Magnetic writer having a dual side gap

Description

BACKGROUND

FIGS. 1A and 1B depict air-bearing surface (ABS) and plan views of a conventional magnetic recording head 10. The magnetic recording transducer 10 may be a perpendicular magnetic recording (PMR) head. 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 transducer 10 includes an underlayer 12 that may include a leading shield, side gap 14, side shields 16, top (write) gap 17, optional top shield 18 and main pole 20.

The side shields 16 are separated from the main pole 20 by a side gap 14. The side shields 16 extend a distance back from the ABS. The gap 14 between the side shields 16 and the main pole 20 may have a substantially constant thickness. Thus, the side shields 16 are conformal with the main pole 20.

The main pole 20 resides on an underlayer 12 and includes sidewalls 22 and 24. The underlayer 12 may include a leading shield. The sidewalls 22 and 24 of the conventional main pole 20 form an angle with the down track direction at the ABS. Thus, the top of the main pole 20 is wider than its bottom. In addition, sidewalls of the pole tip forms a chisel angle with the yoke direction (i.e. perpendicular to the ABS) at and near the ABS. Typically, the chisel angle is constant at and near the ABS.

Although the transducer 10 functions, performance of the transducer 10 may suffer at higher recording densities. For example, in the range of close to or above one Tb/in², the main pole 20, side gaps 14 and side shields 16 are scaled down in size. In this size range, the conventional transducer 10 suffers from a reduced write field. Further, reductions in the depth of the side shields 16 in the yoke direction (perpendicular to the plane of the page in FIG. 1A) may result in a significant increase in the wide area track erasure. Thus, performance of the conventional transducer 10 may suffer at higher recording densities.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

FIGS. 1A-1B depict ABS and plan views of a conventional magnetic recording head.

FIGS. 2A, 2B and 2C depict side, ABS and plan views of an exemplary embodiment of a magnetic recording disk drive and transducer having a dual side gap.

FIG. 3 depicts another exemplary embodiment of a magnetic recording transducer having a dual side gap.

FIG. 4 depicts another exemplary embodiment of a magnetic recording transducer having a dual side gap.

FIG. 5 depicts another exemplary embodiment of a magnetic recording transducer having a dual side gap.

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

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 2A, 2B and 2C depict various views of an exemplary embodiment of a disk drive and transducer 100. FIG. 2A depicts a side view of the disk drive. FIGS. 2B and 2C depict ABS and plan views of portions of the transducer 100. For clarity, FIGS. 2A-2C are not to scale. For simplicity not all portions of the disk drive and transducer 100 are shown. In addition, although the disk drive and transducer 100 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 200 may be configured for other types of magnetic recording included but not limited to heat assisted magnetic recording (HAMR).

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

The transducer 100 includes an underlayer 106, a main pole 110, coil(s) 120, side shields 130, side gap 140 and optional trailing shield 150. The underlayer 106 may include a leading shield (LS) at and near the ABS. In other embodiments, the leading shield may be omitted. The coil(s) 120 are used to energize the main pole 110. One turn is depicted in FIG. 2A. Another number of turns may, however, be used. Typically, multiple turns are used. Note that only a portion of the coil(s) 120 may be shown in FIG. 2A. If, for example, the coil(s) 120 is a spiral, or pancake, coil, then additional portions of the coil(s) 120 may be located further from the ABS. Alternatively a helical may be used. Further, additional coils may also be used.

The main pole 110 is shown as having a top wider than the bottom. The main pole 110 thus includes sidewalls having sidewall angles that are greater than or equal to zero. In an embodiment, these sidewall angles differ at different distances from the ABS. In other embodiments, other geometries may be used. For example, the top may be the same size as or smaller than the bottom. The main pole 110 is depicted as having a trapezoidal shape including a flat bottom. In other embodiment, the main pole 110 may have another shape. For example, the main pole 110 may have a triangular cross section at the ABS, with a flat trailing edge facing the optional shield 150 and a vertex closest to the underlayer/leading shield 106. In some embodiments, the main pole 110 may have leading surface bevel and/or a trailing surface bevel. Thus, the main pole 110 may be shorter in the down track direction at the ABS than at location(s) recessed from the ABS.

The transducer 100 also includes magnetic side shields 130 and nonmagnetic side gap 140. The side shields 130 may be magnetically and, in some embodiments, physically connected with the trailing shield 150 and leading shield of the underlayer 106. In such embodiments, a full wraparound shield is formed. In other embodiments, the side shields 130 may be physically and/or magnetically disconnected from the trailing shield 150 and/or the leading shield of the underlayer 106. Further, the shields 106, 130 and/or 150 may be configured differently. In some embodiments, the shield(s) 106 and/or 150 may be omitted. The side shields 130 are also depicted as symmetric in the cross track direction. In other embodiments, asymmetries in the cross track direction may be present.

The side gap 140 may include one or more sublayers as well as a seed layer. Further, although depicted as a single gap surrounding the main pole 110, the gap 140 may include separate side gaps (between the main pole 110 and side shields 130) and write gap (between the main pole 110 and trailing shield 150). In addition, although depicted as symmetric, the gap 140 may be asymmetric. For example, the gap between a side of the main pole 110 and one side shield may be wider than the gap between the opposite side of the main pole 110 and the other side shield.

As can be seen in FIG. 2C, the side shields 130 and side gap 140 are configured such that the side gap 140 includes a first side gap 142 and a second side gap 144. The side shield 130 is conformal with the pole 110 for both side gaps 142 and 144. The first side gap 142 is between the second side gap 144 and the ABS. Between these two side gaps 142 and 144, is plateau 146. The side gap 142 has a width d1, while the second side gap 144 has a width d2 that is different from d1 (d1≠d2). In the embodiment shown, the first side gap 142 is narrower than the second side gap 144 (d1<d2).

As discussed below, the widths d1 and d2 of the side gaps 142 and 144, respectively, may depend upon the distance the side gaps 142 and 144, respectively, extend into the ABS. In some embodiments, the width of the second side gap 144 is at least twice the width of the first side gap 142 (d2≧2*d1). In some such embodiments, the second side gap 144 width is at least three multiplied by the first side gap 142 width (d2≧3*d1). In some embodiments, the width of the second side gap 144 is at least four multiplied by the width of the first side gap 142 (d2≧4*d1). In some embodiments, the second side gap 144 width is not more than sixty nanometers greater than the first side gap width (d1+60 nm≧d2). In some such embodiments, the second side gap 144 width is not more than forty nanometers greater than the first side gap width and not less than thirty nanometers greater than the first side gap width (d1+40 nm≧d2≧d1+30 nm). In general, the smaller the first side gap 142, the larger the difference between the first side gap 142 width and the second side gap 144 width. For example, if the first side gap 142 has a width d1 of approximately forty nanometers, then the second side gap 144 may have a width d2 of at least twice and not more than three times the first side gap width. If the first side gap 142 is smaller, then the difference between the widths may be greater. For example, if the first side gap 142 has a width d1 of thirty nanometers, then the second side gap 144 may have a width d2 that is at least three times and not more than four times the first side gap 142 width. Other configurations including other relationships between the side gap widths are possible.

The side gaps 142 and 144 are also desired to be narrow. The first side gap 142 may be not more than sixty nanometers wide and greater than zero nanometers wide. In some embodiments, the width of the first side gap 142 is not more than forty nanometers. In some such embodiments, the first side gap 142 may be not more than twenty nanometers wide.

The first side gap 142 is also desired to extend only a limited distance from the ABS in the yoke direction. The distance the first side gap 142 extends from the ABS in the yoke direction is a first throat height, TH1. The depth of the side shields 130 where the second gap 144 terminates is a second throat height, TH2. In some embodiments, the first throat height is not more than one hundred nanometers (TH1≦100 nm). For example 50 nanometers≦TH1≦100 nanometers in some cases. However, in some such embodiments, the first side gap 142 may terminate less than or equal to fifty nanometers from the ABS in the yoke direction (TH1≦50 nm). The first side gap 142 may also be desired to terminate at least twenty nanometers from the ABS (20 nm≦TH1). The second throat height TH2 is the depth of the side shields in the embodiment shown in FIGS. 2A-2C. In some embodiments, the second throat height is not more than six hundred nanometers. Thus, the side shields 130 may terminate not more than six hundred nanometers from the ABS. In other embodiments, the second throat height may be smaller. For example, in some embodiments, TH2 is not greater than four hundred fifty nanometers.

The first side gap 142 may be desired to extend only a limited distance from the ABS because wide area track erasure (WATER) may be adversely affected by a deeper first side gap 142. For example, if the second side gap 144 were eliminated, the first side gap 142 may extend to the back of the side shields 130, which may be six hundred nanometers from the ABS. Such a transducer may suffer the drawbacks described above including WATER. In contrast, if the first side gap 142 terminates at too small a distance from the ABS, then the track width and adjacent track interference (ATI) may increase. To mitigate both issues, the first side gap 142 is present and narrow, but may extend only a limited distance from the ABS.

The side gap 140 also includes a plateau 146 between the first side gap 142 and the second side gap 144. The plateau 146 may be configured to be just wide enough to cover the distance between the widths d1 and d2 of the side gaps 142 and 144. In the embodiment shown, the plateau 146 has an edge along the side shield 130 that is substantially parallel to the ABS. In other embodiments, other configurations are possible. For example, the edge of the plateau 146 adjoining the side shield 130 may be at an angle of not more than forty degrees from the ABS. In some such embodiments, this angle is not more than twenty degrees. Further, this angle may not exceed ten degrees.

The magnetic transducer 100 may have improved performance, particularly at higher recording densities. The dual conformal side gap 140 allows for improved writability of the main pole 110 while addressing WATER issues that might otherwise render the transducer unusable. In particular, the narrow, conformal first side gap 142 at and near the ABS may allow for narrower track widths and writing at higher areal densities. The addition of the second conformal side gap 144 recessed from the ABS may improve flux shunting and WATER. Thus, overall performance of the transducer 100 may be improved at higher areal densities.

FIG. 3 depicts a plan view of another exemplary embodiment of the magnetic recording apparatus, or transducer 100′. For clarity, FIG. 3 is not to scale. For simplicity not all portions of the transducer 100′ are shown. In addition, although the transducer 100′ is 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 PMR disk drive. However, in other embodiments, the disk drive may be configured for other types of magnetic recording included but not limited to HAMR. Because the transducer 100′ is analogous to the transducer 100, similar components have similar labels. Thus, the transducer 100′ includes a side gap 140′, main pole 110 and side shields 130′ that are analogous to the side gap 140, the main pole 110 and the side shields 130, respectively.

The side shields 130′ may be magnetically and, in some embodiments, physically connected with the trailing shield (not shown in FIG. 3) and leading shield (not shown in FIG. 3) of the underlayer (not shown in FIG. 3). In such embodiments, a full wraparound shield is formed. In other embodiments, the side shields 130′ may be physically and/or magnetically disconnected from the trailing shield and/or the leading shield of the underlayer. The side shields 130′ and side gap 140′ are also depicted as symmetric in the cross track direction. In other embodiments, asymmetries in the cross track direction may be present.

The side gap 140′ includes a first side gap 142, a second side gap 144 and a plateau 146′ that are analogous to the first side gap 142, the second side gap 144 and the plateau 146. Thus, the widths d1 and d2 of the side gaps 142 and 144, respectively, as well as the throat heights TH1 and TH2 for the side gaps 142 and 144, respectively, may be configured as described above. However the plateau 146′ is explicitly depicted as being at an angle, θ, from parallel to the ABS. The plateau 146′ may be configured to be just wide enough to cover the distance between the widths d1 and d2 of the side gaps 142 and 144 at the angle θ. The plateau 146′ may be at an angle θ of not more than forty degrees from the ABS. In some embodiments, θ is not more than twenty degrees. In some such embodiments, θ may not exceed ten degrees. In embodiments in which the angle θ is zero degrees, the edge of the plateau 146′ is substantially parallel to the ABS.

The magnetic transducer 100′ may share the benefits of the magnetic transducer 100. In particular, the magnetic transducer 100′ may have improved performance at higher recording densities. Improved writability of the main pole 110 may be achieved while addressing WATER and/or ATI issues. Thus, overall performance of the transducer 100′ may be improved at higher areal densities.

FIG. 4 depicts a plan view of another exemplary embodiment of the magnetic recording apparatus, or transducer 100″. For clarity, FIG. 4 is not to scale. For simplicity not all portions of the transducer 100″ are shown. In addition, although the transducer 100″ is 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 PMR disk drive. However, in other embodiments, the disk drive may be configured for other types of magnetic recording included but not limited to HAMR. Because the transducer 100″ is analogous to the transducer(s) 100 and/or 100′, similar components have similar labels. Thus, the transducer 100″ includes a side gap 140″, main pole 110 and side shields 130″ that are analogous to the side gap 140/140′, the main pole 110 and the side shields 130/130′, respectively.

The side shields 130″ may be magnetically and, in some embodiments, physically connected with the trailing shield and leading shield. In such embodiments, a full wraparound shield is formed. In other embodiments, the side shields 130″ may be physically and/or magnetically disconnected from the trailing shield and/or the leading shield of the underlayer. The side shields 130″ and side gap 140″ are also depicted as symmetric in the cross track direction. In other embodiments, asymmetries in the cross track direction may be present.

The side gap 140″ includes a first side gap 142, a second side gap 144 and a plateau 146″ that are analogous to the first side gap 142, the second side gap 144 and the plateau 146/146′. Thus, the widths d1 and d2 of the side gaps 142 and 144, respectively, as well as the throat heights TH1 and TH2 for the side gaps 142 and 144, respectively, may be configured as described above. The plateau 146′ is explicitly depicted as being at an angle, θ1, from parallel to the ABS. This angle θ1 is analogous to the angle θ described above and may be configured similarly.

In addition, the side shields 130″ and side gap 140″ are configured such that the side gap 140″ includes a third side gap 148 and a third plateau 149. Like the first side gap 142 and second side gap 144, the third side gap 148 is conformal with the main pole 110. The third side gap 148 has a width, d3, that is different from the widths d1 and d2 of the first side gap 142 and second side gap 144, respectively. In the embodiment shown, the width of the third side gap 148 is greater than the width of the second side gap 144 (d3>d2). Consequently, the third side gap 148 width is greater than the first side gap 142 width (d3>d1). In other embodiments, however, the third side gap 148 might be less wide than the second side gap 144. The third side gap extends to the third throat height TH3. In some embodiments, the third throat height does not exceed six hundred nanometers. The third throat height is also greater than the second throat height (TH3>TH2), as shown in FIG. 4.

The plateau 149 may be configured to be just wide enough to cover the distance between the widths d2 and d3 of the side gaps 144 and 148 at the angle θ2. The angle θ2 may be zero degrees and may be in the same range as the angles θ and θ1. In some embodiments, therefore, the edge of the plateau 149 formed by the wall of the side shield 130″ may be parallel to the ABS. In other embodiments, the plateau 149 may be at an angle θ2 of not more than forty degrees from the ABS. In some embodiments, θ2 is not more than twenty degrees. In some such embodiments, θ2 may not exceed ten degrees. Although three gaps 142, 144 and 148 are shown, in another embodiment, additional gaps may be included.

The magnetic transducer 100″ may share the benefits of the magnetic transducer 100 and/or 100′. In particular, the magnetic transducer 100″ may have improved performance at higher recording densities. Improved writability of the main pole 110 may be achieved while addressing WATER and/or ATI issues. Thus, overall performance of the transducer 100″ may be improved at higher areal densities.

FIG. 5 depicts a plan view of another exemplary embodiment of the magnetic recording apparatus, or transducer 100″. For clarity, FIG. 5 is not to scale. For simplicity not all portions of the transducer 100′″ are shown. In addition, although the transducer 100′″ is 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 PMR disk drive. However, in other embodiments, the disk drive may be configured for other types of magnetic recording included but not limited to HAMR. Because the transducer 100′″ is analogous to the transducer(s) 100, 100′ and/or 100″, similar components have similar labels. Thus, the transducer 100′″ includes side gaps 140′″ and 140′, main pole 110 and side shields 130′″ and 130′ that are analogous to the side gap 140/140′/140″, the main pole 110 and the side shields 130/130′/130″, respectively.

The side shields 130′ and 130′″ may be magnetically and, in some embodiments, physically connected with the trailing shield and leading shield. In such embodiments, a full wraparound shield is formed. In other embodiments, the side shields 130′ and 130′″ may be physically and/or magnetically disconnected from the trailing shield and/or the leading shield of the underlayer.

In the embodiment shown in FIG. 5, the side shields 130′ and 130′″ and side gaps 140′″ and 140′ are configured to be asymmetric in the cross-track direction. Although a particular configuration is shown, other asymmetric configurations may be possible. Thus, one side includes side shield 130′ and side gap 140′ that includes a first side gap 142, a second side gap 144 and plateau 146′. The other side includes side shield 130′″ and a side gap 140′″ that includes a single conformal side gap 145. The side gap 145 has a width d4 that may be larger than the width d1 of the first side gap 142 (d4>d1). In some embodiments, the side gap 145 width is less than the second side gap 144 width (d4<d2). However in other embodiments, the side gap 145 width may be greater than or equal to the second side gap 144 width (d4≧d2).

The magnetic transducer 100′″ may share the benefits of the magnetic transducers 100, 100′ and/or 100″. In particular, the magnetic transducer 100′″ may have improved performance at higher recording densities. Improved writability of the main pole 110 may be achieved while addressing WATER and/or ATI issues. Thus, overall performance of the transducer 100′″ may be improved at higher areal densities.

FIG. 6 depicts an exemplary embodiment of a method 200 for providing a magnetic recording transducer which includes multiple conformal side gaps. For simplicity, some steps may be omitted, interleaved, combined and/or performed in another order. The method 200 is described in the context of providing a single magnetic recording disk drive and transducer 100. However, the method 200 may be used to fabricate multiple magnetic recording transducers at substantially the same time and may be used to fabricate other transducers including but not limited to the transducers 100′, 100″ and 100′″. 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(s) have been fabricated.

The main pole 110 is provided, via step 202. Step 202 may include forming a trench in one or more layers. The shape and location of the trench corresponds to the pole. For example, a photoresist mask having the desired shape may be provided on an intermediate layer. Hard mask layer(s) may be deposited on the photoresist mask and the photoresist mask removed. The hard mask so formed has an aperture having a shape corresponding to the photoresist mask. An etch or other removal process may then be performed in order to form the trench corresponding to the main pole. The trench formed has the desired geometry and location for formation of the main pole. For example, the top of the trench may be wider than the bottom so that the top of the main pole may be wider than the bottom. If a leading edge bevel is desired, the bottom of the trench may slope in the yoke direction. The trench may also be narrower in the pole tip region, near the ABS, than in the yoke region recessed from the ABS. After formation of other structures, such as a bottom or side gap, the formation of the main pole 110 may be completed by deposition of magnetic pole materials and, in some embodiments, a planarization or other process that removes any excess pole materials. In some embodiments, this portion of step 202 includes plating or otherwise depositing high saturation magnetization magnetic material(s). Further, a top, or trailing, bevel may be formed in the main pole 110. Formation of the trailing bevel may include covering a portion of the main pole recessed from the ABS and then ion milling the main pole at an angle from the down track direction. This step may be performed after or interleaved with formation of the side shields.

The side shields 130 are provided, via step 204. Step 204 may include configuring the walls of the side shields 130 closest to the main pole 110 such that the desired gap 140 may be formed. Step 204 may include multiple deposition and/or patterning steps to form the walls of the side shields 130 adjoining the side gap 140. For example, the portion of the side shield 130 adjacent to the first gap 142 may be formed first. The portion of the side shield 130 adjacent to the second gap 144 may be formed later.

The bottom, side gap 140 and/or write gap(s) are provided, via step 206. Step 206 may include depositing one or more nonmagnetic layers such that the bottom and side gaps are formed in the trench. In order to form first side gap 142 and second side gap 144, additional masking and/or deposition steps may also be performed. In some embodiments, at least part of step 206 may be performed before deposition of the pole material(s) in step 202. For example, at least the bottom portion of the gap, between the main pole 110 and the underlayer/leading shield 106 may be provided before plating of the main pole 110. However, formation of the write gap is carried out after the pole materials have been provided.

The coils 120 may also be formed, via step 208. Step 208 includes multiple masking and deposition steps that may be performed before and/or after the steps 202, 204 and 206. For example, if the coil 120 is a spiral coil, then step 208 may be completed before the steps 202, 204 and 206. In other embodiments, the coil 120 may be a toroidal (helical) coil, some of which is formed before the main pole 120 and some of which may be formed after the main pole 110.

The shield(s) 106 and/or 140 are optionally provided, via step 210. Step 210 may include plating or otherwise providing the magnetic material(s) for the leading and/or trailing shields.

Using the method 200, a magnetic transducer having improved performance may be fabricated. In particular, the magnetic field magnitude, gradient in the magnetic field, WATER, ATI and/or other properties may be enhanced at higher areal densities. Thus, performance of the transducer may be improved.