Method for fabricating a magnetic writer using multiple etches

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to provisional U.S. Patent Application Ser. No. 61/914,884, filed on Dec. 11, 2013, which is hereby incorporated by reference in its entirety.

BACKGROUND

FIGS. 1A and 1B depict air-bearing surface (ABS) and yoke 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 α0 with the down track direction at the ABS and an angle α1 with the down track direction at the distance x1 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, α1 is greater than α0. For example, if α0 is on the order of 13°, then α1 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.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

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

FIG. 2 depicts a flow chart of an exemplary embodiment of a method for providing a magnetic recording transducer.

FIGS. 3A and 3B depict ABS and yoke views of an exemplary embodiment of a magnetic recording transducer during fabrication.

FIGS. 4A and 4B depict ABS and yoke views of an exemplary embodiment of a magnetic recording transducer during fabrication.

FIGS. 5A, 5B and 5C depict ABS, yoke and side views of an exemplary embodiment of a magnetic recording disk drive during fabrication.

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

FIG. 7 depicts a flow chart of an exemplary embodiment of a method for providing a magnetic recording transducer.

FIGS. 8A-8C through 10A, 10B, 10C and 10D depict various views of an exemplary embodiment of a magnetic recording transducer fabricated using the method.

FIGS. 11 through 16A, 16B, 16C and 16D depict various views of an exemplary embodiment of a magnetic recording transducer fabricated using the method.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 2 depicts an exemplary embodiment of a method 100 for providing a magnetic recording transducer. For simplicity, some steps may be omitted, interleaved, and/or combined. FIGS. 3A and 3B through 5A, 5B and 5C depict various views of a transducer 200 during fabrication using the method 100. For clarity, FIGS. 3A-5C are not to scale. For simplicity not all portions of the disk drive and transducer 200 are shown. In addition, although the disk drive and transducer 200 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 is not shown. For simplicity, only single components are shown. However, multiples of each component 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).

Referring to FIGS. 2-5C, the method 100 is described in the context of providing a magnetic recording disk drive and transducer 200. However, the method 100 may be used to fabricate multiple magnetic recording transducers 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 head. For example, the method 100 may start after a read transducer, return pole/shield and/or other structure have been fabricated.

A trench is formed in an intermediate layer using multiple etches, via step 102. The trench is formed such that the trench has different sidewall angles in different portions of the pole. For example, the sidewall angles at and near the ABS may be larger (further from perpendicular to the surface of the intermediate layer) than the sidewall angles in regions recessed from the ABS (termed the yoke herein). Step 102 includes using multiple etches in order to form various sidewall angles. A first etch may provide a first portion of the trench having a first sidewall angle, while a second etch may provide a second portion of the trench having a second sidewall angle. For example, a first etch may be performed on the portion of the intermediate layer corresponding to the yoke, while the second etch may be performed on the portion of the intermediate layer corresponding to the pole tip, including ABS location. In some embodiments, the pole tip is masked during the first etch and the yoke region covered by a mask during the second etch. In other embodiments, the yoke region may be uncovered during the second etch. In some such embodiments, the second etch of the pole tip region may also etch the yoke region. In other such embodiments, the second etch of the pole tip region is configured to leave the yoke region substantially unchanged. For example, the intermediate layer in the yoke region may be made of a different material than the intermediate layer in the pole tip region. This different material may not be removed by the etch chemistry used to form the trench in the pole tip region. In other embodiments, the pole tip region of the trench may be formed by the first etch, while the yoke region of the trench is formed by second etch.

FIGS. 3A-3B and 4A-4B depict one embodiment of the transducer during step 102. FIGS. 3A and 3B depict ABS (pole tip) and recessed views of the transducer after the first etch is performed. An underlayer 202 and intermediate layer 204 are shown. The underlayer 202 may include a bottom (or leading edge) shield. The intermediate layer 204 may include one or more layers. The layers may be vertical and/or may be into the plane of the page. For example, the intermediate layer 204 in the recessed view may be formed of different material(s) than in the ABS view. A mask 206 having an aperture corresponding to the trench has been formed on the intermediate layer. This mask 206 and its aperture are in both the ABS and recessed regions. In addition, a mask 210 covers the intermediate layer in the pole tip region, including at the ABS. Because the mask 210 is not present in the recessed region, a portion of the intermediate layer has been removed by the etch, forming trench 208. FIGS. 4A-4B depict the transducer 200 after a second etch has been performed. The mask 210 is removed prior to the second etch. Thus, a trench 208′ in the intermediate layer 204′ has been formed. Because the second etch is completed, more of the intermediate layer 204′ has been removed. In some embodiments, the intermediate layer 204′ has been removed by the second etch in both the pole tip and yoke regions. In other embodiments, additional portions of the intermediate layer 204′ have been removed only in the pole tip region. The trench 208′ extends into the ABS and has a location that corresponds to the aperture in the mask 206. As can be seen in FIGS. 4A-4B, the geometry of the trench changes. For example, the trench 208′ is wider in the recessed view than in the ABS view. In addition, the sidewall angles, α2 and α1, differ. In some embodiments, α2 is at least twelve degrees and not more than sixteen degrees. The sidewall angle is larger at the ABS than recessed from the ABS. Although α1 is shown as nonzero, in some embodiments, the sidewall angle for the trench 208′ is zero degrees (substantially vertical sidewalls) in some portion of the trench. For example, α1 may be at least zero degrees and not more than five degrees. In some such embodiments, α1 is not more than three degrees. Thus, the sidewall angles may decrease to zero as the distance from the ABS increases. In some embodiments, the sidewall angle goes to zero at least fifteen nanometers and not more than thirty nanometers from the ABS. However, in other embodiments, the sidewall angle may reach zero degrees at a different distance from the ABS. For example, the sidewall angle may go to zero degrees up to two hundred nanometers from the ABS.

The main pole is provided in the trench 208′, via step 104. In some embodiments, step 104 includes depositing a seed layer, such as Ru and/or magnetic seed layer(s). High saturation magnetization magnetic material(s) are also provided. For example, such magnetic materials may be plated and/or vacuum deposited. FIGS. 5A, 5B and 5C depicted ABS, recessed and side views of the transducer 200 after step 104 has been performed. The pole 210 is thus shown. For simplicity, any seed layers are not shown. Also shown in FIG. 5C are coil(s) 220, slider 230 and media 240. Although not shown, the slider 220 and thus the transducer 200 are generally attached to a suspension. In general, the disk drive includes the write transducer 200 and a read transducer (not shown). However, for clarity, only the write transducer 200 is shown. The coil(s) 220 are used to energize the main pole 210. Two turns are depicted in FIG. 5C. Another number of turns may, however, be used. Note that only a portion of the coil(s) 210 may be shown in FIG. 5C. If, for example, the coil(s) 220 is a spiral, or pancake, coil, then additional portions of the coil(s) 220 may be located further from the ABS. Further, additional coils may also be used.

The pole 210 has sidewall angles that decrease with increasing distance from the ABS. Thus, the sidewall angles of the pole 210 are less in the recessed view than in the ABS view. FIGS. 5A and 5B depict the pole 210 as being conformal with the trench 208′. In some embodiments, however, at least a portion of the pole 210 is not conformal with the sides of the trench. In some embodiments, the pole 210 may have leading and/or trailing surface bevels, as shown in FIG. 5C.

Using the method 100, a magnetic transducer 200 having improved performance may be fabricated. For example, the sidewall angles of the pole may vary because of the manner in which the trench is formed. This may be achieved while exposing the ABS to only a single etch in forming the trench. In addition, a nonconformal side gap might be provided. This may also improve performance of the transducer 200. These benefits may be achieved without significantly complicating processing. Thus, performance of the disk drive may be improved.

FIG. 6 depicts an exemplary embodiment of a method 110 for providing a magnetic recording transducer. For simplicity, some steps may be omitted, interleaved, and/or combined. The method 110 is described in the context of providing a magnetic recording disk drive and transducer 200 depicted in FIGS. 3A-5C. However, the method 110 may be used to fabricate multiple magnetic recording heads at substantially the same time. The method 110 may also be used to fabricate other magnetic recording transducers. The method 110 is also described in the context of particular layers. A particular layer may include multiple materials and/or multiple sub-layers. The method 110 also may start after formation of other portions of the magnetic recording head. For example, the method 110 may start after a read transducer, return pole/shield and/or other structure have been fabricated.

Referring to FIGS. 3A-6, the intermediate layer 204 is provided in steps 112-116. A first layer is deposited, via step 112. The first layer deposited may be a full film (or blanket) deposition of aluminum oxide, silicon oxide, or some other reactive ion etchable material. If the intermediate layer is to be a single material, then steps 114 and 116 may be skipped. If, however, multiple layers are to be provided in a direction perpendicular to the ABS, then steps 114 and 116 may be performed. A portion of the first layer may be removed, via step 114. In some embodiments, the portion of the first layer removed includes the region in which the pole tip and side shield(s) are to be formed. Step 114 may be performed by providing a mask on the first layer having an aperture in the region desired to be removed and etching the first layer while the mask is in place. A second layer may then be provided, via step 116. Step 116 may include full film depositing the second layer and performing a planarization such as a chemical mechanical planarization (CMP). Thus, the intermediate layer includes different materials in different regions. In some embodiments, steps 114 and 116 may be repeated for other areas. In other embodiments, steps 114 and 116 may be achieved by depositing the first layer in step 112 in the presence of a mask. Steps 114 and 116 may be performed by lifting off the mask and depositing the second layer.

A first etch of the intermediate layer 208 is performed, via step 118. Thus, a portion of the trench is formed. This portion of the trench has a particular sidewall angle. Step 118 may be performed in the presence of one or more masks. If one mask is present, then the mask may expose only the portion of the intermediate layer to be removed in step 118. Alternatively, the aperture may expose regions of the intermediate layer that are not to be removed in step 118 if multiple materials are present and the etch chemistry used in step 118 only removes the desired material(s). Multiple masks may also be used. One mask may have a first aperture under which the entire trench is to be formed. Another mask may expose a portion of the first aperture and cover another portion of the first aperture. Thus, only a portion of the trench may be formed.

A second etch of the intermediate layer 208 is performed, via step 120. A second portion of the intermediate layer is removed and a second portion of the trench formed in step 120. Step 120 may be performed in an analogous manner to step 118. Thus, a trench 208′ having varying sidewall angles may be provided.

The method 110 may be used to perform step 102 of the method 100 depicted in FIG. 2. Consequently, the method 110 may be used in fabricating a transducer 200 with the benefits described above. For example, the sidewall angles of the pole may vary because of the manner in which the trench is formed. This may be achieved while exposing the ABS to only a single etch in forming the trench. In addition, a nonconformal side gap might be provided. This may also improve performance of the transducer 200. These benefits may be achieved without significantly complicating processing. Thus, performance of the disk drive may be improved.

FIG. 7 depicts an exemplary embodiment of a method 150 for providing a pole for a magnetic recording transducer having a main pole having varying a gradient in the side gap width. For simplicity, some steps may be omitted, interleaved, and/or combined. The method 150 is also described in the context of providing a magnetic recording transducer 250 depicted in FIGS. 8A-8C through FIGS. 10A-10D depict an exemplary embodiment of a transducer 250 during fabrication using the method 150. 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.

The first material(s) for the intermediate layer are provided, via step 152. This step may include full film depositing aluminum oxide, silicon oxide or another layer on an underlayer. A first portion of the first material(s) may optionally be removed, via step 154. Thus, an aperture may be formed in the first material(s). A second set of material(s) is optionally provided in the aperture formed in the first material(s), via step 156. Thus, an intermediate layer having multiple constituents may be formed in steps 152-156. For example, materials that are etchable using different etch chemistries may be used in steps 152-156. The material(s) may have the same or different etch characteristics for a particular etch chemistry. Thus, an intermediate layer in which the etching may be tailored is provided in steps 152-156.

At least one mask that exposes a portion of the intermediate layer is provided, via step 158. A first etch is performed, via step 160. For example, a reactive ion etch (RIE) appropriate for the portion of the intermediate layer to be removed may be performed in step 160. FIGS. 8A, 8B and 8C depict ABS, recessed and plan views of one embodiment of a transducer 250 after step 160 has been performed. Thus, an underlayer 252 and intermediate layer 254 have been formed. In this embodiment, steps 154 and 156 have been omitted. The intermediate layer 254 may thus be a single layer of, for example, aluminum oxide or silicon oxide. The underlayer 252 may be a single layers or multiple layers. For example, in some embodiments, the portion of the underlayer 252 at and/or near the ABS is a leading shield. Also shown are masks 256 and 260. The mask 256 include an aperture 258 over both the pole tip region at/near the ABS and a recessed region. The second mask 260 covers the portion of the intermediate layer 254 around the ABS location. The ABS location is the surface that will form the ABS of the transducer 250. A trench 262 has been formed by step 160. Because of the presence of the mask 260, the trench 262 is only in the region recessed from the ABS. Thus, the trench 262 corresponds to the location and geometry desired form the pole in the yoke and paddle regions.

The mask 260 is removed, via step 162. Thus, an additional portion of the intermediate layer 254 is exposed in the aperture 258. An additional etch is performed, via step 164. If the intermediate layer 254 is a single layer, the same etch chemistry may be used for the RIE in step 164 as for step 160. In the embodiment shown in FIGS. 8A-10D, the etch chemistry may be suitable to remove aluminum oxide. The same etch chemistry may thus be used for steps 160 and 164 or different etch chemistries which both remove aluminum oxide may be used in steps 160 and 164. However in other embodiments, in which the intermediate layer includes different constituents, different etch chemistries may be used in steps 160 and 164. FIGS. 9A, 9B and 9C depict ABS, recessed and plan views of the transducer 250 after step 164 is performed. Thus, trench 262 has been formed in both the ABS/pole tip and recessed/yoke and paddle regions. The sidewall angle, α1, in the recessed view may be less than the sidewall angle, α2, at the ABS. in some embodiments, α1 is at least zero degrees and not more than five degrees. In some such embodiments, α1 is not more than three degrees. In contrast α2 is at least twelve degrees and not more than sixteen degrees.

A seed layer that is resistant to an etch of the intermediate layer 254 is deposited in the trench, via step 166. In some embodiments, this seed layer may serve as at least part of the gap. The seed layer may include material(s) such as Ru. In other embodiments, a magnetic seed layer may be used in lieu of or in addition to a nonmagnetic seed layer.

The main pole may then be provided, via step 168. Step 168 includes depositing high saturation magnetization magnetic material(s), for example via electroplating. In some embodiments, the pole provided in step 168 fills the trench 262. However, in other embodiments, the pole may occupy only a portion of the trench. For example, a mask such as a photoresist may be provided. The mask has an aperture that exposes only a portion of the trench 262. In some embodiments, all of the pole tip/ABS region is exposed, but only a portion of the yoke and paddle regions are exposed. The magnetic material(s) for the main pole may then be plated and the mask removed. A planarization, such as a chemical mechanical planarization (CMP) may also be performed. A leading bevel may be naturally formed in the magnetic pole in step 168 due to the shape of the trench 262 and the deposition techniques used. A trailing bevel may also be provided in step 168. For example, a portion of the main pole may be covered by a mask after the planarization. Another portion of the main pole at and near the ABS may be removed, for example via an ion mill. The portion of the trench 262 between the main pole and the seed layer(s) provided in step 166 may be optionally refilled with a nonmagnetic material, such as aluminum oxide, via step 170. In embodiments in which a side shield is provided, the refill and seed layers provided in step 166 may be used to form a side gap that is conformal in some regions and nonconformal in other regions. FIGS. 10A, 10B, 10C and 10D depict ABS, recessed, plan and yoke/paddle views, respectively, of the transducer. Thus, the main pole 270 is shown. In addition, a seed layer 265 and refill 266 have been provided. At and near the ABS, shown in FIGS. 10A, 10B and 10C, the pole 270 fills the trench. However, further from the ABS, the refill 266 occupies a region between the edges of the trench/seed layer 264 and the pole 270. Near the ABS, as shown in FIGS. 10A and 10B, the seed layer 264 may form the side gap. Thus, the side gap may be conformal in these region. Further from the ABS, for example as shown in FIG. 10D, the seed layer 264 and refill 266 form the side gap. In these regions, the side gap may be nonconformal with the pole/trench.

The portion of the intermediate layer outside of the trench 262 may optionally be removed, via step 172. The side shield(s) may be provided, via step 174. Step 174 may also include providing a wraparound shield. The magnetic material(s) may thus be plated or otherwise deposited.

Using the method 150, the pole 270 may be provided. The sidewall angles of the pole 270 may vary because of the manner in which the trench is formed and/or because the pole may be deposited with another mask in place. This may be achieved while exposing the ABS to only a single etch in forming the trench. In addition, a nonconformal side gap might be provided. This may also improve performance of the transducer 250. These benefits may be achieved without significantly complicating processing. Thus, performance of the disk drive may be improved.

FIGS. 11-16D depict another embodiment of a transducer 250′ fabricated using the method 150. In this embodiment, however, steps 154 and 156 are not skipped. FIG. 11 depicts a side view of the transducer 250′ after step 152 is performed. Thus, as shown in FIG. 11, a first intermediate layer 254′ is provided on an underlayer 252′. In the embodiment shown, the underlayer 252′ includes a first underlayer 252A that may be NiFe and a second underlayer 252B that may be Ru.

FIGS. 12A and 12B depict side and plan views of the transducer 250′ after step 156 has been performed. Thus, a portion of the first intermediate layer 254A has been removed and replaced with a second intermediate layer 254B. The region in which the second intermediate layer 254B is formed includes the side shield area, as shown in FIG. 12B. In the embodiment shown, the region in which the second intermediate layer 254B is shown has a footprint that substantially matches that of the side shield to be formed. However, the second intermediate layer 254B may have a footprint with a different shape. In some embodiments the first intermediate layer 254A is silicon oxide, while the second intermediate layer is aluminum oxide or NiFe. Note that in alternate embodiments, the second intermediate layer could be full film deposited first, a portion removed and the region occupied by this portion refilled with the first intermediate layer.

FIGS. 13A, 13B, 13C and 13D depict ABS, recessed, plan and side views of the transducer 250′ after step 160 has been performed. Thus, the mask 256′ having aperture 258′ has been formed. Mask 260′ that covers the region near the ABS is also shown. A trench 262 has also been provided in the first intermediate layer 254A.

FIGS. 14A, 14B, 14C and 14D depict ABS, recessed, plan and side views of the transducer 250′ after step 164 has been performed. Thus, the trench 262′ has been formed in both intermediate layers 254A and 254B. Also note that in FIG. 14D that the second intermediate layer 254B has a surface that slopes in the direction perpendicular to the ABS such that the trench 262′ has a varying height and width.

FIGS. 15A, 15B, 15C, 15D and 15E depict ABS, recessed, plan, side and yoke views of the transducer 250′ after step 170 has been performed. Consequently, seed layer 264′, pole 270′ and refill 266′ have been provided. As can be seen in FIGS. 15A, 15B and 15D, the pole 270′ has a leading bevel.

FIGS. 16A, 16B, 16C and 16D depict ABS, recessed, plan, side and yoke views of the transducer 250′ after step 174 has been performed. Thus, side shields 274 and trailing shield 276 have been formed. Also shown is gap layer 272. The side shields 274 and trailing shield 276 together form a wraparound shield. As can be seen in FIG. 16C, the shields occupy substantially the same footprint as did the second intermediate layer 254B. The seed layer 264′ forms the side gap in FIGS. 16A and 16B, but layers 264′ and 266′ form the gap for the further from the ABS location.

Using the method 150, the magnetic transducers 250 and/or 250′ may be provided. The sidewall angles of the pole 270′ may vary because of the manner in which the trench is formed and/or because the pole may be deposited with another mask in place. This may be achieved while exposing the ABS to only a single etch in forming the trench. In addition, a nonconformal side gap might be provided. This may also improve performance of the transducer 250′. These benefits may be achieved without significantly complicating processing. Thus, performance of the disk drive may be improved.