FeCo layer with bcc-structure is employed as the interface material thereof for the CCP-NOL layer  16  so as to enhance the MR ratio in the same manner as the pinned layer  14 . As the FeCo layer with bcc-structure, the Fe X Co 100-X (X=30 to 100), as occasion demands, containing additive, may be employed. 
         [0077]    The cap layer  19  functions as protecting the spin valve film. The cap layer  19  may be made of a plurality of metallic layers, e.g., a double-layered structure of Cu/Ru. The layered turn of the Cu layer and the Ru layer may be switched so that the Ru layer is located in the side of the free layer  18 . The exemplified structure is particularly desired for the free layer  19  of NiFe because the magnetostriction of the interface mixing layer formed between the free layer  18  and the cap layer  19  can be lowered due to the non-solution between Ru and Ni. 
         [0078]    The cap layer  19  may be made of another metallic layer instead of the Cu layer and/or the Ru layer. The structure of the cap layer  19  is not limited only if the cap layer  19  can protect the spin valve film. If the protective function of the cap layer  19  can be exhibited, the cap layer  19  may be made of still another metal. Attention should be paid to the metallic layer because the kind of material of the cap layer may change the MR ratio and the long reliability. In view of the stable MR ratio and long reliability, the Cu layer and/or the Ru layer is preferable for the cap layer. 
         [0079]    The top electrode  20  functions as flowing a current perpendicular to the film surface of the spin valve film. The current can be flowed perpendicular to the film surface of the spin valve film by applying a voltage between the bottom electrode  11  and the top electrode  20 . The top electrode  20  may be made of material with low electric resistance (e.g., Cu or Au) (Apparatus to be employed for manufacturing a magneto-resistance effect element) 
         [0080]      FIG. 8  is a schematic view illustrating a film forming apparatus for manufacturing a magneto-resistance effect element in this embodiment. As shown in  FIG. 8 , the transfer chamber (TC)  50  is disposed at the center of the apparatus such that the load lock chamber  51 , the pre-cleaning chamber  52 , the first metallic film-forming chamber (MC 1 )  53 , the second metallic film-forming chamber (MC 2 )  54  and the oxide layer-nitride layer forming chamber (OC)  60  are disposed so as to be connected with the transfer chamber  50  via the gate valves, respectively. In the apparatus, the substrate on which various films are to be formed is transferred from one chamber from another chamber under the vacuum condition via the corresponding gate valve. Therefore, the surface of the substrate can be maintained clean. 
         [0081]    The metallic film-forming chambers  53  and  54  include a plurality of targets (five to ten targets) which is called as a multi-structured target. As the film forming means, a sputtering method such as a DC magnetron sputtering or an RF magnetron sputtering, an ion beam sputtering, a vacuum deposition, a CVD (Chemical Vapor Deposition) or an MBE (Molecular Beam Epitaxy) can be employed. 
       (Schematic Explanation of the Method for Manufacturing a Magneto-Resistance Effect Element) 
       [0082]    Hereinafter, the method for manufacturing a magneto-resistance effect element will be schematically described. First of all, on the substrate (not shown) are subsequently formed the bottom electrode  11 , the underlayer  12 , the pinning layer  13 , the pinned layer  14 , the bottom metallic layer  15 , the spacer layer  16 , the top metallic layer  17 , the free layer  18 , the cap layer  19  and the top electrode  20 . 
         [0083]    A substrate is set into the load lock chamber  51  so that some metallic films are formed in the metallic film-forming chambers  53  and  54  and some oxide and/or nitride layers are formed in the oxide layer-nitride layer forming chamber  60 . The ultimate vacuum of the metallic film-forming chambers  53  and  54  is preferably set to 1×10 −8  Torr or below, normally within a range of 5×10 −10  Torr to 5×10 −9  Torr. The ultimate vacuum of the transfer chamber  50  is set in the order of 10 −9  Torr. The ultimate vacuum of the oxide layer-nitride layer forming chamber  60  is set to 8×10 −8  Torr or below. 
       (1) Formation of Underlayer  12   
       [0084]    The bottom electrode  11  is formed on the (not shown) substrate by means of micro-process in advance. Then, the underlayer  12  is formed as a layer of Ta/Ru on the bottom electrode  11 . The Ta layer functions as the buffer layer  12   a  for relaxing the surface roughness of the bottom electrode  11 . The Ru layer functions as the seed layer  12   b  for controlling the crystalline orientation and the size of crystal grain of the spin valve film to be formed thereon. 
       (2) Formation of Pinning Layer  13   
       [0085]    Then, the pinning layer  13  is formed on the underlayer  12 . The pinning layer  13  may be made of an antiferromagnetic material such as PtMn, PdPtMn, IrMn, RuRhMn. 
       (3) Formation of Pinned Layer  14   
       [0086]    Then, the pinned layer  14  is formed on the pinning layer  13 . The pinned layer  14  may be formed as the synthetic pinned layer of the bottom pinned layer  141  (Co 90 Fe 10 )/the magnetic coupling layer  142  (Ru)/the top pinned layer  143  (Co 90 Fe 10 ). 
       (4) Formation of CCP-NOL Layer  16   
       [0087]    Then, the CCP-NOL layer  16  is formed with the current confined structure (CCP structure) in the oxide layer-nitride layer forming chamber  60 . The CCP-NOL layer  16  can be formed below. 
         [0088]    First of all, a metallic layer m 1  (e.g., made of Cu) as a supplier for the current confining paths is formed on the top pinned layer  143  (or the functional layer), and a metallic layer m 2  (e.g., AlCu or Cu) to be converted into the corresponding insulating layer is formed on the metallic layer m 1 . 
         [0089]    Then, the conversion treatment is performed onto the metallic layer m 2  by oxidizing or nitriding. Moreover, the conversion treatment can be performed through a plurality of steps. For example, in the first step, the ion beams of inert gas such as Ar are irradiated. The irradiation of ion beams corresponds to a pre-treatment for the formation of the CCP-NOL layer  16 , and is called as a “PIT (Pre-ion treatment)”. According to the PIT, the elements of the metallic layer m 1  are pumped up and infiltrated into the metallic layer m 2 . Therefore, the PIT is effective as an energy treatment. 
         [0090]    As the energy treatment, thermal treatment may be employed. In this case, the metallic layers m 1  and m 2  are heated within a range of 100 to 300° C. Moreover, after the metallic layer m 2  is converted into the corresponding insulating layer  161  by the exposure of oxygen gas, the energy treatment using the ion beam irradiation of Ar or the like may be conducted onto the insulating layer  161  (metallic layer m 2 ). The post-treatment is called as an “AIT (Ion-beam assisted oxidation)”. 
         [0091]    The Cu element of the metallic layer m 1  are pumped up into the metallic layer m 2  (insulating layer  161 ) made of e.g., AlCu. 
         [0092]    In addition to the PIT treatment, the oxidizing or the nitriding can be conducted under the energy assist using the ion beams. The energy assisted treatment is called as an “IAO(Ion-beam assisted oxidation)”. 
         [0093]    With the PIT treatment and the AIT treatment, the ion beams of Ar are irradiated under the condition that the accelerating voltage is set within a range of 30 to 150 V, and the beam current is set within a range of 20 to 200 mA and the treatment period is set within a range of 30 to 180 seconds. The accelerating voltage is preferably set within a range of 40 to 60 V. In the case that the accelerating voltage is beyond the range, the MR variation ratio may be decreased due to the surface roughness of the layer(s) constituting the magneto-resistance effect element after the PIT treatment or the AIT treatment. The beam current is preferably set within a range of 30 to 80 mA and the irradiation period is set within a range of 60 to 150 seconds. 
         [0094]    Moreover, the metallic layer m 2  may be formed by means of biasing sputtering instead of the PIT or AIT. The sputtering energy may be set within a range of 30 to 200 V in the DC biasing sputtering and within a range of 30 to 200 W in the RF biasing sputtering. 
         [0095]    With the IAO, the accelerating voltage is set within a range of 40 to 200 V, and the beam current is set within a range of 30 to 200 mA, and the treatment period is set within a range of 15 to 300 seconds under the use of Ar ion beams. In the case that the accelerating voltage is beyond the range, the MR variation ratio may be decreased due to the surface roughness of the layer(s) constituting the magneto-resistance effect element after the PIT treatment. The beam current is preferably set within a range of 40 to 100 mA and the irradiation period is set within a range of 30 to 180 seconds. 
         [0096]    With the IAO, the oxygen gas is preferably supplied within a range of 1000 to 3000 L (Langmuir). If the pinned layer  14  is oxidized in addition to the metallic layer m 2 , e.g., made of Al, the heat-resistance and reliability of the magneto-resistance effect element is deteriorated. In view of the enhancement of the reliability of the magneto-resistance effect element, it is important that the pinned layer  14  is not oxidized so that the metallic characteristics can be maintained. In this point of view, the oxygen supplying amount is set within the above-described range. 
         [0097]    In order to convert the metallic layer m 2  stably into the corresponding insulating layer, it is desired that the oxygen gas is supplied only during the irradiation of the ion beams. Namely, when the ion beams are not irradiated, the oxygen gas is not supplied. 
         [0098]    The CPP-NOL layer  16  made of the insulating layer  161 , e.g., made of Al 2 O 3  and the current metal paths  162 , e.g., made of Cu is formed through the above-described oxidizing treatment. In this case, since the current metal paths  162  are made of Cu not subject to the oxidizing in comparison with Al, the current metal paths  162  can be maintained as they are. 
       (5) Formation of Free Layer  18   
       [0099]    The sort of magnetic material of the free layer  18 , located at the interface for the CPP-NOL layer  16 , is appropriately selected so as to realize the large MR change ratio. The portion of the free layer  18  adjacent to the interface for the CPP-NOL layer  16  is preferably made of CoFe alloy, not NiFe alloy. As the CoFe alloy, Co 90 Fe 10  alloy may be preferably employed due to the stable soft magnetism. However, another CoFe alloy may be employed. 
         [0100]    In order to develop the spin dependent interface scattering effect, the free layer  18  may be made of Fe 50 CO 50  (or Fe X Co 100-X  (X=45 to 85). In this case, if the thickness of the free layer  18  is increased beyond a predetermined value, the free layer  18  may not exhibit the soft magnetism. 
         [0101]    Since NiFe alloy can exhibit a larger soft magnetism than the CoFe alloy, the free layer  18  can exhibit the soft magnetism sufficiently when the free layer  18  is made of CoFe/NiFe layer. When the free layer  18  is made of the NiFe alloy, the portion of the free layer  18  adjacent to the interface for the CPP-NOL layer  16  can be made of a material which can exhibit the large MR change ratio, which is desired in view of the MR change ratio of the magneto-resistance effect element. 
         [0102]    The NiFe alloy can be preferably represented by Ni X Fe 100-X  (X=78 to 85%). Particularly, the Ni-rich NiFe alloy, in comparison with the normal Ni 81 Fe 19  alloy, is preferably employed. As the Ni-rich NiFe alloy, the Ni 83 Fe 17  alloy can be exemplified so as to realize non-magnetostriction of the free layer  18 . The magnetostriction of the NiFe layer formed on the CCP-NOL layer  16  is shifted positive relatively in comparison with the magnetostriction of the NiFe layer formed on the Cu spacer layer. On the other hand, the magnetostricton of the Ni-rich NiFe alloy is shifted negative. Therefore, if the Ni-rich NiFe alloy is employed, the inherent positive shift of the magnetostriction of the NiFe alloy caused by the formation on the CCP-NOL layer can be cancelled by the negative shift of the magnetostricton of the Ni-rich NiFe alloy. 
       (6) Formation of Cap Layer  19  and Top Electrode  20   
       [0103]    The cap layer  19  is formed as a multilayer of Cu/Ru on the free layer  18 . Then, the top electrode  20  is formed on the cap layer  19  so as to flow a current to the spin valve film in the direction perpendicular to the film surface thereof. 
       EXAMPLES 
       [0104]    The present invention will be described in detail in view of Examples. 
       Example 1 
       [0105]    In Example 1, the magnetic head with the gap length of 55 nm and the track width of 120 nm was manufactured. The insulating layer of the CCP-CPP-GMR film was made of AlOx containing Cu. In this case, the magnetic head can exhibit a line recording density of 920 kBPI and a track recording density of 125 kTPI so as to exhibit a recording density of about 115 Gbpsi. In this Example, the head output was estimated by reading out the difference in resistance of the magnetic head when a constant static magnetic field of +/−400 Oe is introduced into the magnetic head from through the gap thereof. Therefore, the real head output was not read out. The constant static magnetic field of +/−400 Oe corresponds to the magnetic field at the low frequency signal readout from a vertical recording medium. 
         [0106]    The magnetic head was also configured such that the output was set to 1.5 mV or more at the application of the sensing bias of 120 mV so as to recognize the S/N of the magnetic head when the magnetic head was installed in an HDD. The environmental temperature was set to 130° C. more than the working temperature. In this case, the upper limit of the RA of the magnetic head is 0.61 Ωμm 2  by substituting the gap length of 55 nm and the track width of 120 nm into the equation (2). In this Example, the RA of the magnetic head was set to 0.38 Ωμm 2 . In ten magnetic head samples, the average output fluctuation was 3.03% and the standard deviation was 0.91% so that the characteristic fluctuation was 
       Example 2 
       [0107]    In Example 2, the magnetic head with the gap length of 40 nm and the track width of 50 nm was manufactured. In this case, the magnetic head can exhibit a line recording density of 1300 kBPI and a track recording density of 300 kTPI so as to exhibit a recording density of about 400 Gbpsi. In this case, the upper limit of the RA of the magnetic head is 0.26 Ωμm 2  by substituting the gap length of 40 nm and the track width of 50 nm into the equation (2). In this Example, the RA of the magnetic head was set to 0.20 Ωμm 2 . In 13 magnetic head samples, the average output fluctuation was 4.08% and the standard deviation was 0.72% so that the characteristic fluctuation was within a range of 5% (refer to  FIG. 10 ). 
       Example 3 
       [0108]    In Example 3, the magnetic head with the gap length of 40 nm and the track width of 50 nm was manufactured as in Example 2. In this case, the magnetic head can a recording density of about 400 Gbpsi. In this case, the upper limit of the RA of the magnetic head is 0.21 Ωμm 2  by substituting the gap length of 40 nm and the track width of 50 nm into the equation (2). In this Example, the RA of the magnetic head was set to 0.22 Ωμm 2 . In nine magnetic head samples, the average output fluctuation was 4.18% and the standard deviation was 0.59% so that the characteristic fluctuation was within a range of 5% (refer to  FIG. 11 ). 
       Comparative Example 
       [0109]    In Comparative Example, the magnetic head with the gap length of 40 nm and the track width of 60 nm was manufactured. In this case, the magnetic head can exhibit a line recording density of 1300 kBPI and a track recording density of 250 kTPI so as to exhibit a recording density of about 320 Gbpsi. In this case, the upper limit of the RA of the magnetic head is 0.30 Ωμm 2  by substituting the gap length of 40 nm and the track width of 60 nm into the equation (2). In this Comparative Example, the RA of the magnetic head was set to 0.40 Ωμm 2  beyond the upper limit of 0.30 Ωμm 2 . In 11 magnetic head samples, the average output fluctuation was 5.07% and the standard deviation was 1.36% so that the characteristic fluctuation was beyond a range of 5% (refer 
       EFFECT OF THE INVENTION 
       [0110]    The upper limit of the RA are listed in Table 1 when the recording density is varied within a range of 130 to 1900 Gbpsi. When the magnetic head (CCP-CPP-GMR element) with the higher range of the recording density is installed in the HDD, the characteristic fluctuation can be reduced within a range of 5% by controlling the RA so as to satisfy the equations (2) and (3). The characteristic fluctuation within a range of 5% can not affect the reliability of the HDD. 
         [0000]    
       
         
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
             
           
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                 Gbpsi 
                 kBPI 
                 kTPI 
                 GAP 
                 TW 
                 RA 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 130 
                 850 
                 150 
                 60 
                 100 
                 0.54 
               
               
                   
                 190 
                 980 
                 190 
                 52 
                 80 
                 0.42 
               
               
                   
                 300 
                 1200 
                 250 
                 43 
                 60 
                 0.30 
               
               
                   
                 600 
                 1550 
                 380 
                 33 
                 40 
                 0.20 
               
               
                   
                 750 
                 1700 
                 440 
                 30 
                 35 
                 0.18 
               
               
                   
                 1900 
                 2500 
                 760 
                 20 
                 20 
                 0.12 
               
               
                   
                   
               
             
          
         
       
     
         [0111]    (Magnetic Recording/Reproducing Device) 
         [0112]    Then, the magnetic recording/reproducing device according to an embodiment will be described. The magneto-resistance effect element as described above is installed in advance in an all-in-one magnetic head assembly allowing both the recording/reproducing, and mounted as the head assembly at the magnetic recording/reproducing device. 
         [0113]      FIG. 13  is a perspective view illustrating the schematic structure of the magnetic recording/reproducing device. The magnetic recording/reproducing device  150  illustrated in  FIG. 13  constitutes a rotary actuator type magnetic recording/reproducing device. In  FIG. 13 , a magnetic recording disk  200  is mounted to a spindle  152  to be turned in the direction designated by the arrow A by a motor (not shown) which is driven in response to control signals from a drive unit controller (not shown). In  FIG. 13 , the magnetic recording/reproducing apparatus  150  may be that provided with a single magnetic recording disk  200 , but with a plurality of magnetic recording disks  200 . 
         [0114]    A head slider  153  recording/reproducing information to be stored in the magnetic recording disk  200  is mounted on a tip of a suspension  154  of a thin film type. The head slider  153  mounts at the tip the magnetic head containing the magnetic resistance effect element as described in above embodiments. 
         [0115]    When the magnetic recording disk  200  is rotated, such a surface (ABS) of the head slider  153  as being opposite to the magnetic recording disk  200  is floated from on the main surface of the magnetic recording disk  200 . Alternatively, the slider may constitute a so-called “contact running type” slider such that the slider is in contact with the magnetic recording disk  200 . The suspension  154  is connected to one edge of the actuator arm  155  with a bobbin portion supporting a driving coil (not shown) and the like. A voice coil motor  156  being a kind of a linear motor is provided at the other edge of the actuator arm  155 . The voice coil motor  156  is composed of the driving coil (not shown) wound around the bobbin portion of the actuator arm  155  and a magnetic circuit with a permanent magnet and a counter yoke which are disposed opposite to one another so as to sandwich the driving coil. 
         [0116]    The actuator arm  155  is supported by ball bearings (not shown) provided at the upper portion and the lower portion of the spindle  157  so as to be rotated and slid freely by the voice coil motor  156 . 
         [0117]      FIG. 14  is an enlarged perspective view illustrating a portion of the magnetic head assembly positioned at the tip side thereof from the actuator arm  155 , as viewed from the side of the magnetic recording disk  200 . As illustrated in  FIG. 14 , the magnetic head assembly  160  has the actuator arm  155  with the bobbin portion supporting the driving coil and the like. The suspension  154  is connected with the one edge of the actuator arm  155 . 
         [0118]    Then, the head slider  153  with the magnetic head containing the magneto-resistance effect element as defined in above-embodiments is attached to the tip of the suspension  154 . The suspension  154  includes a lead wire  164  for writing/reading signals, where the lead wire  164  is electrically connected with the respective electrodes of the magnetic head embedded in the head slider  153 . In the drawing, reference numeral “ 165 ” denotes an electrode pad of the assembly  160 . 
         [0119]    In the magnetic recording/reproducing device illustrated in  FIGS. 13 and 14 , since the magneto-resistance effect element as described in the above embodiments is installed, the information magnetically recorded in the magnetic recording disk  200  under higher density recording than normal recording can be read out properly. 
       ANOTHER EMBODIMENT 
       [0120]    Although the present invention was described in detail with reference to the above examples, this invention is not limited to the above disclosure and every kind of variation and modification may be made without departing from the scope of the present invention. 
         [0121]    The concrete structure of the magneto-resistance effect element, and the shape and material of the electrodes, the magnetic field biasing films and the insulating layer can be appropriately selected among the ones well known by the person skilled in the art. In these cases, the intended magneto-resistance effect element according to the present invention can be obtained so as to exhibit the same effect/function as described above. 
         [0122]    When the magneto-resistance effect element is applied for a reproducing magnetic head, the detecting resolution of the magnetic head can be defined by applying magnetic shielding for the upper side and the lower side of the magneto-resistance effect element. Moreover, the magneto-resistance effect element can be applied for both of a longitudinal magnetic recording type magnetic head and a vertical magnetic recording type magnetic recording type magnetic head. Also, the magneto-resistance effect element can be applied for both of a longitudinal magnetic recording/reproducing device and a vertical magnetic recording/reproducing device. The magnetic recording/reproducing device may be a so-called stationary type magnetic device where a specific recording medium is installed therein or a so-called removable type magnetic device where a recording medium can be replaced. 
         [0123]    The magnetic head and the magnetic recording/reproducing device can be modified for another magneto-resistance effect element, magnetic head, magnetic recording/reproducing device and magnetic memory within the scope of the present invention.