USPatent applicationPatented

Magnetic reader having a crystal decoupling structure

Granted 29 Nov 2016 · 3 office actions

Current assignee: JPMorgan Chase Bank · originally Western Digital

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Inventors: Zhipeng Li, Jianxin Fang, Christian Kaiser, Tong Zhao +4 · Examiner: Carlos E Garcia · AU 2688 · TC 2600

Application· this page
14/749,260
filed 24 Jun 2015
Publication
Not published
not published
Patent
US 9,508,365
granted 29 Nov 2016

Life of the application

18 dated events
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Abstract

A magnetic read apparatus has an air-bearing surface (ABS) and includes a shield, a crystal decoupling structure on the shield and a read sensor on the crystal decoupling structure. The crystal decoupling structure includes at least one of a magnetic high crystalline temperature amorphous alloy layer and a combination of a high crystalline temperature amorphous layer and an amorphous magnetic layer. The high crystalline temperature amorphous layer has a crystalline temperature of at least three hundred degrees Celsius. The amorphous magnetic layer is amorphous as-deposited.

Description

7 parts
›BACKGROUND

FIG. 1 depicts a flow chart of a conventional method for fabricating a read transducer used in magnetic recording technology applications. The conventional read transducer includes shields, magnetic bias structures, and a sensor. The read sensor is between the shields in the down track direction and between the magnetic bias structures in the cross-track direction. The read sensor is typically a giant magnetoresistive (GMR) sensor or tunneling magnetoresistive (TMR) sensor. The read sensor typically includes an antiferromagnetic (AFM) layer, a pinned layer on the AFM layer, a nonmagnetic spacer layer, and a free layer. In addition, seed layer(s) are typically be used. The free layer has a magnetization sensitive to an external magnetic field. Thus, the free layer functions as a sensor layer for the magnetoresistive sensor.

The bottom shield is deposited, via step 12 . Step 12 typically includes depositing a soft material, such as NiFe. A layer of CoFeB is deposited, via step 14 . CoFeB is typically amorphous as-deposited. A NiFe magnetic seed layer is then deposited, via step 16 . The amorphous CoFeB layer thus separates the NiFe in the magnetic seed layer from the NiFe in the shield.

After deposition of the NiFe magnetic seed layer in step 16 , the substrate for the reader is heated, via step 18 . The substrate is heated to nominally two hundred eighty-five degrees Celsius. Thus, the portion of the read transducer that has been fabricated is heated to approximately two hundred eighty five degrees Celsius. While the substrate is heated, the AFM layer for the sensor is deposited, via step 20 . The heating is then typically terminated.

The remainder of the sensor stack is deposited, via step 22 . Thus, the tunneling barrier or conductive spacer layer and free layer are provided in step 22 . The sensor is defined, via step 24 . Step 24 typically includes masking the layers that have been deposited and milling the exposed layers. Thus, the track width in the cross track direction and the stripe height in a direction perpendicular to the ABS may be defined. The magnetic bias structures and top shield are also provided.

Although the method for fabricating conventional transducer functions, there are drawbacks. The exchange coupling between the AFM layer and the pinned layer, as measured by the exchange field (the shift in the hysteresis loop for the pinned layer) may be lower than desired. The quality of the tunneling barrier layer deposited in step 22 may not be as desired. Accordingly, what is needed is a system and method for improving the performance of a magnetic recording read transducer.

›BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 depicts a flow chart of a method for fabricating a conventional magnetic recording read transducer.

FIGS. 2A-2B depicts side and ABS views of an exemplary embodiment of a portion of a magnetic read apparatus.

FIG. 3 depicts an ABS view of another exemplary embodiment of a portion of a portion of a magnetic read transducer.

FIG. 4 depicts another exemplary embodiment of a portion of a magnetic read transducer.

FIG. 5 depicts another exemplary embodiment of a portion of a magnetic read transducer.

FIG. 6 depicts another exemplary embodiment of a portion of a magnetic read transducer.

FIG. 7 depicts another exemplary embodiment of a portion of a magnetic read transducer.

FIG. 8 depicts another exemplary embodiment of a portion of a magnetic read transducer.

FIG. 9 depicts another exemplary embodiment of a portion of a magnetic read transducer.

FIG. 10 is flow chart depicting an exemplary embodiment of a method for providing a magnetic recording read transducer.

›DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS · 1 of 5

FIGS. 2A-2B depict side and ABS views of an exemplary embodiment of a portion of a magnetic read apparatus 100 . For clarity, FIGS. 2A-2B are not to scale. In the embodiment shown, the magnetic read apparatus is a disk drive including a media 101 , a slider 102 and a read transducer 103 . The read transducer 103 may be part of a read head or may be part of a merged head that also includes a write transducer. Further, only a portion of the components of the read transducer 103 and disk drive 100 are depicted.

The transducer 103 includes soft magnetic shields 104 and 170 , insulator 106 , read sensor 130 , capping layer 150 and side bias structures 160 that may be separated from the read sensor 110 by the insulating layer 106 . The transducer 103 also includes a crystal decoupling structure 110 and may include a seed structure 120 . The crystal decoupling structure is between the sensor 130 and the shield 104 . Further, the crystal decoupling structure 110 is between the seed structure 120 and the shield 104 . The shields 104 and 170 are soft magnetic shields. For example, the shields 104 and 170 may be NiFe shields. The seed structure 120 includes a magnetic seed layer. In some embodiments, the seed structure 120 also includes a nonmagnetic spacer layer.

The crystal decoupling structure 110 is used to break the structural coupling between the shield 104 and the read sensor 130 or magnetic seed layer 120 . In addition, the crystal decoupling structure 110 allows the magnetic coupling between the shield 104 and the read sensor 130 or magnetic seed layer 120 to be maintained. For example, the shield 104 may have a large grain size while the seed structure 120 and/or sensor 130 may have a smaller grain size. Similarly, the shield 104 may have a particular crystal structure, such as face-centered cubic (FCC), and orientation while the seed structure 120 and/or sensor 130 may have a different crystal structure and/or orientation. However, the shield 104 may still be magnetically (e.g. exchange) coupled with the seed structure 120 and/or sensor 130 .

In order to achieve these characteristics, the crystal decoupling structure 110 includes one or more layers that have a high crystalline temperature. The crystalline temperature is the temperature at which the material transitions from amorphous to crystalline. This high crystalline temperature is at least three hundred degrees Celsius. In some embodiments, the high crystalline temperature for the crystal decoupling structure 110 is at least three hundred and fifty degrees Celsius. The high crystalline temperature may be higher, for example four hundred degrees Celsius or more. The layer(s) having the high crystalline temperature are amorphous as-deposited and remain amorphous up to the high crystalline temperature.

The crystal decoupling structure 110 may thus include at least one of a magnetic high crystalline temperature amorphous alloy layer and a combination of a high crystalline temperature amorphous layer and an amorphous magnetic layer. A high crystalline temperature amorphous layer is a layer that has the high crystalline temperature described above. Such a layer may be nonmagnetic. Thus, such a layer is amorphous up to at least the crystalline temperature. This layer may include materials such as Ta, Hf, W and/or Ti. In some embodiments, for example, the high crystalline temperature amorphous layer is a Ta layer. The amorphous magnetic layer is amorphous as-deposited and magnetic. However, the amorphous magnetic layer need not have an intrinsic high crystalline temperature. For example, CoFeB may be used for the amorphous magnetic layer. Because of the presence of the high crystalline temperature layer, however, the amorphous magnetic layer may remain amorphous to higher temperatures than in the absence of the high crystalline temperature layer.

A magnetic high crystalline temperature amorphous alloy is a layer that is magnetic, has the high crystalline temperature described above and is an alloy of particular materials. For example, the high crystalline temperature amorphous alloy may be an alloy of CoFeB and one or more of Ta, Hf, W and Ti. For example, a CoFeBTa layer may be used. Note that CoFeB, CoFeBTa and other like materials do not indicate a particular stoichiometry other than the presence of the materials listed. The crystal decoupling structure is thus amorphous as deposited and has a high crystalline temperature.

Because of the crystal decoupling structure 110 , performance of the read sensor 130 and magnetic read apparatus 100 may be improved. For example, portions of the transducer 103 may be brought to higher temperatures during fabrication without crystallizing the structure 110 . Thus, the crystal structure of the shield 104 may be decoupled from that of the seed structure 120 and/or read sensor 130 . As a result, portions of the read sensor 130 may be grown at an elevated temperature on the seed structure 120 having the desired crystallographic properties. Portions of the read sensor 130 may, therefore, also have the desired crystal structure and magnetic properties. For example, the exchange field between an AFM layer (not shown in FIGS. 2A-2B ) and a pinned layer (not shown in FIGS. 2A-2B ) may be improved. Thus, the magnetic moment of the pinned layer may be better fixed in a particular direction. The transducer 103 may also be subjected to higher anneal temperatures. For example, annealing for a tunneling barrier layer (not shown in FIGS. 2A-2B ) without adversely affecting the crystal structure of the layers 110 and 120 . Thus, the magnetoresistance of the sensor 130 may be enhanced. Consequently, use of the crystal decoupling structure 110 may improve performance of the magnetic read apparatus 100 .

FIG. 3 depicts an ABS view of another exemplary embodiment of a portion of a magnetic read apparatus 100 ′. For clarity, FIG. 3 is not to scale. The transducer 103 ′/magnetic read apparatus 100 ′ are analogous to the read transducer 103 and magnetic read apparatus 100 of FIGS. 2A and 2B . Consequently, similar components have analogous labels. The read transducer 103 ′ thus includes soft magnetic shields 104 and 170 , insulator 106 , crystal decoupling structure 110 , seed structure 120 ′, read sensor 130 ′, capping layer 150 and side bias structures 160 that are analogous to the soft magnetic shields 104 and 170 , insulator 106 , crystal decoupling structure 110 , seed structure 120 , read sensor 130 , capping layer 150 and side bias structures 160 , respectively.

›DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS · 2 of 5

In the transducer 103 ′, the read sensor 130 ′ is explicitly depicted as including a pinning layer 131 , a pinned layer 132 , a nonmagnetic layer 133 , a reference layer 134 , a nonmagnetic spacer layer 135 and a free layer 136 . The pinned layer 132 , nonmagnetic spacer layer 133 and reference layer 134 together form a pinned structure, such as a synthetic antiferromagnet. Thus, the magnetic moments of the layers 132 and 134 may be antiferromagnetically coupled through the layer 133 via an RKKY interaction. In other embodiments, the layers 133 and 134 may be omitted. The pinned layer 132 has its magnetic moment fixed, or pinned, by an exchange interaction with the pinning layer 131 . In the embodiment shown, the pinning layer 131 is an AFM layer. The nonmagnetic spacer layer 133 may be conductive or an insulating tunneling barrier layer, such as crystalline MgO. The read sensor 130 is, therefore, a giant magnetoresistive or tunneling magnetoresistive read sensor in the embodiment shown. Thus, the resistance of the read sensor 130 may be used to read data.

The seed structure 120 ′ is shown as explicitly including layers 122 and 124 . The magnetic seed layer 122 may be a soft magnetic layer, such as NiFe. The spacer layer 124 is nonmagnetic and conductive. The seed structure 120 ′ has the appropriate crystal structure and orientation for growth of the AFM layer 131 .

The magnetic read apparatus 100 ′ and read transducer 103 ′ may share the benefits of the magnetic read apparatus 100 and read transducer 103 , respectively. The crystal decoupling structure 110 may improve performance of the read sensor 130 ′. For example, portions of the transducer 103 ′ may be brought to higher temperatures during fabrication without crystallizing the structure 110 . Thus, the crystal structure of the shield 104 may be decoupled from that of the seed structure 120 ′. For example, the AFM layer 131 may be grown at an elevated temperature up to or near the high crystalline temperature of the crystal decoupling structure 110 . For example, the substrate (layers below the AFM layer 131 ) may be heated to three hundred degrees Celsius (or higher) for and during deposition of the AFM layer 131 . Because of its high crystalline temperature, the crystal decoupling structure 110 may retain its amorphous structure during this heating. Thus, the crystal structure of the magnetic seed layer 122 may remain unaffected by the presence of the shield 104 . For example, the grain size of the magnetic seed layer 122 may remain small throughout fabrication of the transducer 103 ′. The AFM layer 131 may then be grown on the magnetic seed structure 120 having the desired crystallographic properties. The AFM layer 131 may, therefore, also have the desired crystal structure and magnetic properties. For example, the exchange field between the AFM layer and a pinned layer may be improved. This is in contrast to growth using the conventional method 10 , for which the CoFeB layer may crystallize, allowing the crystal structure of the underlying shield to affect the seed layer and, therefore, the AFM layer. The transducer 103 ′ may also be subjected to higher anneal temperatures for a tunneling barrier layer 135 without adversely affecting the crystal structure of the layers 110 and 120 ′. Thus, the magnetoresistance of the sensor 130 ′ may be enhanced. Consequently, performance of the magnetic transducer 103 ′ and magnetic read apparatus 100 ′ may be improved.

FIG. 4 depicts an ABS view of another exemplary embodiment of a portion of a magnetic read transducer including the crystal decoupling structure 110 ′. For clarity, FIG. 4 is not to scale and only a portion of the transducer is shown. In particular, the crystal decoupling structure 110 ′ and shield 104 that are analogous to the crystalline decoupling structure 110 and shield 104 , respectively, are shown.

The crystal decoupling structure 110 ′ includes a high crystalline temperature layer 112 and an amorphous magnetic layer 114 . The high crystalline temperature layer 112 has a crystalline temperature of at least three hundred degrees Celsius. As stated previously, the crystalline temperature is the temperature at which the layer transitions from amorphous (as-deposited) to crystalline. The high crystalline temperature layer 112 may have a crystalline temperature of at least three hundred fifty degrees Celsius. In some embodiments, the crystalline temperature of the layer 112 is at least four hundred degrees Celsius. For example, the layer 112 may include one or more of Ta, Hf, W and Ti. In some embodiments, the layer 112 is a Ta layer. A Ta layer 112 , for example, has a crystalline temperature of four hundred degrees Celsius. The high crystalline temperature layer 112 is also desired to be thin. In some embodiments, the high crystalline temperature layer 112 has a thickness of not more than three Angstroms. The high crystalline temperature layer 112 may have a thickness of at least one Angstrom and not more than two Angstroms. In some embodiments, therefore, the high crystalline temperature layer 112 is less than one monolayer thick.

The amorphous magnetic layer 114 is magnetic and amorphous as-deposited. At high temperatures, the amorphous magnetic layer 114 may crystallize. For example, the amorphous magnetic layer 114 may be a CoFeB layer. The thickness of such an amorphous magnetic layer may be at least ten Angstroms and not more than thirty Angstroms. If the high crystalline temperature layer 112 is omitted, the CoFeB layer 114 would have a crystalline temperature of not more than three hundred degrees Celsius and may start crystallizing at a temperature of approximately two hundred eighty-five degrees Celsius. In the presence of the high crystalline temperature layer 112 , the crystalline temperature of the CoFeB layer 114 may be high. In some embodiments, the crystalline temperature of the amorphous magnetic layer 114 may be approximately the same as the high crystalline temperature layer 112 . In the embodiment shown in FIG. 4 , the high crystalline temperature layer 112 is between the amorphous magnetic layer 114 and the shield 104 . In some embodiments, the high crystalline temperature layer 112 adjoins, or shares an interface with, the shield 104 . The high crystalline temperature layer 112 may also adjoin the amorphous magnetic layer 112 .

›DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS · 3 of 5

A magnetic read apparatus and read transducer that utilizes the crystal decoupling structure 110 ′ may share the benefits of the magnetic read apparatus 100 / 100 ′ and read transducer 103 / 103 ′. The crystal decoupling structure 110 ′ may remain amorphous to higher temperatures. Thus, the amorphous magnetic layer 114 and the high crystalline temperature layer 112 may remain amorphous to temperatures close or up to the crystalline temperature of the layer 112 . Thus, portions of the transducer may be brought to higher temperatures during fabrication without crystallizing the structure 110 ′ or the seed structure 120 / 120 ′. Thus, the crystal structure of the shield 104 may be decoupled from that of the layers above the crystal decoupling structure 110 ′. As a result, the AFM layer and tunneling barrier layer may have improved crystal structure, resulting in increased exchange field and tunneling magnetoresistance. Consequently, a magnetic read apparatus and/or read transducer that utilizes the crystal decoupling structure 110 ′ may have improved performance.

FIG. 5 depicts another exemplary embodiment of a portion of a magnetic read transducer including the crystal decoupling structure 110 ″. For clarity, FIG. 5 is not to scale and only a portion of the transducer is shown. In particular, the crystal decoupling structure 110 ″ and shield 104 that are analogous to the crystalline decoupling structure 110 / 110 ′ and shield 104 , respectively, are shown. The crystal decoupling structure 110 ″ includes high crystalline temperature layer 112 and amorphous magnetic 114 analogous to the layers 112 and 114 depicted in FIG. 4 . Thus, the thicknesses, materials, and characteristics of the layers 112 and 114 in the crystal decoupling structure 110 ″ are analogous to the thicknesses, materials and characteristics of the layers 112 and 114 in the crystal decoupling structure 110 ′. However, the embodiment depicted in FIG. 5 locates the amorphous magnetic layer 114 between the high crystalline temperature layer 112 and the shield 104 . In some embodiments, the amorphous magnetic layer 114 adjoins the shield 104 and the high crystalline temperature layer 112 .

A magnetic read apparatus and read transducer that utilizes the crystal decoupling structure 110 ″ may share the benefits of devices that utilize the crystal decoupling structure 110 ′. The crystal decoupling structure 110 ″ may remain amorphous to higher temperatures. Thus, the amorphous magnetic layer 114 and the high crystalline temperature layer 112 may remain amorphous to temperatures close or up to the crystalline temperature of the layer 112 . Thus, portions of the transducer may be brought to higher temperatures during fabrication without crystallizing the structure 110 ″ or the seed structure 120 / 120 ′. Thus, the crystal structure of the shield 104 may be decoupled from that of the layers above the crystal decoupling structure 110 ″. As a result, the AFM layer and tunneling barrier layer may have improved crystal structure, resulting in increased exchange field and tunneling magnetoresistance. Consequently, a magnetic read apparatus and/or read transducer that utilizes the crystal decoupling structure 110 ″ may have improved performance.

FIG. 6 depicts another exemplary embodiment of a portion of a magnetic read transducer including the crystal decoupling structure 110 ″′. For clarity, FIG. 6 is not to scale and only a portion of the transducer is shown. In particular, the crystal decoupling structure 110 ″′ and shield 104 that are analogous to the crystalline decoupling structure 110 / 110 ′/ 110 ″ and shield 104 , respectively, are shown. The crystal decoupling structure 110 ″′ includes high crystalline temperature layer 112 and amorphous magnetic 114 analogous to the layers 112 and 114 depicted in FIGS. 4-5 . Thus, the thicknesses, materials, and characteristics of the layers 112 and 114 in the crystal decoupling structure 110 ″′ are analogous to the thicknesses, materials and characteristics of the layers 112 and 114 in the crystal decoupling structure(s) 110 ′/ 110 ″.

The crystal decoupling structure 110 ″′ includes an additional high crystalline temperature layer 116 . The additional high crystalline temperature layer 116 is analogous to the high crystalline temperature layer 112 . Thus, the material(s) used, thickness range(s) and/or other characteristics of the layer 116 may be analogous to those of the layer 112 . For example, the layer 112 may include three Angstroms of Ta, while the layer 116 includes one to three Angstroms of Ta and/or Hf.

A magnetic read apparatus and read transducer that utilizes the crystal decoupling structure 110 ″′ may share the benefits of devices that utilize the crystal decoupling structure 110 ′/ 110 ″. Thus, portions of the transducer may be brought to higher temperatures during fabrication without crystallizing the structure 110 ″′ or the seed structure 120 / 120 ′. Thus, the crystal structure of the shield 104 may be decoupled from that of the layers above the crystal decoupling structure 110 ″′. As a result, the AFM layer and tunneling barrier layer may have improved crystal structure, resulting in increased exchange field and tunneling magnetoresistance. Consequently, a magnetic read apparatus and/or read transducer that utilizes the crystal decoupling structure 110 ″′ may have improved performance.

FIG. 7 depicts another exemplary embodiment of a portion of a magnetic read transducer including the crystal decoupling structure 110 ″″. For clarity, FIG. 7 is not to scale and only a portion of the transducer is shown. In particular, the crystal decoupling structure 110 ″″ and shield 104 that are analogous to the crystalline decoupling structure 110 / 110 ′/ 110 ″/ 110 ″′ and shield 104 , respectively, are shown. The crystal decoupling structure 110 ″″ includes high crystalline temperature layer 112 , amorphous magnetic 114 and additional high crystalline temperature layer 116 analogous to the layers 112 , 114 and 116 depicted in FIGS. 4-6 . Thus, the thicknesses, materials, and characteristics of the layers 112 , 114 and 116 in the crystal decoupling structure 110 ″″ are analogous to the thicknesses, materials and characteristics of the layers 112 , 114 and 116 in the crystal decoupling structure(s) 110 ′/ 110 ″/ 110 ″′.

›DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS · 4 of 5

The crystal decoupling structure 110 ″″ includes an additional amorphous magnetic layer 118 . The additional amorphous magnetic layer 118 is analogous to the amorphous magnetic layer 114 . Thus, the material(s) used, thickness range(s) and/or other characteristics of the layer 118 may be analogous to those of the layer 114 . For example, the layer 118 may include at least ten and not more than thirty Angstroms of CoFeB. The crystal decoupling structure 110 ″″ may, in some embodiments, be considered to include multiple repeats of a bilayer. The bilayer includes a high crystalline temperature layer 112 or 116 and an amorphous magnetic layer 114 or 118 . FIG. 7 depicts two repeats of the bilayer. In other embodiments, another number of repeats may be used. The top amorphous magnetic layer or bottom high crystalline temperature layer may be omitted in some embodiments.

A magnetic read apparatus and read transducer that utilizes the crystal decoupling structure 110 ″″ may share the benefits of devices that utilize the crystal decoupling structure 110 ′/ 110 ″/ 110 ″′. Thus, portions of the transducer may be brought to higher temperatures during fabrication without crystallizing the structure 110 ″″ or the seed structure 120 / 120 ′. Thus, the crystal structure of the shield 104 may be decoupled from that of the layers above the crystal decoupling structure 110 ″″. As a result, the AFM layer and tunneling barrier layer may have improved crystal structure, resulting in increased exchange field and tunneling magnetoresistance. Consequently, a magnetic read apparatus and/or read transducer that utilizes the crystal decoupling structure 110 ″″ may have improved performance.

FIG. 8 depicts another exemplary embodiment of a portion of a magnetic read transducer including the crystal decoupling structure 110 ″″′. For clarity, FIG. 8 is not to scale and only a portion of the transducer is shown. In particular, the crystal decoupling structure 110 ″″′ and shield 104 that are analogous to the crystalline decoupling structure 110 / 110 ′/ 110 ″/ 110 ″′/ 110 ″″ and shield 104 , respectively, are shown. The crystal decoupling structure 110 ″″′ thus has a high crystalline temperature in the ranges described above. The crystal decoupling structure 110 ″″′ also structurally decouples the shield 104 from the layers above the crystal decoupling structure 110 ″″′. Thus, the structure 110 ″″′ is amorphous. The crystal decoupling structure 110 ″″′ may also allow the shield 104 to be magnetically coupled with the layer(s) above the crystal decoupling structure 110 ″″′.

The crystal decoupling structure 110 ″″′ includes a magnetic high crystalline temperature amorphous alloy layer 119 . This layer 119 is an alloy of at least one high crystalline temperature material and at least one amorphous magnetic material. For example, the amorphous magnetic material may be CoFeB. The high crystalline temperature material may include at least one of Ta, Hf, W and/or Ti. The layer may, therefore, include a CoFeBTa alloy. In some embodiments, the magnetic high crystalline temperature alloy layer 119 has a thickness of at least ten Angstroms and not more than twenty Angstroms. In some embodiments, the thickness is nominally fifteen Angstroms.

A magnetic read apparatus and read transducer that utilizes the crystal decoupling structure 110 ″″′ may share the benefits of devices that utilize the crystal decoupling structure 110 ′/ 110 ″/ 110 ″′/ 110 ″″. Thus, portions of the transducer may be brought to higher temperatures during fabrication without crystallizing the structure 110 ″″′ or the seed structure 120 / 120 ′. Thus, the crystal structure of the shield 104 may be decoupled from that of the layers above the crystal decoupling structure 110 ″″′. As a result, the AFM layer and tunneling barrier layer may have improved crystal structure, resulting in increased exchange field and tunneling magnetoresistance. Consequently, a magnetic read apparatus and/or read transducer that utilizes the crystal decoupling structure 110 ″″′ may have improved performance.

Various embodiments of crystal decoupling structures 110 , 110 ′, 110 ″, 110 ″′, 110 ″″ and 110 ″″′ have been described. Various features of the crystal decoupling structures 110 , 110 ′, 110 ″, 110 ″′, 110 ″″ and 110 ″″′ have been highlighted. One of ordinary skill in the art will recognize that various features of the crystal decoupling structures 110 , 110 ′, 110 ″, 110 ″′, 110 ″″ and 110 ″″′ may be combined in a manner not inconsistent with the apparatus and method described herein.

FIG. 9 is an exemplary embodiment of a method 200 for providing a read transducer. For simplicity, some steps may be omitted, interleaved, combined, have multiple substeps and/or performed in another order unless otherwise specified. The method 200 is described in the context of providing a magnetic recording apparatus 100 and transducer 103 . However, the method 200 may be used in fabricating the transducer 103 ′ and/or another magnetic read apparatus. The method 200 may be used to fabricate multiple devices at substantially the same time. 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 is described in the context of a disk drive. However, the method may be used in other applications employing a magnetoresistive and bias structures. The method 200 also may start after formation of other portions of the magnetic recording transducer.

A shield 104 is provided, via step 202 . Step 202 may include depositing a NiFe layer, which may be several hundred nanometers or more. In addition, the footprint of the shield may be defined by providing a mask over the shield layer and removing the exposed portion of the shield layer.

A crystal decoupling structure 110 is provided on the shield 104 , via step 204 . Step 204 may include forming a magnetic high crystalline temperature amorphous alloy. In other embodiments, step 204 may include depositing one or more high crystalline temperature amorphous layer(s) interleaved with amorphous magnetic layer(s). Thus, the crystal decoupling structure 110 , 110 ′, 110 ″, 110 ″′, 110 ″″ and/or 110 ″″′ may be fabricated.

›DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS · 5 of 5

A read sensor 130 is provided on the crystal decoupling structure 110 , via step 206 . Step 206 may include depositing a stack of layers for the read sensor and defining the read sensor in the cross-track and stripe height directions. Step 206 may include heating the portion of the magnetic read apparatus 100 that has already been fabricated to a temperature of at least two hundred and fifty degrees Celsius and not more than the crystalline temperature of the crystal decoupling structure formed in step 204 . In some embodiments, the temperature to which the device is heated may be at least three hundred degrees Celsius. In some embodiments, it is ensured that the portion of the transducer 103 that has been fabricated is at a temperature that is less than the crystalline temperature. For example, the substrate may be heated to three hundred or three hundred and twenty-five degrees Celsius during deposition of an AFM layer 131 and/or during annealing of a tunneling barrier layer 133 . In such embodiments, the crystalline temperature for the crystal decoupling structure 110 may be at least three hundred fifty degrees Celsius. Fabrication of the apparatus 100 may then be completed. For example, the magnetic bias structures 160 and shield 170 may be formed.

Using the method 200 , the transducers 103 and/or 103 ′ and the crystal decoupling structures 110 , 110 ′, 110 ″, 110 ″′, 110 ″″ and/or 110 ″″′ may be fabricated. Thus, the benefits of one or more of the crystal decoupling structures 110 , 110 ′, 110 ″, 110 ″′, 110 ″″ and/or 110 ″″′ may be achieved. Consequently, biasing of the free layers 112 and 116 in the read sensor 110 may be improved.

FIG. 10 is an exemplary embodiment of a method 210 for providing a magnetic read apparatus including a read transducer. For simplicity, some steps may be omitted, interleaved, combined, have multiple substeps and/or performed in another order unless otherwise specified. The method 210 is described in the context of providing a magnetic recording apparatus 100 and transducer 103 . However, the method 210 may be used in fabricating the transducer 103 ′ and/or another magnetic read apparatus. The method 210 may be used to fabricate multiple devices at substantially the same time. The method 210 is also described in the context of particular layers. A particular layer may include multiple materials and/or multiple sub-layers. The method 210 is described in the context of a disk drive. However, the method may be used in other applications employing a magnetoresistive and bias structures. The method 210 also may start after formation of other portions of the magnetic recording transducer.

A shield 104 is provided, via step 212 . Step 212 may include depositing a thick NiFe layer. In addition, the footprint of the shield may be defined by providing a mask over the shield layer and removing the exposed portion of the shield layer.

A crystal decoupling structure is provided on the shield 104 , via step 214 . Step 214 may include forming a magnetic high crystalline temperature amorphous alloy. In other embodiments, step 214 may include depositing one or more high crystalline temperature amorphous layer(s) interleaved with amorphous magnetic layer(s). Thus, the crystal decoupling structure 110 , 110 ′, 110 ″, 110 ″′, 110 ″″ and/or 110 ″″′ may be fabricated.

The seed layer 120 / 120 ′ is deposited, via step 216 . For example, the magnetic seed layer 122 and spacer layer 124 may be fabricated in step 202 . Thus, a NiFe seed layer 122 and a nonmagnetic spacer layer 124 may be deposited.

The substrate is heated to a temperature that does not exceed the crystalline temperature of the crystal decoupling layer 110 , via step 218 . In some embodiments, the temperature to which the substrate is heated is less than crystalline temperature. Thus, at least the shield 104 , the crystal decoupling structure 110 , 110 ′, 110 ″, 110 ″″ and 110 ″″′ and seed structure 120 / 120 ′ are heated. In some embodiments, the structures 104 , 120 / 120 ′ and 110 , 110 ′, 110 ″, 110 ″′, 110 ″″ and/or 110 ″″′ are heated to at least three hundred degrees Celsius.

The pinning, or AFM, layer is deposited while the substrate is heated in step 218 , via step 220 . Thus, the AFM layer 131 of the sensor 130 ′ is deposited. The heating of step 218 may then be terminated. The remainder of the sensor stack is then deposited, via step 222 . Step 222 may include depositing the pinned layer 132 , optionally depositing the nonmagnetic layer 133 , optionally depositing the reference layer 134 , depositing the nonmagnetic spacer/tunneling barrier layer 136 , depositing the free layer 138 and depositing the capping layer. The sensor stack is typically then annealed, via step 224 . For example, the sensor stack may be annealed at a temperature of three hundred to three hundred and twenty-five degrees Celsius. In other embodiments, an anneal temperature of three hundred and fifty degrees Celsius might be used. In other embodiments other anneal temperatures may be used, however, the anneal temperature is desired to be less than the high crystalline temperature of the crystal decoupling structure 110 .

The sensor 130 is then defined, via step 226 . Step 226 may include providing a mask covering the portion of the sensor stack that forms the read sensor 104 . The exposed portion of the stack may then be milled. The magnetic bias structures 160 are provided, via step 228 . The top shield 170 is also formed, via step 230 .

Thus, the magnetic transducer 103 / 103 ′ may be fabricated. The method 210 may also fabricates the crystal decoupling structures (s) 110 , 110 ′, 110 ″, 110 ″′, 110 ″″ and/or 110 ″″′. Thus, the benefits of one or more of the crystal decoupling structures 110 , 110 ′, 110 ″, 110 ″′, 100 ″″ and/or 100 ″″′ may be achieved.

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IPC · International Patent Classification
Section G — Physics
  • G11B5/39
  • G11B5/31

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