Abstract:
A compact write element includes a conductive shield layer, an insulating write gap layer, a pole pedestal, a coil, and a conductive pole layer, and, in some embodiments also includes a backgap. The pole pedestal and the coil, and, in some embodiments the backgap, constitute a self-aligned array of components that may be formed in a single masking operation to allow for very tight tolerances between the components for a shorter yoke length. The pole layer is substantially flat and parallel to the conductive shield layer, providing for a shorter stack height. Also, a compact MR read/write head includes such a write element and a magnetic data storage and retrieval system includes the compact MR read/write head having such a write element.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application is a Divisional of U.S. application Ser. No. 09/336,646, filed 18 Jun. 1999 now U.S. Pat. No. 6,466,402, which is hereby incorporated by reference in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates generally to magnetic data storage systems, more particularly to magnetoresistive read/write heads, and most particularly to an especially compact write structure. 
     Magnetic disk drives are used to store and retrieve data for digital electronic apparatuses such as computers. In  FIGS. 1A and 1B , a magnetic disk data storage system  10  includes a sealed enclosure  12 , a disk drive motor  14 , and a magnetic disk, or media,  16  supported for rotation by a drive spindle S 1  of motor  14 . Also included are an actuator  18  and an arm  20  attached to an actuator spindle S 2  of actuator  18 . A suspension  22  is coupled at one end to the arm  20 , and at its other end to a read/write head or transducer  24 . The transducer  24  typically includes an inductive write element with a sensor read element (both of which will be described in greater detail with reference to  FIG. 2A ). As the motor  14  rotates the magnetic disk  16 , as indicated by the arrow R, an air bearing is formed under the transducer  24  causing it to lift slightly off of the surface of the magnetic disk  16 , or, as it is sometimes termed in the art, to “fly” above the magnetic disk  16 . With the arm  20  held stationary, data bits can be read along a circumferential “track” as the magnetic disk  16  rotates. Further, information from concentric tracks can be read from the magnetic disk  16  as the actuator  18  causes the transducer  24  to pivot in an arc as indicated by the arrows P. The design and manufacture of magnetic disk data storage systems is well known to those skilled in the art.  
       FIG. 2A  depicts a magnetic read/write head  24  including a read element  26  and a write element  28 . Edges of the read element  26  and write element  28  also define an air bearing surface ABS, in a plane  29 , which can be aligned to face the surface of the magnetic disk  16  (see  FIGS. 1A and 1B ). The read element  26  includes a first shield  30 , an intermediate layer  32 , which functions as a second shield, and a read sensor  34  that is located within a dielectric medium  35  between the first shield  30  and the second shield  32 . The most common type of read sensor  34  used in the read/write head  24  is the magnetoresistive (AMR or GMR) sensor which is used to detect magnetic field signals from a magnetic medium through changing resistance in the read sensor. 
     The write element  28  is typically an inductive write element which includes the intermediate layer  32 , which functions as a first pole, and a second pole  38 . A first pole pedestal  42  may be connected to a first pole tip portion  43  of the first pole  32 , and a second pole pedestal  44  may be connected to the second pole tip portion  45  of the second pole  38 . The first pole  32  and the second pole  38  are attached to each other by a backgap  40  located distal to their respective pole tip portions,  43  and  45 . The first pole  32 , the second pole  38 , and the backgap  40  collectively form a yoke  41  together with the first pole pedestal  42  and the second pole pedestal  44 , if present. The area around the first pole tip portion  43  and the second pole tip portion  45  near the ABS is sometimes referred to as the yoke tip region  46 . A write gap  36  is formed between the first pole pedestal  42  and the second pole pedestal  44  in the yoke tip region  46 . The write gap  36  is formed of a non-magnetic electrically insulating material. This non-magnetic material can be either integral with (as is shown here) or separate from a first insulation layer  47  that lies between the first pole  32  and the second pole  38 , and extends from the yoke tip region  46  to the backgap  40 . 
     Also included in write element  28  is a conductive coil layer  48 , formed of multiple winds  49 . The conductive coil layer  48  is positioned within a coil insulation layer  50  that lies  above the first insulation layer  47 . The first insulation layer  47  thereby electrically insulates the coil layer  48  from the first pole  32 , while the coil insulation layer  50  electrically insulates the winds  49  from each other and from the second pole  38 . In some prior art fabrication methods, the formation of the coil insulation layer includes a thermal curing of an electrically insulating material, such as photoresistive “photoresist” material. 
       FIG. 2B  shows a plan view of the read/write head  24  taken along line  2 B— 2 B of  FIG. 2A . This view better illustrates how the coil layer  48  of write element  28  is configured as a spiral with each wind  49  passing around the backgap  40  and beneath the second pole  38  in the region between the backgap  40  and the second pole tip region  45 . Because of the magnetic properties of the yoke  41 , when a write current is passed through coil layer  48  a magnetic flux is induced in the first and second poles  32  and  38 . The write gap  36 , being non-magnetic, allows the magnetic flux to fringe out from the yoke  41 , thus forming a fringing gap field. Data may be written to the magnetic disk  16  by placing the ABS of read/write head  24  proximate to the magnetic disk  16  such that the fringing gap field crosses the surface of the magnetic disk  16 . Moving the surface of the magnetic disk  16  through the fringing gap field causes a reorientation of the magnetic domains on the surface of the magnetic disk  16 . As the magnetic disk  16  is moved relative to the write element  28 , the write current in coil layer  48  is varied to change the strength of the fringing gap field, thereby encoding data on the surface of the magnetic disk  16  with a corresponding variation of oriented magnetic domains. 
     Returning to  FIG. 2A , a number of parameters that influence the performance of the write element  28  are also shown. The first of these parameters is the yoke length YL, sometimes defined as the distance from the backgap  40  to the first pole pedestal  42 . A shorter yoke length YL favors higher data recording rates as it tends to reduce the flux rise time. The flux rise time is a measure of the time lag between the moment a current passed  through coil layer  48  reaches its maximum value and the moment the fringing flux field between the first pole  32  and the second pole  38  reaches its maximum. Ideally, the response would be instantaneous, but various factors such as the physical dimensions and the magnetic properties of the yoke  41  cause the flux rise time to increase. A shorter flux rise time is desirable both to increase the rate with which data may be written to a magnetic disk  16 , and also to decrease the length of, and the spacing between, data bits on the magnetic disk  16 . Shorter data bits more closely spaced together is desirable for increasing the total storage capacity of the magnetic disk  16 . 
     Write elements according to the prior art are manufactured through common photolithography techniques well known in the art involving repeated cycles of masking with “photoresist,” depositing layers of various materials, followed by stripping away remaining photoresist. Each cycle through this process typically fabricates one element of the final structure. Consequently, tolerance for mask misalignment must be accounted for in the designs for these devices. In particular, prior art write elements leave a separation of at least 4 microns between pole pedestals  42  and  44  and the coil layer  48 . A similar gap of at least 4 microns is found between the backgap  40  and the coil layer  48 . These separations add extra length to the yoke length YL that increases the flux rise time and hinders write performance. 
     Another parameter of the write element  28  is the stack height SH, sometimes defined as the distance between the top surface of the first pole  32  and the top of the second pole  38 , as shown in  FIG. 2A . The stack height SH is influenced by the apex angle α, which characterizes the angle of the slope region of the second pole  38  near the yoke tip portion  46  measured relative to a horizontal reference such as the intermediate layer  32 . Increasing the stack height SH makes it difficult to control the track width within narrow set tolerances, decreasing the production yield. Consequently, increasing the apex angle α has the effect of increasing the stack height SH to the detriment of write performance.  
     A further problem associated with the apex angle α relates to the magnetic properties of the second pole  38 . Increasing the apex angle α increases the topography over which the second pole  38  must be formed near the yoke tip portion. The second pole  38  is typically formed by sputtering or plating, techniques well suited for producing flat layers, but not as well suited for forming complex surfaces. Consequently, a further problem associated with the apex angle α is lower production yields resulting from the difficulties encountered in producing uniformity in the second pole  38 , especially in the slope region. Still another problem associated with apex angle α relates to the magnetic properties of the second pole  38  in the slope region, which will be described with reference to  FIGS. 3A–3C . 
     The trend towards higher density recording in the disk drive industry has forced a number of materials changes in the components of the drives, which has, in turn, created additional problems. In particular, in order to achieve higher data densities on the surface of the magnetic disk  16 , the traditional magnetic media have not been found to be sufficient. To obtain smaller bits it has been necessary to develop recording media with higher magnetic coercivities. To write to a magnetic medium with a higher magnetic coercivity requires that the write element  28  produce a stronger fringing flux field. To produce a stronger fringing flux field further requires the use of magnetic materials capable of carrying larger magnetic fluxes. In other words, for high density recording applications, new materials for components of the yoke  41  need to have high magnetic saturation (Bs) values. 
     Permalloy, a nickel alloy containing 20% by weight of iron, is the material most frequently used to form magnetic components of prior art recording devices. However, Permalloy has an unacceptably low Bs for use in high density recording. Consequently, designers of magnetic recording devices have turned to high Bs materials such as nickel alloys containing between 35% and 55% by weight of iron. Replacing Permalloy with higher Bs materials would be a simple matter except for the issue of magnetostriction.  
     When a material with a non-zero magnetostriction is subjected to a stress, a magnetic field is produced in response. Similarly, when such a material is placed in a magnetic field, a stress in the material develops. Permalloy has been an advantageous material in magnetic recording devices because it has a magnetostriction value of nearly zero. The higher Bs materials, on the other hand, exhibit much higher magnetostriction values. These higher magnetostriction values create additional problems for high density recording applications. 
       FIGS. 3A–3C  illustrate how the apex angle α coupled with high Bs materials is problematic for high density recording.  FIG. 3A  shows a plan view of the second pole  38  showing a typical arrangement of magnetic domains  51  as they appear on the top surface of the second pole  38  when fabricated from high Bs materials. Arrows within the magnetic domains  51  indicate the orientations of the domains&#39; magnetizations. Through much of the body of the second pole  38  the magnetic fields of the domains  51  are favorably oriented perpendicular to the long axis of the second pole  38 . However, in the second pole tip region  45  the magnetization of domains  51  are aligned parallel to the long axis of the second pole  38 . In the intervening slope region, the magnetic domains are disordered. 
       FIG. 3B  shows a cross-sectional view along the line  3 B— 3 B of  FIG. 3A . Similarly,  FIG. 3C  is an ABS view along the line  3 C— 3 C of  FIG. 3B . In  FIG. 3C  the orientations of the magnetization within the magnetic domains are represented by dots and circled dots. Dots and circled dots show, respectfully, orientations into and out from the plane of the drawing. From  FIGS. 3A–3C  it can be seen that within the second pole tip region  45  the magnetic domains form a layered structure with magnetization orientations perpendicular to the ABS. This layered structure is sometimes referred to as a striped domain pattern. 
     It has been found that with increasing apex angle α the stresses in the magnetic film in the slope region of the second pole  38  also increase. Some of the stress in the magnetic film  is inherent from the manufacturing process. Additional stresses may increase during the operation of the read/write head  24  as heat is generated within the device and differences in coefficients of thermal expansion between different materials create minor dimensional changes. The retention of photoresist as an insulator in some prior art devices is especially troublesome in this regard, as photoresist has a relatively large coefficient of thermal expansion. Consequently, photoresist retained beneath the second pole  38  has the effect, when the device is in use, of creating especially large stresses in the slope region of the second pole  38 . Therefore, since the effect of magnetostriction is to counteract a stress with a magnetic field, undesirable magnetic fields in the slope region of the second pole  38  tend to increase both as the apex angle α increases and when photoresist is retained beneath the second pole  38 . These undesirable magnetic fields give rise to the striped domain pattern and disordered domains. 
     The striped domain pattern in the second pole tip region  45  and the disordered domains in the slope region are detrimental to the performance of the write element  28 . In particular, these misoriented domains resist changes in the magnetization of the yoke  41 . Consequently, when a write current is introduced into the coil layer  48  and a magnetic field is induced in the yoke  41 , the flux rise time is lengthened by the resistance to change of the misoriented domains. Longer flux rise times and poorer performance are, therefore, associated with an increasing apex angle α and with the use of retained photoresist beneath the second pole  38 . 
       FIG. 4  shows a more desirable arrangement of magnetic domains  51  for the second pole  38 . Arrows within the magnetic domains  51  indicate magnetic orientation. With such an idealized arrangement, the magnetization of the yoke  41  should respond more quickly to changes in the write current in coil layer  48 , thus improving the write performance of the write element  28  by reducing the flux rise time.  
     Thus, what is desired is a write element with a substantially flat second pole and a shorter yoke length YL. Such a write element would eliminate the apex angle α, have a smaller stack height SH, and would not have the misoriented magnetic domain problems associated with the slope region. Further, it is desired to be able to fabricate a write element without retaining any photoresist as an insulator. It is additionally desired that fabrication of such a write element should be inexpensive, quick, and simple.  
     SUMMARY OF THE INVENTION 
     The present invention provides a compact structure for a write element of a read/write head of a magnetic data storage device. The structure includes both a substantially flat second pole, significantly less space between the coil and the backgap, and significantly less space between the coil and the pole pedestal. Additionally, a method for the fabrication of such a compact write element is provided. 
     In an embodiment of the present invention a compact magnetic write structure is provided comprising a conductive shield layer defining a plane, an insulating write gap layer at least partially covering the conductive shield layer, a self-aligned array comprising a conductive pole pedestal and a coil, and a conductive pole layer disposed over the coil and contacting the pole pedestal. The conductive pole layer defines a plane substantially parallel to the plane of the conductive shield layer. The separation between the pole pedestal and the coil is no greater than about 2.0 microns. A further embodiment of the present invention includes both a backgap opening in the insulating write gap layer, and a backgap as part of the self-aligned array. The backgap contacts the conductive shield through the backgap opening. 
     Additional embodiments of the present invention are directed to a compact MR read/write head that further includes a MR read element. The read element itself comprises two conductive shields separated by an insulator layer in which the MR sensor is disposed, and one of the conductive shields also serves as the first pole of the compact magnetic write structure. Still other embodiments are directed to a magnetic data storage and retrieval system additionally incorporating a magnetic medium and a medium support, where the medium support is capable of supporting the magnetic medium and moving it in relation to the read/write head.  
     This compact magnetic write structure is advantageous because it provides a substantially flat second pole without a slope region. Eliminating the slope region serves to both reduce the magnetostrictive induced resistance to magnetization changes in the yoke, and to reduce the stack height. Both of these changes reduce the flux rise time and improve writing performance. The structure is further advantageous for limiting the separation between the pole pedestal and the coil to no greater than about 2.0 microns, thereby reducing the yoke length for further writing performance enhancement. The embodiment in which the separation between the backgap and the coil to no greater than about 2.0 microns is similarly advantageous for further reducing the yoke length. Still another advantage is the ability to fabricate the structure without retaining photoresist as an insulator. This is also advantageous for lowering the flux rise time by reducing unwanted stresses in high Bs magnetic materials caused by large mismatches in coefficients of thermal expansion. 
     Yet another embodiment of the present invention is directed to a method for manufacturing a magnetic write structure. The method includes providing a substrate including a conductive shield layer and an insulating write gap layer. The conductive shield layer defines a plane, and the insulating write gap layer at least partially covers the conductive shield layer. The method further includes forming over the substrate a self-aligned array comprising a plurality of components including a conductive pole pedestal and a coil. The pole pedestal and the coil contact the write gap layer, and the separation between the pole pedestal and the coil is no greater than about 2.0 microns. Additionally, the method includes forming a conductive pole layer over the self-aligned array. The pole layer is in contact with the pole pedestal and defines a plane that is substantially parallel to the plane of the conductive shield layer. The present invention further includes a planarization step prior to the formation of the pole layer helping to ensure that the plane of the pole layer is substantially parallel to the plane of the conductive shield layer.  
     Additional embodiments of this invention are directed to a method for manufacturing a magnetic write structure in which the insulating write gap layer is provided with a backgap opening, the plurality of components of the self-aligned array further includes a conductive backgap, and the conductive backgap is disposed above and contacts the conductive shield layer through the backgap opening. The separation between the backgap and the coil in these embodiments is no greater than about 2.0 microns. In still other embodiments a seed layer is formed above and in contact with the insulating write gap layer. 
     These methods for manufacturing magnetic write structures are advantageous because they incorporate a self-aligned array. A self-aligned array allows the pole pedestal and the coil to be formed with the same mask, thereby allowing these two components to be formed as close together as masking technology will allow without having to leave excess space between them to allow for the possible misalignment of successive masks. Embodiments incorporating a backgap also take advantage of the self-aligned array to minimize the space between the backgap and the coil. A further advantage of the self-aligned array is that it reduces the total number of masking operations needed to form a magnetic write structure, thus saving time and reducing manufacturing costs. 
     Another advantage of this manufacturing method derives from the planarization step preceding the formation of the pole layer. The planarization achieves three important goals. The first goal is to expose the backgap and the second pole pedestal. The second is to reduce the overall stack height of the finished write structure, improving the write performance of the finished device. The third goal served by the planarization step is that the pole layer formed over the planarized surface is itself substantially flat and substantially parallel to the plane of the conductive shield layer. This serves to simplify the geometry of the pole layer, thereby reducing or substantially eliminating domain striping and further improving write performance of the finished device.  
     These and other advantages of the present invention will become apparent to those skilled in the art upon a reading of the following descriptions of the invention and a study of the several figures of the drawing.  
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will be readily understood by the following detailed description in conjunction with the accompanying drawings, and like reference numerals designate like elements. 
         FIG. 1A  is a partial cross-sectional elevation view of a magnetic data storage system; 
         FIG. 1B  is a top plan view along line  1 B— 1 B of  FIG. 1A ; 
         FIG. 2A  is a cross-sectional view of a read/write head according to the prior art; 
         FIG. 2B  is a top plan view along line  2 B— 2 B of  FIG. 2A ; 
         FIG. 3A  is a top plan view showing a typical arrangement of magnetic domains at the surface of a prior art second pole; 
         FIG. 3B  is a cross-sectional view along the line  3 B— 3 B of  FIG. 3A ; 
         FIG. 3C  is an ABS view along the line  3 C— 3 C of  FIG. 3B ; 
         FIG. 4  is a top plan view showing a more desirable arrangement of magnetic domains at the surface of the second pole sought to be achieved by the present invention; 
         FIG. 5  is a cross-sectional view of a read/write head according to an embodiment of the present invention; 
         FIGS. 6A–6E  are cross-sectional views of a read/write head at various stages of fabrication, according to an embodiment of the present invention;  
         FIG. 6F  is a top plan view along the line  6 F in  FIG. 6E  showing the relationship of the components of a self-aligned array according to an embodiment of the present invention; 
         FIGS. 6G–6M  are further cross-sectional views of a read/write head at various stages of fabrication, according to an embodiment of the present invention; 
         FIG. 6N  is a top plan along the line  6 N in  FIG. 6M  illustrating the narrowing of the second pole pedestal according to an embodiment of the present invention; and 
         FIGS. 6O–6R  are further cross-sectional views of a read/write head at various stages of fabrication, according to an embodiment of the present invention  
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIGS. 1A ,  1 B,  2 A,  2 B,  3 A– 3 C, and  4  were discussed with reference to the prior art. 
       FIG. 5  is a cross-sectional view of a read/write head  50  according to an embodiment of the present invention, including a read element  26  and a write element  60 . Edges of the read element  26  and write element  28  also define an air bearing surface ABS, in a plane  29 , which can be aligned to face the surface of the magnetic disk  16 . The read element  26  includes a first shield  30 , a conductive shield layer  32 , which functions as a second shield, and a read sensor  34  that is located within a dielectric medium  35  between the first shield  30  and the conductive shield layer  32 . Embodiments of the present invention may include a read sensor  34  that may be any type magnetoresistive sensor to detect magnetic field signals from a magnetic disk  16 . 
     The write element  60  includes conductive shield layer  32 , which functions as a first pole, and a second pole  52 . The conductive shield layer  32  includes a first pole tip portion  43 , and the second pole  52  includes a second pole tip portion  56 . A second pole pedestal  58  is connected to the second pole tip portion  56  of the second pole  52 . The conductive shield layer  32  and the second pole  52  are joined together by a backgap  62  located distal to their respective pole tip portions,  43  and  56 . The conductive shield layer  32 , the second pole  52 , the backgap  62 , and the second pole pedestal  58  collectively form a yoke  64 . Additional embodiments of the present invention may also include a first pole pedestal (not shown) that may be connected to the first pole tip portion  43  of the conductive shield layer  32 . The components of the yoke  64  may be formed from any electrically conductive material, however, high Bs materials such as CoNiFe alloys and nickel alloys containing iron in the 35% to 55% by weight range, such as Ni-35% Fe, Ni-45% Fe, and Ni-55% Fe work well.  
     The area within the space enclosed by the yoke  64  contains a write gap layer  66 , a coil  68  comprising individual winds  69 , wind insulators  70 , a pole pedestal insulator  72 , a backgap insulator  74 , and a second pole insulation layer  76 . The write gap layer  66  is a continuous film extending from the ABS to the backgap  62 . The write gap layer  66  separates the first pole tip portion  43  from the second pole pedestal  58 , and the conductive shield layer  32  from the coil  68 . The pole pedestal insulator  72  isolates the second pole pedestal  58  from the nearest wind  69 ′ of coil  68 . Similarly, the backgap insulator  74  isolates the backgap  62  from the nearest wind  69 ″ of coil  68 . The wind insulators  70  separate the individual winds  69  of coil  68  from one another. The second pole insulation layer  76  insulates the second pole  52  from the coil  68 . The coil  68  may be made from any conductive material, however, copper works well. Likewise, the write gap layer  66 , the wind insulators  70 , the pole pedestal insulator  72 , the backgap insulator  74 , and the second pole insulation layer  76 , may be made from any non-magnetic electrically insulating material such as alumina (Al 2 O 3 ) or silica (SiO 2 ). 
       FIGS. 6A–6R  illustrate a method for manufacturing a magnetic write structure according to the present invention.  FIG. 6A  shows the starting point of the process. A substrate  80  is provided including a support member  82 , a conductive shield layer  32 , and an insulating write gap layer  66  at least partially covering the conductive shield layer  32 . Embodiments including a read element  26  will further include within the substrate  80  a first shield  30 , and a read sensor  34  located within a dielectric medium  35 . The conductive shield layer  32  functions as a second shield for read element  26 . 
     The support member  82  is a base on which a plurality of write structures may be assembled. It should be thick enough to provide good mechanical support for handling. The support member  82  should be substantially flat and chemically inert so that substantially flat layers may be formed above it, and so that those layers do not chemically react with it.  Ideally, the support member  82  should also be fairly inexpensive. Silicon wafers are known to work well for support member  82 . 
     The materials and fabrication methods for the first shield  30 , the read sensor  34 , and the dielectric medium  35  are well known in the art. The conductive shield layer  32  may be formed from any electrically conductive material, however, high Bs materials such as CoNiFe alloys and nickel alloys containing iron in the 35% to 55% by weight range, such as Ni-35% Fe, Ni-45% Fe, and Ni-55% Fe work well for producing write elements for high density recording applications. The conductive shield layer  32  may be formed by any number of common fabrication techniques well known in the art such as plating. The insulating write gap layer  66  may be formed of any electrically insulating material, with alumina and silica commonly used, and may be formed by any well known deposition technique such as chemical vapor deposition (CVD). A backgap opening  85  in the insulating write gap layer  66  is provided in some embodiments. The backgap opening may be formed by common techniques well known in the art such as masking followed, for example, by reactive ion etching (RIE) or wet etching. 
       FIG. 6B  shows the formation of a seed layer  86  above and in contact with the insulating write gap layer  66 . The seed layer also covers the conductive shield layer  32  where the conductive shield layer  32  is exposed by an opening in the insulating write gap layer  66 . The seed layer  86  may improve the adhesion of subsequent metallic layers, and also forms a useful etch stop when reactive ion etching (RIE) is used to remove subsequently formed insulating layers that are not part of the final structure. The seed layer  86  is typically deposited by sputtering a material having the same composition as that of film to be plated. The thickness of the seed layer  86  is about 0.1 microns to about 0.5 microns thick. 
     Formed above the seed layer  86  is a first insulation layer  88 . The first insulation layer  88  may be formed of any electrically insulating material, such as silica, and may be formed  by any suitable deposition technique such as CVD. The first insulation layer  88  should be at least as thick as the coil  68  will ultimately be, in the range of 0.5 microns to 2.0 microns. 
       FIG. 6C  shows a first mask  90  disposed above and in contact with the first insulation layer  88 . The first mask  90  is formed of photoresist and patterned by photolithography techniques well known in the art. The first mask  90  includes openings to expose the first insulation layer  88 . These openings are situated above locations where portions of the first insulation layer  88  will subsequently be removed to create voids. The voids to be formed in the first insulation layer  88  will ultimately be filled with conductive materials to form the individual winds  69  of coil  68 , and the second pole pedestal  58 . In some embodiments a void in the first insulation layer  88  will also be created to allow for the subsequent formation of the backgap  62 . 
       FIG. 6D  illustrates a stage in the construction of the magnetic write structure after voids in the first insulation layer  88  have been formed. The voids may be created by RIE, for example, using the seed layer  86  as an etch stop.  FIG. 6E  shows the partially constructed magnetic write structure after the remnants of the first mask  90  have been removed by any appropriate stripping technique well known to the photolithography arts. The first insulation layer  88  is left with a pole pedestal void  92 , at least one coil void  94 , and in some embodiments a backgap void  96 .  FIG. 6F  shows a plan view of the pattern of voids created in the first insulation layer  88  as viewed along the line  6 F in  FIG. 6E . 
       FIGS. 6G–6I  illustrate the formation of coil  68 , beginning with the formation of a second mask  98  having an aperture, wherein the aperture exposes at least one coil void  94 . Except for the coil voids  94  exposed by the aperture, the second mask  98  otherwise completely covers the surface of the magnetic write structure being created. The second mask  98  is formed of photoresist and patterned by well known photolithography techniques.  
       FIG. 6H  further illustrates the formation of coil  68 . As previously noted, coil  68  is comprised of individual winds  69 . The individual winds  69  are formed of an electrically conductive material such as copper within the coil voids  94  by any suitable technique, for example, by plating. The individual winds  69 , once formed, should be about 0.5 microns to about 2.0 microns in thickness. Following the formation of the individual winds  69 , the second mask  98  may be removed by any appropriate stripping technique. The removal of the second mask  98  completes the formation the coil  68 . The partially constructed magnetic write structure is shown in  FIG. 6I  following the removal of second mask  98 . 
       FIGS. 6J–6L  show the formation of the second pole pedestal  58 , and in some embodiments the backgap  62 . In  FIG. 6J  a third mask  100  is formed of photoresist and patterned by photolithography techniques. The third mask  100  is patterned to cover the coil  68 . An electrically conductive material, preferably with a high Bs value, is formed within the pole pedestal void  92 , and in some embodiments the backgap void  96 . This may be accomplished by any suitable technique known in the art, for example, by plating. The material deposited in the pole pedestal void  92 , and in some embodiments the material deposited in the backgap void  96 , should fill these voids to a thickness in the range of about 0.5 microns to about 2.0 microns. Examples of high Bs materials include nickel alloys containing iron in the 35% to 55% by weight range, such as Ni-35% Fe, Ni-45% Fe, and Ni-55% Fe.  FIG. 6K  shows the partially constructed magnetic write structure following the completion of this operation.  FIG. 6K  includes a second pole pedestal  58  and a backgap  62 . 
       FIG. 6L  illustrates the partially constructed magnetic write structure following the completion of the self-aligned array  102 , comprising the coil  68 , the second pole pedestal  58 , and in some embodiments the backgap  62 . The self-aligned array  102  is completed by removing the third mask  100 , removing the remnants of the first insulation layer  88 , and by removing the seed layer  86  from everywhere except where it is covered by the individual  winds  69 , the second pole pedestal  58 , and the backgap  62 . The seed layer  86  must be removed from these locations because otherwise it would create electrical short circuits. The third mask  100  may be removed by any appropriate stripping technique. The remnants of the first insulation layer  88  may be removed by any suitable technique such as ion milling. Lastly, the portions of the seed layer  86  exposed by the removal of the remnants of the first insulation layer  88  may themselves be removed by any suitable process such as RIE. 
     In some embodiments of the present invention forming the second pole pedestal  58  further involves narrowing the width of the second pole pedestal  58 . Narrowing the width of the second pole pedestal  58  is desirable for narrowing the trackwidth the magnetic write structure ultimately will produce when used to transfer data to a magnetic disk  16 . Narrowing the second pole pedestal  58  is shown in  FIGS. 6M–6O . In  FIG. 6M  a fourth mask  104  is formed above and in contact with the coil  68 . The fourth mask  104  is formed of photoresist and patterned by photolithography techniques.  FIG. 6N  shows a plan view of the partially completed magnetic write structure as viewed along line  6 N in  FIG. 6M . This figure shows the initial width W of the second pole pedestal  58  prior to the narrowing process, and the final width W′ following the completion of the narrowing process. The width of the second pole pedestal  58  may be reduced from W to W′, for example, by low angle ion milling. Narrowing the second pole pedestal  58  is completed by removing the fourth mask  104  by any appropriate stripping technique.  FIG. 6O  shows the partially completed magnetic write structure after the formation of the self-aligned array  102 , and in some embodiments after the second pole pedestal  58  has been narrowed from a width of W to a width of W′. 
       FIG. 6P  shows the formation of a second insulating layer  106  above and covering the self-aligned array. The second insulating layer  106  fills the spaces between individual winds  69  forming the wind insulators  70  shown in  FIG. 5 . The second insulating layer  106   also fills the space between the second pole pedestal  58  and its nearest individual wind  69 ′, and the space between the backgap  62  and its nearest individual wind  69 ″ forming, respectfully, the pole pedestal insulator  72  and the backgap insulator  74  shown in  FIG. 5 . The second insulating layer  106  may be formed of any electrically insulating material such as alumina or silica, and may be deposited by any suitable technique such as CVD. 
     The second insulating layer  106  is planarized to expose the second pole pedestal  58 , and in some embodiments the backgap  62 .  FIG. 6Q  shows the partially completed magnetic write structure following the planarization of the second insulating layer  106 . Following planarization the second pole pedestal  58  has a first surface  108 , the backgap  62  has a first surface  110 , and the second insulating layer  106  has a first surface  112 . All three of these surfaces are substantially coplanar with each other. Planarization may be accomplished by any suitable technique such as chemical mechanical polishing (CMP). 
     A conductive pole layer  52  is formed above and in contact with the second insulating layer  106 , the second pole pedestal  58 , and the backgap  62  as shown in  FIG. 6R . Conductive pole layer  52  should be substantially parallel to the plane of conductive shield layer  32 , and no more than 10° away from parallel. The conductive pole layer  52  may be formed from any electrically conductive material, however, high Bs materials such as CoNiFe alloys and nickel alloys containing iron in the 35% to 55% by weight range, such as Ni-35% Fe, Ni-45% Fe, and Ni-55% Fe work well for producing write elements for high density recording applications. The conductive pole layer  52  may be formed by any suitable fabrication technique such as plating.  FIG. 6R  also shows the plane  29  of the air bearing surface (ABS) that must be exposed to make the magnetic write structure operable. This may be accomplished by any suitable method such as grinding and lapping. 
     In summary, the present invention provides structures and methods for providing a magnetic recording device that can be used in high data density applications with improved  write performance. The invention has been described herein in terms of several preferred embodiments. Other embodiments of the invention, including alternatives, modifications, permutations and equivalents of the embodiments described herein, will be apparent to those skilled in the art from consideration of the specification, study of the drawings, and practice of the invention. The embodiments and preferred features described above should be considered exemplary, with the invention being defined by the appended claims, which therefore include all such alternatives, modifications, permutations and equivalents as fall within the true spirit and scope of the present invention.