Shingle magnetic writer having a low sidewall angle pole

Description

BACKGROUND

FIG. 1 is an air-bearing surface (ABS) view of a conventional magnetic recording transducer 10 for shingle magnetic recording. In shingle magnetic recording blocks of data are written such that the tracks in a block overlap in one direction. Thus, the bits in one track for the block are written, then the bits for the next track, and so on. Each track in the block except the first track written overlaps a previously written adjoining track along the radial direction. Similarly, each track except the last track is overlapped by a next adjacent track in the block. Thus, the tracks are aligned in a manner analogous to shingles on a roof.

The conventional shingle magnetic recording transducer 10 has an underlayer 12 that may include a leading shield, side gap 14, side shields 16, top gap 17, a top (or trailing) shield 18 and a main pole 20. The main pole 20 resides on an underlayer/leading shield 12. The side shields 16 are separated from the main pole 20 by a side gap 14. The gap 14 between the side shields 16 and the main pole 20 may have a substantially constant thickness.

The main pole 20 includes sidewalls that form a nonzero angle, γ, with the down track direction at the ABS. The sidewall angle, γ, is set based on the skew angle the down track direction of the transducer 10 makes with the media (not shown in FIG. 1). At skew, the down track direction makes an angle with the media down track direction depending upon where in the disk recording is being performed. At a zero skew angle, the down track direction of the head matches the media down track direction. Generally, the skew angle is symmetric around this zero skew angle and reaches a maximum skew angle, β_max. Stated differently, the skew angle generally ranges from −β_max to β_max. For shingle magnetic recording, the sidewall angle is set to be equal to the maximum skew angle (γ=β_max). Typically, this means that the sidewall angle is at least thirteen degrees.

Although the conventional magnetic recording head 10 functions, the conventional magnetic recording head 10 is desired to be used at higher areal densities. Accordingly, what is needed is a system and method for improving the performance of a magnetic recording head at higher areal densities and, therefore, lower track widths.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 depicts view of a conventional shingle magnetic recording head.

FIGS. 2A and 2B depict a side view and an ABS view of an exemplary embodiment of a shingle magnetic recording disk drive.

FIGS. 3A-3C are views of an exemplary embodiment of a portion of the disk drive at various skew angles.

FIG. 4 is an ABS view of another exemplary embodiment of a portion of a shingle magnetic recording transducer.

FIG. 5 depicts a flow chart of an exemplary embodiment of a method for providing a shingle magnetic recording transducer.

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

FIGS. 7-10A and 10B depict various views of an exemplary embodiment of a single magnetic recording transducer during fabrication.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 2A and 2B depict a side view and an air-bearing surface (ABS) view of an exemplary embodiment of a shingle magnetic recording write apparatus, or disk drive, 100. For clarity, FIGS. 2A-2B are not to scale. The disk drive 100 includes a slider 104 having a shingle magnetic write transducer 110. For simplicity not all portions of the disk drive 100 and transducer 110 are shown. In addition, although the disk drive 100 and transducer 110 are depicted in the context of particular components other and/or different components may be used. For example, circuitry used to drive and control various portions of the disk drive is not shown. For simplicity, only single components are shown. However, multiples of each components and/or their sub-components, might be used. The disk drive may be a perpendicular magnetic recording (PMR) disk drive. However, in other embodiments, the disk drive may be configured for other types of magnetic recording included but not limited to heat assisted magnetic recording (HAMR).

The disk drive 100 includes a media 102 and a slider 104 on which the transducer 110 has been fabricated. Although not shown, the slider 104 and thus the transducer 110 are generally attached to a suspension. In general, the slider 104 includes the write transducer 110 and a read transducer (not shown). However, for clarity, only the write transducer 110 is shown.

The transducer 110 includes a main pole 120, shield(s) 130, a side gap 140 (which also resides below the main pole 120 in the embodiment shown), write gap 142 and coil(s) 112. The shield(s) 130 include an optional leading shield 132, optional side shields 134 and an optional trailing shield 136 (collectively termed shields 130). The coil(s) 112 are used to energize the main pole 120. One turn is depicted in FIG. 2A. Another number of turns may, however, be used. Note that only a portion of the coil(s) 112 may be shown in FIG. 2A. If, for example, the coil(s) 112 is a spiral, or pancake, coil, then additional portions of the coil(s) 112 may be located further from the ABS. Further, additional coils and/or additional layers of coils may also be used.

The main pole 120 has a top (trailing surface) wider than the bottom (leading surface). The main pole 114 thus includes sidewalls having sidewall angles that are greater than or equal to zero. The main pole 120 is depicted as having a trapezoidal shape. In other embodiments, the main pole 120 may have a triangular shape. Thus, the bottom may be an edge instead of a surface. In some embodiments, the main pole 120 may have leading (bottom) bevel and/or a trailing (top) bevel. Thus, the main pole 120 may be shorter in the down track direction at the ABS than at location(s) recessed from the ABS. In some embodiments, the leading bevel may be a real leading bevel. Such a leading bevel is formed by configuring the top surface of the leading shield 132 (or other part of the underlayer) and thus the gap 140 to slope at a nonzero angle from a direction perpendicular to the ABS. The real leading bevel of the main pole 120, when present, generally follows the contours of this surface. Note that a real leading bevel is in contrast to a “natural” leading bevel that may be formed because the trench in which the main pole 120 is formed is narrower near the ABS and thus fills more rapidly with the material for the gap 140 than portions of the trench further form the ABS.

The gap layer 140 may include one or more sublayers as well as a seed layer. Further, although depicted as a single gap 140 below and along the sides of the main pole 120 is shown, the gap 140 may include separate side gaps (between the mail pole 120 and side shields 134) and bottom gap (between the main pole 120 and leading shield 132). In addition, the write gap 142 and side gap 140 may be a single structure. However, in such embodiments, the write gap 142 generally does not extend further in the cross track direction than the side gap 140. Although depicted as symmetric, the gap 140 may be asymmetric. For example, the gap 142 between a side of the main pole 120 and one side shield 134 may be wider than the gap 142 between the opposite side of the main pole 120 and the other side shield 134.

As discussed above, the main pole 120 has a top wider than the bottom. Thus, the sidewalls of the main pole 120 form a sidewall angle, a, with the down track direction. The sidewalls may be symmetric, forming the same sidewall angle with the down track direction. In other cases, the sidewall angles differ. In some embodiments, the sidewall angle is at least zero degrees and less than thirteen degrees. In some embodiments, the sidewall angle is less than ten degrees. In some embodiments, the sidewall angle is at least three degrees and not greater than eight degrees. For example, the sidewall angle is at least five degrees and not greater than seven degrees. In some cases, the sidewall angle is nominally six degrees.

In shingle magnetic recording, the down track direction of the main pole 120 and transducer 110 may be at a skew angle, β, from the media down track direction. During recording for at least part of media 102. The skew angle varies up to a maximum skew angle, β_max. In some embodiments, the skew angle is symmetric around a zero skew angle (media down track direction parallel to the down track direction of the head). For example, FIGS. 3A-3C depict views of an exemplary embodiment of a portion of the disk drive 100 at various skew angles. In FIG. 3A, the disk drive is shown when the transducer 110 is oriented at a zero skew angle (β=0). Thus, the down track direction for the transducer is aligned with the down track direction of the media. Tracks 104 are also shown. The position of the main pole 120 while recording bits for each track 120 is also shown. FIG. 3B depicts the disk drive 100 when the transducer is oriented at an intermediate skew angle. In FIG. 3C, the transducer 110 is oriented at the largest skew angle, (β=β_max). This may occur at the inside diameter or outside diameter of the disk 102. In general, if the situation shown in FIG. 3C is at the outside diameter, then at the inside diameter, β=−β_max. Thus, the skew angle may vary between −β_max and β_max. In other embodiments, the skew angle may not be symmetric around a zero skew angle.

The sidewall angle of the main pole 120 may also be set based on the skew angle. More specifically, the sidewall angle of the main pole 120 may be less than the maximum skew angle (α<β_max). For example, if the maximum skew angle is thirteen degrees, then the sidewall angle is less than thirteen degrees. The sidewall angle may be in the ranges described above, including nominally six degrees. For different maximum skew angles, the sidewall angle may differ.

Performance of the transducer 110 and disk drive 100 may be improved by shaping of the main pole 120. Use of a smaller sidewall angle may allow for a higher write field without adversely affecting track width. For example, the smaller sidewall angles may allow for more magnetic material to be contained in the tip of the main pole 120 without requiring a wider track width. The top (trailing) surface off the main pole 120 may have the same width in the cross track direction but provide a higher write field. The profile of the magnetic field for the main pole may also be improved. For example, the field may be stronger at the track edge, which is advantageous for shingled magnetic recording performance. These features may be enhanced by using a leading bevel for the main pole. Shingled magnetic recording may thus be extended to smaller track widths. For example, shingled magnetic recording may be performed at track widths of sixty nanometers or less. Consequently, performance of the shingled magnetic writer 100 may be improved.

FIG. 4 is an ABS view of another exemplary embodiment of a portion of a disk drive 100′ used in shingled magnetic recording. For clarity, FIG. 4 is not to scale. The disk drive 100′ and transducer 110′ are analogous to the disk drive 100 and transducer 110, respectively. Consequently, analogous components have similar labels. The shingled magnetic recording transducer 110′ includes an optional leading shield 132, optional side shields 134′, optional trailing shield 136, gap 140′, write gap 142 and main pole 120′ that are analogous to the optional leading shield 132, optional side shields 134, optional trailing shield 136, gap 140, write gap 142 and main pole 120, respectively.

As can be seen in FIG. 4, the main pole 120′ is asymmetric. Consequently, the gap 140′ and side shields 134′ are also asymmetric. The sidewall angle is α on one side of the main pole 120′ and α′ on the other side of the main pole 120′. In some embodiments, both the sidewall angles α and α′ may still desired to be less than the maximum skew angle. In addition, both the sidewall angles α and α′ may still be in the ranges described above. Thus, α and α′ may be less than thirteen degrees and at least zero degrees. In some embodiments, the sidewall angles are each less than ten degrees. In some embodiments, the sidewall angles are at least three degrees and not greater than eight degrees. For example, the sidewall angles may each be at least five degrees and not greater than seven degrees. In alternate embodiments, only one sidewall angle may be less than the maximum skew angle and/or in the ranges described above.

The shingled magnetic writer 110′ may share the benefits of the shingled magnetic writer 110. Use of a smaller sidewall angle may allow for a higher write field without adversely affecting track width. The profile of the field for the main pole may also be improved. These benefits may be enhanced by using a leading bevel for the main pole 120′. Consequently, performance of the shingled magnetic writer 100′ may be improved.

FIG. 5 depicts an exemplary embodiment of a method 200 for providing a shingled magnetic recording transducer or analogous data storage device. For simplicity, some steps may be omitted, interleaved, performed in another order and/or combined. The method 200 may be used to fabricate multiple magnetic recording heads at substantially the same time. The method 200 is described in the context of the shingled magnetic transducer 110. The method 200 may be used to fabricate other shingled magnetic recording transducer including but not limited to the transducer 110′. 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 transducer.

The main pole 120 having the desired sidewall angle(s) is formed, via step 202. In some embodiments, step 202 includes forming a trench in one or more nonmagnetic layers. For example, one or more reactive ion etches (RIEs) may form the trench. The trench has a shape and location that corresponds to the pole. In other embodiments the trench may be provided in the side shields. Magnetic material(s) for the pole are deposited. The transducer may then be planarized. A trailing edge bevel may optionally be formed on the trailing surface (top) of the main pole. A leading edge bevel may be formed naturally or be a real leading edge bevel.

The side gap 140 is provided, via step 204. Step 204 may include depositing a Ru layer, for example via chemical vapor deposition, sputtering or another method. Additional layer(s) may also be provided. In some embodiments, step 204 is performed before step 202. Thus, the main pole 120 is provided on the side gap 140 in such embodiments.

The side shields 134 may optionally be provided, via step 206. The coil(s) 112 for the main pole are provided, via step 208. Step 208 may be interleaved with other steps of the method 200. For example, portions of the coil(s) 112 may be formed before the main pole 114 and side shields 134. The coil(s) formed may be helical coil(s) or spiral coils.

Using the method 200, a shingled magnetic transducer 110 having improved performance may be fabricated. Thus, the benefits of the transducer 110 and/or 110′ may be achieved.

FIG. 6 depicts an exemplary embodiment of a method 220 for providing a shingled magnetic recording transducer having reduced sidewall angles. For simplicity, some steps may be omitted, interleaved, performed in another order and/or combined. FIGS. 7-10A and 10B depict an exemplary embodiment of a shingled magnetic write transducer 300 formed using the method 220. For clarity, FIGS. 7-10A and 10B are not to scale. The method 220 may be used to fabricate multiple magnetic recording heads at substantially the same time. The method 220 may also be used to fabricate other magnetic recording transducers. The method 220 is also described in the context of particular layers. A particular layer may include multiple materials and/or multiple sub-layers. The method 220 also may start after formation of other portions of the magnetic recording transducer. For example, the method 220 may start after a read transducer has been fabricated.

A leading shield or other underlayer having a beveled surface is optionally provided, via step 222. A beveled surface extends from the ABS at an angle that is less than ninety degrees.

A side gap is provided, via step 224. Step 224 may include depositing an intermediate layer on the leading shield/underlayer, forming a trench in the desired location of the pole and having the desired profile for the main pole, then depositing the side gap material(s) in at least trench. In some embodiments, the side gap include multiple sublayers. FIG. 7 depicts a side view of the shingled magnetic recording transducer 300 after step 224 is performed. Thus, an underlayer/leading shield 302 is shown. The leading shield may not extend as far back from the ABS in the stripe height direction. Thus, the dashed line indicates the back edge of an embodiment of the leading shield. As can be seen in FIG. 7, the underlayer/leading shield 302 has a beveled surface 303. The beveled surface 303 is at a nonzero, acute angle with respect to both the ABS and the yoke direction. In the embodiment shown, the gap 304 has also been deposited and is conformal to the underlayer. In another embodiment, the gap may be nonconformal.

The main pole is provided, via step 226. Step 226 includes depositing a high moment magnetic material, for example via plating. The magnetic material(s) for the pole may also planarization performed in step 226. Leading and/or trailing bevels in the main pole may also be provided as part of step 226. FIGS. 8A and 8B depict side and ABS views of the shingled magnetic write transducer 300 after the magnetic material is plated and a planarization performed. Thus, the pole 310 is formed. The pole 310 has sidewall angles α and is symmetric. In other embodiments, the pole 310 may have different sidewall angles. The pole 310 also has a real leading bevel 312 corresponding to the sloped surface 303 of the underlayer/leading shield 302. Also shown is intermediate layer 305 in which the trench for the main pole was formed. FIGS. 9A and 9B depict side and ABS views, respectively, of the transducer 300 after step 226 is performed and in which a trailing bevel is used. As can be seen in FIG. 9A, the main pole 310 has a leading bevel 312 corresponding to the bevel in the underlayer/leading shield 302. The main pole 310 also has a trailing bevel 314. Thus, the height of the main pole 310 at the ABS has been reduced.

The side shields are provided, via step 228. Step 228 may include removing portions of the intermediate layer 305, depositing seed layer(s) and plating the soft magnetic and/or other material(s) for the side shields. Step 228 may be performed before steps 224 and 226 in some embodiments. In other embodiments, step 228 may be performed after steps 224 and 226. Alternatively, portions of the steps 224, 226 and 228 may be interleaved.

A top, or write gap layer may also be provided, via step 230. The trailing shield may optionally be formed, via step 232. Step 232 may include depositing a high moment, soft material. As seed layer might also be deposited in step 232. The coils are provided, via step 234. Portions of step 234 may be interleaved with portions of other steps in the method 220. FIGS. 10A and 10B depict side and ABS views of the transducer 300 after step 234 is performed. Thus, the write gap 330 and trailing shield 340 are shown.

Using the method 220, a shingle magnetic transducer having improved performance may be fabricated. Because of the shape of the main pole 310, the field magnitude and shape may be improved. Thus, a transducer having improved performance for shingled writing may be fabricated.