Method for fabricating a magnetic writer having a gradient side gap

This application claims priority to provisional U.S. Patent Application Ser. No. 61/893,101, filed on Oct. 18, 2013, which is hereby incorporated by reference in its entirety.

FIGS. 1A, 1B and 1C depict ABS, yoke and plan views of a conventional magnetic recording head 10 . The magnetic recording transducer 10 may be a perpendicular magnetic recording (PMR) head. The conventional magnetic recording transducer 10 may be a part of a merged head including the write transducer 10 and a read transducer (not shown). Alternatively, the magnetic recording head may be a write head including only the write transducer 10 . The conventional transducer 10 includes an underlayer 12 , side gap 14 , side shields 16 , top gap 17 , optional top shield 18 and main pole 20 .

The main pole 20 resides on an underlayer 12 and includes sidewalls 22 and 24 . The sidewalls 22 and 24 of the conventional main pole 20 form an angle α 0 with the down track direction at the ABS and an angle α 1 with the down track direction at the distance x 1 from the ABS. As can be seen in FIGS. 1A and 1B , portions of the main pole 20 recessed from the ABS in the stripe height direction are wider in the cross track direction than at the ABS. In addition, the angle between the sidewalls 22 and 24 and the down track direction increases. Thus, α 1 is greater than α 0 . For example, if α 0 is on the order of 13°, then al may be 25°.

The side shields 16 are separated from the main pole 20 by a side gap 14 . The side shields 16 extend a distance back from the ABS. The gap 14 between the side shields 16 and the main pole 20 may have a substantially constant thickness. Thus, the side shields 16 are conformal with the main pole 20 .

Although the conventional magnetic recording head 10 functions, there are drawbacks. In particular, the conventional magnetic recording head 10 may not perform sufficiently at higher recording densities. For example, the write field of the conventional main pole 20 may not have a sufficiently high magnitude write field without introducing adjacent track interference (ATI) issues. Accordingly, what is needed is a system and method for improving the performance of a magnetic recording head.

FIGS. 1A-1C depict ABS, yoke and plan views of a conventional magnetic recording head.

FIG. 2 depicts an exemplary embodiment of a magnetic recording disk drive.

FIGS. 3A, 3B and 3C depict ABS, yoke and plan views of an exemplary embodiment of a magnetic recording transducer.

FIG. 4 depicts a flow chart of an exemplary embodiment of a method for providing a magnetic recording transducer.

FIG. 5 depicts a flow chart of another exemplary embodiment of a method for providing a main pole of a magnetic recording transducer.

FIG. 6 depicts a flow chart of another exemplary embodiment of a method for providing a magnetic recording transducer.

FIGS. 7A and 7B through 16A, 16B and 16C depict various views of an exemplary embodiment of a magnetic recording transducer fabricated using the method.

FIGS. 17A and 17B through 29A, 29B and 29C depict various views of an exemplary embodiment of a magnetic recording transducer fabricated using the method.

FIG. 2 depicts a side view of an exemplary embodiment of a portion of a disk drive 100 including a write transducer 120 . FIGS. 3A, 3B and 3C depict ABS, yoke and plan views of the transducer 120 . For clarity, FIGS. 2, 3A, 3B and 3C are not to scale. For simplicity not all portions of the disk drive 100 and transducer 120 are shown. In addition, although the disk drive 100 and transducer 120 are depicted in the context of particular components other and/or different components may be used. For example, circuitry used to drive and control various portions of the disk drive 100 is not shown. For simplicity, only single components 102 , 110 , 120 , 130 , 140 and 150 are shown. However, multiples of each components 102 , 110 , 120 , 130 , 140 , 150 and/or their sub-components, might be used. The disk drive 100 may be a perpendicular magnetic recording (PMR) disk drive. However, in other embodiments, the disk drive 100 may be configured for other types of magnetic recording included but not limited to heat assisted magnetic recording (HAMR).

The disk drive 100 includes media 102 , a slider 110 and a write transducer 120 . Additional and/or different components may be included in the disk drive 100 . Although not shown, the slider 110 and thus the transducer 120 are generally attached to a suspension (not shown). The transducer 120 is fabricated on the slider 110 and includes an air-bearing surface (ABS) proximate to the media 102 during use. In general, the disk drive 100 includes a write transducer 120 and a read transducer (not shown). However, for clarity, only the write transducer 120 is shown. The transducer 120 includes a main pole 130 , coils 135 , side shields 140 , top gap 141 and side gap 150 . In other embodiments, different and/or additional components may be used in the write transducer 120 .

The coil(s) 135 are used to energize the main pole 130 . Two turns 135 are depicted in FIG. 2 . Another number of turns may, however, be used. Note that only a portion of the coil(s) 135 is shown in FIG. 2 . If, for example, the coil(s) 135 form a helical coil, then additional portion(s) of the coil(s) 135 may be located on the opposite side of the main pole 130 as is shown. If the coil(s) 135 is a spiral, or pancake, coil, then additional portions of the coil(s) 135 may be located further from the ABS. Further, additional coils may also be used.

The main pole 130 includes a pole tip region 132 close to the ABS and a yoke region 134 recessed from the ABS. The pole tip region 132 is shown as having top and bottom bevels 131 and 133 , respectively, near the ABS. This portion is shown in FIG. 3A . In addition, the pole tip region 134 includes sidewalls 136 and 138 in the cross track direction. The sidewalls are configured such that the pole 130 has a bottom and a top wider than the bottom.

The sidewalls 136 and 138 form sidewall angles with the down track direction. At the ABS, the sidewall 136 forms sidewall angle α 0 with respect to the down track direction. In some embodiments, the sidewalls 136 and 138 are symmetric. Thus, although not labeled, the sidewall 138 would form substantially the same sidewall angle with the down track direction as the sidewall 136 . In some embodiments, α 0 is not more than fourteen degrees. In some such embodiments, α 0 is at least twelve degrees. For example, α 0 may be nominally 13.5°. At a distance recessed from the ABS, the sidewall 136 forms sidewall angle α 1 with the down track direction. In some embodiments, the sidewall angle α 1 is less than α 0 at x 1 . For example, if α 0 is 12-14 degrees, then α 1 is greater than or equal to zero degrees and not more than 12-14 degrees. In some embodiments, α 1 is zero degrees. However, in other embodiments, the sidewall angles may vary in another manner. In some such embodiments, the sidewall angle may increase with increasing distance from the ABS. Further, the manner in which the sidewall angle changes from α 0 to α 1 may differ in different embodiments. For example, the sidewall angle may remain α 0 from the ABS to some distance from the ABS. The sidewall angle may then change to α 1 in a manner analogous to a step function. In other embodiments, the sidewall angle may change from α 0 to α 1 in another manner including but not limited to a linear or piece-wise linear fashion. Further, in the embodiment shown, the sidewall angle remains α 1 . In other embodiments, additional changes may be present,

Also shown are side gaps 150 that separate the main pole 130 from the side shields 140 . As can best be seen in FIG. 3C , the side gaps 150 have a conformal region 152 and a nonconformal region 154 . Thus, the width of the side gap 150 in the cross track direction changes in the nonconformal region 154 . Stated differently, because the distance between the pole 130 and the side shields 140 changes in the nonconformal region 154 , the side gap 150 has a gradient in width. This gradient side gap 150 may also be made of multiple materials. Thus, a dashed line indicates the layer forming the conformal region 152 and part of the nonconformal region 154 . The remainder of the nonconformal region 154 may be formed by other materials. For example, the conformal region 152 may be formed by Ru and/or Ta seed layers. However, the remainder of the nonconformal region 154 (between the dashed line and the main pole 130 ) may be formed from a material such as aluminum oxide. In other embodiments, the conformal region 152 and nonconformal region 154 of the side gap 150 may be formed of the same material. In some embodiments, the conformal region 152 extends not more than four hundred nanometers from the ABS. In some embodiments, the conformal region 152 extends not more than two hundred nanometers and at least ten nanometers from the ABS. In other embodiments, the conformal region 152 extends at least eighty and not more than one hundred and twenty nanometers from the ABS.

The magnetic disk drive 100 may exhibit improved performance. The gradient in width of the side gap 150 in the conformal region 154 allows less of the flux from the main pole 130 to be absorbed by the side shields 140 . Thus, the magnetic write flux and reverse overwrite (ReOW) may be improved. The small, constant side gap width in the conformal region 152 may reduce the adjacent track interference (ATI). Performance may be improved. In embodiments in which the sidewall angle of the main pole 130 decreases away from the ABS, the magnetic field generated by the main pole 130 and used to write to the media 102 may be enhanced. The ReOW gain may be further improved. The gradient in the magnetic field may also be improved while maintaining substantially the same side fields. As a result, ATI may not be adversely affected. Further, the pole tip region 132 of the main pole 130 may have an increased magnetic volume. Stated differently, the pole tip region 132 may include more magnetic material. As a result, the cross track magnetic anisotropy may be improved and domain lockup issues mitigated. Thus, performance of the disk drive 100 may be improved.

FIG. 4 depicts an exemplary embodiment of a method 200 for providing a magnetic recording transducer having a gradient in the side gap width. For simplicity, some steps may be omitted, interleaved, and/or combined. The method 200 is described in the context of providing a magnetic recording disk drive 100 and transducer 120 depicted in FIGS. 2, 3A, 3B and 3C . However, the method 200 may be used to fabricate multiple magnetic recording heads at substantially the same time. The method 200 may also be used to fabricate other magnetic recording transducers. The method 200 is also described in the context of particular layers. A particular layer may include multiple materials and/or multiple sub-layers. The method 200 also may start after formation of other portions of the magnetic recording head. For example, the method 200 may start after a read transducer, return pole/shield and/or other structure have been fabricated.

Referring to FIGS. 2, 3A-3C and 4 , the main pole 130 is provided using multiple masks, via step 202 . These masks have apertures which overlap in a region in which the main pole 130 is formed. For example, step 202 may include using one or more damascene processes. In such embodiments, a trench may be formed in a layer using a first mask having a first aperture therein. The first aperture exposes the layer and corresponds to the location of the trench. In embodiments in which the sidewalls 136 and 138 are desired to have sidewall angles that change a particular distance from the ABS, the trench may be fabricated such that portions of the trench sidewalls form different angles with the down track direction. A second mask may then be provided. The second mask has another aperture therein. The aperture in the second mask overlaps a portion of the trench. The material(s) for the pole 130 are deposited, for example via plating. One or more ferromagnetic materials may be used. Because of the use of multiple masks, the ferromagnetic materials may occupy only a portion of the trench. Excess pole material(s) external to the trench may also be removed. The pole tip 132 and yoke 134 may be formed. Other methods may also be used to form the pole 130 including but not limited to full film deposition of magnetic materials and removal for example via milling and/or lapping. In such embodiments, multiple masks may also be used.

The side gap 150 is provided, via step 204 . Step 204 includes depositing one or more materials such that the side gap 150 has both a conformal region 152 and a nonconformal region 154 . The conformal region is thus between the ABS and the nonconformal region. In some embodiments, a portion of the side gap may be formed before the ferromagnetic materials for the pole are deposited. For example, one or more nonmagnetic seed layers may be deposited before the ferromagnetic materials. In some embodiments, these layers form the conformal region 152 . Additional side gap material(s) may be deposited after formation of the pole 130 . For example, a nonmagnetic material such as aluminum oxide may be provided. This material may fill in a region between the pole and the nonmagnetic seed layer(s).

The side shield 140 are provided, via step 206 . Step 206 may be performed by depositing the side shield materials on the side gap 150 .

Using the method 200 , the magnetic disk drive 100 and magnetic transducer 120 may be provided. Thus, the benefits of the magnetic transducers 120 may be achieved. For example, enhanced magnetic write flux and improved ReOW and reduced ATI may be attained. Thus, performance of the disk drive 100 may be improved.

FIG. 5 depicts an exemplary embodiment of a method 210 for providing a pole for a magnetic recording transducer having a gradient in the side gap width. For simplicity, some steps may be omitted, interleaved, and/or combined. The method 210 is described in the context of providing the pole 130 of the magnetic recording disk drive 100 and transducer 120 depicted in FIGS. 2, 3A, 3B and 3C . However, the method 210 may be used to fabricate multiple poles at substantially the same time. The method 210 may also be used to fabricate other poles for other magnetic recording transducers. The method 210 is also described in the context of particular layers. A particular layer may include multiple materials and/or multiple sub-layers. The method 210 also may start after formation of other portions of the magnetic recording head. For example, the method 200 may start after a read transducer, return pole/shield and/or other structure have been fabricated.

Referring to FIGS. 2, 3A-3C and 5 , a first mask with a first aperture is provided on an intermediate layer, via step 212 . The first mask may be a hard mask. The aperture corresponds to the location and shape of a trench desired to be formed in the intermediate layer. In some embodiments, the intermediate layer is aluminum oxide.

A portion of the intermediate layer is removed to define the trench, via step 214 . In some embodiments, the trench is formed using a reactive ion etch (RIE). For example, an aluminum oxide RIE may be used for an aluminum oxide intermediate layer. Further, the conditions under which the RIE is performed may be selected such that the trench has a nonzero sidewall angle with the down track direction. For example, the trench may have an angle α 0 with the down track direction.

A seed layer that is resistant to an etch of the intermediate layer is deposited in the trench, via step 216 . In some embodiments, a Ru layer is deposited in step 216 . In other embodiments, a Ta or other layer may be deposited. In some embodiments, a multilayer seed layer may be provided in step 216 .

A second mask having a second aperture is provided, via step 218 . The second aperture overlaps a portion of the trench. Stated differently, a portion of the second aperture is in the same location as a portion of the first aperture. However, the apertures are not identical. Consequently, the second aperture may cover a portion of the trench. Similarly, the second aperture may leave uncovered a portion of the underlying layer(s) that the first aperture covered. In some embodiments, the sidewall angle of the second mask is different from the sidewall angle of the trench formed using the first mask. In some embodiments, the second mask is a photoresist mask and may have vertical sidewalls. In other embodiments, other angles are possible for the second mask. In some embodiments, the sidewall angles may be the same as for the trench. In some embodiments, the second mask substantially covers the top layer of the transducer 120 except for the second aperture. However, in other embodiments, a frame mask may be used.

The material(s) for the main pole 130 are provided, via step 220 . Step 220 may include plating high saturation magnetization materials. Because of the formation of the trench and the presence of the second mask, the pole materials fill the overlap region of the trench/first aperture and the second aperture. Excess pole materials may also be removed in step 220 . For example, a planarization such as a chemical mechanical planarization (CMP) and/or a wet etch may be used to remove pole materials outside of the trench. Consequently, the main pole 130 that may be used in conjunction with the gradient side gap 150 may be provided.

Using the method 200 , the magnetic disk drive 100 and magnetic transducer 120 may be provided. Thus, the benefits of the magnetic transducers 120 may be achieved. For example, enhanced magnetic write flux and improved ReOW and reduced ATI may be attained. Thus, performance of the disk drive 100 may be improved.

FIG. 6 depicts an exemplary embodiment of a method 250 for providing a magnetic recording transducer 120 having a gradient side gap and, in some embodiments, a main pole that may has a varying sidewall angle. For simplicity, some steps may be omitted, interleaved, and/or combined. The method 200 is also described in the context of providing a magnetic recording head 100 and transducer 120 depicted in FIGS. 2, 3A, 3B and 3C . FIGS. 7A-B though FIGS. 16A-C depict an exemplary embodiment of a transducer 300 during fabrication using the method 250 . FIGS. 7A-B - FIGS. 16A-C correspond to one embodiment of the method 250 . FIGS. 17A-B through FIGS. 29A-C depict a transducer 400 that corresponds to another embodiment of the method 250 . Referring to FIGS. 6-16C , the method 250 may be used to fabricate multiple magnetic recording heads at substantially the same time. The method 250 may also be used to fabricate other magnetic recording transducers. The method 250 is also described in the context of particular layers. A particular layer may include multiple materials and/or multiple sub-layers. The method 250 also may start after formation of other portions of the magnetic recording transducer. For example, the method 250 may start after a read transducer, return pole/shield and/or other structure have been fabricated.

A line mask is provided on an intermediate layer, via step 252 . The line may be a photoresist line. A first mask with a first aperture is provided on the intermediate layer using the line mask, via step 254 . Step 254 includes depositing a hard mask layer on the intermediate layer and line mask and then removing the line mask. FIGS. 7A and 7B depict plan and ABS views of the transducer 300 during step 254 . Thus, an underlayer 302 and intermediate layer 304 are shown. The intermediate layer 304 may be aluminum oxide. Also depicted are the line mask 306 as well as the hard mask layer 308 for the first mask being formed. FIGS. 8A-8B depict plan and ABS views of the transducer 300 after step 254 is performed. Thus, the mask 308 having aperture 310 has been formed through removal of the mask 306 . The aperture 310 corresponds to the location and shape of a trench desired to be formed in the intermediate layer.

The trench is then formed in the intermediate layer 304 , via step 256 . Step 256 may be using an aluminum oxide RIE. For example, an aluminum oxide RIE may be sued for an aluminum oxide intermediate layer. FIGS. 9A-9B depict plan and ABS views of the transducer 300 after step 256 is performed. Thus, trench 312 has been formed in the intermediate layer 304 ′. Further, the conditions under which the aluminum oxide RIE is may be selected such that the trench 312 has a nonzero sidewall angle with the down track direction.

A seed layer that is resistant to an etch of the aluminum oxide intermediate layer is deposited in the trench, via step 258 . FIGS. 10A-10B depict the transducer 300 after step 258 is performed. Thus, a seed layer 314 has been deposited. The dashed in FIG. 10A indicates the presence of the trench 312 under the seed layer 314 . A remaining portion of the trench 312 ′ remains open. In some embodiments, a Ru layer is deposited in step 258 . In other embodiments, a Ta or other layer may be deposited. In some embodiments, a multilayer seed layer may be provided in step 258 .

A second mask having a second aperture is provided, via step 260 . In some embodiments, step 260 includes providing a photoresist layer and developing the second aperture using photolithographic techniques. The second aperture overlaps a portion of the trench. Stated differently, a portion of the second aperture is in the same location as a portion of the first aperture. However, the apertures are not identical. FIGS. 11A-11C depict plan, ABS and recessed views of the transducer 300 . Thus, a mask 316 having aperture 318 therein is shown. The aperture 318 and trench 312 ′ overlap near the ABS. This can be seen in FIG. 11B , which depicts the trench 312 ′ as wider than the aperture 318 at the ABS. In contrast, at a location recessed from the ABS, the overlap region is smaller than the trench 312 ′. This may be seen, for example, in FIG. 11C , which depicts the trench 312 ′ as wider than the aperture 318 . In the embodiment shown, the sidewall angle of the second mask 316 is different from the sidewall angle of the trench 312 ′. It is noted that the region in which the overlap is smaller than the trench 312 ′ adjoins the nonconformal portion of the side gap. Part of this region is depicted in FIG. 11C . The region in which the aperture 318 is larger than the trench 312 ′ and, therefore, the overlap includes the sidewalls of the trench 312 ′, corresponds to the conformal region of the side gap. The second mask 316 has vertical sidewalls for the aperture 318 .

Materials for the pole are deposited, via step 262 . Step 262 may include plating high saturation magnetization materials. Because of the formation of the trench 312 ′ and the aperture 318 of the second mask 316 , the pole materials fill the overlap region of the trench/first aperture and the second aperture. In addition, the second mask 316 may be removed. FIGS. 12A-12C depict plan, ABS and recessed views of the transducer 300 after step 262 is performed. Consequently, the main pole materials 320 are shown. As can be seen in FIGS. 12A-12C , particularly FIGS. 12B and 12C , the pole materials 320 fill the trench 312 ′ in the conformal region near the ABS but do not fill the trench 312 ′ in the nonconformal region recessed from the ABS.

A refill step is performed, via step 264 . A nonmagnetic material is provided to refill a portion of the trench 312 ′ in which there are no pole materials 320 . Excess pole materials may also be removed in step 266 . For example, a CMP and/or a wet etch may be used to remove pole materials outside of the trench. FIGS. 13A-13C depict plan, ABS and recessed views of the transducer 300 after step 266 is performed. In the embodiment shown in FIGS. 13A-13C , no wet etch is performed. Thus, the magnetic materials outside of the trench are removed through the CMP and the pole 320 ′ is formed. In addition, the refill 322 is shown. In some embodiments, the refill 322 is aluminum oxide. In other embodiments, other materials may be used. Thus, the seed layer 314 may be used to form the side gap in the conformal region at the ABS, while the seed layer 314 and the refill 322 may form the nonconformal portion of the side gap recessed from the ABS.

An ion mill may be performed to remove the excess seed layer 314 and mask layer outside of the trench 312 ′, via step 268 . A portion of the intermediate layer outside of the trench 312 ′ is removed, via step 270 . Step 270 may be performed using a wet etch for the intermediate layer. For example, an aluminum oxide may be performed. FIGS. 14A-14C depict plan, ABS and recessed views of the transducer 300 during step 270 . A mask 324 has been provided to protect the pole 320 ′ during the removal of the intermediate layer. FIGS. 15A-15C depict plan, ABS and recessed views of the transducer 300 after step 270 is performed. Thus, the intermediate layer has been removed. The seed layer 314 , which may be Ru in the embodiment shown, also acts as a stop layer for the wet etch. Thus, the pole 320 and refill 322 remain after the wet etch is performed.

The side shields are provided, via step 272 . Step 272 may include depositing a high permeability material, such as NiFe, while the mask 324 is in place. This may include plating such a material. The mask 324 may then be removed. FIGS. 16A-16C depict plan, ABS and side views of the transducer 300 after step 272 is performed. Note that for clarity, the seed layer 314 is not labeled in FIG. 16A . Thus, side shields 330 are shown. As can be seen in FIG. 16A , the side shields do not extend to sides of the trench in the embodiment shown. However, in other embodiments, the side shields 330 may extend a different distance in the stripe height direction. Further, the side gap 332 is shown. Near the ABS, the side gap 332 is made up of the seed layer 314 . However, further from the ABS, the side gap 332 includes both the seed layer 314 and the refill 322 . In some embodiments, the conformal region of the side gap 332 extends not more than four hundred nanometers from the ABS. In some embodiments, the conformal region the side gap 332 extends not more than two hundred nanometers and at least ten nanometers from the ABS. In other embodiments, the conformal region the side gap 332 extends at least eighty and not more than one hundred and twenty nanometers from the ABS.

Using the method 250 , the magnetic transducer 300 may be provided. Thus, benefits analogous to those of the magnetic transducers 120 may be achieved. For example, enhanced magnetic write flux and improved ReOW and reduced ATI may be attained for the transducer 300 . Thus, performance of the transducer 300 may be improved.

FIGS. 17A-B through FIGS. 29A-C depict a transducer 400 that corresponds to another embodiment of the method 250 . Referring to FIGS. 6 and 17A -B through 29 A-C, the method 250 may be used to fabricate multiple magnetic recording heads at substantially the same time.

A line mask is provided on an intermediate layer and a first mask having an aperture therein in steps 252 and 254 , respectively. FIGS. 17A and 17B depict plan and ABS views of the transducer 400 during step 254 . Thus, an underlayer 402 and intermediate layer 404 are shown. The intermediate layer 304 may be aluminum oxide. Also depicted are the line mask 406 as well as the hard mask layer 408 for the first mask being formed. FIGS. 18A-18B depict plan and ABS views of the transducer 400 after step 254 is performed. Thus, the mask 408 having aperture 410 has been formed through removal of the mask 406 . The aperture 410 corresponds to the location and shape of a trench desired to be formed in the intermediate layer.

The trench is then formed in the intermediate layer 404 in step 256 as discussed above. FIGS. 19A-19B depict plan and ABS views of the transducer 400 after step 256 is performed. Thus, trench 412 has been formed in the intermediate layer 404 ′. Further, the conditions under which the aluminum oxide RIE is may be selected such that the trench 412 has a nonzero sidewall angle with the down track direction.

A seed layer is deposited in the trench in step 258 . FIGS. 20A-20B depict the transducer 400 after a first layer seed layer is deposited in step 258 . Thus, a Ta seed layer 414 has been deposited. A remaining portion of the trench 412 ′ remains open.

A second mask having a second aperture is provided in step 260 in a manner discussed above. However, in this embodiment, a frame mask is used. FIGS. 21A-21C depict plan, ABS and recessed views of the transducer 400 . Thus, a frame mask 416 having aperture 418 therein is shown. The aperture 418 and trench 412 ′ overlap near the ABS. This can be seen in FIG. 21B , which depicts the trench 412 ′ as wider than the aperture 418 at the ABS. In contrast, at a location recessed from the ABS, the overlap region is smaller than the trench 412 ′. This may be seen, for example, in FIG. 21C , which depicts the trench 412 ′ as wider than the aperture 418 . In the embodiment shown, the sidewall angle of the second, frame mask 416 is different from the sidewall angle of the trench 412 ′. The region in which the overlap is smaller than the trench 412 ′ adjoins the nonconformal portion of the side gap. Part of this region is depicted in FIG. 21C . The region in which the aperture 418 is larger than the trench 412 ′ and, therefore, the overlap includes the sidewalls of the trench 412 ′, corresponds to the conformal region of the side gap. The second mask 416 has vertical sidewalls for the aperture 418 .

In addition, step 258 is completed by depositing a second seed layer. FIGS. 22A-22C depict plan, ABS and recessed views of the transducer 400 . The seed layer 419 has been deposited. Thus, the Ta layer 414 of the seed layer is below the frame mask 416 while the Ru layer 419 may reside on the frame mask 416 .

Materials for the pole are deposited in step 262 as discussed above. FIGS. 23A-23C depict plan, ABS and recessed views of the transducer 400 after step 262 is performed. Consequently, the main pole materials 420 are shown. As can be seen in FIGS. 23A-23C , particularly FIGS. 23B and 23C , the pole materials 420 fill the trench 312 ′ in the conformal region near the ABS but do not fill the trench 312 ′ in the nonconformal region recessed from the ABS. The frame mask 416 may then be removed, for example through a CMP and/or lift off. FIGS. 24A-24C depict plan, ABS and recessed views of the transducer 400 after the mask 416 has been removed. Further, a wet etch of pole materials outside of the aperture 418 has been performed. Thus, a portion of step 266 has been performed. Thus, only the pole material in the aperture 418 remains.

A refill step is performed in step 264 as discussed above. FIGS. 25A-25C depict plan, ABS and recessed views of the transducer 400 . A refill material 422 , such as aluminum oxide has been provided.

Remaining excess pole materials may be removed in step 266 . A CMP may be used to remove pole materials outside of the trench, completing step 266 . FIGS. 26A-26C depict plan, ABS and recessed views of the transducer 400 after step 266 is completed. Thus, the remaining magnetic materials outside of the trench are removed through the CMP and the pole 420 ′ is formed.

An ion mill may be performed to remove the excess seed layers 414 and 419 and mask layer outside of the trench 412 ′ in step 268 in a manner described above. FIGS. 26A-26C depict plan, ABS and recessed views of the transducer 400 after step 268 is performed. Thus, the seed layers 414 ′ and 419 ′ may be used to form the side gap in the conformal region at the ABS, while the seed layers 414 ′ and 419 ′ in combination with the refill 422 ′ may form the nonconformal portion of the side gap recessed from the ABS.

A portion of the intermediate layer outside of the trench 412 ′ is removed in step 270 as described above. FIGS. 27A-27C depict plan, ABS and recessed views of the transducer 400 during step 270 . A mask 424 has been provided to protect the pole 320 ′ during the removal of the intermediate layer. FIGS. 28A-28C depict plan, ABS and recessed views of the transducer 400 after step 270 is performed. Thus, the intermediate layer has been removed. The seed layer 414 also acts as a stop layer for the wet etch. Thus, the seed layers 414 ′ and 419 ′, the pole 420 ′ and refill 422 ′ remain after the wet etch is performed.

The side shields are provided in a manner described above via step 272 . FIGS. 29A-29C depict plan, ABS and side views of the transducer 400 after step 272 is performed. Note that for clarity, the seed layers 414 and 419 are not labeled in FIG. 29A . Thus, side shields 430 are shown. As can be seen in FIG. 29A , the side shields do not extend to sides of the trench in the embodiment shown. However, in other embodiments, the side shields 430 may extend a different distance in the stripe height direction. Further, the side gap 432 is shown. Near the ABS, the side gap 432 is made up of the seed layers 414 and 419 . However, further from the ABS, the side gap 432 includes the seed layers 414 and 419 as well as the refill 422 . In some embodiments, the conformal region of the side gap 432 extends not more than four hundred nanometers from the ABS. In some embodiments, the conformal region the side gap 432 extends not more than two hundred nanometers and at least ten nanometers from the ABS. In other embodiments, the conformal region the side gap 432 extends at least eighty and not more than one hundred and twenty nanometers from the ABS.

Using the method 250 , the magnetic transducer 400 may be provided. Thus, benefits analogous to those of the magnetic transducers 120 may be achieved. For example, enhanced magnetic write flux and improved ReOW and reduced ATI may be attained for the transducer 400 . Thus, performance of the transducer 400 may be improved.