Magnetic recording write transducer having an improved trailing surface profile

Information

  • Patent Grant
  • 9082423
  • Patent Number
    9,082,423
  • Date Filed
    Monday, March 24, 2014
    10 years ago
  • Date Issued
    Tuesday, July 14, 2015
    9 years ago
Abstract
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.
Description
BACKGROUND


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.





BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS


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.





DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS


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 (α21). 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 (α21). 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 (α212). 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 (α21). 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 (α212). 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 (α2123). 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 (α212). 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.

Claims
  • 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; andwherein 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, anda 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; andwherein 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; andwherein 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; andremoving 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; andion 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.
CROSS-REFERENCE TO RELATED APPLICATIONS

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.

US Referenced Citations (691)
Number Name Date Kind
6016290 Chen et al. Jan 2000 A
6018441 Wu et al. Jan 2000 A
6025978 Hoshi et al. Feb 2000 A
6025988 Yan Feb 2000 A
6032353 Hiner et al. Mar 2000 A
6033532 Minami Mar 2000 A
6034851 Zarouri et al. Mar 2000 A
6043959 Crue et al. Mar 2000 A
6046885 Aimonetti et al. Apr 2000 A
6049650 Jerman et al. Apr 2000 A
6055138 Shi Apr 2000 A
6058094 Davis et al. May 2000 A
6073338 Liu et al. Jun 2000 A
6078479 Nepela et al. Jun 2000 A
6081499 Berger et al. Jun 2000 A
6094803 Carlson et al. Aug 2000 A
6099362 Viches et al. Aug 2000 A
6103073 Thayamballi Aug 2000 A
6108166 Lederman Aug 2000 A
6118629 Huai et al. Sep 2000 A
6118638 Knapp et al. Sep 2000 A
6125018 Takagishi et al. Sep 2000 A
6130779 Carlson et al. Oct 2000 A
6134089 Barr et al. Oct 2000 A
6136166 Shen et al. Oct 2000 A
6137661 Shi et al. Oct 2000 A
6137662 Huai et al. Oct 2000 A
6160684 Heist et al. Dec 2000 A
6163426 Nepela et al. Dec 2000 A
6166891 Lederman et al. Dec 2000 A
6173486 Hsiao et al. Jan 2001 B1
6175476 Huai et al. Jan 2001 B1
6178066 Barr Jan 2001 B1
6178070 Hong et al. Jan 2001 B1
6178150 Davis Jan 2001 B1
6181485 He Jan 2001 B1
6181525 Carlson Jan 2001 B1
6185051 Chen et al. Feb 2001 B1
6185077 Tong et al. Feb 2001 B1
6185081 Simion et al. Feb 2001 B1
6188549 Wiitala Feb 2001 B1
6190764 Shi et al. Feb 2001 B1
6193584 Rudy et al. Feb 2001 B1
6195229 Shen et al. Feb 2001 B1
6198608 Hong et al. Mar 2001 B1
6198609 Barr et al. Mar 2001 B1
6201673 Rottmayer et al. Mar 2001 B1
6204998 Katz Mar 2001 B1
6204999 Crue et al. Mar 2001 B1
6212153 Chen et al. Apr 2001 B1
6215625 Carlson Apr 2001 B1
6219205 Yuan et al. Apr 2001 B1
6221218 Shi et al. Apr 2001 B1
6222707 Huai et al. Apr 2001 B1
6229782 Wang et al. May 2001 B1
6230959 Heist et al. May 2001 B1
6233116 Chen et al. May 2001 B1
6233125 Knapp et al. May 2001 B1
6237215 Hunsaker et al. May 2001 B1
6252743 Bozorgi Jun 2001 B1
6255721 Roberts Jul 2001 B1
6258468 Mahvan et al. Jul 2001 B1
6266216 Hikami et al. Jul 2001 B1
6271604 Frank, Jr. et al. Aug 2001 B1
6275354 Huai et al. Aug 2001 B1
6277505 Shi et al. Aug 2001 B1
6282056 Feng et al. Aug 2001 B1
6296955 Hossain et al. Oct 2001 B1
6297955 Frank, Jr. et al. Oct 2001 B1
6304414 Crue, Jr. et al. Oct 2001 B1
6307715 Berding et al. Oct 2001 B1
6310746 Hawwa et al. Oct 2001 B1
6310750 Hawwa et al. Oct 2001 B1
6317290 Wang et al. Nov 2001 B1
6317297 Tong et al. Nov 2001 B1
6322911 Fukagawa et al. Nov 2001 B1
6330136 Wang et al. Dec 2001 B1
6330137 Knapp et al. Dec 2001 B1
6333830 Rose et al. Dec 2001 B2
6340533 Ueno et al. Jan 2002 B1
6342311 Inturi et al. Jan 2002 B1
6349014 Crue, Jr. et al. Feb 2002 B1
6351355 Min et al. Feb 2002 B1
6353318 Sin et al. Mar 2002 B1
6353511 Shi et al. Mar 2002 B1
6356412 Levi et al. Mar 2002 B1
6359779 Frank, Jr. et al. Mar 2002 B1
6369983 Hong Apr 2002 B1
6376964 Young et al. Apr 2002 B1
6377535 Chen et al. Apr 2002 B1
6381095 Sin et al. Apr 2002 B1
6381105 Huai et al. Apr 2002 B1
6389499 Frank, Jr. et al. May 2002 B1
6392850 Tong et al. May 2002 B1
6396660 Jensen et al. May 2002 B1
6399179 Hanrahan et al. Jun 2002 B1
6400526 Crue, Jr. et al. Jun 2002 B2
6404600 Hawwa et al. Jun 2002 B1
6404601 Rottmayer et al. Jun 2002 B1
6404706 Stovall et al. Jun 2002 B1
6410170 Chen et al. Jun 2002 B1
6411522 Frank, Jr. et al. Jun 2002 B1
6417998 Crue, Jr. et al. Jul 2002 B1
6417999 Knapp et al. Jul 2002 B1
6418000 Gibbons et al. Jul 2002 B1
6418048 Sin et al. Jul 2002 B1
6421211 Hawwa et al. Jul 2002 B1
6421212 Gibbons et al. Jul 2002 B1
6424505 Lam et al. Jul 2002 B1
6424507 Lederman et al. Jul 2002 B1
6430009 Komaki et al. Aug 2002 B1
6430806 Chen et al. Aug 2002 B1
6433965 Gopinathan et al. Aug 2002 B1
6433968 Shi et al. Aug 2002 B1
6433970 Knapp et al. Aug 2002 B1
6437945 Hawwa et al. Aug 2002 B1
6445536 Rudy et al. Sep 2002 B1
6445542 Levi et al. Sep 2002 B1
6445553 Barr et al. Sep 2002 B2
6445554 Dong et al. Sep 2002 B1
6447935 Zhang et al. Sep 2002 B1
6448765 Chen et al. Sep 2002 B1
6451514 Iitsuka Sep 2002 B1
6452742 Crue et al. Sep 2002 B1
6452765 Mahvan et al. Sep 2002 B1
6456465 Louis et al. Sep 2002 B1
6459552 Liu et al. Oct 2002 B1
6462920 Karimi Oct 2002 B1
6466401 Hong et al. Oct 2002 B1
6466402 Crue, Jr. et al. Oct 2002 B1
6466404 Crue, Jr. et al. Oct 2002 B1
6468436 Shi et al. Oct 2002 B1
6469877 Knapp et al. Oct 2002 B1
6477019 Matono et al. Nov 2002 B2
6479096 Shi et al. Nov 2002 B1
6483662 Thomas et al. Nov 2002 B1
6487040 Hsiao et al. Nov 2002 B1
6487056 Gibbons et al. Nov 2002 B1
6490125 Barr Dec 2002 B1
6496330 Crue, Jr. et al. Dec 2002 B1
6496334 Pang et al. Dec 2002 B1
6504676 Hiner et al. Jan 2003 B1
6512657 Heist et al. Jan 2003 B2
6512659 Hawwa et al. Jan 2003 B1
6512661 Louis Jan 2003 B1
6512690 Qi et al. Jan 2003 B1
6515573 Dong et al. Feb 2003 B1
6515791 Hawwa et al. Feb 2003 B1
6532823 Knapp et al. Mar 2003 B1
6535363 Hosomi et al. Mar 2003 B1
6552874 Chen et al. Apr 2003 B1
6552928 Qi et al. Apr 2003 B1
6562487 Vas'ko et al. May 2003 B1
6577470 Rumpler Jun 2003 B1
6583961 Levi et al. Jun 2003 B2
6583968 Scura et al. Jun 2003 B1
6597548 Yamanaka et al. Jul 2003 B1
6611398 Rumpler et al. Aug 2003 B1
6618223 Chen et al. Sep 2003 B1
6629357 Akoh Oct 2003 B1
6633464 Lai et al. Oct 2003 B2
6636394 Fukagawa et al. Oct 2003 B1
6639291 Sin et al. Oct 2003 B1
6650503 Chen et al. Nov 2003 B1
6650506 Risse Nov 2003 B1
6654195 Frank, Jr. et al. Nov 2003 B1
6657816 Barr et al. Dec 2003 B1
6661621 Iitsuka Dec 2003 B1
6661625 Sin et al. Dec 2003 B1
6674610 Thomas et al. Jan 2004 B1
6680863 Shi et al. Jan 2004 B1
6683763 Hiner et al. Jan 2004 B1
6687098 Huai Feb 2004 B1
6687178 Qi et al. Feb 2004 B1
6687977 Knapp et al. Feb 2004 B2
6691226 Frank, Jr. et al. Feb 2004 B1
6697294 Qi et al. Feb 2004 B1
6700738 Sin et al. Mar 2004 B1
6700759 Knapp et al. Mar 2004 B1
6704158 Hawwa et al. Mar 2004 B2
6707083 Hiner et al. Mar 2004 B1
6713801 Sin et al. Mar 2004 B1
6721138 Chen et al. Apr 2004 B1
6721149 Shi et al. Apr 2004 B1
6721203 Qi et al. Apr 2004 B1
6724569 Chen et al. Apr 2004 B1
6724572 Stoev et al. Apr 2004 B1
6729015 Matono et al. May 2004 B2
6735850 Gibbons et al. May 2004 B1
6737281 Dang et al. May 2004 B1
6744608 Sin et al. Jun 2004 B1
6747301 Hiner et al. Jun 2004 B1
6751055 Alfoqaha et al. Jun 2004 B1
6754049 Seagle et al. Jun 2004 B1
6756071 Shi et al. Jun 2004 B1
6757140 Hawwa Jun 2004 B1
6760196 Niu et al. Jul 2004 B1
6762910 Knapp et al. Jul 2004 B1
6765756 Hong et al. Jul 2004 B1
6775902 Huai et al. Aug 2004 B1
6778358 Jiang et al. Aug 2004 B1
6781927 Heanuc et al. Aug 2004 B1
6785955 Chen et al. Sep 2004 B1
6791793 Chen et al. Sep 2004 B1
6791807 Hikami et al. Sep 2004 B1
6798616 Seagle et al. Sep 2004 B1
6798625 Ueno et al. Sep 2004 B1
6801408 Chen et al. Oct 2004 B1
6801411 Lederman et al. Oct 2004 B1
6803615 Sin et al. Oct 2004 B1
6806035 Atireklapvarodom et al. Oct 2004 B1
6807030 Hawwa et al. Oct 2004 B1
6807332 Hawwa Oct 2004 B1
6809899 Chen et al. Oct 2004 B1
6816345 Knapp et al. Nov 2004 B1
6828897 Nepela Dec 2004 B1
6829160 Qi et al. Dec 2004 B1
6829819 Crue, Jr. et al. Dec 2004 B1
6833979 Knapp et al. Dec 2004 B1
6834010 Qi et al. Dec 2004 B1
6859343 Alfoqaha et al. Feb 2005 B1
6859997 Tong et al. Mar 2005 B1
6861937 Feng et al. Mar 2005 B1
6870712 Chen et al. Mar 2005 B2
6873494 Chen et al. Mar 2005 B2
6873547 Shi et al. Mar 2005 B1
6879464 Sun et al. Apr 2005 B2
6888184 Shi et al. May 2005 B1
6888704 Diao et al. May 2005 B1
6891702 Tang May 2005 B1
6894871 Alfoqaha et al. May 2005 B2
6894877 Crue, Jr. et al. May 2005 B1
6906894 Chen et al. Jun 2005 B2
6909578 Missell et al. Jun 2005 B1
6912106 Chen et al. Jun 2005 B1
6934113 Chen Aug 2005 B1
6934129 Zhang et al. Aug 2005 B1
6940688 Jiang et al. Sep 2005 B2
6942824 Li Sep 2005 B1
6943993 Chang et al. Sep 2005 B2
6944938 Crue, Jr. et al. Sep 2005 B1
6947258 Li Sep 2005 B1
6950266 McCaslin et al. Sep 2005 B1
6954332 Hong et al. Oct 2005 B1
6958885 Chen et al. Oct 2005 B1
6961221 Niu et al. Nov 2005 B1
6969989 Mei Nov 2005 B1
6975486 Chen et al. Dec 2005 B2
6987643 Seagle Jan 2006 B1
6989962 Dong et al. Jan 2006 B1
6989972 Stoev et al. Jan 2006 B1
7006327 Krounbi et al. Feb 2006 B2
7007372 Chen et al. Mar 2006 B1
7012832 Sin et al. Mar 2006 B1
7023658 Knapp et al. Apr 2006 B1
7026063 Ueno et al. Apr 2006 B2
7027268 Zhu et al. Apr 2006 B1
7027274 Sin et al. Apr 2006 B1
7035046 Young et al. Apr 2006 B1
7041985 Wang et al. May 2006 B1
7046490 Ueno et al. May 2006 B1
7054113 Seagle et al. May 2006 B1
7057857 Niu et al. Jun 2006 B1
7059868 Yan Jun 2006 B1
7070698 Le Jul 2006 B2
7092195 Liu et al. Aug 2006 B1
7110289 Sin et al. Sep 2006 B1
7111382 Knapp et al. Sep 2006 B1
7113366 Wang et al. Sep 2006 B1
7114241 Kubota et al. Oct 2006 B2
7116517 He et al. Oct 2006 B1
7124654 Davies et al. Oct 2006 B1
7126788 Liu et al. Oct 2006 B1
7126790 Liu et al. Oct 2006 B1
7131346 Buttar et al. Nov 2006 B1
7133253 Seagle et al. Nov 2006 B1
7134185 Knapp et al. Nov 2006 B1
7154715 Yamanaka et al. Dec 2006 B2
7170725 Zhou et al. Jan 2007 B1
7177117 Jiang et al. Feb 2007 B1
7193815 Stoev et al. Mar 2007 B1
7196880 Anderson et al. Mar 2007 B1
7199973 Lille Apr 2007 B2
7199974 Alfoqaha Apr 2007 B1
7199975 Pan Apr 2007 B1
7211339 Seagle et al. May 2007 B1
7212379 Hsu et al. May 2007 B2
7212380 Hsiao et al. May 2007 B2
7212384 Stoev et al. May 2007 B1
7238292 He et al. Jul 2007 B1
7239478 Sin et al. Jul 2007 B1
7248431 Liu et al. Jul 2007 B1
7248433 Stoev et al. Jul 2007 B1
7248449 Seagle Jul 2007 B1
7271982 MacDonald et al. Sep 2007 B2
7280325 Pan Oct 2007 B1
7283327 Liu et al. Oct 2007 B1
7284316 Huai et al. Oct 2007 B1
7286329 Chen et al. Oct 2007 B1
7289303 Sin et al. Oct 2007 B1
7292409 Stoev et al. Nov 2007 B1
7296337 McFadyen Nov 2007 B2
7296339 Yang et al. Nov 2007 B1
7307814 Seagle et al. Dec 2007 B1
7307818 Park et al. Dec 2007 B1
7310204 Stoev et al. Dec 2007 B1
7318947 Park et al. Jan 2008 B1
7322095 Guan et al. Jan 2008 B2
7333295 Medina et al. Feb 2008 B1
7337530 Stoev et al. Mar 2008 B1
7342752 Zhang et al. Mar 2008 B1
7343667 Lille Mar 2008 B2
7349170 Rudman et al. Mar 2008 B1
7349179 He et al. Mar 2008 B1
7354664 Jiang et al. Apr 2008 B1
7363697 Dunn et al. Apr 2008 B1
7371152 Newman May 2008 B1
7372665 Stoev et al. May 2008 B1
7375926 Stoev et al. May 2008 B1
7377024 Chen May 2008 B2
7379269 Krounbi et al. May 2008 B1
7386933 Krounbi et al. Jun 2008 B1
7389577 Shang et al. Jun 2008 B1
7417824 Kameda Aug 2008 B2
7417832 Erickson et al. Aug 2008 B1
7419891 Chen et al. Sep 2008 B1
7428124 Song et al. Sep 2008 B1
7430098 Song et al. Sep 2008 B1
7436620 Kang et al. Oct 2008 B1
7436638 Pan Oct 2008 B1
7440220 Kang et al. Oct 2008 B1
7440230 Hsu et al. Oct 2008 B2
7443632 Stoev et al. Oct 2008 B1
7444740 Chung et al. Nov 2008 B1
7446980 Le Nov 2008 B2
7468862 Sasaki et al. Dec 2008 B2
7493688 Wang et al. Feb 2009 B1
7506431 Hsiao et al. Mar 2009 B2
7508627 Zhang et al. Mar 2009 B1
7522377 Jiang et al. Apr 2009 B1
7522379 Krounbi et al. Apr 2009 B1
7522382 Pan Apr 2009 B1
7532432 Ikeda et al. May 2009 B2
7542246 Song et al. Jun 2009 B1
7551406 Thomas et al. Jun 2009 B1
7552523 He et al. Jun 2009 B1
7554767 Hu et al. Jun 2009 B1
7558019 Le et al. Jul 2009 B2
7562437 Pentek et al. Jul 2009 B2
7576951 Allen et al. Aug 2009 B2
7583466 Kermiche et al. Sep 2009 B2
7595967 Moon et al. Sep 2009 B1
7633713 Chen et al. Dec 2009 B2
7639457 Chen et al. Dec 2009 B1
7660080 Liu et al. Feb 2010 B1
7672080 Tang et al. Mar 2010 B1
7672086 Jiang Mar 2010 B1
7684160 Erickson et al. Mar 2010 B1
7688546 Bai et al. Mar 2010 B1
7691434 Zhang et al. Apr 2010 B1
7695761 Shen et al. Apr 2010 B1
7712206 Jiang et al. May 2010 B2
7719795 Hu et al. May 2010 B2
7726009 Liu et al. Jun 2010 B1
7729086 Song et al. Jun 2010 B1
7729087 Stoev et al. Jun 2010 B1
7736823 Wang et al. Jun 2010 B1
7748104 Bonhote et al. Jul 2010 B2
7757380 Baer et al. Jul 2010 B2
7768743 Guthrie et al. Aug 2010 B2
7770281 Pentek Aug 2010 B2
7777988 Guan et al. Aug 2010 B2
7785666 Sun et al. Aug 2010 B1
7788797 Kim et al. Sep 2010 B2
7793406 Zheng Sep 2010 B2
7796356 Fowler et al. Sep 2010 B1
7800858 Bajikar et al. Sep 2010 B1
7804666 Guan et al. Sep 2010 B2
7819979 Chen et al. Oct 2010 B1
7821736 Che et al. Oct 2010 B2
7829264 Wang et al. Nov 2010 B1
7846643 Sun et al. Dec 2010 B1
7855854 Hu et al. Dec 2010 B2
7869160 Pan et al. Jan 2011 B1
7872824 Macchioni et al. Jan 2011 B1
7872833 Hu et al. Jan 2011 B2
7894159 Lengsfield, III et al. Feb 2011 B2
7898766 Guan et al. Mar 2011 B2
7910267 Zeng et al. Mar 2011 B1
7911735 Sin et al. Mar 2011 B1
7911737 Jiang et al. Mar 2011 B1
7916426 Hu et al. Mar 2011 B2
7918013 Dunn et al. Apr 2011 B1
7920358 Jiang et al. Apr 2011 B2
7924528 Sasaki et al. Apr 2011 B2
7968219 Jiang et al. Jun 2011 B1
7969684 Le et al. Jun 2011 B2
7982989 Shi et al. Jul 2011 B1
7995307 Zheng Aug 2011 B2
8008912 Shang Aug 2011 B1
8012804 Wang et al. Sep 2011 B1
8015692 Zhang et al. Sep 2011 B1
8018677 Chung et al. Sep 2011 B1
8018678 Zhang et al. Sep 2011 B1
8018679 Hsiao et al. Sep 2011 B2
8024748 Moravec et al. Sep 2011 B1
8031433 Yan et al. Oct 2011 B2
8036069 Jin et al. Oct 2011 B1
8051552 Jiang et al. Nov 2011 B2
8066892 Guthrie et al. Nov 2011 B2
8072705 Wang et al. Dec 2011 B1
8074345 Anguelouch et al. Dec 2011 B1
8077418 Hu et al. Dec 2011 B1
8077434 Shen et al. Dec 2011 B1
8077435 Liu et al. Dec 2011 B1
8077557 Hu et al. Dec 2011 B1
8079135 Shen et al. Dec 2011 B1
8081403 Chen et al. Dec 2011 B1
8091210 Sasaki et al. Jan 2012 B1
8097846 Anguelouch et al. Jan 2012 B1
8104166 Zhang et al. Jan 2012 B1
8111479 Chen et al. Feb 2012 B2
8116043 Leng et al. Feb 2012 B2
8116171 Lee Feb 2012 B1
8125856 Li et al. Feb 2012 B1
8134794 Wang Mar 2012 B1
8136224 Sun et al. Mar 2012 B1
8136225 Zhang et al. Mar 2012 B1
8136805 Lee Mar 2012 B1
8141235 Zhang Mar 2012 B1
8146236 Luo et al. Apr 2012 B1
8149536 Yang et al. Apr 2012 B1
8151441 Rudy et al. Apr 2012 B1
8163185 Sun et al. Apr 2012 B1
8164760 Willis Apr 2012 B2
8164855 Gibbons et al. Apr 2012 B1
8164864 Kaiser et al. Apr 2012 B2
8165709 Rudy Apr 2012 B1
8166631 Tran et al. May 2012 B1
8166632 Zhang et al. May 2012 B1
8169473 Yu et al. May 2012 B1
8171618 Wang et al. May 2012 B1
8179636 Bai et al. May 2012 B1
8191237 Luo et al. Jun 2012 B1
8194365 Leng et al. Jun 2012 B1
8194366 Li et al. Jun 2012 B1
8196285 Zhang et al. Jun 2012 B1
8200054 Li et al. Jun 2012 B1
8201320 Allen et al. Jun 2012 B2
8203800 Li et al. Jun 2012 B2
8208350 Hu et al. Jun 2012 B1
8220140 Wang et al. Jul 2012 B1
8222599 Chien Jul 2012 B1
8225488 Zhang et al. Jul 2012 B1
8227023 Liu et al. Jul 2012 B1
8228633 Tran et al. Jul 2012 B1
8231796 Li et al. Jul 2012 B1
8233233 Shen et al. Jul 2012 B1
8233235 Chen et al. Jul 2012 B2
8233248 Li et al. Jul 2012 B1
8238056 Guan et al. Aug 2012 B2
8248728 Yamaguchi et al. Aug 2012 B2
8248896 Yuan et al. Aug 2012 B1
8254060 Shi et al. Aug 2012 B1
8257597 Guan et al. Sep 2012 B1
8259410 Bai et al. Sep 2012 B1
8259539 Hu et al. Sep 2012 B1
8262918 Li et al. Sep 2012 B1
8262919 Luo et al. Sep 2012 B1
8264792 Bai et al. Sep 2012 B2
8264797 Emley Sep 2012 B2
8264798 Guan et al. Sep 2012 B1
8270126 Roy et al. Sep 2012 B1
8276258 Tran et al. Oct 2012 B1
8277669 Chen et al. Oct 2012 B1
8279719 Hu et al. Oct 2012 B1
8284517 Sun et al. Oct 2012 B1
8288204 Wang et al. Oct 2012 B1
8289821 Huber Oct 2012 B1
8291743 Shi et al. Oct 2012 B1
8295132 Jin et al. Oct 2012 B2
8300358 Maruyama et al. Oct 2012 B2
8307539 Rudy et al. Nov 2012 B1
8307540 Tran et al. Nov 2012 B1
8308921 Hiner et al. Nov 2012 B1
8310785 Zhang et al. Nov 2012 B1
8310901 Batra et al. Nov 2012 B1
8315019 Mao et al. Nov 2012 B1
8316527 Hong et al. Nov 2012 B2
8320076 Shen et al. Nov 2012 B1
8320077 Tang et al. Nov 2012 B1
8320219 Wolf et al. Nov 2012 B1
8320220 Yuan et al. Nov 2012 B1
8320722 Yuan et al. Nov 2012 B1
8322022 Yi et al. Dec 2012 B1
8322023 Zeng et al. Dec 2012 B1
8323727 Pentek et al. Dec 2012 B2
8325569 Shi et al. Dec 2012 B1
8333008 Sin et al. Dec 2012 B1
8334093 Zhang et al. Dec 2012 B2
8336194 Yuan et al. Dec 2012 B2
8339738 Tran et al. Dec 2012 B1
8339749 Mochizuki et al. Dec 2012 B2
8341826 Jiang et al. Jan 2013 B1
8343319 Li et al. Jan 2013 B1
8343364 Gao et al. Jan 2013 B1
8345383 Yan et al. Jan 2013 B2
8347488 Hong et al. Jan 2013 B2
8349195 Si et al. Jan 2013 B1
8351307 Wolf et al. Jan 2013 B1
8355222 Mino et al. Jan 2013 B2
8357244 Zhao et al. Jan 2013 B1
8373945 Luo et al. Feb 2013 B1
8375564 Luo et al. Feb 2013 B1
8375565 Hu et al. Feb 2013 B2
8381391 Park et al. Feb 2013 B2
8385157 Champion et al. Feb 2013 B1
8385158 Hu et al. Feb 2013 B1
8394280 Wan et al. Mar 2013 B1
8400731 Li et al. Mar 2013 B1
8404128 Zhang et al. Mar 2013 B1
8404129 Luo et al. Mar 2013 B1
8405930 Li et al. Mar 2013 B1
8409453 Jiang et al. Apr 2013 B1
8413317 Wan et al. Apr 2013 B1
8416540 Li et al. Apr 2013 B1
8419953 Su et al. Apr 2013 B1
8419954 Chen et al. Apr 2013 B1
8422176 Leng et al. Apr 2013 B1
8422342 Lee Apr 2013 B1
8422841 Shi et al. Apr 2013 B1
8424192 Yang et al. Apr 2013 B1
8441756 Sun et al. May 2013 B1
8443510 Shi et al. May 2013 B1
8444866 Guan et al. May 2013 B1
8449948 Medina et al. May 2013 B2
8451556 Wang et al. May 2013 B1
8451563 Zhang et al. May 2013 B1
8454846 Zhou et al. Jun 2013 B1
8455119 Jiang et al. Jun 2013 B1
8456961 Wang et al. Jun 2013 B1
8456963 Hu et al. Jun 2013 B1
8456964 Yuan et al. Jun 2013 B1
8456966 Shi et al. Jun 2013 B1
8456967 Mallary Jun 2013 B1
8458892 Si et al. Jun 2013 B2
8462592 Wolf et al. Jun 2013 B1
8468682 Zhang Jun 2013 B1
8470186 Chen et al. Jun 2013 B2
8472288 Wolf et al. Jun 2013 B1
8480911 Osugi et al. Jul 2013 B1
8486285 Zhou et al. Jul 2013 B2
8486286 Gao et al. Jul 2013 B1
8488272 Tran et al. Jul 2013 B1
8491801 Tanner et al. Jul 2013 B1
8491802 Gao et al. Jul 2013 B1
8493693 Zheng et al. Jul 2013 B1
8493695 Kaiser et al. Jul 2013 B1
8495813 Hu et al. Jul 2013 B1
8498084 Leng et al. Jul 2013 B1
8506828 Osugi et al. Aug 2013 B1
8514517 Batra et al. Aug 2013 B1
8518279 Wang et al. Aug 2013 B1
8518832 Yang et al. Aug 2013 B1
8520336 Liu et al. Aug 2013 B1
8520337 Liu et al. Aug 2013 B1
8524068 Medina et al. Sep 2013 B2
8526275 Yuan et al. Sep 2013 B1
8531801 Xiao et al. Sep 2013 B1
8532450 Wang et al. Sep 2013 B1
8533937 Wang et al. Sep 2013 B1
8537494 Pan et al. Sep 2013 B1
8537495 Luo et al. Sep 2013 B1
8537502 Park et al. Sep 2013 B1
8545999 Leng et al. Oct 2013 B1
8547659 Bai et al. Oct 2013 B1
8547667 Roy et al. Oct 2013 B1
8547730 Shen et al. Oct 2013 B1
8555486 Medina et al. Oct 2013 B1
8559141 Pakala et al. Oct 2013 B1
8563146 Zhang et al. Oct 2013 B1
8565049 Tanner et al. Oct 2013 B1
8576517 Tran et al. Nov 2013 B1
8578594 Jiang et al. Nov 2013 B2
8582234 Linville et al. Nov 2013 B2
8582238 Liu et al. Nov 2013 B1
8582241 Yu et al. Nov 2013 B1
8582253 Zheng et al. Nov 2013 B1
8588039 Shi et al. Nov 2013 B1
8593914 Wang et al. Nov 2013 B2
8597528 Roy et al. Dec 2013 B1
8599520 Liu et al. Dec 2013 B1
8599657 Lee Dec 2013 B1
8603593 Roy et al. Dec 2013 B1
8607438 Gao et al. Dec 2013 B1
8607439 Wang et al. Dec 2013 B1
8611035 Bajikar et al. Dec 2013 B1
8611054 Shang et al. Dec 2013 B1
8611055 Pakala et al. Dec 2013 B1
8614864 Hong et al. Dec 2013 B1
8619512 Yuan et al. Dec 2013 B1
8625233 Ji et al. Jan 2014 B1
8625941 Shi et al. Jan 2014 B1
8628672 Si et al. Jan 2014 B1
8630068 Mauri et al. Jan 2014 B1
8634280 Wang et al. Jan 2014 B1
8638529 Leng et al. Jan 2014 B1
8643980 Fowler et al. Feb 2014 B1
8649123 Zhang et al. Feb 2014 B1
8665561 Knutson et al. Mar 2014 B1
8670211 Sun et al. Mar 2014 B1
8670213 Zeng et al. Mar 2014 B1
8670214 Knutson et al. Mar 2014 B1
8670294 Shi et al. Mar 2014 B1
8670295 Hu et al. Mar 2014 B1
8675318 Ho et al. Mar 2014 B1
8675455 Krichevsky et al. Mar 2014 B1
8681594 Shi et al. Mar 2014 B1
8689430 Chen et al. Apr 2014 B1
8693141 Elliott et al. Apr 2014 B1
8703397 Zeng et al. Apr 2014 B1
8705205 Li et al. Apr 2014 B1
8711518 Zeng et al. Apr 2014 B1
8711528 Xiao et al. Apr 2014 B1
8717709 Shi et al. May 2014 B1
8720044 Tran et al. May 2014 B1
8721902 Wang et al. May 2014 B1
8724259 Liu et al. May 2014 B1
8749790 Tanner et al. Jun 2014 B1
8749920 Knutson et al. Jun 2014 B1
8753903 Tanner et al. Jun 2014 B1
8760807 Zhang et al. Jun 2014 B1
8760818 Diao et al. Jun 2014 B1
8760819 Liu et al. Jun 2014 B1
8760822 Li et al. Jun 2014 B1
8760823 Chen et al. Jun 2014 B1
8763235 Wang et al. Jul 2014 B1
8780498 Jiang et al. Jul 2014 B1
8780505 Xiao Jul 2014 B1
8786983 Liu et al. Jul 2014 B1
8790524 Luo et al. Jul 2014 B1
8790527 Luo et al. Jul 2014 B1
8792208 Liu et al. Jul 2014 B1
8792312 Wang et al. Jul 2014 B1
8793866 Zhang et al. Aug 2014 B1
8797680 Luo et al. Aug 2014 B1
8797684 Tran et al. Aug 2014 B1
8797686 Bai et al. Aug 2014 B1
8797692 Guo et al. Aug 2014 B1
8813324 Emley et al. Aug 2014 B2
20020034043 Okada et al. Mar 2002 A1
20050219747 Hsu et al. Oct 2005 A1
20060268456 Sasaki et al. Nov 2006 A1
20070230046 Le et al. Oct 2007 A1
20070236831 Che et al. Oct 2007 A1
20080002292 Le et al. Jan 2008 A1
20080112082 Guan et al. May 2008 A1
20080198507 Maruyama et al. Aug 2008 A1
20080225441 Yamada et al. Sep 2008 A1
20080259498 Lengsfield et al. Oct 2008 A1
20080278861 Jiang et al. Nov 2008 A1
20090002885 Sin Jan 2009 A1
20090021863 Zheng Jan 2009 A1
20090103211 Chen et al. Apr 2009 A1
20090116145 Guan et al. May 2009 A1
20090147410 Jiang et al. Jun 2009 A1
20090154012 Mochizuki et al. Jun 2009 A1
20090154019 Hsiao et al. Jun 2009 A1
20090268344 Guan et al. Oct 2009 A1
20100061016 Han et al. Mar 2010 A1
20100165517 Araki et al. Jul 2010 A1
20100172054 Yamaguchi et al. Jul 2010 A1
20100277832 Bai et al. Nov 2010 A1
20100290157 Zhang et al. Nov 2010 A1
20110086240 Xiang et al. Apr 2011 A1
20110134567 Chen et al. Jun 2011 A1
20110134569 Allen et al. Jun 2011 A1
20110151279 Allen et al. Jun 2011 A1
20120026629 Hirata et al. Feb 2012 A1
20120044598 Bai et al. Feb 2012 A1
20120087042 Zhou et al. Apr 2012 A1
20120111826 Chen et al. May 2012 A1
20120216378 Emley et al. Aug 2012 A1
20120237878 Zeng et al. Sep 2012 A1
20120298621 Gao Nov 2012 A1
20120314324 Guan Dec 2012 A1
20130216702 Kaiser et al. Aug 2013 A1
20130216863 Li et al. Aug 2013 A1
20130257421 Shang et al. Oct 2013 A1
20140154529 Yang et al. Jun 2014 A1
20140175050 Zhang et al. Jun 2014 A1
Provisional Applications (1)
Number Date Country
61917757 Dec 2013 US