Abstract:
A studded trailing shield design and method for manufacture thereof. The studded trailing shield design maintains critical spacing between the trailing shield and the write pole and also maintains critical spacing between the studded, trailing shield connecting structure, even in a head design having read and write elements that are not aligned with one another.

Description:
FIELD OF THE INVENTION 
     The present invention relates to perpendicular magnetic recording and more particularly to a novel trailing magnetic shield design and a method for manufacturing such a shield design. 
     BACKGROUND OF THE INVENTION 
     The heart of a computer&#39;s long term memory is an assembly that is referred to as a magnetic disk drive. The magnetic disk drive includes a rotating magnetic disk, write and read heads that are suspended by a suspension arm adjacent to a surface of the rotating magnetic disk and an actuator that swings the suspension arm to place the read and write heads over selected circular tracks on the rotating disk. The read and write heads are directly located on a slider that has an air bearing surface (ABS). The suspension arm biases the slider toward the surface of the disk, and when the disk rotates, air adjacent to the disk moves along with the surface of the disk. The slider flies over the surface of the disk on a cushion of this moving air. When the slider rides on the air bearing, the write and read heads are employed for writing magnetic transitions to and reading magnetic transitions from the rotating disk. The read and write heads are connected to processing circuitry that operates according to a computer program to implement the writing and reading functions. 
     The write head traditionally includes a coil layer embedded in first, second and third insulation layers (insulation stack), the insulation stack being sandwiched between first and second pole piece layers. A gap is formed between the first and second pole piece layers by a gap layer at an air bearing surface (ABS) of the write head and the pole piece layers are connected at a back gap. Current conducted to the coil layer induces a magnetic flux in the pole pieces which causes a magnetic field to fringe out at a write gap at the ABS for the purpose of writing the aforementioned magnetic transitions in tracks on the moving media, such as in circular tracks on the aforementioned rotating disk. 
     In recent read head designs a spin valve sensor, also referred to as a giant magnetoresistive (GMR) sensor, has been employed for sensing magnetic fields from the rotating magnetic disk. The sensor includes a nonmagnetic conductive layer, hereinafter referred to as a spacer layer, sandwiched between first and second ferromagnetic layers, hereinafter referred to as a pinned layer and a free layer. First and second leads are connected to the spin valve sensor for conducting a sense current therethrough. The magnetization of the pinned layer is pinned perpendicular to the air bearing surface (ABS) and the magnetic moment of the free layer is located parallel to the ABS, but free to rotate in response to external magnetic fields. The magnetization of the pinned layer is typically pinned by exchange coupling with an antiferromagnetic layer. 
     The thickness of the spacer layer is chosen to be less than the mean free path of conduction electrons through the sensor. With this arrangement, a portion of the conduction electrons is scattered by the interfaces of the spacer layer with each of the pinned and free layers. When the magnetizations of the pinned and free layers are parallel with respect to one another, scattering is minimal and when the magnetizations of the pinned and free layer are antiparallel, scattering is maximized. Changes in scattering alter the resistance of the spin valve sensor in proportion to cos θ, where θ is the angle between the magnetizations of the pinned and free layers. In a read mode the resistance of the spin valve sensor changes proportionally to the magnitudes of the magnetic fields from the rotating disk. When a sense current is conducted through the spin valve sensor, resistance changes cause potential changes that are detected and processed as playback signals. 
     When a spin valve sensor employs a single pinned layer it is referred to as a simple spin valve. When a spin valve employs an antiparallel (AP) pinned layer it is referred to as an AP pinned spin valve. An AP spin valve includes first and second magnetic layers separated by a thin non-magnetic coupling layer such as Ru. The thickness of the spacer layer is chosen so as to be antiparallel coupled to the magnetizations of the ferromagnetic layers of the pinned layer. A spin valve is also known as a top or bottom spin valve depending upon whether the pinning layer is at the top (formed after the free layer) or at the bottom (before the free layer). 
     The spin valve sensor is located between first and second nonmagnetic electrically insulating read gap layers and the first and second read gap layers are located between ferromagnetic first and second shield layers. In a merged magnetic head a single ferromagnetic layer functions as the second shield layer of the read head and as the first pole piece layer of the write head. In a piggyback head the second shield layer and the first pole piece layer are separate layers. 
     Magnetization of the pinned layer is usually fixed by exchange coupling one of the ferromagnetic layers (APl) with a layer of antiferromagnetic material such as PtMn. While an antiferromagnetic (AFM) material such as PtMn does not in and of itself have a magnetization, when exchange coupled with a magnetic material, it can strongly pin the magnetization of the ferromagnetic layer. 
     In order to meet the ever increasing demand for improved data rate and data capacity, researchers have recently been focusing their efforts on the development of perpendicular recording systems. A traditional longitudinal recording system, such as one that incorporates the write head described above, stores data as magnetic bits oriented longitudinally along a track in the plane of the surface of the magnetic disk. This longitudinal data bit is recorded by a fringing field that forms between the pair of magnetic poles separated by a write gap. 
     A perpendicular recording system, by contrast, records data as magnetization oriented perpendicular to the plane of the magnetic disk. The magnetic disk has a magnetically soft underlayer covered by a thin magnetically hard top layer. The perpendicular write head has a write pole with a very small cross section and a return pole having a much larger cross section. A strong, highly concentrated magnetic field emits from the write pole in a direction perpendicular to the magnetic disk surface, magnetizing the magnetically hard top layer. The resulting magnetic flux then travels through the soft underlayer, returning to the return pole where it is sufficiently spread out and weak that it will not erase the signal recorded by the write pole when it passes back through the magnetically hard top layer on its way back to the return pole. 
     One of the features of perpendicular recording systems is that the high coercivity top layer of the magnetic medium has a high switching field. This means that a strong magnetic field is needed to switch the magnetic moment of the medium when writing a magnetic bit of data. In order to decrease the switching field and increase recording speed, attempts have been made to angle or “cant” the write field being emitted from the write pole. Canting the write field at an angle relative to the normal of the medium makes the magnetic moment of the medium easier to switch by reducing the switching field. Modeling has shown that a single pole writer in a perpendicular recording system can exhibit improved transition sharpness (ie. better field gradient and resolution), achieve better media signal to noise ratio, and permit higher coercive field media for higher areal density magnetic recording if, according to the Stoner-Wohlfarth model for a single particle, the effective flux field is angled. A method that has been investigated to cant the magnetic field has been to provide a trailing magnetic shield adjacent to the write head, to magnetically attract the field from the write pole. 
     The trailing shield can be a floating design, in that the magnetic trailing shield is not directly, magnetically connected with the other structures of the write head. Magnetic field from the write pole results in a flux in the shield that essentially travels through the magnetic medium back to the return pole of the write head. Various dimensions of the shield are critical for the floating trailing shield to operate correctly. For instance, effective angling or canting of the effective flux field is optimized when the write pole to trailing shield separation (gap) is about equal to the head to soft underlayer spacing (HUS) and the trailing shield throat height is roughly equal to half the track-width of the write pole. This design improves write field gradient at the expense of effective flux field. To minimize effective flux field lost to the trailing shield and still achieve the desired effect, the gap and shield thickness are adjusted to minimize saturation at the shield and effective flux field lost to the shield respectively. 
     A problem that associated with floating trailing shield designs is that the flux shunted to the return pole through the magnetic medium tends to cause saturation of the return pole at the ABS. When the flux is shunted to the return pole through the magnetic medium, it is combined with the desired flux from the write pole, which also flows through the magnetic medium. 
     One way to overcome this would be to directly magnetically couple the trailing shield to the return pole rather than relying on the magnetic medium to conduct the flux to the return pole. Constructing such a direct magnetic connection from the trailing shield to the return pole is challenging, however, due in large part to the large distance between the trailing shield and the return pole. In addition, in many designs the read sensor and write pole are not aligned, and in such designs the return pole also may not be aligned with the write pole. The challenge presented by such designs is construct a connecting structure that can provide a desired spacing from the write pole, while also connecting to the non-aligned return pole. 
     Therefore, there is a strong felt need for a practical, manufacturable trailing shield design that provides direct magnetic connection with the return pole. Such a trailing shield would preferably be usable in a magnetic head design in which the read head and write head are not aligned. 
     SUMMARY OF THE INVENTION 
     The present invention provides a magnetic write head having a trailing magnetic shield for use in perpendicular magnetic data recording. The write head includes a return pole and a write pole. A magnetic pedestal is connected with a front ABS end of the return pole and extends toward the write pole. First and second magnetic studs extend from laterally opposed ends of the return pole. A trailing shield extends from one of the studs to the other and is separated from the write pole by a non-magnetic, electrically conductive seed layer that also acts as trailing shield gap layer. 
     The writer and trailing shield design can advantageously be used in a magnetic head in which the magnetoresistive read sensor is laterally misaligned with the write pole of the write head. In a possible embodiment of the invention, the return pole and the pedestal can be laterally aligned with the read sensor, while the studs, write pole and the trailing shield can be laterally aligned with one another, but not laterally aligned with the read sensor, return pole and pedestal. 
     The first and second studs can be notched at their laterally inward ends to provide exceptional control of spacing between the write pole and the stud structure. The notches result in laterally outwardly disposed upward extending un-notched portions. Third and fourth studs, which may be integral with the trailing shield itself and may be deposited in the same deposition step, may connect with the upper surfaces of these upward extending portions of the first and second studs. 
     The present invention, therefore, provides a trailing shield design, which also provides magnetic shielding completely surrounding the write while also maintaining a desired separation from surrounding shield. The stud and pedestal portions of the structure provide excellent magnetic shielding to protect an adjacent magnetic medium from field such as from the shaping layer or the write coil. 
     These and other features and advantages of the invention will be apparent upon reading of the following detailed description of preferred embodiments taken in conjunction with the Figures in which like reference numerals indicate like elements throughout. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a fuller understanding of the nature and advantages of this invention, as well as the preferred mode of use, reference should be made to the following detailed description read in conjunction with the accompanying drawings which are not to scale. 
         FIG. 1  is a schematic illustration of a disk drive system in which the invention might be embodied; 
         FIG. 2  is an ABS view of a slider, taken from line  2 - 2  of  FIG. 1 , illustrating the location of a magnetic head thereon; 
         FIG. 3  is a cross sectional view, taken from line  3 - 3  of  FIG. 2  and rotated 90 degrees counterclockwise, of a magnetic head according to an embodiment of the present invention; 
         FIG. 4  is an ABS view taken from line  4 - 4  of  FIG. 3  and enlarged; 
         FIGS. 5-18  are ABS views similar to that of  FIG. 4 , showing a magnetic head in various intermediate stages of manufacture and illustrating a method of manufacturing a magnetic head according to an embodiment of the invention; and 
         FIG. 19  is an ABS view of an alternate embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The following description is of the best embodiments presently contemplated for carrying out this invention. This description is made for the purpose of illustrating the general principles of this invention and is not meant to limit the inventive concepts claimed herein. 
     Referring now to  FIG. 1 , there is shown a disk drive  100  embodying this invention. As shown in  FIG. 1 , at least one rotatable magnetic disk  112  is supported on a spindle  114  and rotated by a disk drive motor  118 . The magnetic recording on each disk is in the form of annular patterns of concentric data tracks (not shown) on the magnetic disk  112 . 
     At least one slider  113  is positioned near the magnetic disk  112 , each slider  113  supporting one or more magnetic head assemblies  221 . As the magnetic disk rotates, slider  113  moves radially in and out over the disk surface  122  so that the magnetic head assembly  121  may access different tracks of the magnetic disk where desired data are written. Each slider  113  is attached to an actuator arm  119  by way of a suspension  115 . The suspension  115  provides a slight spring force which biases slider  113  against the disk surface  122 . Each actuator arm  119  is attached to an actuator means  127 . The actuator means  127  as shown in  FIG. 1  may be a voice coil motor (VCM). The VCM comprises a coil movable within a fixed magnetic field, the direction and speed of the coil movements being controlled by the motor current signals supplied by controller  129 . 
     During operation of the disk storage system, the rotation of the magnetic disk  112  generates an air bearing between the slider  113  and the disk surface  122  which exerts an upward force or lift on the slider. The air bearing thus counter-balances the slight spring force of suspension  115  and supports slider  113  off and slightly above the disk surface by a small, substantially constant spacing during normal operation. 
     The various components of the disk storage system are controlled in operation by control signals generated by control unit  129 , such as access control signals and internal clock signals. Typically, the control unit  129  comprises logic control circuits, storage means and a microprocessor. The control unit  129  generates control signals to control various system operations such as drive motor control signals on line  123  and head position and seek control signals on line  128 . The control signals on line  128  provide the desired current profiles to optimally move and position slider  113  to the desired data track on disk  112 . Write and read signals are communicated to and from write and read heads  121  by way of recording channel  125 . 
     With reference to  FIG. 2 , the orientation of the magnetic head  121  in a slider  113  can be seen in more detail.  FIG. 2  is an ABS view of the slider  113 , and as can be seen the magnetic head including an inductive write head and a read sensor, is located at a trailing edge of the slider. The above description of a typical magnetic disk storage system, and the accompanying illustration of  FIG. 1  are for representation purposes only. It should be apparent that disk storage systems may contain a large number of disks and actuators, and each actuator may support a number of sliders. 
     With reference now to  FIG. 3 , the magnetic head  221  for use in a perpendicular magnetic recording system is described. The head  221  includes a write element  302  and a read sensor  304 . The read sensor is preferably a giant magnetoresistive (GMR) sensor and is preferably a current perpendicular to plane (CPP) GMR sensor. CPP GMR sensors are particularly well suited for use in perpendicular recording systems. However, the sensor  304  could be another type of sensor such as a current in plane (CIP) GMR sensor or, a tunnel junction sensor (TMR) or some other type of sensor. The sensor  304  is located between and insulated from first and second magnetic shields  306 ,  308  and embedded in a dielectric material  307 . The magnetic shields, which can be constructed of for example CoFe or NiFe, absorb magnetic fields, such as those from uptrack or down track data signals, ensuring that the read sensor  304  only detects the desired data track located between the shields  306 ,  308 . A non-magnetic, electrically insulating gap layer  309  may be provided between the shield  308  and the write head  302 . 
     With continued reference to  FIG. 3 , the write element  302  includes a write pole  310 , that is magnetically connected with a magnetic shaping layer  312 , and is embedded within an insulation material  311  ( FIG. 4 ) near the ABS. The write pole has a small cross section at the air bearing surface and is constructed of a material having a high saturation moment, such as FeNi or CoFe. The shaping layer  312  is constructed of a magnetic material such as CoFe or NiFe and has a cross section parallel to the ABS surface that is significantly larger than that of the write pole  310 . 
     The write element  302  also has a return pole  314  that preferably has a surface exposed at the ABS surface and has a cross section parallel with the ABS surface that is much larger than that of the write pole  310 . The return pole  314  is magnetically connected with the shaping layer  312  by a back gap portion  316 . The return pole  314  and back gap  316  can be constructed of, for example, NiFe, CoFe or some other magnetic material. 
     An electrically conductive write coil  317 , shown in cross section in  FIG. 3 , passes through the write element  302  between the shaping layer  312 , and the return pole  314 . The write coil  317  is surrounded by an electrically insulating material  320  that electrically insulates the turns of the coil  317  from one another and electrically isolates the coil  317  from the surrounding magnetic structures  310 ,  312 ,  316 ,  314 . When a current passes through the coil  317 , the resulting magnetic field causes a magnetic flux to flow through the return pole  314 , back gap  316 , shaping layer  312  and write pole  310 . This magnetic flux causes a write field to be emitted toward an adjacent magnetic medium. 
     The write head element  302  also includes a trailing shield  322 . The trailing shield  322  is connected to the return pole  314  by a pedestal connector structure  316  that can be understood more clearly with reference to  FIG. 4 . The connector structure, referred to generally as  316  in  FIG. 4 , includes a pedestal  318  formed at a first elevation, first and second stud portions  321 ,  322  formed at a second elevation above the first elevation, and third and fourth stud portions  324 ,  326  formed at a third elevation above the second elevation. 
     The pedestal portion is formed generally at the elevation of the coil  317 , but may extend slightly below the bottom of the coil  317  and slight above the top of the coil  317  to account for insulation layers  320  at the top and bottom of the coil  317 . The first and second stud portions  321 ,  322  cannot be seen in  FIG. 3 , because they are located into the plane of the page. The first and second stud portions  321 ,  322  are preferably at the same level as the shaping layer  312 , preferably having bottom surfaces that are coplanar with the bottom surfaces of the shaping layer  312  and having top surfaces that are coplanar with the top surface of the shaping layer  312 . The top surfaces of the first and second stud portions  321 ,  322  are also coplanar with the bottom surface of the write pole  310 . The top surfaces of the third and fourth stud portions  324 ,  326  are magnetically connected with the trailing edge shield and may be integral therewith. 
     A non-magnetic, electrically conductive seed layer  328 , which also serves as a trailing edge gap, is disposed between the trailing edge shield  322  and the write pole  310 . The gap layer  328  can be for example Rh or some other suitable material, and because it is deposited on a smooth planar surface and can be left intact in the finished head (as will be described in further detail herein below) it can vary precisely define the gap distance between the write pole  310  and the trailing shield  322 . 
     The return pole  314 , back gap  316 , shaping layer  312 , as well as all of the pedestal  318 , stud portions  321 ,  322 ,  324 ,  326 , and the trailing shield can all be constructed of a magnetic material that is capable of being electroplated, such as for example NiFe. 
     With reference to  FIG. 4 , the shields  306 ,  308  and the return pole  314  may all be constructed having outer portions  330  that are recessed from the ABS. Such recessed outer wing portions have been found to prevent stray field writing, which can occur when magnetic charges accumulate at the corners of a magnetic structure. 
     With reference still to  FIG. 4 , the first and second studs  321 ,  322  have notches  332 ,  334  which ensure a desired amount of spacing is maintained between the studs  321 ,  322  and the write pole  310 . Also, it can be seen that, while the return pole  314  is aligned with the read sensor  304 , the write pole  310  as well as the trailing shield  322  and all of the trailing shield connecting pedestal structure  316  (which includes the pedestal  318  and studs  321 ,  322 ,  324  and  326 ) are aligned with one another, but not with the read sensor  304 . This advantageously allows a desired critical spacing to be maintained between the write pole  310  and the trailing shield  322  and connecting structure  316 . 
     It can be seen that the write pole  310  is completely surrounded by magnetic shielding material  322 ,  316 . This advantageously shields the adjacent magnetic medium in the area around the write pole  310 , preventing the magnetic medium in that area from being affected by magnetic fields such as from the coil  317 , shaping layer  312 , or the environment. The reason that the spacing between the connecting structure  316  and the write pole  310  is important is that if the spacing is too large, the shielding effect of this structure will be less than optimal. However, if the spacing is too small, flux will leak from the write pole  310  to the trailing shield connecting structure  316 . It should also be pointed out that the write pole  310 , which can be a high Bsat material such as CoFe or NiFe 50 , is set within a dielectric material, such as Alumina Al 2 O 3 , which is provided beneath and beside the write pole  310 . 
     With reference now to  FIGS. 5-16  a method for constructing a magnetic  221  according to an embodiment of the invention is described. With particular reference to  FIG. 5 , the read sensor  304 , shields  306 ,  308  insulation layer  309  and return pole  314  are constructed using photolithographic methods and deposition methods that will be familiar to those skilled in the art. Thereafter, with reference to  FIG. 6 , the coil  317  is constructed. The construction of the coil may can be performed by methods familiar to those skilled in the art, such as forming a photoresist frame and plating a coil of, for example Cu. The coil  317  may also be constructed by a damascene method. Then with reference to  FIG. 7 , the pedestal  318  can be constructed. The pedestal  318  can be for example NiFe and can be constructed by forming a photoresist frame, sputter depositing an electrically conductive seed layer and then electroplating the pedestal  318 . It should be noted at this point that the pedestal  318  can be laterally aligned with the return pole  314  and the read sensor  304 . The term “laterally” as used herein refers to a direction that is parallel with the ABS and perpendicular to the data track direction (ie. from one side to the other as the various layers are deposited). After the pedestal  318  has been constructed a layer of dielectric material such as Al 2 O 3  can be deposited to form the insulation layer  320 . A chemical mechanical polishing process (CMP) can be performed to form a smooth planar surface across the top of the pedestal  318 , and the insulation layer  320 . 
     With reference now to  FIG. 8 , the first and second stud portions  321 ,  322  are formed using a combination of photolithography and electroplating. A seed layer may need to be deposited too. Note that the stud portions  321 ,  322  may be laterally out of alignment with the pedestal  318 , return pole  314  and read sensor  304 . With reference now to  FIG. 9 , a dielectric material  902  such as Al 2 O 3  is deposited and a chemical mechanical polishing process (CMP) performed to create a smooth, coplanar surface across the stud portions  321 ,  322  and the dielectric layer  902 . Then, with reference to  FIG. 10 , a layer of write pole material  1002  is deposited. This material may be a single layer of high Bsat material such as CoFe or NiFe 50 , or could also be constructed as multiple laminated layers of magnetic material separated by very thin layers of non-magnetic material. A photoresist mask  1004  is then formed over the write pole material  1002 . The photoresist mask  1004  is formed to cover only a portion of the stud portions  321 ,  322  and also to cover the space between the stud portions  321 ,  322 , leaving portions of the stud portions  321 ,  322  to extend laterally beyond the edges of the photoresist mask  1004 . Thereafter, with reference to  FIG. 11 , a material removal process  1102 , such as ion beam etching (IBE). is performed to remove portions of the write pole material  1002  that are not covered by the photoresist mask  1004 . This material removal process  1102  is performed sufficiently to expose the portions of the studs  321 ,  322  that are not covered by the photoresist mask  1004 . In addition the material removal process  1102  is performed sufficiently to open up alignment marks (not shown). 
     With reference now to  FIG. 12 , the first photoresist mask  1004  is removed. A hard mask  1202  is then formed. The hard mask  1202  can include for example diamond like carbon (DLC) Duramide SiO 2  or Tis. The hard mask  1202  is formed to cover the area where the write pole  310  is desired to be and to also cover the areas not covered by the remaining write pole material  1002 , including the previously exposed portions of the studs  321 ,  322 . An ion mill  1204  is then performed to remove portions of the write pole material  1002  that are not protected by the hard mask  1202 . The ion mill  1204  is preferably performed at angle, to form a write pole  302  with a desired trapezoidal shape as viewed from the ABS. The ion mill  1204  can also be performed sufficiently to remove a desired amount of material from the studs  321 ,  322  in the areas not covered by the hard mask  1202 . 
     With reference to  FIG. 13 , a dielectric material  1302  such as alumina Al 2 O 3  can be deposited and a CMP performed to expose the top of the write pole  310 . It can be seen that the ion mill  1204  performed with reference to  FIG. 12  removed a portion of the studs  321 ,  322  to form notches  1304 ,  1306  and raised outer portions  1308 ,  1310 . 
     With reference to  FIG. 14 , the remaining hard mask  1202  ( FIG. 12 ) is removed, such as by a reactive ion etch RIE, and a non-magnetic, electrically conductive seed layer  328  is deposited. The seed layer  328  can be constructed of, for example, Rh and has a thickness that will define the trailing shield gap height. The seed layer  328  is advantageously deposited over a smooth planar surface in the area over and around the write pole  310 , which allows for improved thickness (ie. gap) control. 
     With reference now to  FIG. 15 , another photoresist mask  1502  is constructed. The photoresist mask  1502  has openings formed over the raised outer portions  1308 ,  1310  of the first and second stud portions  321 ,  322 . Another ion milling process  1504  is then performed to expose the tops of the raised outer portions  1308 ,  1310  of the studs  321 ,  322  and to also expose alignment marks (not shown). 
     With reference to  FIG. 16 , the previously formed mask  1502  is removed. Then, with reference to  FIG. 17  another photoresist mask  1702  is formed. The mask  1702  is constructed with an opening exposing the areas over the raised outer portions  1308 ,  1310  of the studs  321 ,  322  and also to expose the area therebetween where the trailing shield will be formed. With reference to  FIG. 18 , a magnetic material, such as NiFe can then be deposited, such as by electroplating, to form the third and fourth studs  324 ,  326  and the trailing shield  322 . Further head construction may continue according to methods familiar to those skilled in the art and may include the deposition of an insulation layer (not shown). 
     With reference now To  FIG. 19 , in an alternate embodiment of the invention, a draped trailing shield  1902  may be provided, to offer additional shielding protection. The draped trailing shield has an undraped portion  1904  that extends downward to a level above the top surface of the write pole  310 . This undraped portion is centrally disposed on the trailing shield, being located in the area of the write pole  310  and being separated from the write pole  310  by a write gap layer/seed layer. The draped trailing shield  1902  also has laterally opposed, downward extending, draped portions, which may extend down to level between the top and bottom layers of the write pole  310  or may extend below the level of the bottom of the write pole  310 . This downward draped configuration of the draped trailing shield  1902  provides additional side shielding, when such shielding is necessary. 
     While various embodiments have been described, it should be understood that they have been presented by way of example only, and not limitation. Other embodiments falling within the scope of the invention may also become apparent to those skilled in the art. Thus, the breadth and scope of the invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.