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2015-07-14
14/223,957
2014-03-24
US 9,082,423 B1
2015-07-14
-
-
Angel Castro
2034-03-24
Smart Summary: A magnetic transducer is designed to improve how data is written onto storage media. It features a special surface with two parts: one that is angled and close to the media, and another that is set back and angled differently. This design helps maintain a consistent gap for writing data, which increases as it moves away from the media. The trailing shield, which helps direct the magnetic field, also has a matching angle to enhance performance. Overall, these changes aim to boost the effectiveness of magnetic recording at higher data densities. 🚀 TL;DR
A magnetic transducer has an ABS, a pole, coil(s) and a trailing shield. The pole includes a trailing surface having first and second portions. The first portion adjoins the ABS and is oriented at a first bevel angle from perpendicular to the ABS. The first bevel angle is nonzero and acute. The second portion adjoins the first portion, is recessed from the ABS and oriented at a second bevel angle from perpendicular to the ABS. The second bevel angle is less than the first bevel angle and nonzero. The trailing shield has a pole-facing surface part of which adjoins the ABS and is oriented at the first bevel angle. A write gap is between the trailing shield and the pole. The write gap has a constant thickness for the first portion of the trailing surface and a thickness that increases with increasing distance from the ABS for the second portion.
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G11B5/11 » CPC main
Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor; Structure or manufacture of housings or shields for heads Shielding of head against electric or magnetic fields
G11B5/112 » CPC further
Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor; Structure or manufacture of housings or shields for heads; Shielding of head against electric or magnetic fields Manufacture of shielding device
This application claims priority to provisional U.S. Patent Application Ser. No. 61/917,757, filed on Dec. 18, 2013, which is hereby incorporated by reference in its entirety.
FIGS. 1A and 1B depict ABS and side views of a conventional magnetic recording transducer 10. The magnetic recording transducer 10 may be a perpendicular magnetic recording (PMR) transducer. 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 write transducer 10 may also be used in shingle magnetic recording schemes, which may allow for a larger pole tip geometry.
The write transducer 10 includes an underlayer 12, a nonmagnetic layer 14, a main pole 20 and a trailing shield 30. The underlayer 12 may include multiple structures which are under the pole 20. The transducer 10 may also include other components including but not limited to coils for energizing the 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 φ0 with the down track direction at the ABS. The trailing surface (top) of the pole is wider than the leading surface (bottom) of the main pole. The top (trailing) surface of the main pole 20 also has a bevel angle φ1 with the stripe height direction. Thus, a write gap of constant width, d, is formed between the trailing shield 30 and the main pole 20.
Although the conventional magnetic recording transducer 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 be shunted by the trailing shield 30. Consequently, insufficient field for writing to the media (not shown in FIGS. 1A-1B) may be provided. Accordingly, what is needed is a system and method for improving the performance of a magnetic recording head.
FIGS. 1A-1B depict ABS and side views of a conventional magnetic recording transducer.
FIGS. 2A, 2B and 2C depict side, close-up side and ABS views of an exemplary embodiment of a magnetic recording disk drive.
FIG. 3 depicts a side view of another exemplary embodiment of a magnetic recording transducer.
FIG. 4 depicts a side view of another exemplary embodiment of a magnetic recording transducer.
FIG. 5 depicts a side view of another exemplary embodiment of a magnetic recording transducer.
FIG. 6 depicts a side view of another exemplary embodiment of a magnetic recording transducer.
FIG. 7 depicts a flow chart of an exemplary embodiment of a method for providing magnetic recording transducer.
FIG. 8 depicts a flow chart of an exemplary embodiment of a method for fabricating a portion of a trailing surface of the main pole.
FIGS. 9-11 depict side views of another exemplary embodiment of a portion of a magnetic recording transducer during fabrication of the trailing surface.
FIGS. 2A, 2B and 2C depicts side, close-up side and ABS views of an exemplary embodiment of a portion of a disk drive 100 including a write transducer 120. For clarity, FIGS. 2A, 2B and 2C 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 are shown. However, multiples of each components and/or and their sub-components, might be used. The disk drive 100 may be a PMR disk drive. However, in other embodiments, the disk drive 100 may be configured for other types of magnetic recording.
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. The transducer 120 is fabricated on the slider 110 and includes an air-bearing surface (ABS) proximate to the media 102 during use. Although not shown, the slider 110 and thus the transducer 120 are generally attached to a suspension (not shown). 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 140 and trailing shield 150. The transducer may also include an underlayer 121, write gap 122, optional side shields 124, and side/bottom gap 126. The underlayer 121 may include a leading shield. The underlayer 121 may include multiple structures on which the main pole 130 is fabricated. At least part of the side/bottom gap 126 is nonmagnetic and, in some embodiments, includes a seed layer for the main pole. As discussed above, portions of the components 121, 122, 124, 126, 130, 140 and 150 may include multiple layers. In other embodiments, different and/or additional components may be used in the write transducer 120.
The coil(s) 140 are used to energize the main pole 130. Two turns 140 are depicted in FIG. 2A. Another number of turns may, however, be used. Note that only a portion of the coil(s) 140 is shown in FIG. 2A. Additional turns and/or additional layers of coils may be used. If, for example, the coil(s) 140 form a spiral, or pancake, coil, then additional portions of the coil(s) 140 may be located further from the ABS. The coil(s) may also be a helical coil. Further, additional coils may also be used.
The main pole 130 includes a pole tip region 131 close to the ABS and a yoke region 135 recessed from the ABS. The pole tip region 131 includes sidewalls 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 pole tip region 131 is shown as having bottom/leading surface 133 and a top/trailing surface. The trailing surface has two portions 132 and 134.
The trailing surface of the main pole 130 is opposite to the leading surface 133 and faces the trailing shield 150. The first portion 132 of the trailing surface is oriented at a first bevel angle, α1, from the stripe height direction (perpendicular to the ABS). This first portion 132 of the trailing surface also adjoins the ABS. The first bevel angle is an acute angle, as shown in FIG. 2B. Thus, the first bevel angle is greater than zero (and thus at a nonzero angle from the ABS) and less than ninety degrees (at a nonzero angle from the stripe height direction). In some embodiments, the first bevel angle is at least fifteen degrees and not more than forty degrees. In some such embodiments, the first bevel angle is at least twenty-five degrees and not more than thirty-three degrees. For example, the first bevel angle may be nominally thirty-three degrees. The first portion 132 of the trailing surface extends not more than one hundred fifty nanometers from the ABS. The second portion 134 thus commences not more than one hundred fifty nanometers from the ABS in such embodiments. In some embodiments, the first portion 132 of the trailing surface extends at least one forty nanometers and not more than eighty nanometers from the ABS. For example, the first portion 132 of the trailing surface may extend to nominally sixty nanometers from the ABS. However, other distances are possible.
The second portion 134 of the trailing surface of the main pole 130 is at a second bevel angle, α2, from the stripe height direction. The second portion 134 of the trailing surface is recessed from the ABS. In some embodiments, the second portion 134 of the trailing surface adjoins the first portion 132 of the trailing surface. The second bevel angle is an acute angle. Thus, the second bevel angle is greater than zero (and thus at a nonzero angle from the ABS) and less than ninety degrees (at a nonzero angle from the stripe height direction). Further, the second bevel angle is smaller than the first bevel angle (α2<α1). In some embodiments, the second bevel angle is a least ten degrees and not more than thirty-five degrees. In some such embodiments, the second bevel angle is a least twenty degrees and not more than thirty degrees. For example, the second bevel angle may be nominally twenty-seven degrees. The second portion 134 of the trailing surface extends from the end of the first portion 132 to at least one hundred nanometers and not more than two hundred fifty nanometers from the ABS. In some such embodiments, the second portion 134 extends from the end of the first portion 132 to not more than one hundred fifty nanometers from the ABS. For example, the second portion 134 of the trailing surface may extend from nominally sixty nanometers from the ABS (the end of the first portion 132) to one hundred fifty nanometers from the ABS. However, other distances are possible.
The trailing shield 150 has a pole-facing surface which faces the trailing surface of the main pole 130. A first portion 152 of the pole-facing surface adjoins the ABS and is at a trailing shield angle, β1, from the stripe height direction at the ABS. In the embodiment shown, the first portion 152 of pole-facing surface is substantially flat and occupies the entire pole-facing surface of the trailing shield 150. In the embodiment shown, the trailing shield angle is substantially the same as the first bevel angle (β1≈α1). In some embodiments, the first portion 152 of pole-facing surface terminates not more than one hundred fifty nanometers from the ABS. For example, the first portion 152 of pole-facing surface may terminate nominally one hundred and five nanometers from the ABS. However, other distances are possible.
Between the pole-facing surface of the trailing shield 150 and trailing surface (132 and 134) of the main pole 130 is the write gap 122. Because the trailing shield angle is substantially the same as the first bevel angle, the write gap 122 thickness is substantially constant between the first portion 152 of pole-facing surface and the first portion 132 of the trailing surface. This thickness is shown in FIG. 2B as d1. However, between the first portion 152 of pole-facing surface and the second portion 134 of the trailing surface, the distance (d2) between the pole 130 and the shield 150 changes. Thus, the write gap 122 has a varying thickness in this region. In some embodiments, the thickness of the write gap 122 increases with increasing distance from the ABS in the region between the pole-facing surface 152 and the second portion 134 of the trailing surface. In some embodiments, the write gap 122 has a thickness d1 of at least ten nanometers and not more than thirty-five nanometers. In some embodiments, the write gap 122 has a thickness d1 is at least eighteen nanometers and not more than thirty nanometers. In some such embodiments, the thickness d1 is nominally twenty-four nanometers at the ABS. However, other widths are possible. The width of the gap d2, however, varies. In some embodiments, d2 varies between at least thirteen nanometers and not more than forty nanometers. In some such embodiments, d2 is at least twenty-three nanometers and not more than thirty-two nanometers some distance from the throat height (location at which the first portion 132 of the trailing surface terminates).
The magnetic disk drive 100 may exhibit improved performance. Because the width d1 of the gap 122 is constant near the ABS, the field produced by the magnetic transducer 120 is relatively constant between different heads. Further, the magnitude of the field may be substantially maintained. The configuration of the main pole 130 and trailing shield 150 allow for reduced shunting of the field by the trailing shield 150. More specifically, the increase in the width of the write gap 122 between the second portion 134 of the trailing surface and the trailing shield 150 reduces the shunting of magnetic field by the trailing shield 150. Saturation of the trailing shield 150 may be reduced or avoided. As a result, performance of the transducer 120 may be improved. This improvement may be achieved without significant degradation of off track erasure performance. The magnetic transducer 120 may also be used in conventional perpendicular magnetic recording as well as shingle recording. Thus, performance of the disk drive 100 may be improved.
FIG. 3 depicts a side view of another exemplary embodiment of a magnetic recording transducer 120′. For clarity, FIG. 3 is not to scale. For simplicity not all portions of the transducer 120′ are shown. The magnetic recording transducer 120′ is analogous to the transducer 120 and may be used in the magnetic disk drive 100. Thus, analogous components have similar labels. Further, as the ABS view of the transducer 120′ is analogous to that of the transducer 120, only a side view is shown.
The transducer 120′ includes a main pole 130′ having a beveled leading surface 133 and a trailing surface including first and second portions 132 and 134. Also shown in FIG. 3 are the trailing shield 150′, the nonmagnetic layer 160 and the write gap 122′. The first portion 132 of the trailing surface is oriented at a first bevel angle, α1, from the stripe height direction. The first bevel angle and first portion 132 of the trailing surface are analogous to those described with respect to FIGS. 2A-2C. Similarly, the second portion 134 of the trailing surface is oriented at a second bevel angle, α2, from the stripe height direction. The bevel angles and portions 132 and 134 of the trailing surface may be configured as described above. For example, the second bevel angle is smaller than the first bevel angle (α2<α1). The size of the bevel angles and extent to which the portions 132 and 134 of the trailing surface extend from the ABS may also be analogous to those described above.
The trailing shield 150′ has a first portion 152′ of pole-facing surface, which faces the trailing surface of the main pole 130′ and is analogous to the first portion 152 of pole-facing surface. The first portion 152′ of pole-facing surface is at a trailing shield angle, β1, from the stripe height direction at the ABS. The trailing shield angle is substantially the same as the first bevel angle (β1≈α1). In some embodiments, the first portion 152′ of the pole-facing surface terminates at least twenty and not more than one hundred nanometers from the ABS. In some such embodiments, the first portion 152′ of the pole facing surface terminates at least forty and not more than eighty nanometers from the ABS. For example, the first pole-facing surface 152′ may terminate nominally seventy-five nanometers from the ABS. However, other distances are possible. Further, in the embodiment shown, the first portion 152′ of the trailing shield's pole facing surface terminates a different distance from the ABS than the first portion 132 of the pole's trailing surface terminates. However, in other embodiments, these surfaces 152′ and 132 may terminate the same distance from the ABS.
The trailing shield 150′ also has a second portion 154 of the pole-facing surface that is recessed from the ABS. The second portion 154 of the pole-facing surface also adjoins the first portion 152′ of pole-facing surface. This second portion 154 of the pole-facing surface is at a second trailing shield angle, β2, from the stripe height direction. The second trailing shield angle is larger than the first bevel angle and thus larger than the second bevel angle (α2<α1<β2). In some embodiments, the second trailing shield angle is at least twenty degrees and not more than fifty degrees. The second trailing shield angle may be at least thirty-five degrees and not more than forty-five degrees. The second portion 154 of the pole-facing surface extends from the end of the first portion 152′ of the pole-facing surface to not more than one hundred fifty nanometers from the ABS. For example, the second portion 154 of pole-facing surface may terminate nominally one hundred and five nanometers from the ABS. However, other distances are possible.
Between pole facing surface (152′ and 154) of the trailing shield 150′ and the trailing surface (132 and 134) of the main pole 130′ is the write gap 122′. Because the trailing shield angle is substantially the same as the first bevel angle, the write gap 122′ thickness is substantially constant between the first portion 152′ of the pole-facing surface of the trailing shield 150′ and the first portion 132 of the trailing surface of the main pole 130′. This thickness is shown in FIG. 3 as d1 and is substantially the same as discussed above. Between the first portion 152′ of the pole-facing surface and the second portion 134 of the trailing surface, the distance (d2) between the pole 130′ and the shield 150′ changes. The thickness of the write gap 122′ increases with increasing distance from the ABS in the region between the first portion 152′ of the pole-facing surface and the second portion 134 of the trailing surface. In some embodiments, d2 is at least twenty-five nanometers. Between the second portion 154 of the pole-facing surface and the second portion 134 of the trailing surface, the thickness (d3) of the write gap 122′ increases more rapidly. This is because the pole 130′ and trailing shield 150′ diverge more quickly because of the second bevel angle β2. In some embodiments, d3 is at least twenty nanometers and not more than sixty nanometers. For example, d3 may be at least thirty five and not more than fifty nanometers. However, other widths are possible.
The magnetic transducer 120′ may share the benefits of the transducer 120 and disk drive 100. Because the width d1 of the gap 122′ is constant near the ABS, the field produced by the magnetic transducer 120′ is relatively constant between different heads. Further, the magnitude of the field may be substantially maintained. The configuration of the main pole 130′ and trailing shield 150′ allow for reduced shunting of the field by the trailing shield 150′. As a result, performance of the transducer 120′ may be improved without significant degradation of off track erasure performance. The magnetic transducer 120′ may also be used in conventional perpendicular magnetic recording as well as shingle recording. Thus, performance of the disk drive 100 using the transducer 120′ may be improved.
FIG. 4 depicts a side view of another exemplary embodiment of a magnetic recording transducer 120″. For clarity, FIG. 4 is not to scale. For simplicity not all portions of the transducer 120″ are shown. The magnetic recording transducer 120″ is analogous to the transducer(s) 120 and/or 120′. The magnetic recording transducer 120″ may be used in the magnetic disk drive 100. Thus, analogous components have similar labels. Further, as the ABS view of the transducer 120″ is analogous to that of the transducer 120, only a side view is shown.
The transducer 120″ includes a main pole 130″ having a beveled leading surface 133 and a trailing surface including first and second portions 132 and 134. Also shown in FIG. 3 are the trailing shield 150″, the nonmagnetic layer 160 and the write gap 122″. The first portion 132 of the trailing surface is oriented at a first bevel angle, α1, from the stripe height direction. The first bevel angle and first portion 132 of the trailing surface are analogous to those described with respect to FIGS. 2A-2C. Similarly, the second portion 134 of the trailing surface is oriented at a second bevel angle, α2, from the stripe height direction. The bevel angles and portions 132 and 134 of the trailing surface may be configured as described above. For example, the second bevel angle is smaller than the first bevel angle (α2<α1). The size of the bevel angles and extent to which the portions 132 and 134 of the trailing surface extend from the ABS may also be analogous to those described above.
The trailing shield 150″ has a first portion 152′ of pole-facing surface, which faces the trailing surface of the main pole 130′ and is analogous to the first portion 152/152′ of pole-facing surface for shields 150 and 150′. The first portion 152 of pole-facing surface is at a trailing shield angle, β1, from the stripe height direction at the ABS that is substantially the same as the first bevel angle (β1≈α1). The trailing shield 150″ also has a second portion 154′ of the pole-facing surface that is recessed from the ABS and adjoins the first portion 152′ of pole-facing surface. This second portion 154 of the pole-facing surface is at a second trailing shield angle, β2, from the stripe height direction. The second trailing shield angle is larger than the first bevel angle and thus larger than the second bevel angle (α2<α1<β2). The size of the trailing shield angles may also be analogous to those described above. The distance the first portion 152′ of the pole-facing surface extends from the ABS is analogous to that described above. For example, the first portion 152′ of the pole facing surface may extend nominally seventy-five nanometers from the ABS. Similarly, the distance the second portion 154′ of the pole-facing surface extends from the ABS is analogous to that described above. For example, the second portion 154′ of the pole facing surface may extend nominally one hundred and five nanometers from the ABS.
The trailing shield 150″ also has a third portion 156 of the pole-facing surface that is recessed from the ABS. The second portion 154′ of the pole-facing surface is between the first portion 152′ of pole-facing surface and the third portion 156 of the pole-facing surface. This third portion 153 of the pole-facing surface is at a third trailing shield angle, β3, from the stripe height direction. The third trailing shield angle is larger than the second trailing shield angle (α2<α1<β2<β3). In some embodiments, the third trailing shield angle is at least forty degrees and not more than eighty degrees. In some such embodiments, the third trailing shield angle is at least fifty degrees and not more than sixty-five degrees. The third portion 156 of the pole-facing surface extends from the end of the second portion 154′ of the pole-facing surface to at least one hundred nanometers and not more than one hundred fifty nanometers from the ABS. However, other distances are possible.
Between the trailing shield 150″ and trailing surface (132 and 134) of the main pole 130″ is the write gap 122″. The widths of the write gap 122″, such as d1, d2 and d3, are analogous to those described above. However, other widths are possible.
The magnetic transducer 120″ may share the benefits of the transducer(s) 120/120′ and disk drive 100. Because the width d1 of the gap 122″ is constant near the ABS, the field produced by the magnetic transducer 120″ is relatively constant between different heads. Further, the magnitude of the field may be substantially maintained. The configuration of the main pole 130″ and trailing shield 150″ allow for reduced shunting of the field by the trailing shield 150″. As a result, performance of the transducer 120″ may be improved without significant degradation of off track erasure performance. The transducer 120″ may also be used in perpendicular magnetic recording as well as with other recording schemes such as shingle recording.
FIG. 5 depicts a side view of another exemplary embodiment of a magnetic recording transducer 120′″. For clarity, FIG. 5 is not to scale. For simplicity not all portions of the transducer 120′″ are shown. The magnetic recording transducer 120′″ is analogous to the transducer(s) 120, 120′ and 120″. The magnetic recording transducer 120′″ may be used in the magnetic disk drive 100. Thus, analogous components have similar labels. Further, as the ABS view of the transducer 120′″ is analogous to that of the transducer 120, only a side view is shown.
The transducer 120′″ is substantially the same as the transducer 120″. Thus, the magnetic recording transducer 120′″ includes a write gap 122′″, main pole 130′″, a trailing shield 150′″ and nonmagnetic layer 160 that are analogous to the write gap 122″, the main pole 130″, the trailing shield 150″ and the nonmagnetic layer 160, respectively. However, as can be seen in FIG. 5, the second portion 134′ of the trailing surface of the main pole 130″ may be slightly curved and have a smoother transition from the first portion 132 of the trailing surface. Similarly, the second portion 154″ and/or third portion 156′ of the pole-facing surface of the trailing shield 150′″ may be slightly curved and have smoother transitions from the portions 152 and 154″, respectively. For example, the trailing shield 150′″ may follow a concave profile (as viewed from the ABS) in the second portion 154″ of the pole-facing surface. The main pole 130′″ and trailing shield 150″ may be closer to that which would be fabricated. The magnetic transducer 120′″ may share the benefits of the transducer(s) 120/120′/120″ and disk drive 100.
FIG. 6 depicts a side view of another exemplary embodiment of a magnetic recording transducer 120″″. For clarity, FIG. 6 is not to scale. For simplicity not all portions of the transducer 120″″ are shown. The magnetic recording transducer 120″″ is analogous to the transducer(s) 120, 120′, 120″ and/or 120″. The magnetic recording transducer 120″″ may be used in the magnetic disk drive 100. Thus, analogous components have similar labels. Further, as the ABS view of the transducer 120″″ is analogous to that of the transducer 120, only a side view is shown.
The transducer 120″″ includes a main pole 130″″ having a beveled leading surface 133 and a trailing surface including a first portion 132′. Also shown in FIG. 3 are the trailing shield 150″″, the nonmagnetic layer 160 and the write gap 122″″. The first portion 132′ of the trailing surface is oriented at a first bevel angle, α1, from the stripe height direction. The first bevel angle and first portion 132′ of the trailing surface are analogous to those described with respect to FIGS. 2A-2C. The size of the bevel angle may be analogous to those described above. However, the trailing surface of the main pole 130″″ includes only the first portion 132′.
The trailing shield 150″″ has a first portion 152′ of pole-facing surface, which faces the trailing surface of the main pole 130′ and is analogous to the first portion 152/152′ of pole-facing surface for shields 150 and 150′. The first portion 152′ of pole-facing surface is at a trailing shield angle, β1, from the stripe height direction at the ABS that is substantially the same as the first bevel angle (β1≈α1). The trailing shield 150″ also has a second portion 154 of the pole-facing surface that is recessed from the ABS and adjoins the first portion 152′ of pole-facing surface. This second portion 154 of the pole-facing surface is at a second trailing shield angle, β2, from the stripe height direction. The second trailing shield angle is larger than the first bevel angle and thus larger than the second bevel angle (α2<α1<β2). The size of the trailing shield angles may also be analogous to those described above. The distance the first portion 152′ of the pole-facing surface extends from the ABS is analogous to that described above. For example, the first portion 152′ of the pole facing surface may extend nominally seventy-five nanometers from the ABS. Similarly, the distance the second portion 154′ of the pole-facing surface extends from the ABS is analogous to that described above. For example, the second portion 154′ of the pole facing surface may extend nominally one hundred and five nanometers from the ABS.
Between the trailing shield 150″″ and trailing surface 132′ of the main pole 130″″ is the write gap 122″″. The widths of the write gap 122′, such as d1 and d2, are analogous to those described above. However, other widths are possible.
The magnetic transducer 120″″ may share the benefits of the transducer(s) 120/120′/120″/120′″ and disk drive 100. Because the width d1 of the gap 122″″ is constant near the ABS, the field produced by the magnetic transducer 120″″ is relatively constant between different heads. Further, the magnitude of the field may be substantially maintained. The configuration of the main pole 130″″ and trailing shield 150″″ allow for reduced shunting of the field by the trailing shield 150″″. As a result, performance of the transducer 120″″ may be improved without significant degradation of off track erasure performance. The transducer 120″ may also be used in perpendicular magnetic recording as well as with other recording schemes such as shingle recording.
FIG. 7 depicts an exemplary embodiment of a method 200 for providing a magnetic recording transducer 120, 120′, 120″, 120′″ and/or 120″″. 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. 2A-2C. 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 including but not limited to any combination of 120′, 120″, 120′″, and/or 120″″. 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. 2A-2C and 7, the main pole 130 is provided, via step 202. Step 202 may include using one or more damascene processes. For example, a trench may be formed in a layer. The trench may be fabricated such that portions of the trench sidewalls form different angles with the down track direction. The width of the trench may also vary to form pole tip and yoke regions. The trench may also be configured so that the beveled leading surface 133 is naturally formed as the trench is filled. The material(s) for the pole 130 deposited, for example via plating. One or more ferromagnetic materials may be used. The pole tip 131 and yoke 135 may be formed. In addition, the trailing surface is formed. The trailing surface may have two portions 132 and 134 as depicted in FIG. 2B. Formation of the trailing surface may include performing multiple ion beam etches. 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.
The coil(s) 140 are provided, via step 204. Portions of step 204 may thus be interleaved with the remaining steps of the method 200. For example, portions of the coil 140 may be provided before the formation of the main pole 130. However, other portions of the coil 140 may be provided after some or all of the main pole 130 has been formed. Step 204 may also include depositing and patterning the material(s) used for the coil(s) 140. Step 204 may include forming a single helical coil or one or more pancake/spiral coil. In such embodiments, a pancake coil 140 may include other turns far from the ABS.
The trailing shield 150 may be provided, via step 206. Step 206 may be performed such that multiple trailing shield angles, β1, β2 and/or β3, are formed.
Using the method 200, the magnetic disk drive 100 and magnetic transducers 120, 120′, 120″, 120′″ and/or 120″″ may be provided. Thus, the benefits of the magnetic transducers 120, 120′, 120″, 120′″ and/or 120″″ may be achieved.
FIG. 8 depicts an exemplary embodiment of a method 220 for providing the trailing surface of the main pole. For simplicity, some steps may be omitted, interleaved, and/or combined. FIGS. 9-11 depict a portion of a magnetic recording transducer 300 during formation using the method 220. The magnetic recording transducer is analogous to the magnetic recording transducers 120, 120′, 120″, 120′″ and/or 120″″. Thus, the method 220 is described in the context of the transducer 300. Although described in the context of forming a single transducer 300, the method 220 may be used to fabricate multiple magnetic recording heads at substantially the same time. The method 220 is also described in the context of particular layers and structures. A particular layer and/or structure may include multiple materials and/or multiple sub-layers. The method 220 also may start after formation of other portions of the magnetic recording head. For example, the method 220 may start after a read transducer, return pole/shield and/or other structure have been fabricated and after the material(s) for the main pole have been deposited.
Referring to 8-11, the trailing surface is defined using steps 222-228. A bevel is formed in the current trailing surface of the main pole, via step 222. Step 222 may include providing an ion milling mask, and then ion beam etching the main pole to expose a first beveled surface. In some embodiments, the ion beam etch is performed using a rotation mode. The ion beam etch may be performed at an angle from normal to the surface being billed (at an angle from the ABS). The angle at which milling is performed depends upon the bevel angle desired in the final device. FIG. 9 depicts the transducer 300 after step 222 is performed. Thus, a first beveled surface 312 has been formed in the main pole 310. The nonmagnetic layer 320 may act as a mask for ion milling. The nonmagnetic layer 320 may remain in the final device. In some embodiments, the nonmagnetic layer 320 is a carbon layer. The depth (distance from the ABS) of the first beveled surface 312 is desired to be substantially the same as the depth of the second portion of the trailing surface. The angle of the first beveled surface 312 may be the second bevel angle, α2.
A thin etch stop layer is deposited, via step 224. In some embodiments, step 224 includes full film depositing a Ta/Ru bilayer. For example, nominally seven nanometers of Ta may be deposited, followed by nominally twenty-five nanometers of Ru being deposited. However, other thicknesses and/or other material(s) may be used. A nonmagnetic bump is provided, via step 226. Step 226 may be performed by depositing the nonmagnetic material(s) and then performing a reactive ion etch (RIE). The RIE removes a portion of the nonmagnetic material(s) and stops on the thin etch stop layer. For example, an aluminum oxide layer may be deposited and an aluminum oxide RIE that stops on the Ru layer may be performed. FIG. 10 depicts the transducer 300 after step 226 is performed. Thus, etch stop layer 322 has been formed and a nonmagnetic bump 324 formed.
An additional portion of the pole material(s) is removed from the first beveled surface, via step 228. Step 228 may be performed using a backside mill that uses the nonmagnetic bump as a mask. The ion beam etch may be performed at an angle from the ABS. The angle at which milling is performed depends upon the bevel angle(s) desired in the final device. FIG. 11 depicts the transducer 300 after step 228 is performed. Thus, trailing surface 312′ has been formed. Further, the bevel angle, α1, at the ABS location is the same as the first bevel angle. The angle α2 is the second bevel angle. The trailing surface 312′ having first and second portions and corresponding first and second bevel angles has been provided.
Using the method 220, the main pole 310/130/130′/130″/130′″/130″″, may be provided. Thus, the benefits of the magnetic transducers 120, 120′, 120″, 120′″, 120″″ and/or 300 may be achieved.
1. A magnetic transducer having air-bearing surface (ABS) comprising:
a main pole including a leading surface and a trailing surface opposite to the leading surface, the trailing surface having a first portion and a second portion, the first portion of the trailing surface adjoining the ABS being oriented at a first bevel angle from a direction perpendicular to the ABS, the first bevel angle being greater than zero and less than ninety degrees, the second portion of the trailing surface adjoining the first portion and being recessed from the ABS, the second portion being oriented at a second bevel angle from the direction perpendicular to the ABS, the second bevel angle being less than the first bevel angle and greater than zero degrees;
a trailing shield having a pole-facing surface, the pole-facing surface being opposite to the trailing surface, a first portion of the pole-facing surface adjoining the ABS being oriented at a first trailing shield angle from the direction perpendicular to the ABS, the first trailing shield angle being substantially the same as the first bevel angle;
a write gap between the trailing shield and the main pole, the trailing surface of main pole and the pole-facing surface of the trailing shield being configured such that the write gap has a constant thickness for the first portion of the trailing surface and a variable thickness for the second portion of the trailing surface, the variable thickness increasing with increasing distance from the ABS;
at least one coil for energizing the main pole; and
wherein the pole-facing surface further includes a second portion recessed from the ABS and adjoining the first portion of the pole-facing surface, the second portion of the pole-facing surface being oriented at a second trailing shield angle from the direction perpendicular to the ABS, the second trailing shield angle being greater than the first trailing shield angle such that the write gap increases with increasing distance from the ABS.
2. The magnetic transducer of claim 1 wherein the first bevel angle is at least fifteen degrees and not more than forty degrees and wherein the second bevel angle is a least ten degrees and not more than thirty-five degrees.
3. The magnetic transducer of claim 1 wherein the first bevel angle is at least twenty-five degrees and not more than thirty-three degrees and wherein the second bevel angle is a least twenty degrees and not more than thirty degrees.
4. The magnetic transducer of claim 1 wherein the first portion of the trailing surface extends not more than one hundred fifty nanometers from the ABS.
5. The magnetic transducer of claim 4 wherein the first portion of the trailing surface extends at least one forty nanometers and not more than eighty nanometers from the ABS.
6. The magnetic transducer of claim 1 wherein the second portion of the trailing surface extends at least one hundred nanometers and not more than two hundred fifty nanometers from the ABS.
7. The magnetic transducer of claim 6 wherein the second portion of the trailing surface extends not more than one hundred fifty nanometers from the ABS.
8. The magnetic transducer of claim 1 wherein the second trailing shield angle is at least twenty degrees and not more than fifty degrees.
9. The magnetic transducer of claim 8 wherein the second trailing shield angle is at least thirty-five degrees and not more than forty-five degrees.
10. The magnetic transducer of claim 1 wherein the pole-facing surface of the trailing shield includes a third portion having a third trailing shield angle from the direction perpendicular to the ABS, the second portion of the pole-facing surface is between the first portion of the pole-facing surface and the third portion of the pole-facing surface, the second trailing shield angle being greater than the first trailing shield angle and less than the third trailing shield angle.
11. The magnetic transducer of claim 10 wherein the third portion of the pole-facing surface of the trailing shield occurs at least one hundred nanometers and not more than one hundred fifty nanometers from the ABS.
12. The magnetic transducer of claim 10 wherein the third trailing shield angle is at least forty degrees and not more than eighty degrees.
13. The magnetic transducer of claim 12 wherein the third trailing shield angle is at least fifty degrees and not more than sixty-five degrees.
14. The magnetic transducer of claim 1 wherein the write gap is at least ten nanometers and not more than thirty-five nanometers between the first portion of the pole-facing surface and the first portion of the trailing surface.
15. The magnetic transducer of claim 14 wherein the write gap is at least eighteen nanometers and not more than thirty nanometers between the first portion of the pole-facing surface and the first portion of the trailing surface.
16. The magnetic transducer of claim 14 wherein the write gap is at least ten nanometers and not more than sixty nanometers between the second portion of the trailing surface and the trailing shield.
17. A disk drive comprising:
a media,
a slider, and
a magnetic transducer coupled with the slider, the magnetic transducer having air-bearing surface (ABS), a main pole, a trailing shield, a write gap and at least one coil for energizing the main pole, the main pole including a leading surface and a trailing surface opposite to the leading surface, the trailing surface having a first portion and a second portion, the first portion of the trailing surface adjoining the ABS being oriented at a first bevel angle from a direction perpendicular to the ABS, the first bevel angle being greater than zero and less than ninety degrees, the second portion of the trailing surface adjoining the first portion and being recessed from the ABS, the second portion being oriented at a second bevel angle from the direction perpendicular to the ABS, the second bevel angle being less than the first bevel angle and greater than zero degrees, the trailing shield having a pole-facing surface, the pole-facing surface being opposite to the trailing surface, a first portion of the pole-facing surface adjoining the ABS being oriented at a first trailing shield angle from the direction perpendicular to the ABS, the first trailing shield angle being substantially the same as the first bevel angle, the write gap being between the trailing shield and the main pole, the trailing surface of main pole and the pole-facing surface of the trailing shield being configured such that the write gap has a constant thickness for the first portion of the trailing surface and a variable thickness for the second portion of the trailing surface, the variable thickness increasing with increasing distance from the ABS; and
wherein the pole-facing surface further includes a second portion recessed from the ABS and adjoining the first portion of the pole-facing surface, the second portion of the pole-facing surface being oriented at a second trailing shield angle from the direction perpendicular to the ABS, the second trailing shield angle being greater than the first trailing shield angle such that the write gap increases with increasing distance from the ABS.
18. A method for providing a magnetic transducer having air-bearing surface (ABS) comprising:
providing a main pole including a leading surface and a trailing surface opposite to the leading surface, the trailing surface having a first portion and a second portion, the first portion of the trailing surface adjoining the ABS being oriented at a first bevel angle from a direction perpendicular to the ABS, the first bevel angle being greater than zero and less than ninety degrees, the second portion of the trailing surface adjoining the first portion and being recessed from the ABS, the second portion being oriented at a second bevel angle from the direction perpendicular to the ABS, the second bevel angle being less than the first bevel angle and greater than zero degrees;
providing a trailing shield having a pole-facing surface, the pole-facing surface being opposite to the trailing surface, a first portion of the pole-facing surface adjoining the ABS being oriented at a first trailing shield angle from the direction perpendicular to the ABS, the first trailing shield angle being substantially the same as the first bevel angle;
providing a write gap between the trailing shield and the main pole, the trailing surface of main pole and the pole-facing surface of the trailing shield being configured such that the write gap has a constant thickness for the first portion of the trailing surface and a variable thickness for the second portion of the trailing surface, the variable thickness increasing with increasing distance from the ABS;
providing at least one coil for energizing the main pole; and
wherein the pole-facing surface further includes a second portion recessed from the ABS and adjoining the first portion of the pole-facing surface, the second portion of the pole-facing surface being oriented at a second trailing shield angle from the direction perpendicular to the ABS, the second trailing shield angle being greater than the first trailing shield angle such that the write gap increases with increasing distance from the ABS.
19. The method of claim 18 wherein the step of providing the main pole further includes:
defining the trailing surface, the step of defining the trailing surface further including:
removing a portion of the main pole to form a first surface having the second bevel angle, the first surface including the second portion of the trailing surface;
depositing an etch stop layer on at least the first surface;
depositing a nonmagnetic layer on the etch stop layer;
removing a portion of the nonmagnetic layer to form a nonmagnetic bump on the second portion of the trailing surface; and
removing an additional portion of the main pole and a portion of the etch stop layer, thereby forming the first portion of the trailing surface.
20. The method of claim 19 wherein the step of removing the portion of the main pole further includes:
providing a carbon hard mask recessed from the ABS; and
ion beam etching the main pole.
21. The method of claim 20 wherein the step of removing the additional portion of the main pole further includes:
ion milling the additional portion of the main pole and the portion of the etch stop layer.