Magnetic recording write apparatus having a stepped conformal trailing shield

This application is a continuation of U.S. application Ser. No. 14/953,982 , filed Nov. 30, 2015 the entirety of which is incorporated by reference herein.

FIGS. 1A and 1B depict ABS and side views of a conventional magnetic recording apparatus 10 . The magnetic recording apparatus 10 may be a perpendicular magnetic recording (PMR) apparatus or other magnetic write apparatus. The conventional magnetic recording apparatus 10 may be a part of a merged head including the write apparatus 10 and a read apparatus (not shown). Alternatively, the magnetic recording head may only include the write apparatus 10 .

The write apparatus 10 includes a leading shield 12 , a nonmagnetic gap layer 14 , optional side shield(s) 15 , a pole 20 and a trailing shield 30 . The apparatus 10 may also include other components including but not limited to coils for energizing the pole 20 . The pole 20 includes sidewalls 22 and 24 that form an angle φ 0 with the down track direction at the ABS. The trailing surface (top) of the pole 20 is wider than the leading surface (bottom) of the pole 20 . The top (trailing) surface of the pole 20 also has a bevel angle φ 1 with the yoke direction. Thus, a write gap of constant width, d, is formed between the trailing shield 30 and the pole 20 . At some distance in, however, the trailing shield 30 rapidly increases in distance from the pole 20 .

Although the conventional magnetic recording apparatus 10 functions, there are drawbacks. In particular, the conventional magnetic write apparatus 10 may not perform sufficiently at higher recording densities. For example, the conventional write apparatus 10 may be subject to increased wide area track erasure (WATER) issues. In particular, the field from the pole 20 during writing to a track may disturb data recorded on other tracks. This is undesirable. Accordingly, what is needed is a system and method for improving the performance of a magnetic recording write apparatus 10 .

FIGS. 1A-1B depict ABS and side views of a conventional magnetic recording apparatus.

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 apparatus.

FIG. 4 depicts a side view of another exemplary embodiment of a magnetic recording apparatus.

FIG. 5 depicts a side view of another exemplary embodiment of a magnetic recording apparatus.

FIG. 6 is a flow chart depicting an exemplary embodiment of a method for providing magnetic recording apparatus.

While the various embodiments disclosed are applicable to a variety of data storage devices such as magnetic recording disk drives, solid-state hybrid disk drives, networked storage systems etc., for the sake of illustration the description below uses disk drives as examples.

FIG. 2A, 2B and 2C depicts side, close-up apex and ABS views of an exemplary embodiment of a portion of a disk drive 100 including a write apparatus 120 . For clarity, FIGS. 2A, 2B and 2C are not to scale. For simplicity not all portions of the disk drive 100 and apparatus 120 are shown. In addition, although the disk drive 100 and write apparatus 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 apparatus 120 . The write apparatus 120 is fabricated on the slider 110 and includes a media-facing surface (MFS). In the embodiment shown, the MFS is an air-bearing surface (ABS) that is proximate to the media 102 during use. Although not shown, the slider 110 and thus the apparatus 120 are generally attached to a suspension (not shown). In general, the disk drive 100 includes a write apparatus 120 and a read apparatus (not shown). However, for clarity, only the write apparatus 120 is shown. The write apparatus 120 includes a pole 130 , coils 140 , write gap 122 and trailing shield 150 . The apparatus may also include a leading shield 123 , optional side shields 124 , and side/bottom gap 126 . Multiple structures on which the leading shield 123 and pole 130 are fabricated may reside below the components shown. At least part of the side/bottom gap 126 is nonmagnetic and, in some embodiments, includes a seed layer for the pole. As discussed above, portions of the components 122 , 123 , 124 , 126 , 130 , 140 and 150 may include multiple layers. In other embodiments, different and/or additional components may be used in the write apparatus 120 .

The coil(s) 140 are used to energize the 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) 140 may also be a helical coil.

The 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 generally 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 132 . In the embodiment shown, both the leading surface 133 and the trailing surface 132 are beveled. For example, the trailing surface 132 is at a bevel angle, α, with respect to a normal to the ABS.

The trailing surface 132 of the pole 130 is opposite to the leading surface 133 and faces the trailing shield 150 . Because of the bevel, the trailing surface 132 is oriented at a bevel angle, α, from the yoke direction (perpendicular to the ABS). This first portion 132 of the trailing surface also adjoins the ABS. The bevel angle is an acute angle, as shown in FIG. 2B . In some embodiments, the bevel angle is at least fifteen degrees and not more than forty degrees. In some such embodiments, the bevel angle is at least twenty-two degrees and not more than twenty-eight degrees.

The trailing shield 150 has a pole-facing surface 152 which faces the trailing surface of the pole 130 . The pole-facing surface 152 has three portions 151 , 153 and 155 . In the embodiment shown, the portions 151 , 153 and 155 adjoin. However, in other embodiments, the pole-facing surface 152 may include other features between the portions 151 , 153 and 155 .

The first portion 151 of the pole-facing surface 152 adjoins the ABS and is at a first trailing shield angle, β 1 , from the yoke direction at the ABS. In some embodiments, the first portion 151 of the pole-facing surface 152 extends at least twenty nanometers and not more than one hundred nanometers from the ABS. In some such embodiments, the first portion 151 of the pole-facing surface 152 extends at least forty and not more than sixty nanometers from the ABS. For example, the first portion 151 may extend nominally seventy nanometers from the ABS. In the embodiment shown, the first trailing shield angle is substantially the same as the bevel angle (β 1 ≈α). As a result, the write gap 122 has a first, constant thickness, t 1 , between the first portion 151 of the pole-facing surface 152 and trailing surface 132 of the pole 130 . The write gap 122 thickness t 1 may not exceed twenty-five nanometers in some embodiments. However, other thicknesses are possible.

The second portion 153 of the pole-facing surface 152 is oriented at a second trailing shield angle, β 2 . The second trialing shield angle is greater than the first trailing shield angle (β 2 >β 1 ). Thus, the write gap 122 has a second thickness, t 2 between the second portion 153 of the pole-facing surface 152 and the trialing surface 132 of the pole 130 . The second thickness is variable. In some embodiments, the second trailing shield angle is at least forty-five degrees and not more than eighty-five degrees. In some embodiments, the second trailing shield angle is at least sixty degrees and not more than seventy-five degrees. In both such embodiments, however, the second trailing shield angle is greater than the first trailing shield angle.

The third portion 155 of the pole-facing surface 152 is oriented at a third trailing shield angle, β 3 , substantially the same as the first trailing shield angle (β 3 ≈ β 1 ). As can be seen in FIG. 2B , the second portion 153 of the pole-facing surface 152 is between the first portion 151 and the third portion 155 . Thus, the write gap 122 has a substantially constant thickness t 1 , then an increasing thickness t 2 followed by a substantially constant thickness t 3 with increasing distance from the ABS in the yoke direction. The thickness t 2 thus varies between t 1 and t 3 . In some embodiments, the thickness t 2 increases monotonically. The t 3 may be at least fifteen nanometers greater than t 1 and not more than fifty nanometers greater than t 1 (t 1 +15 nm≤t 2 ≤t 1 +50 nm). In some such embodiments, the t 3 is at least twenty nanometers greater than t 1 and not more than thirty nanometers greater than t 1 (t 1 +20 nm≤t 2 ≤t 1 +30 nm). However, other thicknesses are possible.

The magnetic disk drive 100 may exhibit improved performance. Because the width t 1 of the gap 122 is constant near the ABS, the field produced by the magnetic apparatus 120 is relatively constant between different heads. Further, the magnitude of the field may be substantially maintained while mitigating wide area track erasure (WATER) issues. Near the ABS, the write gap 122 may remain small. Thus, a sufficiently high magnetic field and desired field magnetic profile may be maintained. The configuration of the pole 130 and trailing shield 150 allow for reduced shunting of the field by the trailing shield 150 because of the increase in thickness of the write gap 122 from t 1 to t 2 and t 3 relatively close to the ABS. Because the increase in thickness of the write gap 122 is limited close to the ABS by limitations on the thickness t 3 , the trailing shield 150 may maintain sufficient volume to more effectively shield other tracks from the write field of the pole 130 . Thus, performance of the disk drive 100 and write apparatus 120 may be improved.

FIG. 3 depicts a side view of another exemplary embodiment of a magnetic recording apparatus 220 that may be used in a data storage device 200 . For clarity, FIG. 3 is not to scale. For simplicity not all portions of the write apparatus 220 are shown. The data storage device 200 may but need not be a disk drive. The magnetic write apparatus 220 is analogous to the write apparatus 120 and may be used in the magnetic disk drive 100 . Thus, analogous components have similar labels. Further, as the ABS view of the apparatus 220 is analogous to that of the apparatus 120 , only an apex view is shown. Thus, the write apparatus 220 includes a write gap 222 , a leading shield 223 , a pole 230 and a trailing shield 250 that are analogous to the write gap 122 , the leading shield 123 , the pole 130 and the trailing shield 150 , respectively.

The pole 230 has a beveled leading surface 233 and a trailing surface 232 analogous to the leading surface 133 and trailing surface 132 , respectively. The trailing surface is beveled at an angle, α, from the yoke direction. In some embodiments, the bevel angle is at least fifteen degrees and not more than forty degrees. In some such embodiments, the bevel angle is at least twenty-two degrees and not more than twenty-eight degrees. The write gap 222 has thicknesses t 1 , t 2 and t 3 that are analogous to those described above.

The trailing shield 250 has a pole-facing surface 252 which faces the trailing surface 232 of the pole 230 . The pole-facing surface 252 has three portions 251 , 253 and 255 that are analogous to the portions 151 , 153 and 155 of the pole-facing surface 152 . In the embodiment shown, the portions 251 , 253 and 25 adjoin. However, in other embodiments, the pole-facing surface 252 may include other features between the portions 251 , 253 and 255 .

The first portion 251 of the pole-facing surface 252 adjoins the ABS and is at a first trailing shield angle, β 1 , from the yoke direction at the ABS. In some embodiments, the first portion 251 of the pole-facing surface 252 extends a distance d 0 from the ABS that is analogous to that described above for the first portion 151 of the pole-facing surface 152 . Thus, d 0 may be at least twenty nanometers and not more than one hundred nanometers. In some such embodiments, d 0 may be at least forty and not more sixty nanometers. The first trailing shield angle is substantially the same as the first bevel angle (β 1 ≈α). The second portion 253 of the pole-facing surface 252 is oriented at a second trailing shield angle, β 2 . The second trialing shield angle is greater than the first trailing shield angle (β 2 >β 1 ). In some embodiments, the second trailing shield angle is at least forty-five degrees and not more than eighty-five degrees. In some embodiments, the second trailing shield angle is at least sixty degrees and not more than seventy-five degrees. In both such embodiments, however, the second trailing shield angle is greater than the first trailing shield angle. The distance, d 1 , that the first and second portions of the pole-facing surface 252 extend from the ABS is desired to be less than the distance the bevel for the trailing surface 232 of the pole 230 extends. Stated differently, d 1 <trailing bevel depth. The third portion 255 of the pole-facing surface 252 is oriented at a third trailing shield angle, 133 , substantially the same as the first trailing shield angle (β 3 ≈β 1 ). The second portion 253 of the pole-facing surface 252 is between the first portion 251 and the third portion 255 . Thus, the write gap 222 has a substantially constant thickness t 1 , then an increasing thickness t 2 followed by a substantially constant thickness t 3 with increasing distance from the ABS in the yoke direction. As mentioned above, the values of the thicknesses t 1 , t 2 and t 3 for the write gap 222 are analogous to those for the write gap 122 .

The pole-facing surface 252 of the trailing shield 250 also has a fourth portion 256 and a fifth portion 257 . The fourth portion 256 is oriented at a fourth trailing shield angle, β 4 , from the yoke direction. The fifth portion 257 is perpendicular to the ABS. The fourth portion 256 of the pole-facing surface 252 adjoins the third portion 252 . However, in other embodiments, additional portions of the pole-facing surface 252 may be between the third portion 255 and the fourth portion 256 . The fourth trailing shield angle is at least forty-five degrees and not more than ninety degrees. The fourth trailing shield angle also exceeds the third trailing shield angle (β 4 >β 3 ). Thus, the distance between the trailing shield 250 and the pole 230 increases rapidly in this region. In some embodiments, the trailing shield terminates 250 at a location recessed from the ABS that is at least one hundred nanometers and not more than four hundred nanometers in a yoke direction from the edge of the fourth portion 256 of the pole-facing surface 252 furthest from the ABS. Stated differently, d 2 may be at least one hundred nanometers and not more than four hundred nanometers. In some embodiments, the trailing shield extends not more than six hundred nanometers from the ABS (S≤six hundred nanometers). In some such embodiments, the trailing shield may extend not more than four hundred nanometers from the ABS. In some such embodiments, the fourth portion 256 of the pole-facing surface 252 extends a distance t 4 parallel to the ABS of at least fifteen nanometers and not more than one hundred nanometers. Stated differently, t 4 is at least fifteen nanometers and not more than one hundred nanometers. In some such embodiments, t 4 is least forty nanometers and not more than sixty nanometers.

The magnetic apparatus 220 may share the benefits of the apparatus 120 and disk drive 100 . Because the width t 1 of the gap 222 is constant near the ABS, the field produced by the magnetic apparatus 220 is relatively constant between different devices. Further, the magnitude of the field may be substantially maintained. The configuration of the pole 230 and trailing shield 250 allow for reduced shunting of the field by the trailing shield 250 while maintaining improved WATER due to the trailing shield 250 . As a result, performance of the apparatus 220 may be improved.

FIG. 4 depicts a side view of another exemplary embodiment of a magnetic recording apparatus 220 ′ that may be used in a data storage device 200 ′. For clarity, FIG. 4 is not to scale. The data storage device 200 ′ may but need not be a disk drive. For simplicity not all portions of the apparatus 220 ′ are shown. The magnetic recording apparatus 220 ′ is analogous to the write apparatus 120 and/or 220 and may be used in the magnetic disk drive 100 and/or 200 . Thus, analogous components have similar labels. Further, as the ABS view of the apparatus 220 is analogous to that of the apparatus 120 , only a side view is shown. Thus, the write apparatus 220 ′ includes a write gap 222 , a leading shield 223 , a pole 230 and a trailing shield 250 ′ that are analogous to the write gap 122 / 222 , the leading shield 123 / 223 , the pole 130 / 230 and the trailing shield 150 / 250 , respectively.

The beveled leading surface 233 and trailing surface 232 of the pole 230 are analogous to the beveled leading surface 133 / 233 and trailing surface 132 / 232 of the pole 130 / 230 depicted in FIGS. 2A-3 . The bevel angle α, first trailing shield angle β 1 , second trailing shield angle β 2 , third trailing shield angle β 3 and fourth trailing shield angle β 4 are analogous to the angles trailing shield angle α, β 1 , β 2 , β 3 and β 4 , respectively. The thicknesses t 1 , t 2 , t 3 and t 4 are analogous to the thicknesses t 1 , t 2 , t 3 and t 4 , respectively, described previously. Similarly, the distances d 0 , d 1 , d 2 and S are analogous to those described previously.

The trailing shield 250 ′ has a pole-facing surface 252 ′ which faces the trailing surface 232 of the pole 230 . The pole-facing surface 252 ′ has five portions 251 , 253 , 255 , 256 ′ and 257 ′ that are analogous to the portions 151 / 251 , 153 / 253 , 155 / 255 , 256 and 257 of the pole-facing surface 152 / 252 , respectively. However, in the embodiment shown, the fourth portion 256 ′ and fifth portion 257 ′ of the pole-facing surface 252 ′ are shorter and do not meet. Instead, a sixth portion 258 is between the fourth portion 256 ′ and the fifth portion 257 ′. The sixth portion 258 is at an sixth trailing shield angle from the yoke direction that is smaller than β 4 .

The magnetic apparatus 220 ′ may share the benefits of the apparatus 120 / 220 and disk drive(s) 100 / 200 . Because the width of the gap 222 is constant near the ABS, the field produced by the magnetic apparatus 220 is relatively constant between different devices. Further, the magnitude of the field may be substantially maintained. The configuration of the pole 230 and trailing shield 250 ′ allow for reduced shunting of the field by the trailing shield 250 while maintaining improved WATER due to the trailing shield 250 ′. In addition, the sixth portion 258 of the pole-facing surface 252 ′ allows for a larger volume of the trailing shield 250 ′. As a result, more magnetic material may be present in the trialing shield 250 ′. Thus, the trailing shield 250 ′ may be better able to shield the pole 230 and provide better WATER. As a result, performance of the apparatus 220 ′ may be improved.

FIG. 5 depicts a side view of another exemplary embodiment of a magnetic recording apparatus 220 ″ that may be used in a data storage device 200 ″. For clarity, FIG. 5 is not to scale. The data storage device 200 ″ may but need not be a disk drive. For simplicity not all portions of the apparatus 220 ″ are shown. The magnetic recording apparatus 220 ″ is analogous to the write apparatus 120 , 220 and/or 220 ′ and may be used in the magnetic disk drive 100 , 200 and/or 200 ′. Thus, analogous components have similar labels. Further, as the ABS view of the apparatus 220 is analogous to that of the apparatus 120 , only a side view is shown. Thus, the write apparatus 220 ″ includes a write gap 222 , a leading shield 223 , a pole 230 and a trailing shield 250 ″ that are analogous to the write gap 122 / 222 , the leading shield 123 / 223 , the pole 130 / 230 and the trailing shield 150 / 250 / 250 ′, respectively.

The beveled leading surface 233 and trailing surface 232 of the pole 230 are analogous to the beveled leading surface 133 / 233 and trailing surface 132 / 232 of the pole 130 / 230 depicted in FIGS. 2A-4 . The bevel angle α, first trailing shield angle β 1 , second trailing shield angle β 2 , third trailing shield angle β 3 and fourth trailing shield angle β 4 are analogous to the angles trailing shield angle α, β 1 , β 2 , β 3 and β 4 , respectively. The thicknesses t 1 , t 2 , t 3 and t 4 are analogous to the thicknesses t 1 , t 2 , t 3 and t 4 , respectively, described previously. Similarly, the distances d 0 , d 1 , d 2 and S are analogous to those described previously.

The trailing shield 250 ″ has a pole-facing surface 252 ″ which faces the trailing surface 232 of the pole 230 . The pole-facing surface 252 ″ has five portions 251 , 253 , 255 ′, 256 ″ and 257 ″ that are analogous to the portions 151 / 251 , 153 / 253 , 155 / 255 , 256 / 256 ′ and 257 / 257 ′ of the pole-facing surface 152 / 252 / 252 ′, respectively. The portions 255 ′, 256 ″, 257 ″ and 258 ′ have different lengths than shown previously. In particular, the third portion 255 ′ having third trailing shield angle β 3 terminates closer to the ABS than the bevel for the trailing surface 232 of the pole 230 shown in FIG. 3 . Thus, the constant width t 3 of the write gap 222 terminates closer to the ABS than the bevel of the trailing surface 232 of the pole 230 .

The magnetic apparatus 220 ″ may share the benefits of the apparatus 120 / 220 / 220 ′ and disk drive(s) 100 / 200 / 200 ′. Because the width of the gap 222 is constant near the ABS, the field produced by the magnetic apparatus 220 is relatively constant between different devices. Further, the magnitude of the field may be substantially maintained. The configuration of the pole 230 and trailing shield 250 ″ allow for reduced shunting of the field by the trailing shield 250 ″ while maintaining improved WATER due to the trailing shield 250 ′. Thus, the trailing shield 250 ″ may be better able to shield the pole 230 and provide better WATER. As a result, performance of the apparatus 220 ″ may be improved.

Various features of the write apparatus 120 , 220 , 220 ′ and 220 ″ are highlighted in the description herein. These features may be combined in manners not explicitly disclosed and which are not inconsistent with the method and apparatus described herein. Similarly, the trailing shield, write gap and pole are described in the context of various distances, in other embodiments, other distances might be used.

FIG. 6 depicts an exemplary embodiment of a method 300 for providing a magnetic recording apparatus 120 , 220 , 220 ′ and/or 220 ″. For simplicity, some steps may be omitted, interleaved, combined and/or include substeps. The method 300 is also described in the context of providing a magnetic recording head 100 and apparatus 120 depicted in FIGS. 2A-2C . The method 300 may also be used to fabricate other magnetic recording apparatuses including but not limited to any combination of 220 , 220 ′ and/or 220 ″. The method 300 may be used to fabricate multiple magnetic recording heads at substantially the same time. The method 300 is also described in the context of particular layers. A particular layer may include multiple materials and/or multiple sub-layers. The method 300 also may start after formation of other portions of the magnetic recording head. For example, the method 300 may start after a read apparatus, return pole/leading shield and/or other structure have been fabricated.

Referring to FIGS. 2A-2C and 6 , the pole 130 is provided, via step 302 . Step 302 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 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 132 is formed. Formation of the trailing surface may include performing one or more 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 write gap is provided, via step 304 . Step 304 includes depositing a nonmagnetic material. One or more layers may be deposited in step 304 . The material may be conformally deposited. In addition, portions of the write gap may be removed to provide the thicknesses t 1 , t 2 , t 3 and t 4 .

The coil(s) 140 are provided, via step 306 . Portions of step 306 may thus be interleaved with the remaining steps of the method 300 . For example, portions of the coil 340 may be provided before the formation of the pole 130 . However, other portions of the coil 140 may be provided after some or all of the pole 130 has been formed. Step 306 may also include depositing and patterning the material(s) used for the coil(s) 140 . Step 306 may include forming one or more helical coils or one or more pancake/spiral coil. In such embodiments, a spiral coil 140 may include other turns far from the ABS.

The trailing shield 150 may be provided, via step 308 . Step 308 may be performed such that multiple trailing shield angles, β 1 , β 2 , β 3 and/or β 4 , are formed.

Using the method 300 , the magnetic disk drive 100 and magnetic apparatuses 120 , 220 , 220 ′ and/or 220 ″ may be provided. Thus, the benefits of the magnetic apparatuses 120 , 220 , 220 ′ and/or 220 ″ may be achieved.