Abstract:
A method provides a magnetic transducer having an air-bearing surface (ABS) location. An intermediate layer having a substantially flat bottom surface is provided. A trench is formed in the intermediate layer. The trench is wider in yoke region than in the pole tip region. The trench has a first depth in the yoke region and a second depth less than the first depth in the pole tip region. A portion of the intermediate layer is at the bottom of the trench at the ABS location. A nonmagnetic layer is provided. The nonmagnetic layer fills part of the trench in the pole tip region such that the trench has a third depth less than the second depth at the ABS location. A main pole is provided. The main pole has a leading bevel adjacent to nonmagnetic layer in the portion of the pole tip region of the trench.

Description:
BACKGROUND 
       FIG. 1  depicts a conventional method  10  for fabricating a conventional magnetic recording head.  FIGS. 2A-2E  depict side (apex) views of a conventional transducer  50  during formation using the method  10 . An underlayer having a sloped surface at the air-bearing surface (ABS) location is provided, via step  12 . The ABS location is the area that will form the ABS once the slider has been lapped and fabrication is completed. Typically, this includes multiple deposition and etch or milling steps in order to provide the sloped surface. An etch stop layer is deposited on the underlayer, via step  14 .  FIG. 2A  depicts the conventional transducer  50  after step  14  has been provided. Thus, underlayer  52  has been provided. The underlayer  52  includes a leading shield  52 A. As can be seen in  FIG. 2A , the upper surface of the leading shield  52 A is sloped at and near the ABS location. An etch stop layer  54  has also been provided. 
     The aluminum oxide intermediate layer is conformally deposited, via step  16 .  FIG. 2B  depicts the conventional transducer  50  after step  16  has been performed. Thus, the intermediate layer  56  has been provided. The top and bottom of the intermediate layer follow the slope in the etch stop layer  54  and underlayer  52 . However, a flat top surface is desired to improve photolithography. Thus, the intermediate layer  56  is planarized, via step  18 .  FIG. 2C  depicts the transducer  50  after step  18  has been performed. The top surface of the intermediate layer  56 ′ is now flat, while the bottom surface remains sloped. 
     A trench has also been formed in the intermediate layer, for example using an aluminum oxide reactive ion etch (RIE), via step  20 . Step  20  typically includes providing a mask having an aperture over the portions of the intermediate layer that are desired to be removed. The RIE is performed in the presence of the mask. The RIE proceeds until the etch stop layer  54  is reached. Thus,  FIG. 2D  depicts an apex view of the transducer after step  20  is performed. At this location, therefore, the intermediate layer  56  has been removed and the etch stop layer  54  exposed. However, in other regions, some or all of the intermediate layer  56 ′ remains. 
     A nonmagnetic seed layer for electroplating is provided, via step  22 . For example Ru or another conductive material may be deposited via chemical vapor deposition (CVD), sputtering, or some other method. The main pole is then provided, via step  24 . Step  24  typically includes plating high saturation magnetization pole materials, planarizing these material(s) using a chemical mechanical planarization (CMP) and forming a trailing (top) bevel, if any. For example, CoFe may be plated in step  12 . Because of the profiles of the underlayer  52 , etch stop layer  54 , the intermediate layer  56  and trench, a leading edge bevel may be formed in the electroplated materials.  FIG. 2E  depicts the transducer  50  after step  24  is performed. Thus, the pole  60  has been fabricated. In this embodiment, a trailing edge bevel may, or may not, be formed. The pole  60  is shown without a trailing edge bevel. However, the pole has a leading bevel  62  due to the slopes of the leading shield  52 A, etch stop layer  54 , intermediate layer  56 ′ (not shown in  FIG. 2E ) and trench on which the pole  60  is formed. 
     Although the conventional magnetic recording head  50  formed using the method  10  functions, there are drawbacks. For example, formation of the leading bevel  62  may require multiple process steps. Fabrication times for the conventional transducer  50  may thus be longer. Yield for the method  10  may also be lower than desired. In addition, variations in the fabrication process may result in poorer performance of the conventional transducer  50 . For example, the sidewalls of the pole  60  may have a different shape (angle) or location than designed. Accordingly, what is needed is a system and method for improving the performance of a magnetic recording head and manufacturing yield. 
    
    
     
       BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS 
         FIG. 1  is a flow chart depicting a conventional method for fabricating a pole in a magnetic recording transducer. 
         FIGS. 2A-2E  depicts apex views of a conventional magnetic recording head during fabrication. 
         FIG. 3  depicts an exemplary embodiment of a method for providing a magnetic recording transducer. 
         FIGS. 4A-4G  depict an exemplary embodiment of a magnetic recording disk drive during fabrication. 
         FIG. 5  depicts another exemplary embodiment of a method for providing a magnetic recording transducer. 
         FIGS. 6A-6B through 13A-13B  depict side (apex) an ABS views of an exemplary embodiment of a magnetic recording transducer during fabrication. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 3  depicts an exemplary embodiment of a method  100  for providing a magnetic recording transducer. For simplicity, some steps may be omitted, interleaved, combined, have multiple substeps and/or performed in another order unless otherwise specified.  FIGS. 4A-4E  depict an exemplary embodiment of a transducer  200  during fabrication using the method  100 . Referring to  FIGS. 3-4E , the method  100  is described in the context of providing a magnetic recording disk drive and transducer  200 . The method  100  may be used to fabricate multiple magnetic recording heads at substantially the same time. The method  100  may also be used to fabricate other magnetic recording transducers. The method  100  is also described in the context of particular layers. A particular layer may include multiple materials and/or multiple sub-layers. The method  100  also may start after formation of other portions of the magnetic recording transducer. For example, the method  100  may start after a read transducer, return pole/shield and/or other structure have been fabricated. For example, the method  100  may start after the underlying structures, including an underlayer, have been provided. The underlayer may include a leading shield. An etch stop layer may also have been provided. Both the underlayer and etch stop layer may be substantially flat. In other words, the top surfaces of the underlayer and etch stop layer may be substantially perpendicular to the ABS location. 
     An intermediate layer is provided on the underlayer, via step  102 . In some embodiments, the intermediate layer is also on the etch stop layer discussed above. The bottom (leading) surface of the intermediate layer is substantially flat because the underlayer is substantially flat. This geometry may be obtained simply by depositing the intermediate layer on the underlying topology. No additional processing of the intermediate layer may be required.  FIG. 4A  depicts an apex view of the transducer  200  after step  102  is performed. Thus, the underlayer  202  and intermediate layer  204  are shown. The intermediate layer  204  may be aluminum oxide or another wet etchable and/or reactive ion etchable (RIEable) layer. Also shown is the ABS location. As can be seen in  FIG. 4A , the bottom and top of the intermediate layer  204  are perpendicular to the ABS location. The intermediate layer  204  has bottom and top surfaces that are substantially parallel to the stripe height direction. Thus, the bottom and top surfaces of the intermediate layer are substantially flat. 
     A trench is formed in the intermediate layer, via step  104 . In some embodiments, step  102  includes performing one or more reactive ion etches (RIEs). The trench has a shape and location that corresponds to a main pole.  FIG. 4B  depicts an apex view and a plan view of the transducer  200  after step  104  is performed. A trench  206  has thus been formed. Because the apex location is shown, most of the intermediate layer has been removed. Only a small portion  204 ′ of the intermediate layer remains. Because the shape of the trench  206  corresponds to that of the main pole, the top of the trench  206  may be wider than the bottom in the cross-track direction (perpendicular to the plane of the page in  FIG. 4B ). In addition, the trench  207  has a pole tip portion  207  at and near the ABS location and a yoke region  205  recessed from the ABS location. The pole tip portion  207  of the trench is narrower in the cross-track direction than the yoke region  205 . Consequently, the depth of the trench varies. In particular, the depth of the trench  206  increases where the trench is wider (in the yoke region), while the sidewalls angles of the trench do not vary significantly. The depth of the trench  206  is in the down track direction. At the ABS location, a portion of the intermediate layer  204 ′ remains. Further into the pole tip region  207 , recessed from the ABS location, the intermediate layer  204 ′ thins. In the yoke region  205  of the trench  206 , the intermediate layer  204 ′ has been completely removed. Thus, the bottom of the trench  206  is formed by part of the intermediate layer  204 ′ in at least the ABS location. In the yoke region  205 , however, the bottom of the trench  206  is formed by another layer, such as the underlayer  202  or an etch stop layer (not shown). In other words, the etch performed in step  104  terminates within the intermediate layer  204  at the ABS location and at least part of the pole tip region  207 . In contrast, the etch performed in step  104  terminates on a layer under the intermediate layer  204  in the yoke region  205 . Further, in some embodiments, the depth of the trench increases monotonically in the pole tip region  207 . In the embodiment shown, the depth increases smoothly and linearly. However, in another embodiment, the trench depth may increase in another manner. 
     A nonmagnetic seed layer is deposited, via step  106 . For example, step  106  may include depositing a Ru layer using CVD or another conformal deposition method.  FIG. 4C  depicts an apex view of the transducer  200  after step  106  is performed. Thus, a nonmagnetic seed layer  208  is shown. The nonmagnetic layer  208  resides at least in the trench  206 . The nonmagnetic layer fills a portion of the trench in the pole tip region  207  faster than in the yoke region  205 . This is not only because of the presence of the intermediate layer  204 ′ but also because the trench  206  is narrower in the pole tip region  207 . Thus, a remaining portion of the trench  206 ′ is shallower at the ABS location than in the yoke region  205 . Stated differently, if the thickness of the nonmagnetic layer  208  is t in the yoke region  205 , then the remaining portion of the trench  206 ′ is shallower by greater than t at the ABS location. The remaining, open portion of the trench  206 ′ monotonically increases in depth. In the embodiment shown, the depth of the remaining portion of the trench  206 ′ increases smoothly and linearly. However, in another embodiment, the trench depth may increase in another manner. 
     A main pole is provided in the trench, via step  108 . In some embodiments, step  108  may include electroplating one or more layers. Other deposition methods may be used in addition to or in lieu of plating. The main pole material(s) have a high saturation magnetization and thus may include material(s) such as CoFe. Step  108  may also include forming a trailing bevel.  FIG. 4D  depicts an apex view of the transducer  200  after fabrication of the main pole  210 . Thus, the main pole  210  includes a pole tip portion  212  and a yoke portion  211 . The main pole  210  also has a leading bevel  213 . 
     Fabrication of the transducer may then be completed, via step  110 . For example, coils, shields, contacts, insulating structures and other components may be provided. In addition, the slider may be lapped and otherwise completed.  FIGS. 4E, 4F and 4G  depict an apex view of the transducer  200 , an ABS view of the transducer  200  and a side view of a disk drive including the transducer  200 . Thus, a media  201 , shield  230  and coils  240  are shown. As can be seen in  FIG. 4E , a trailing bevel  214  has been fabricated in the pole tip region  212  (not labeled in  FIG. 4E ). Note that although a PMR transducer  200  is shown, in other embodiments, the method  100  may be used in fabricating a pole for a heat assisted magnetic recording (HAMR) or other write transducer. 
     Using the method  100 , a magnetic transducer having improved performance may be fabricated. The method  100  forms the leading bevel  213  without complicated processing steps. Instead, the shape of the trench  206 , intermediate layer  204 ′ and nonmagnetic layer  208  naturally result in formation of the leading bevel  213 . Reduction in complexity of formation in the leading bevel  213  may improve fabrication time and yield. Further, it is posited that because formation of the trench  206  terminates within the intermediate layer  204 ′ in step  104 , the variation in the width of the trench may be reduced over the conventional method, which terminates at the underlying etch stop layer. Thus, performance and/or yield may be improved. In addition, the geometry of the pole tip  212  is not adversely affected by use of the method  100 . It is noted that any leading shield that is part of the underlayer  202  may be further spaced apart from the pole tip  212  by the nonmagnetic layer  208 . However, it is believed that this does not significantly or adversely affect performance. Thus, performance and yield may be improved while fabrication is simplified using the method  100 . 
       FIG. 5  depicts an exemplary embodiment of a method  150  for providing a magnetic recording transducer having a leading edge bevel. For simplicity, some steps may be omitted, interleaved, performed in another order and/or combined.  FIGS. 6A-6B  though  FIGS. 13A-13B  depict an exemplary embodiment of a transducer  250  during fabrication using the method  150 . Referring to  FIGS. 5-13B , the method  150  may be used to fabricate multiple magnetic recording heads at substantially the same time. The method  150  may also be used to fabricate other magnetic recording transducers. The method  150  is also described in the context of particular layers. A particular layer may include multiple materials and/or multiple sub-layers. The method  150  also may start after formation of other portions of the magnetic recording transducer. For example, the method  150  may start after a read transducer, return pole/shield and/or other structure have been fabricated. 
     An underlayer that is substantially flat is provided, via step  152 . Step  152  may include forming a leading shield in the underlayer. However, in contrast to the underlayer for the conventional transducer  50  the top surface of the leading shield may be substantially perpendicular to the ABS location. 
     An etch stop layer is provided on the underlayer, via step  154 . The etch stop layer may include multiple sublayers. Alternatively, multiple etch stop layer may be considered to be provided. The top surface of the etch stop layer(s) is substantially flat.  FIGS. 6A and 6B  depict apex and ABS views, respectively, of the transducer  250  after step  154  has been performed. Thus, an underlayer  252  is shown. The underlayer  252  includes a leading shield  252 A that may be formed of NiFe. A remaining portion of the underlayer  252 B is nonmagnetic. In the embodiment shown, the portion of the underlayer  252 B is aluminum oxide. The etch stop layer  254  is also shown. The etch stop layer  254  includes a NiFe layer  254 A and a Ru layer  254 B. In other embodiments, other layer(s) and/or material(s) may be used. The top surfaces of the underlayer  252  and etch stop layer  254  are substantially flat and, therefore, perpendicular to the ABS location. Thus, the top surfaces of the layers  252  and  254  are parallel to the stripe height and cross-track directions. 
     An intermediate layer is full film deposited on the etch stop  254 , via step  106 . In some embodiments, the intermediate layer is an aluminum oxide layer.  FIGS. 7A and 7B  depict apex and ABS views, respectively, of the transducer  250  after step  106  is performed. Thus, the intermediate layer  256  is shown. The bottom (leading) surface of the intermediate layer  256  is substantially flat because the underlayer  252  and etch stop layer  254  are substantially flat. Thus, as can be seen the top and bottom surfaces of the intermediate layer  256  are parallel to the stripe height and cross track directions. This geometry may be obtained simply by depositing the intermediate layer on the underlying topology. No additional processing of the intermediate layer may be required. Note that in other embodiments, the top surface of the intermediate layer  256  may not be flat. However, it is believed that in such embodiments subsequent processing, for example photolithography, may be adversely affected by such a top surface. 
     One or more RIEs are performed to remove a portion of the intermediate layer  256  and form a trench therein, via step  158 . Step  158  may include forming a mask having an aperture corresponding to the location and footprint of the trench. Further, the RIE(s) performed in step  158  terminate within the intermediate layer  256  at and near the ABS location. However, the etch(es) terminate at the etch stop layer  254  in the yoke region. Thus, the depth of the trench formed in the intermediate layer varies at least in part because the width of the trench varies.  FIGS. 8A and 8B  depict apex and ABS views of the transducer  250  after step  158  is performed. Thus, a trench  257  has been formed in the intermediate layer  256 ′. The bottom of the trench is  257  formed by the intermediate layer  256 ′ at and near the ABS location. Stated differently, a portion of the intermediate layer  256 ′ lies between the bottom of the trench  257  and the etch stop layer  254  and underlayer  252 . Because the etch is terminated in the intermediate layer  257  at and near the ABS location, the trench  257  may have a triangular shape at the ABS location. In the yoke, however, the trench is wider and deeper. The etch that forms the trench  257  may also terminate on or in the etch stop layer  254 . Further, because the bottom of the trench may be on the etch stop layer  254  in the yoke region, the trench  257  may be trapezoidal in cross section instead of triangular. Further, in some embodiments, the depth of the trench  257  increases monotonically in the pole tip region. In the embodiment shown, the depth increases smoothly and linearly. However, in another embodiment, the trench depth may increase in another manner. 
     A seed layer that may be resistant to an etch of the intermediate layer  256 ′ is deposited in the trench, via step  160 . In some embodiments, a Ru layer is deposited in step  160 . In other embodiments, a Ta or other layer may be deposited. In some embodiments, a multilayer seed layer may be provided in step  160 . The deposition performed in step  160  is conformal.  FIGS. 9A and 9B  depict apex and ABS views of the transducer  250  after step  160  is performed. Thus, a seed layer  258  has been deposited. A remaining portion of the trench  257 ′ remains open. The nonmagnetic layer  258  resides at least in the trench  257 . The nonmagnetic layer fills a portion of the trench in the pole tip region faster than in the yoke region. This is not only because of the presence of the intermediate layer  254 ′ but also because the trench  257  is narrower in the pole tip region than in the yoke region. Thus, a remaining portion of the trench  257 ′ is shallower at the ABS location than in the yoke region  205 . Stated differently, if the thickness of the nonmagnetic layer  258  is t in the yoke region, then the remaining portion of the trench  257 ′ is shallower by greater than t (and in some embodiments at least 2t) at the ABS location. The remaining, open portion of the trench  257 ′ monotonically increases in depth in the area around the ABS location. In the embodiment shown, the depth of the remaining portion of the trench  257 ′ increases smoothly and linearly. However, in another embodiment, the trench depth may increase in another manner. 
     The main pole is provided using steps  162 ,  164  and, optionally,  166 . The material(s) for the main pole are deposited, via step  162 . In some embodiments, step  162  includes plating the pole materials.  FIGS. 10A and 10B  depict apex and ABS views of the transducer  250  after step  162  is performed. Thus, the pole material(s)  260  have been provided. The pole material(s)  260  may include a single material (e.g. an alloy), a multilayer or other structure(s). Because of the shape of the trench  257 ′, nonmagnetic layer  258  and intermediate layer  256 ′, the pole material(s)  260  have a leading bevel  261  adjoining the nonmagnetic layer  258 . 
     The main pole material(s) may be planarized, via step  164 . Step  164  may utilize a chemical mechanical planarization. In addition, an ion mill may be performed to remove the mask and/or other material(s) outside of the trench.  FIGS. 11A and 11B  depict apex and ABS views of the transducer  250  after step  164  has been performed. The top of the pole material(s)  260 ′ are thus substantially flat. In addition, the pole material(s)  260 , seed layer  258  and mask outside of the trench (not labeled in  FIGS. 11A-13B ) have been removed. Thus, the remaining portion of the pole material(s) are in the trench. 
     A trailing bevel may optionally be formed, via step  166 . Step  166  may include providing a nonmagnetic structure on the pole material(s)  260  that is recessed from the ABS location, then milling the pole material(s).  FIGS. 12A and 12B  depict apex and ABS view of the transducer  250  after step  166  has been performed. In the transducer  250 , therefore, the pole  260 ′ does include a trailing bevel  264 . Also shown is nonmagnetic structure  262  that may be used in forming the trailing bevel  266 . In some embodiments, step  166  may be interleaved with step(s)  168 ,  170  and/or  172 . 
     The coil(s) that are used to energize the main pole  260 ′ are provided, via step  168 . Step  168  may include forming a helical or spiral coil. Thus, a portion of the coil(s) may be formed before the pole. Single or multiple layers of turns may also be formed. A write gap is formed, via step  170 . The write gap lies on top of the main pole  260 ′. The shield(s) may be provided, via step  172 . Step  172  may include providing side shields, a trailing shield, and/or a wraparound shield (which includes side and trailing shields).  FIGS. 13A and 13B  depict apex and ABS views of the transducer  250  after step  172  is performed. Thus, a write gap  266  and shield(s)  268  are shown. In the embodiment shown, the shield  268  is a wraparound shield. In some embodiments, other and/or different structures may be fabricated. Fabrication of the transducer may be completed. For example, the transducer  250  may be lapped to the ABS location and contacts and/or other structures may be provided. 
     Using the method  150 , a main pole  260  having improved performance may be fabricated more simply and with higher yield. For example, the leading bevel  261  may be more simply and readily formed. This may improve fabrication time and yield. Further, the variation in the width main pole  260 ′ at the ABS location may be reduced. Thus, performance and/or yield may be improved. In addition, the geometry of the pole tip for the pole  260 ′ is not adversely affected by use of the method  100 . It is noted that the leading shield  252 A may be further spaced apart from the pole tip by the nonmagnetic layer  258 . However, it is believed that this does not significantly or adversely affect performance. Thus, performance and yield may be improved while fabrication is simplified using the method  150 .