Method for fabricating a magnetic writer using multiple etches of damascene materials

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to provisional U.S. Patent Application Ser. No. 61/941,337, filed on Feb. 18, 2014, which is hereby incorporated by reference in its entirety.

BACKGROUND

FIG. 1 depicts an air-bearing surface (ABS) view of a conventional magnetic recording transducer 10. The magnetic recording transducer 10 may be a perpendicular magnetic recording (PMR) head. The conventional transducer 10 includes an underlayer 12, side gap 14, side shields 16, top gap 17, optional top, or trailing, 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. The side shields 16 are separated from the main pole 20 by a side gap 14. The side shields 16 extend at least from the top of the main pole 20 to the bottom of the main pole 20. The side shields 16 also 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

FIG. 1 depicts an ABS view 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, 3B, 3C and 3D depict side, ABS, yoke and apex views of an exemplary embodiment of a magnetic recording disk drive.

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

FIGS. 5A-5C through 21A-21D depict various views of an exemplary embodiment of a magnetic recording transducer during fabrication.

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, performed in another order and/or combined. The method 100 is described in the context of providing a single magnetic recording disk drive and transducer. However, the method 100 may be used to fabricate multiple magnetic recording transducers at substantially the same time. 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.

An intermediate layer including multiple sublayers is provided, via step 102. Step 102 includes providing a first sublayer and a second sublayer. The first sublayer is provided in at least the side shield region. The side shield region includes the area in which the side shield(s) are to be fabricated. The side shield region also includes a portion of the location at which the air-bearing surface (ABS location) is formed. The second sublayer may be provided in the region outside of the shield region. In some embodiments, step 102 includes full film depositing the material(s) for the first sublayer, then removing a portion of the materials to form the first sublayer. The material(s) for the second sublayer are then provided, for example via deposition and planarization to remove excess material. Thus, the intermediate layer that includes the first and second sublayers and that has a substantially flat top surface is formed.

A trench is formed in an intermediate layer using multiple etches, via step 104. A first etch performed in step 104 removes a portion of the second sublayer. A first portion of the trench may thus be provided. This first portion of the trench has a first sidewall angle. A second etch removes a portion of the first sublayer. A second portion of the trench having a second sidewall angle is thus formed. The second sidewall angle in the second portion of the trench is greater than the first sidewall angle. The second portion of the trench includes an additional portion of the ABS location. The trench is, therefore, formed such that the trench has different sidewall angles in different portions of the pole. The first etch may be performed on the second sublayer located in a region corresponding to the yoke, while the second etch may be performed on the first sublayer 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 first sublayer in the yoke region may be made of a different material than the second sublayer 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.

The main pole is provided in the trench, via step 106. 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. Step 104 also includes planarizing the magnetic materials and, in at least some embodiments, forming leading and/or trailing edge bevels. The main pole formed in step 104 has sidewalls that have the second sidewall angle in the second portion of the trench and sidewall angles that correspond to the first sidewall angle in the first portion of the trench. Thus, the main pole is conformal with the trench in the second portion of the trench but may be nonconformal in the first portion of the trench recessed from the ABS. In some embodiments, the main pole has sidewall angles of at least twelve and not more than sixteen degrees in the second portion of the trench, which includes the ABS location. The main pole has a sidewall angle of at least zero degrees and not more than five degrees in the first portion of the trench. In some embodiments, the pole may have leading and/or trailing surface bevels.

A side gap that may include conformal and nonconformal regions is optionally provided, via step 108. Part of step 108 may be performed in step 106. Some or all of step 108 may also be performed before step 106. For example, a nonmagnetic seed layer, such as Ru described above, may form all or part of the side gap provided in step 108. Such a seed layer may be the conformal portion of the side gap. An side additional gap layer may also be provided. In some such embodiments, this additional side gap layer is recessed from the ABS and may be used to form all or part of the nonconformal side gap.

Side shield(s) may also be optionally provided, via step 110. The side shields may be provided by removing a portion of the intermediate layer around the pole at and near the ABS location. A soft magnetic material, such as NiFe may then refill this region, forming the side shield(s). In some embodiments, step 110 include forming a wraparound shield of which the side shields are a part.

Using the method 100, a magnetic transducer 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. These benefits may be achieved without significantly complicating processing. Thus, performance of the disk drive may be improved.

FIGS. 3A, 3B, 3C and 3D depict various views of a transducer 200 fabricated using the method 100. For clarity, FIGS. 3A-3D are not to scale. FIG. 3A depicts a side view of a disk drive including the transducer 200. FIGS. 3B, 3C and 3D depict ABS, recessed (“yoke”) and side (apex) views of the transducer 200. The recessed/yoke view shown in FIG. 3C may be taken at location x1 in FIG. 3D. 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 components and/or their sub-components, might be used. The disk drive 200 may be a perpendicular magnetic recording (PMR) disk drive. However, in other embodiments, the disk drive 200 may be configured for other types of magnetic recording included but not limited to heat assisted magnetic recording (HAMR).

The disk drive includes a media 202 and a slider 204 including a transducer 200. The slider 204 and transducer 200 have an ABS formed at the ABS location described above. For example, the slider 204 may be lapped to the ABS during fabrication. An underlayer 202, intermediate layer 204, main pole 210, coil 220, gap 222 and shield 230 are shown. The underlayer 202 may include a bottom (or leading edge) shield. The intermediate layer 204 may have included multiple sublayers, at least some of which may have been removed during fabrication. The main pole 210 includes a leading surface 214, a trailing surface 216 and sidewalls 214 and 218. The leading surface 214 is a leading edge bevel. The trailing surface 216 is a trailing bevel 216. In FIG. 3A one turn and one layer of turns is depicted for the coil 220. Another number of turns and/or another number of layers may, however, be used. Note that only a portion of the coil(s) 220 may be considered to be shown in FIG. 3A. 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.

As can be seen in FIGS. 3B-3C, the geometry of the pole 210 changes with distance from the ABS. For example, the main pole 210 is wider in the recessed view than in the ABS view. The sidewalls 212 and 218 of the main pole also form sidewall angles α0 and α1, with the down track direction. The sidewall angles, α0 and α1, differ. Thus, the sidewall angles of the main pole 210 may also change with distance from the ABS. In some embodiments, α0 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 main pole 210 is zero degrees (substantially vertical sidewalls). For example, al may be at least zero degrees and not more than five degrees. In some such embodiments, al 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.

In addition, the portion of the side gap 222 shown is conformal. In some embodiments, the entire side gap 222 is conformal to the pole. However, in other embodiments, the side gap 222 may have nonconformal portions.

Using the method 100, a magnetic transducer 200 having improved performance may be fabricated. For example, the sidewall angles of the pole may vary. 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. 4 depicts an exemplary embodiment of a method 150 for providing a pole for a magnetic recording transducer having a main pole having varying sidewall angles and/or a side gap having conformal and nonconformal regions. 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. 5A-5C though FIGS. 21A-21D 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.

First material(s) for the intermediate layer are provided via full-film deposition, via step 152. This step may include full film depositing aluminum oxide or another layer on an underlayer. FIGS. 5A, 5B and 5C depict apex/side, ABS and plan views of the transducer 250 after step 152 is performed. Thus, the materials 262 for the first sublayer have been full film deposited on the underlayer 252. The underlayer 252 includes two portions 252A and 252B. First underlayer portion 252A may be a leading shield and include soft magnetic material(s) such as NiFe. The second underlayer portion 252B may be a nonmagnetic material such as Ru. The first sublayer 262 is to form part of an intermediate layer 260.

A first portion of the material(s) for the first sublayer outside of the shield region are removed, via step 154. The side shield region includes part of the ABS. Step 154 may include providing a mask that covers the side shield region and then removing the exposed portion of the material(s) for the first sublayer. FIGS. 6A, 6B and 6C depict side, ABS and plan views, respectively, of the transducer during step 154. Thus, a hard mask layer 270 and a photoresist mask 272 have been provided. The hard mask layer may be a Cr layer. FIGS. 7A, 7B and 7C depict side, ABS and plan views, respectively, of the transducer during step 154 after the exposed portion of the hard mask layer 270 have been removed, leaving hard mask 270′. The exposed portions of the hard mask layer 270 may have been removed using a reactive ion etch (RIE). FIGS. 8A, 8B and 8C depict side, ABS and plan views, respectively, of the transducer after step 154 has been completed. Thus, the first sublayer 262′ remains in the shield region. The underlayer 252A/252B have been exposed.

The material(s) for the second sublayer are full-film deposited, via step 156. For example, silicon oxide may be provided in step 156. FIGS. 9A, 9B and 9C depict side, ABS and plan views, respectively, of the transducer after step 156 has been completed. Thus, a second sublayer material(s) 264 have been deposited.

At least the second sublayer material(s) 264 are then planarized, via step 158. A chemical mechanical planarization (CMP) that exposes the first sublayer 262′ is performed in step 158. FIGS. 10A, 10B and 10C depict side, ABS and plan views, respectively, of the transducer after step 158 has been completed. Thus, the first sublayer 262′ in the shield region and the second sublayer 264′ outside of the shield region have been formed from the remaining portions of layers 262 and 264, respectively. Steps 152-158 may thus be considered to form the intermediate layer 260.

A mask is provided on the intermediate layer 260, via step 160. The mask covers the first sublayer 262′ and exposed a part of the second sublayer 264′ In some embodiments the mask includes at least one hard mask as well as a photoresist mask. FIGS. 11A, 11B, 11C and 11D depict side, ABS, recessed and plan views, respectively, of the transducer after step 160 has been completed. Thus, a first hard mask layer 273 and a second hard mask 274 have been provided. The second hard mask 274 has an aperture 276 that has a shape and location corresponding to the pole. The layers 273 and 274 together form hard mask 275. Also shown is mask 278 that covers at least the first sublayer 262′.

A first etch is performed, via step 162. For example, a reactive ion etch (RIE) appropriate for the portion of the intermediate layer to be removed may be performed in step 162. The etch may be a silicon oxide RIE that removes a portion of the second sublayer 264′. For example, the RIE may use fluorine-based chemistry that may provide a smaller trench sidewall angle. Thus, a portion of the trench for the main pole is provided in step 162. FIGS. 12A, 12B, 12C and 12D depict side, ABS, recessed and plan views, respectively, of the transducer 250 after step 162 has been completed. A trench 280 in the sublayers 262″ and 264″ has been formed by step 162. Because of the presence of the mask 278′, the trench 280 is only in the region recessed from the ABS. Thus, the trench 280 corresponds to the location and geometry desired form the pole in the yoke and paddle regions.

The mask 278 is removed, via step 164. Thus, an additional portion of the intermediate layer 254 is exposed in the aperture 258. Step 164 may include performing a resist strip. Note that in some embodiments, the photoresist mask 278 may be omitted. In such embodiments, step 164 may be skipped.

A second etch is performed, via step 166. The etch chemistry is appropriate for the first sublayer 262″. For example, an aluminum oxide RIE may be used in step 166. This RIE may use a chlorine-based chemistry. The RIEs performed in steps 162 and 166 may use different chemistries in order to provide different sidewall angles in different portions of the trench. Step 166 also etches through the first hard mask layer 273. FIGS. 13A, 13B, 13C and 13D depict side, ABS, recessed and plan views, respectively, of the transducer 250 after step 166 has been completed. Thus, the trench 280′ has been formed in both the ABS/pole tip and recessed/yoke and paddle regions. A remaining portion of the first sublayer 262′″ is shown. The sidewall angles of the trench 280′ differ at different distances from the ABS. In some embodiments, the sidewall angle at the ABS is at least twelve degrees and not more than sixteen degrees. The sidewall angle further from the ABS is less than the sidewall angle at the ABS. In some embodiments, the sidewall angle for the trench 280′ in the recessed view at least zero degrees and not more than five degrees.

A seed layer that is resistant to an etch of the first sublayer 262′″ is deposited in the trench, via step 168. 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. FIGS. 14A, 14B, 14C and 14D depict side, ABS, recessed and plan views, respectively, of the transducer 250 after step 170 has been completed.

A plating mask is provided, via step 170. The mask may be a photoresist mask that covers a portion of the trench 280′. FIGS. 14A, 14B, 14C and 14D depict side, ABS, recessed and plan views, respectively, of the transducer 250 after step 170 has been completed. Thus, seed layer 282 and plating mask 284 are shown. The mask 284 has an aperture that exposes only a portion of the trench 280′. 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 main pole materials may then be plated, via step 172. Step 172 includes depositing high saturation magnetization magnetic material(s), for example via electroplating. FIGS. 15A, 15B, 15C and 15D depict side, ABS, recessed and plan views, respectively, of the transducer 250 after the pole materials have been deposited. The pole material(s) 290 are thus shown. The pole material(s) occupy only a portion of the trench. The mask 284 may be removed as part of step 172. FIGS. 16A, 16B, 16C and 16D depict side, ABS, recessed and plan views, respectively, of the transducer 250 after step 172 has been completed. Thus, the mask 284 has been removed. Because of the use of the mask 284, the main pole materials 290 have vertical sidewalls in a portion of the pole the recessed from the ABS.

The portion of the trench 280′ between the main pole materials 290 and the seed layer(s) 282 provided in step 168 may be optionally refilled with a nonmagnetic material, via step 174. The refill and seed layer(s) 282 be used to form a side gap that is conformal in some regions and nonconformal in other regions. FIGS. 17A, 17B, 17C and 17D depict side, ABS, recessed and plan views, respectively, of the transducer 250 after step 174 has been completed. Thus, gap layer 292 has been provided. The gap layer 292 may be aluminum oxide and/or silicon oxide.

A planarization, such as a CMP is performed, via step 176. A leading bevel may be naturally formed in the magnetic pole in step 172 due to the shape of the trench 280′ above the first sublayer 262′″ and the deposition techniques used. A trailing bevel may also be provided as part of step 176. 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. FIGS. 18A, 18B, 18C and 18D depict side, ABS, recessed and plan views, respectively, of the transducer 250 after step 176 has been completed. The remaining portion of the gap 292 and the seed layer 282 form the side gap. Thus, as can be seen in FIGS. 18B-18D, the side gap 282/292 is not conformal for regions recessed from the ABS. Near the ABS, the side gap 282 is conformal. At and near the ABS, the pole 290′ fills the trench. However, further from the ABS, the gap 292 occupies a region between the edges of the trench/seed layer 282 and the pole 290′. In the embodiment shown, the main pole 290′ does not include a trailing bevel. However, in other embodiments, a trialing bevel may be provided. The main pole 290′ may be viewed as being formed in steps 170, 172, and 176. The side gap may be viewed as being formed in steps 168, 174 and 176.

The remaining portion of the first sublayer 262′″ is removed, via step 178. Step 178 includes providing a mask. FIGS. 19A, 19B, 19C and 1D depict side, ABS, recessed and plan views, respectively, of the transducer 250 after the mask has been provided for step 178. Thus, layers 294, 296 and 298 that form the mask have been provided. The layer 294 may be a Ta layer, the layer 296 may be a Ru layer, while the layer 298 may be a photoresist mask. An etch, such as a wet etch may be used to remove the remaining portion of the first sublayer 262″. FIGS. 20A, 20B, 20C and 20D depict side, ABS, recessed and plan views, respectively, of the transducer 250 after step 178 has been completed. Thus, the sublayer 262′″ has been removed.

The side shield(s) may be provided, via step 180. Step 174 may include providing a wraparound shield. magnetic material(s) may thus be plated or otherwise deposited. Thus, the soft magnetic material(s) for the shield may be deposited. In some embodiments, the materials are planarized. Thus, only side shields may be provided, the side shields may be separated from a trailing shield by a nonmagnetic layer, or the trailing shield may then be provided directly on the side shields. The FIGS. 21A, 21B, 21C and 21D depict side, ABS, recessed and plan views, respectively, of the transducer 250 after step 180 has been completed. Thus, side shield 300 has been provided. In the embodiment shown in FIGS. 21A-21D, the shield 300 is a side shield. In other embodiments, a wraparound shield may be provided.

Using the method 150, the pole 290′ may be provided. The sidewall angles of the pole 290′ 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 side gap having conformal and nonconformal regions may 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.