Method for fabricating a magnetic write pole using vacuum deposition

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to provisional U.S. Patent Application Ser. No. 61/948,945, filed on Mar. 6, 2014, which is hereby incorporated by reference in its entirety.

BACKGROUND

FIG. 1 depicts a conventional method 10 for fabricating a conventional magnetic recording head. The method starts after a nonmagnetic intermediate layer, such as aluminum oxide, is provided. A trench has also been formed in the intermediate layer, for example using reactive ion etch(es) (RIE(s)). A seed layer for electroplating has also been provided. For example Ru or another conductive material may be deposited. The high saturation magnetization pole materials are plated, via step 12. For example, CoFe may be plated in step 12. Because of the profile of the trench, a leading edge bevel may be formed in the electroplated materials. For example, the trench may be shallower at the air-bearing surface (ABS), which allows for formation of the leading bevel. The magnetic materials are planarized, via step 14. Thus, the main pole is substantially formed. However, the top of the main pole is substantially flat. Thus, a trailing bevel may be provided in the main pole, via step 16. In some cases, the formation of the trailing bevel is interleaved with other steps, such as formation of the side and trailing shields. Fabrication of the transducer may then be completed.

FIG. 2 depicts an ABS view of a conventional magnetic recording head 50 formed using the method 10. The conventional magnetic recording transducer 50 may be a part of a merged head including the write transducer 50 and a read transducer (not shown). Alternatively, the magnetic recording head may be a write head including only the write transducer 50. The conventional transducer 50 includes an underlayer 52, side gap 54, main pole 60, side shields 70, top (write) gap 56, and optional top (trailing) shield 72.

Although the conventional magnetic recording head 50 formed using the method 10 functions, there are drawbacks. In particular, the conventional magnetic recording head 50 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. For example, the reverse overwrite and magnetic field gradient may be less than desired. 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 is a flow chart depicting a conventional method for fabricating a pole in a magnetic recording transducer.

FIG. 2 depicts ABS view of a conventional magnetic recording head.

FIG. 3 depicts an exemplary embodiment of a method for providing a magnetic recording transducer.

FIG. 4 depicts an exemplary embodiment of a magnetic recording disk drive.

FIGS. 5A and 5B depict ABS and side (apex) views of an exemplary embodiment of a magnetic recording transducer.

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

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

FIGS. 8 through 17A and 17B depict various views of an exemplary embodiment of a magnetic recording transducer fabricated using the method.

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. The method 100 is described in the context of providing a 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. The method 100 may start after the intermediate layer in which the main pole is to be formed has already been provided.

A trench is formed in the intermediate layer, via step 102. 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.

A main pole is provided in the trench, via step 104. The main pole is void-free and includes a vacuum deposited portion and an additional portion that may not be vacuum deposited. For example, in some embodiments, step 104 may include vacuum depositing a first main pole material layer that thin enough to preclude filling of the trench. The vacuum deposition may include ion beam deposition (IBD). The first main pole layer may then undergo an ion beam etch (IBE). The IBE removes some, but not all of the first main pole layer. A second main pole layer is then vacuum deposited. In some embodiments, the second main pole layer is sufficiently thin to preclude filling of the trench. The IBE and/or deposition steps may be repeated until a desired portion of the trench has been filled. For example, the second main pole layer may be partially removed via an IBE and a third main pole layer vacuum deposited using IBD. In some embodiments, the third main pole layer is etched. In other embodiments, the third main pole layer may not be etched.

An addition additional main pole layer may then be deposited in another manner. For example, the additional main pole layer may be electroplated. Note that although the deposition methods differ, the same material may be deposited. For example, CoFe may be deposited via IBDs, then etched using IBE(s). In some embodiments, the CoFe may include at least sixty-three atomic percent and no more than seventy-one atomic percent of Fe. However, other concentrations of Fe and/or other materials may be used in other embodiments. An additional layer of CoFe might be deposited, for example using electroplating. This electroplated CoFe may have the same concentration range of Fe as the vacuum deposited layers. However, in other embodiments, other materials may be used for the vacuum deposited and/or electroplated layers.

Fabrication of the transducer may then be completed. Via step 106. For example, coils, shields, contacts, insulating structures and other components may be provided. In addition, the slider may be lapped and otherwise completed.

Using the method 100, a magnetic transducer having improved performance may be fabricated. In particular, some portion of the main pole may be formed using vacuum deposition. This formation process allows for a higher saturation magnetization main pole. This is because vacuum deposited materials may have a higher saturation magnetization than the same materials that are provided using another mechanism, such as electroplating. Thus overwrite gain, writeability and field gradient may be improved. Further, step 104 allows void free vacuum deposition. Vacuum deposition of pole materials may otherwise result in formation of voids within the main pole due to shadowing. Because such voids may be avoided or reduced using the method 100, the performance and reliability of the man pole may be improved. In addition, the domain structure of the main pole may be closer to that desired. Vacuum deposited pole materials, particularly at thicknesses used for the main pole, may exhibit stripe domains. Such domains degrade the performance of the magnetic pole. Use of the method 100 may reduce or eliminate the formation of a stripe domain structure. Thus, performance of the main pole may be improved. Finally, the use of materials provided in another manner, such as electroplating, to complete the pole may facilitate fabrication without adversely affecting performance of the main pole.

FIG. 4 depicts a side view of an exemplary embodiment of a portion of a disk drive 200 including a write transducer 220. FIGS. 5A and 5B depict ABS and apex (side) views of the transducer 220. For clarity, FIGS. 4, 4A and 5B are not to scale. For simplicity not all portions of the disk drive 200 and transducer 220 are shown. In addition, although the disk drive 200 and transducer 220 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 200 is not shown. For simplicity, only single components 202, 210, 220, 230 and 240 are shown. However, multiples of each component 202, 210, 220, 230 and 240 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 100 may be configured for other types of magnetic recording included but not limited to heat assisted magnetic recording (HAMR).

The disk drive 200 includes media 202, a slider 210 and a write transducer 220. Additional and/or different components may be included in the disk drive 200. Although not shown, the slider 210 and thus the transducer 220 are generally attached to a suspension (not shown). The transducer 220 is fabricated on the slider 210 and includes an air-bearing surface (ABS) proximate to the media 202 during use. In general, the disk drive 200 includes the write transducer 220 and a read transducer (not shown). However, for clarity, only the write transducer 220 is shown. The transducer 220 includes a main pole 230 residing on an underlayer and coils 240. The underlayer may have multiple structures therein including but not limited to a leading edge shield and gap. Although not separately labeled, the transducer 220 may include side shields, a top/write gap, a side gap and/or a trailing shield. In other embodiments, different and/or additional components may be used in the write transducer 220.

The coil(s) 240 are used to energize the main pole 230. Two turns 240 are depicted in FIG. 5A. Another number of turns may, however, be used. Note that only a portion of the coil(s) 240 is shown in FIG. 4. If, for example, the coil(s) 240 form a helical coil, then additional portion(s) of the coil(s) 240 may be located on the opposite side of the main pole 230 as is shown. If the coil(s) 240 is a spiral, or pancake, coil, then additional portions of the coil(s) 240 may be located further from the ABS. Further, additional coils may also be used.

The main pole 230 includes a pole tip region 232 close to the ABS and a yoke region 234 recessed from the ABS. The pole tip region 232 is shown as having top and bottom bevels 231 and 233, respectively, near the ABS. The leading edge bevel 231 may be formed due to the profile of the trench. For example, the trench may be shallower at the ABS. This portion is shown in FIG. 5B. In addition, the pole tip region 232 includes sidewalls in the cross track direction. The sidewalls are configured such that the pole 230 has a bottom and a top wider than the bottom. Thus, the main pole 230 is shown as having a sidewall angle α0 at the ABS. However, other geometries are possible.

The main pole 230 is also shown as including a vacuum deposited portion 236 and an additional portion 238. In some embodiments, the portions 236 and 238 are formed of the same materials, such as CoFe. However, the saturation magnetization and method for depositing the portions 236 and 248 differ. Consequently, these regions are separated by a dashed line in FIGS. 5A and 5B. The vacuum deposited portion is shown as occupying a greater fraction of the pole 230 in the pole tip region 232 than in the yoke/regions that are recessed from the ABS. In some embodiments, the vacuum deposited portion forms all of the pole at and near the ABS. The vacuum deposited portion 236 may be a single layer or may include multiple layers. In some embodiments, the vacuum deposited portion 236 includes one or more layers of IBD CoFe, at least some of which have undergone an IBE. The additional portion 238 occupies a greater portion of the yoke. The additional portion 238 may be deposited in another manner, for example using electroplating.

The magnetic disk drive 200 and write transducer 220 may enjoy the benefits discussed above. For example, the main pole 230 may have a higher saturation magnetization, having the desired domain structure, sufficient overwrite and magnetic field gradient. Thus, performance of the transducer 220 may be improved. In addition, because the additional portion 238 may be deposit using methods such as electroplating, yield and throughput may not be sacrificed.

FIG. 6 depicts an exemplary embodiment of a method 110 for providing a magnetic recording transducer having a main pole with a vacuum deposited portion. For simplicity, some steps may be omitted, interleaved, performed in another order and/or combined. The method 110 is described in the context of providing a magnetic recording disk drive 200 and transducer 220 depicted in FIGS. 4, 5A and 5B. 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, intermediate layer, trench in the intermediate layer and/or other structures have been fabricated.

Referring to FIGS. 4, 5A-5B and 6, a first main pole layer is vacuum deposited, via step 112. The first main pole layer may be a magnetic layer. For example, the first main pole layer may include CoFe having at least sixty-three atomic percent Fe and not more than seventy-one atomic percent Fe. On other embodiments, other magnetic materials may be used. The first main pole layer does not fill the trench. Stated differently, the first layer from opposite sides of the trench may not come together to close the trench. Formation of voids may thus be prevented. In some embodiments, the first main pole layer has a thickness of at least ten nanometers and not more than one hundred nanometers. In some such embodiments, the first main pole layer is nominally forty-five nanometers thick (e.g. at least forty and not more than fifty nanometers). In some embodiments, step 112 includes performing an IBD at a deposition angle. For example, the deposition angle may be at least zero degrees and not more than sixty degrees from normal (perpendicular) to the surface of the intermediate layer. In some embodiments, the deposition angle for IBD is nominally fifty-one degrees. In some embodiments, the IBD may be performed in a rotation mode (beam rotating about the normal to the surface of the intermediate layer at the deposition angle).

A portion of the first main pole layer is removed, via step 114. For example, an IBE may be used. The IBE may remove at least one nanometer and not more than ten nanometers of the first main pole layer. For example, step 114 may remove nominally five nanometers (e.g. at least three nanometers and not more than seven nanometers) from the first main pole layer. The IBE may be carried out at an etch angle of at least zero degrees and not more than sixty degrees from perpendicular to the surface of the intermediate layer. For example, the etch angle for the IBE of step 114 may be nominally fifty-five degrees. In some embodiments, the IBE may be performed in a sweep mode (beam sweeping across the device being built at the etch angle from the normal to the surface of the intermediate layer).

A second main pole layer is vacuum deposited, via step 116. The second main pole layer may be a magnetic layer. For example, the first second pole layer may include CoFe having at least sixty-three atomic percent Fe and not more than seventy-one atomic percent Fe. On other embodiments, other magnetic materials may be used. In some embodiments, the first and second main pole layers include the same magnetic materials. However, the first and second main pole layers might include different materials in other embodiments. The second main pole layer only partially fills the trench. The second main pole layer on opposite sides of the trench may, therefore, not meet to close off the trench. Formation of voids may thus be prevented. In some embodiments, the second main pole layer has a thickness of at least ten nanometers and not more than one hundred nanometers. In some such embodiments, the second main pole layer is nominally forty-five nanometers thick (e.g. at least forty and not more than fifty nanometers). In some embodiments, step 116 includes performing an IBD at a deposition angle. For example, the deposition angle may be at least zero degrees and not more than sixty degrees from normal to the surface of the intermediate layer. In some embodiments, the deposition angle for IBD is nominally thirty-eight degrees. This angle may be desired to be smaller than the angle used in step 112 because the trench has been further filled by the first and second main pole layers. In some embodiments, the IBD of step 116 may be performed in a rotation mode.

A portion of the second main pole layer may optionally be removed, via step 118. For example, an IBE may be used. The IBE may remove at least one nanometer and not more than ten nanometers of the second main pole layer. For example, step 118 may remove nominally five nanometers (e.g. at least three nanometers and not more than seven nanometers) from the second main pole layer. The IBE may be carried out at an etch angle of at least zero degrees and not more than sixty degrees from perpendicular to the surface of the intermediate layer. For example, the etch angle for the IBE of step 118 may be nominally forty degrees. In some embodiments, the IBE of step 118 may be performed in a sweep mode. Note, however, that step 118 may be omitted in some embodiments. Steps 116 and 118 may also optionally be repeated additional time(s) to provide the desired level of filling of the trench. For example, a third main pole layer may be vacuum deposited. This deposition might performed using IBD at a deposition angle analogous to those described above. Part of the third main pole layer might also be optionally be removed. This removal may be accomplished using an IBE at an etch angle analogous to those discussed above. Thus, using steps 112, 114, 116 and 118 may be used to form the vacuum deposited portion 236 of the main pole 230.

An additional main pole layer is provided without using vacuum deposition, via step 120. For example, step 120 may include plating the additional main pole layer. The trench is filled in step 120. In some embodiments, the additional main pole layer not only fills the trench, but covers a portion of the magnetic transducer outside of the trench. The additional main pole layer may include CoFe having at least sixty-three atomic percent Fe and not more than seventy-one atomic percent Fe. On other embodiments, other magnetic materials may be used. Fabrication of the main pole and transducer may then be completed. For example, a planarization such as a chemical mechanical planarization (CMP) and an additional etch may remove the pole material(s) outside of the trench. A trailing bevel 233 may also be formed in the main pole 230. For example, a portion of the main pole 230 recessed from the ABS may be masked and the main pole materials milled to form the trailing bevel 233. Other structures, such as side and trailing shield(s) (or a wraparound shield) and gaps may be provided.

Using the method 110, a main pole 230 having improved performance may be fabricated. In particular, a portion 236 of the main pole may be formed using vacuum deposition and etching of multiple layers. This formation process allows for a higher saturation magnetization, void-free main pole. Thus overwrite gain, field gradient and reliability may be improved. Further, the domain structure of the main pole 230 may be closer to that desired. Use of the method 110 may reduce or eliminate the formation of a stripe domain structure. Thus, performance of the main pole may be improved. Finally, the use of electroplated materials 238 for the main pole 230 may facilitate fabrication without adversely affecting performance of the main pole. Thus, performance of the main pole 230 fabricated using the method 110, and the transducer 220 and disk drive 200 in which it resides, may be improved.

FIG. 7 depicts an exemplary embodiment of a method 150 for providing a magnetic recording transducer having a main pole formed at least in part using vacuum deposition. For simplicity, some steps may be omitted, interleaved, performed in another order and/or combined. FIGS. 8 though FIGS. 17A-B depict an exemplary embodiment of a transducer 250 during fabrication using the method 150. Referring to FIGS. 7-17B, 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.

The trench is then formed in the intermediate layer, via step 152. Step 152 may include forming a mask having an aperture corresponding to the location and footprint of the trench. An etch, such as a reactive ion etch (RIE) appropriate for the intermediate layer may be used. For example, an aluminum oxide RIE may be used for an aluminum oxide intermediate layer. FIG. 8 depicts an ABS view of the transducer 250 after step 152 is performed. An underlayer 252, which may include a leading shield, resides under the intermediate layer 254. A mask 256 having aperture 258 is also shown. Although a single hard mask layer is shown, the mask 256 may include multiple layers. A trench 260 has been formed in the intermediate layer 254.

A seed layer that may be resistant to an etch of the intermediate layer is deposited in the trench, via step 154. In some embodiments, a Ru layer is deposited in step 154. In other embodiments, a Ta or other layer may be deposited. In some embodiments, a multilayer seed layer may be provided in step 152. FIG. 9 depicts an ABS view of the transducer 250 after step 152 is performed. Thus, a seed layer 262 has been deposited. A remaining portion of the trench 260 remains open.

A first main pole layer is provided using a first IBD, via step 156. In some embodiments, the IBD may be performed in a rotation mode in step 156. FIG. 10 depicts an ABS view of the transducer 250 after step 156 is performed. Thus, the first main pole layer 270 is shown. Also indicated in FIG. 10 is the deposition angle, a, for the first IBD. For example, the first main pole layer 270 may include the material(s) and have the thickness(es) described above with respect to the method 110. Further, as can be seen in FIG. 10, a portion of the trench 260 (not labeled in FIG. 10 for clarity) remains open.

A portion of the first main pole layer is removed using a first IBE, via step 158. The IBE may be performed at an etch angle and may be accomplished using a sweep mode. The etch angle(s) and amount of material removed may be analogous to that described above for the method 110. FIG. 11 depicts an ABS view of the transducer 250 after step 158 is performed. Thus, a portion of the first main pole layer has been removed, leaving first main pole layer 270′. Also shown is the etch angle, β, for the first IBE of step 158. Because of the angle at which the IBE is performed, the material at the top of the remaining portion of the trench may be removed faster. Thus, the top of the remaining portion of the trench 260 (not labeled in FIG. 11) may be opened further.

A second main pole layer is provided using a second IBD, via step 160. In some embodiments, the second IBD may be performed in a rotation mode in step 160. FIG. 12 depicts an ABS view of the transducer 250 after step 160 is performed. Thus, the second main pole layer 272 is shown. Also indicated in FIG. 11 is the deposition angle, a′, for the second IBD. For example, the second main pole layer 272 may include the material(s) and have the thickness(es) described above with respect to the method 110. Further, as can be seen in FIG. 12, a portion of the trench 260 (not labeled in FIG. 12 for clarity) remains open.

A portion of the second main pole layer may optionally be removed using a second IBE, via step 162. The second IBE may be performed at an etch angle and may be accomplished using a sweep mode. The etch angle(s) and amount of material removed may be analogous to that described above for the method 110. FIG. 13 depicts an ABS view of the transducer 250 after step 162 is performed. Thus, a portion of the second main pole layer has been removed, leaving first main pole layer 272′. Also shown is the etch angle, β′, for the second IBE of step 162. Because of the angle at which the IBE is performed, the material at the top of the remaining portion of the trench may be removed faster. Thus, the top of the remaining portion of the trench 260 (not labeled for clarity in FIG. 13) may be opened further.

A third main pole layer may optionally be provided using a third IBD, via step 164. In some embodiments, the third IBD may be performed in a rotation mode in step 164. The third main pole layer may include the material(s) and have the thickness(es) described above with respect to the method 110. The IBD may be performed in an analogous manner and at analogous deposition angles as for the steps 156 and 160. Further, a portion of the trench 260 remains open after step 164. A portion of the third main pole layer may optionally be removed using a third IBE, via step 166. The third IBE may be performed at an etch angle and may be accomplished using a sweep mode. The etch angle(s) and amount of material removed may be analogous to that described above for steps 158 and 162. The top of the remaining portion of the trench 260 may be opened further in step 166. One or more of the steps 156, 158, 160, 162, 164 and/or 166 may optionally be repeated, via step 168. Thus, the desired thickness of vacuum deposited (IBD) material may be provided.

An additional main pole layer is provided without using vacuum deposition, via step 170. For example, step 170 may include plating the additional main pole layer. FIG. 14 depicts an ABS view of the transducer 250 after step 170 is performed. In the embodiment shown in FIGS. 14-17B, two IBD layers 270′ and 272′ are used. The plated materials 274 not only fill the trench 260 (not labeled in FIGS. 14-17B), but also cover a portion of the magnetic transducer 250/intermediate layer 254 outside of the trench. The material(s) and thicknesses plated in step 170 may be analogous to those described above.

The main pole material(s) may be planarized, via step 172. Step 172 may utilize a CMP. In addition, an ion mill may be performed to remove the mask 256 and/or other material(s) outside of the trench. FIG. 15 depicts the transducer 250 after step 172 has been performed. Thus, the seed layer 262′ and the pole materials 270″, 272″ and 274′ remain in the trench.

A portion of the main pole material(s) may be removed to form a trailing bevel, via step 174. Step 174 may include masking a portion of the transducer recessed from the ABS and performing an ion mill. In some embodiments, step 174 may be interleaved with step(s) 176 and/or 178. FIGS. 16A and 16B depict ABS and apex (side) views of the transducer 250 after step 174 is performed. Thus, trailing bevel 275 has been formed. The pole materials 270″, 272″ and 274′ form main pole 276. In the embodiment shown, the plated pole material(s) 274′ are not at the ABS after formation of the bevel 275. However, in other embodiments, some portion of the plated pole material(s) 274′ may reside at the ABS. In addition, a leading shield 252A is explicitly shown in underlayer 252.

A write gap is formed, via step 176. The write gap lies on top of the main pole 276. Note that the side gap may be formed by the seed layer 262′. The shield(s) are provided, via step 178. Step 178 may include providing side shields, a trailing shield, and/or a wraparound shield (which includes side and trailing shields). FIGS. 17A and 17B depict ABS and apex views of the transducer 250 after step 178 is performed. Thus, gap 280 and shield(s) 290 are shown. In the embodiment shown, the shield 290 is a wraparound shield. In some embodiments, a magnetic seed may be used. This is indicated by the dashed line in the shield 290 in FIG. 17B.

Using the method 150, a main pole 276 having improved performance may be fabricated. In particular, portions 720″ and 272″ of the main pole may be formed using IBD and IBE. This formation process allows for a higher saturation magnetization, void-free main pole 276. Thus overwrite gain, field gradient and reliability may be improved. Further, the domain structure of the main pole 276 may be closer to that desired. Use of the method 150 may reduce or eliminate the formation of a stripe domain structure. Thus, performance of the main pole 276 may be improved. Finally, the use of electroplated materials 274′ for the main pole 276 may facilitate fabrication without adversely affecting performance of the main pole. Thus, performance of the main pole 276 and transducer 250 fabricated using the method 150 may be improved.