Tapered main pole structure with variable peg gap for heat-assisted magnetic recording technology

Abstract

This disclosure aims to provide a heat-assisted magnetic recording (HAMR) writer head with increased areal density capacity, improved writing efficiency, and enhanced reliability. [Solution] Disclosed are a writer head for a heat-assisted magnetic recording device and a method for manufacturing a writer head. The writer head comprises several layers, including a waveguide cutoff layer, a waveguide layer, a near-field transducer layer, a heat sink layer, and a peg layer. The peg layer comprises small triangular portions extending from the air bearing surface to the optical component. The writer head further comprises a principal pole adjacent to the optical component.

Description

Technical Field

[0001] The present disclosure relates to a high-performance heat-assisted magnetic recording (HAMR) writer head and a method for fabricating a HAMR writer head for use, for example, in a hard disk drive (HDD).

Background Art

[0002] A magnetic writer head is an important component of an HDD and converts the current in a coil into a strong magnetic field applied to a media platter for efficient and high-density information writing. As the technology of HDDs progresses, higher areal density capacity (ADC) is required. One way to increase the ADC, i.e., the amount of data per square inch, is to reduce the particle size of the media platter.

[0003] The growth of the ADC largely depends on the reduction of the media bit and the writer head structure to accommodate smaller particles. To maintain the stability of the electron bits on the media when the particle size is shrinking, it is necessary for the media particles to have a larger anti-electric field. However, limitations occur due to the degradation of the magnetic performance in the reduced writer head operating at GHz frequencies.

[0004] Writer heads used in perpendicular magnetic recording (PMR) apply a perpendicular magnetic field to the media bits using a main pole (MP). However, as the size is reduced, especially when the particles on the media become smaller with greater coercivity, the writability substantially decreases. Heat-assisted magnetic recording (HAMR) and microwave-assisted magnetic recording (MAMR) technologies use energy sources (from heat and microwaves, respectively) to temporarily soften the media, and as a result, the magnetic field from the miniaturized writer head is sufficient for efficient writing operation.

[0005] Heat-assisted magnetic recording (HAMR) technology provides a way to substantially increase the amount of data that can be stored on an HDD. A HAMR writer head consists of a miniature laser diode that can temporarily transfer heat to small particles on a media platter to reduce the switching magnetic field, and a magnetic writer element that applies magnetic flux to the heated media particles to write information. The sharp thermal gradient, which translates into a high magnetic gradient on the media, enables higher data storage densities than those achievable with conventional perpendicular magnetic recording technology. Improvements to writer head technology are needed. [Overview of the project]

[0006] In some embodiments, the technology described herein relates to a writer head for a heat-assisted magnetic recording (HAMR) device, the writer head comprising an optical component including: a triangular layer having a tapered edge; a first cladding layer positioned adjacent to the triangular layer; a waveguide (WG) layer positioned adjacent to the first cladding layer; a second cladding layer positioned adjacent to the WG layer; a near-field transducer (NFT) layer positioned adjacent to the cladding layer; a heat sink layer positioned adjacent to the NFT layer; and a triangular peg gap layer positioned adjacent to the heat sink layer and having a tapered angle of about 20 to about 70 degrees; and a main magnetic pole positioned adjacent to the triangular peg gap layer and the heat sink layer and having a saturation magnetization of about 24 kG or more.

[0007] In some embodiments, the technology described herein relates to a writer head in which the surface of the principal magnetic pole has a taper angle equal to the taper angle of the triangular peg gap layer. In some embodiments, the techniques described herein relate to a writer head in which the surface of the principal magnetic pole opposite the tapered peg gap layer includes a flat surface.

[0008] In some embodiments, the technology described herein relates to a writer head in which the surface of the principal magnetic pole opposite to the tapered peg gap layer includes a taper that includes an angle equal to and opposite to the angle of the triangular peg gap layer.

[0009] In some embodiments, the techniques described herein relate to a writer head in which the surface of the principal magnetic pole opposite to the tapered peg gap layer includes a slope having an angle of about -15 degrees to about -45 degrees.

[0010] In some embodiments, the technology described herein relates to a writer head in which the surface of the principal magnetic pole opposite to the tapered peg gap layer includes a slope having an angle of about -15 to about -45 degrees, and the surface of the heat sink layer in contact with the principal magnetic pole includes a taper having an angle of about -15 to about -45 degrees.

[0011] In some embodiments, the technology described herein relates to a writer head in which the principal magnetic poles include a first layer adjacent to a peg gap layer and a second layer adjacent to the first layer, wherein the first layer has a lower magnetic moment than the second layer.

[0012] In some embodiments, the technology described herein relates to a writer head in which the first layer has a thickness of about 10 nm to about 50 nm. In some embodiments, the technology described herein relates to a writer head in which the first layer comprises one or more of CoFe, NiFe, and CoFeNi and a dopant containing a transition metal.

[0013] In some embodiments, the technology described herein relates to a lighter head in which the dopant comprises one or more of palladium or rhenium. In some embodiments, the technology described herein relates to a writer head in which the triangular layer includes a waveguide blocker layer containing ruthenium.

[0014] In some embodiments, the technology described herein relates to a lighter head in which a triangular layer comprises one or more alumina or silica. In some embodiments, the technology described herein relates to a lighter head in which the NFT layer comprises a first NFT layer comprising a first metal and a second NFT layer comprising a transition metal, wherein the first NFT layer comprises one or more of gold, silver, copper, alloys thereof, graphene, and metal oxides, and the second NFT layer comprises one of Rh or Ir.

[0015] In some embodiments, the technology described herein relates to a lighter head in which the heat sink layer comprises one or more of gold, ruthenium, aluminum nitride, or silicon carbide. In some embodiments, the technology described herein relates to a writer head in which the optical component further includes a laser diode configured to generate a light beam.

[0016] In some embodiments, the technology described herein relates to a writer head in which a magnetic component is operably connected to a main magnetic pole by a first connector and includes a first return magnetic pole positioned opposite the optical component with respect to the main magnetic pole.

[0017] In some embodiments, the technology described herein relates to a writer head in which the magnetic component further includes a coil comprising 0 to 6 loops, the coil being positioned between a first return pole and a principal pole.

[0018] In some embodiments, the technology described herein relates to a writer head in which the distance between the first return pole and the principal pole is about 50 nm to about 1,000 nm. In some embodiments, the technology described herein relates to a writer head in which the first return pole has a thickness of about 500 nm to about 1,500 nm.

[0019] In some embodiments, the technology described herein relates to a writer head in which the first return pole includes a first pedestal having a thickness of about 1.5 μm to about 2.5 μm and a height of about 200 nm to about 1,000 nm.

[0020] In some embodiments, the technology described herein relates to a writer head in which the first return pole further comprises a first magnetic leading shield (MLS) having a thickness of about 100 nm to about 1,000 nm and a height of about 500 nm to about 2,000 nm.

[0021] In some embodiments, the technology described herein relates to a writer head in which the magnetic component includes a first yoke positioned between a first connector and a main magnetic pole. In some embodiments, the technology described herein relates to a writer head in which the main magnetic poles include an inclined trailing edge having an angle of about 15 degrees to about -75 degrees.

[0022] In some embodiments, the technology described herein relates to a writer head in which a magnetic component is operably connected to a main pole by a second connector and includes a second return pole positioned on the opposite side of the main pole from a first return pole.

[0023] In some embodiments, the technology described herein relates to a writer head in which the distance between the second return pole and the main pole is from about 100 nm to about 1,000 nm. In some embodiments, the technology described herein relates to a writer head in which the second return pole has a thickness of from about 100 nm to about 1,500 nm.

[0024] In some embodiments, the technology described herein relates to a writer head in which the second return pole includes a second pedestal having a thickness of from about 1.5 μm to about 2.5 μm and a height of from about 200 nm to about 1,000 nm.

[0025] In some embodiments, the technology described herein relates to a writer head in which the second return pole further includes a second magnetic leading shield (MLS) having a thickness of from about 100 nm to about 800 nm and a height of from about 500 nm to about 1,000 nm.

[0026] In some embodiments, the technology described herein relates to a writer head in which the magnetic component further includes a first coil and a second coil, the first coil and the second coil are combined to include from 0 to 6 loops, the first coil is positioned between the first return pole and the main pole, the second coil is positioned between the second return pole and the main pole, and the first coil and the second coil include the same number of loops.

Brief Description of the Drawings

[0027] [Figure 1A] An exemplary optical component for a writer head according to one embodiment is shown. [Figure 1B] An exemplary optical component for a writer head according to one embodiment is shown. [Figure 1C]An exemplary optical component for a writer head according to one embodiment is shown. [Figure 1D] An exemplary optical component for a writer head according to one embodiment is shown. [Figure 1E] An exemplary optical component for a writer head according to one embodiment is shown. [Figure 2A] An exemplary optical component for a writer head according to one embodiment is shown. [Figure 2B] An exemplary optical component for a writer head according to one embodiment is shown. [Figure 2C] An exemplary optical component for a writer head according to one embodiment is shown. [Figure 2D] An exemplary optical component for a writer head according to one embodiment is shown. [Figure 2E] An exemplary optical component for a writer head according to one embodiment is shown. [Figure 3A] An exemplary writer head according to one embodiment is shown. [Figure 3B] An exemplary writer head according to one embodiment is shown. [Figure 3C] An exemplary writer head according to one embodiment is shown. [Figure 3D] An exemplary writer head according to one embodiment is shown. [Figure 3E] An exemplary writer head according to one embodiment is shown. [Figure 3F] An exemplary writer head according to one embodiment is shown. [Figure 3G] An exemplary writer head according to one embodiment is shown. [Figure 3H] An exemplary writer head according to one embodiment is shown. [Figure 3I] An exemplary writer head according to one embodiment is shown. [Figure 3J] An exemplary writer head according to one embodiment is shown. [Figure 4] This shows a graphical representation of the performance indicators of a writer head according to one embodiment. [Figure 5]This shows a graphical representation of the performance indicators of a writer head according to one embodiment. [Modes for carrying out the invention]

[0028] This disclosure is not limited to the systems, devices, and methods described herein, as they are modifiable. The terms used herein are for illustrative purposes only and are not intended to limit the scope of any particular version or embodiment.

[0029] product A heat-assisted magnetic recording (HAMR) writer head can be assembled to assist in writing data onto a recording medium. In some embodiments, the writer head comprises an optical component and a magnetic component. The optical component may be configured to heat the recording medium to soften it. The magnetic component may be configured to apply a concentrated magnetic flux to the heated recording medium in order to write data onto the heated recording medium. By softening the recording medium, the optical component allows the magnetic component to write data onto the recording medium more efficiently. This allows the magnetic component to achieve a higher storage density on the recording medium compared to a writer head without a heating element.

[0030] Figures 1A to 1E show exemplary optical components for a HAMR writer head. In some embodiments, the optical component is positioned adjacent to the main magnetic pole 109. In some embodiments, the optical component comprises a laser diode configured to generate a light beam. In some embodiments, the optical component comprises multiple layers. In some embodiments, the optical component comprises a triangular layer 101 having a tapered edge. In some embodiments, the triangular layer comprises one of alumina or silica. The taper angle may be any angle effective for generating the desired magnetic field. In some embodiments, the taper angle is about 20 to about 70 degrees. In some embodiments, the taper angle is about 45 degrees.

[0031] In some embodiments, the triangular layer 101 may be a waveguide (WG) barrier layer. The waveguide barrier layer may be configured to prevent diffuse light from reaching the recording medium. The waveguide barrier layer may contain any material that substantially prevents diffuse light from reaching the recording medium. In some embodiments, the waveguide barrier layer contains ruthenium. In some embodiments, the waveguide barrier layer is positioned near the air-bearing surface (ABS) 110.

[0032] In some embodiments, the optical component further comprises a waveguide layer 102 positioned adjacent to the triangular layer 101. The waveguide layer 102 may be operably connected to near-field transducer (NFT) layers 105, 106 and configured to direct light from the laser diode to the NFT layers 105, 106. In some embodiments, the waveguide layer 102 comprises a tapered portion of a certain angle extending to or near the air bearing surface 110. In some embodiments, the angle of the tapered portion is the taper angle determined by the tapered edge of the triangular layer 101. The waveguide layer 102 may further comprise a flat portion substantially parallel to the rear of the principal magnetic pole 109. In some embodiments, the waveguide layer 102 has a thickness of about 50 nm to about 200 nm. In some embodiments, the waveguide layer 102 has a thickness of about 120 nm.

[0033] In some embodiments, the thickness of the waveguide layer 102 is expressed as a ratio of the thickness of the waveguide layer 102 to the average particle size of the recording medium. In some embodiments, the ratio of the thickness of the waveguide layer 102 to the average particle size of the recording medium is about 7 to about 29.

[0034] In some embodiments, the optical component may further comprise a first cladding layer 103 positioned between the waveguide layer 102 and the triangular layer 101 and configured to bond the waveguide layer 102 and the triangular layer. In some embodiments, the first cladding layer 103 is positioned along the entire length of the waveguide layer 102. In some embodiments, the first cladding layer 103 is positioned along a portion of the waveguide layer 102. In some embodiments, the first cladding layer 103 is positioned near the air bearing surface 110. The first cladding layer 103 may comprise any material known to those skilled in the art that is effective in bonding the waveguide layer 102 and the triangular layer 101. In some embodiments, the first cladding layer 103 comprises an insulator. In some embodiments, the first cladding layer 103 comprises a dielectric material. In some embodiments, the first cladding layer 103 has a thickness of about 10 nm to about 400 nm. In some embodiments, the first cladding layer 103 has a thickness of about 100 nm.

[0035] In some embodiments, the thickness of the first cladding layer 103 is expressed as a ratio of the thickness of the first cladding layer 103 to the average particle size of the recording medium. In some embodiments, the ratio of the thickness of the first cladding layer 103 to the average particle size of the recording medium is approximately 1.4 to approximately 57.

[0036] In some embodiments, the optical component may further include a second cladding layer 104 positioned between the waveguide layer 102 and the NFT layers 105, 106 and configured to bond the waveguide layer 102 and the NFT layers 105, 106. In some embodiments, the second cladding layer 104 is positioned along the entire length of the waveguide layer 102. In some embodiments, the second cladding layer 104 is positioned along a portion of the waveguide layer 102. In some embodiments, the second cladding layer 104 is positioned near the air bearing surface 110. The second cladding layer 104 may include any material known to those skilled in the art that is effective in bonding the waveguide layer 102 and the NFT layers 105, 106. In some embodiments, the second cladding layer 104 includes an insulator. In some embodiments, the second cladding layer 104 includes a dielectric material. In some embodiments, the second cladding layer 104 has a thickness of about 10 nm to about 400 nm. In some embodiments, the second cladding layer 104 has a thickness of about 100 nm.

[0037] In some embodiments, the thickness of the second cladding layer 104 is expressed as a ratio of the thickness of the second cladding layer 104 to the average particle size of the recording medium. In some embodiments, the ratio of the thickness of the second cladding layer 104 to the average particle size of the recording medium is approximately 1.4 to approximately 57.

[0038] In some embodiments, the optical component further includes near-field transducer (NFT) layers 105, 106. The NFT layers 105, 106 may be configured to focus laser-induced plasmons onto the recording medium. In some embodiments, the NFT layers 105, 106 may be configured to induce heating at nanoscale points on the recording medium, enabling magnetic recording on narrow tracks and allowing for high areal density capacitance (ADC). In some embodiments, the NFT layers 105, 106 extend to or near the air bearing surface 110. The NFT layers 105, 106 may have a flat portion substantially parallel to the rear of the main magnetic pole 109. In some embodiments, the NFT layers 105, 106 have a thickness of about 17 nm to about 115 nm. In some embodiments, the NFT layers 105, 106 comprise a first NFT layer 105 and a second NFT layer 106.

[0039] In some embodiments, the thickness of the NFT layers 105 and 106 is expressed as a ratio of the thickness of the NFT layers 105 and 106 to the average particle size of the recording medium. In some embodiments, the ratio of the thickness of the NFT layers 105 and 106 to the average particle size of the recording medium is approximately 2.5 to approximately 16.5.

[0040] In some embodiments, the first NFT layer 105 contains a metal having good optical and plasmon properties. In some embodiments, the first NFT layer 105 contains one or more of gold, silver, copper, their alloys, graphene, and metal oxides. In some embodiments, the first NFT layer 105 is recessed from the air bearing surface 110. In some embodiments, the first NFT layer 105 has a thickness of about 15 nm to about 100 nm.

[0041] In some embodiments, the thickness of the first NFT layer 105 is expressed as a ratio of the thickness of the first NFT layer 105 to the average particle size of the recording medium. In some embodiments, the ratio of the thickness of the first NFT layer 105 to the average particle size of the recording medium is about 2 to about 14.

[0042] In some embodiments, the second NFT layer 106 contains a robust transition metal. In some embodiments, the second NFT layer 106 contains either rhodium or iridium. In some embodiments, the second NFT layer 106 extends to the air bearing surface 110. In some embodiments, the second NFT layer 106 has a length of about 0.6 μm to about 1.0 μm. In some embodiments, the second NFT layer 106 has a thickness of about 2 nm to about 15 nm. In some embodiments, the second NFT layer 106 has a thickness of about 5 nm.

[0043] In some embodiments, the thickness of the second NFT layer 106 is expressed as a ratio of the thickness of the second NFT layer 106 to the average particle size of the recording medium. In some embodiments, the ratio of the thickness of the second NFT layer 106 to the average particle size of the recording medium is about 0.2 to about 2.

[0044] The NFT layers 105 and 106 may have any resistivity that is effective for focusing laser-induced plasmons onto the recording medium. In some embodiments, the NFT layers 105 and 106 have resistivity ranging from about 8.0 μΩ·cm to about 20.0 μΩ·cm.

[0045] In some embodiments, the optical component further includes a heat sink layer 107. The heat sink layer 107 may be configured to dissipate heat from the main magnetic pole 109. The heat sink layer 107 may contain any material effective for use as a heat sink. In some embodiments, the heat sink layer 107 contains one or more of gold, ruthenium, aluminum nitride, hexagonal boron nitride, or silicon carbide. In some embodiments, the heat sink layer does not extend to the air bearing surface 110. In some embodiments, the heat sink layer 107 has a thickness of about 10 nm to about 3 μm, depending on the design.

[0046] In some embodiments, the thickness of the heat sink layer 107 is expressed as a ratio of the thickness of the heat sink layer 107 to the average particle size of the recording medium. In some embodiments, the ratio of the thickness of the heat sink layer 107 to the average particle size of the recording medium is approximately 1.4 to approximately 500.

[0047] In some embodiments, the heat sink layer 107 includes a thin, flat layer. Figures 1A and 1B show an exemplary heat sink layer 107 including a flat layer. In some embodiments, the flat layer has a uniform thickness. In some embodiments, the heat sink layer 107 includes a layer that is thin near the air bearing surface 110 and widens as the heat sink layer 107 extends through the optical component to create a segmented yoke design for the main pole 109. Figures 1C and 1D show an optical component with a segmented yoke design. In some embodiments, the heat sink layer 107 includes a first portion including a thin layer and a second portion including a taper angle for creating a sloped main pole design for the main pole 109. In such embodiments, the second portion may have a taper angle of about -15 to about -45 degrees. In such embodiments, the second portion may have a taper angle of about -30 degrees. Figure 1E shows an exemplary heat sink layer 107 comprising a first portion containing a thin layer and a second portion having a tapered angle for creating a sloped main magnetic pole design.

[0048] In some embodiments, the optical component further comprises a triangular peg gap layer 108 containing an insulator. In some embodiments, the triangular peg gap layer 108 is configured to isolate the optical component from the main magnetic pole 109 near the air bearing surface 110. In some embodiments, the triangular peg gap layer 108 contains one of Ir or Rh. In some embodiments, the triangular peg gap layer 108 is positioned near the air bearing surface 110. In some embodiments, the peg layer 106 is configured to isolate the NFT layers 105, 106 from the main magnetic pole 109 near the air bearing surface 110. The use of a triangular peg gap layer that physically isolates the optical component from the main magnetic pole 109 near the air bearing surface 110 but does not isolate the heat sink layer 107 from the main magnetic pole 109 results in improved characteristics of the writer head. In some embodiments, the peg gap layer 108 provides a variable peg gap, which is maximum at the air bearing surface 110 and decreases as the peg gap layer 108 extends into the optical component. In some embodiments, the peg gap layer 108 is material-free and formed by the absence of material within the main magnetic pole 109. In some embodiments, the optical component includes a second oxide layer positioned between the peg gap layer 108 and the heat sink layer 107.

[0049] In some embodiments, the peg gap layer 108 has a height of about 30 nm to about 100 nm. In some embodiments, the peg gap layer 108 has a height of about 50 nm. In some embodiments, the height of the peg gap layer 108 is expressed as a ratio of the height of the peg layer 108 to the average particle size of the recording medium. In some embodiments, the ratio of the height of the peg layer 108 to the average particle size of the recording medium is about 4 to about 14.

[0050] The improved characteristics include an increased magnetic field at the recording location, a decreased magnetic field angle at the recording location, and a lower main pole temperature during recording, compared to a writer head with a peg gap layer extending through the optical components and insulating the heat sink layer 107 from the main magnetic pole 109. These improvements result in a significant increase in areal density capacity, as well as improved writing efficiency and writer head reliability.

[0051] In some embodiments, the optical component further comprises a first oxide layer positioned between the NFT layers 105, 106 and the heat sink layer 105. In some embodiments, the first oxide layer is positioned along the entire length of the heat sink layer 107. In some embodiments, the first oxide layer is positioned along a portion of the length of the heat sink layer 107. In some embodiments, the first oxide layer comprises one of silica or alumina. In some embodiments, the first oxide layer has a thickness of about 1 nm to about 20 nm.

[0052] In some embodiments, the thickness of the first oxide layer is expressed as the ratio of the thickness of the first oxide layer to the average particle size of the recording medium. In some embodiments, the ratio of the thickness of the first oxide layer to the average particle size of the recording medium is about 0.1 to about 3.

[0053] The main magnetic pole 109 may be configured to apply concentrated magnetic flux to the recording medium. The main magnetic pole 109 may have any saturation magnetization effective for writing data onto the recording medium. In some embodiments, the main magnetic pole 109 includes a material having the highest available magnetic moment. In some embodiments, the main magnetic pole 109 includes a material having a high available magnetic moment, such as a magnetic moment of about 24 kG or more. In some embodiments, the main magnetic pole 109 includes a material having a magnetic moment of about 24 kG.

[0054] In some embodiments, the main pole 109 further comprises a main pole portion extending along the air bearing surface 110. In some embodiments, the main pole portion has a thickness of about 200 nm to about 800 nm. In some embodiments, the main pole portion has a thickness of about 400 nm.

[0055] In some embodiments, the thickness of the main pole portion is expressed as the ratio of the thickness of the main pole portion to the average particle size of the recording medium. In some embodiments, the ratio of the thickness of the main pole portion to the average particle size of the recording medium is approximately 28 to approximately 57.

[0056] In some embodiments, the trailing edge 111 of the main pole 109 is flat and does not have a second tapered portion. Figures 1A and 1C show an exemplary main pole 109 with a flat trailing edge. In some embodiments, the main pole 109 has a taper 112 on the opposite side of the peg gap layer 108. In some embodiments, the taper 112 has a similar shape and angle to the peg gap layer 108. In some embodiments, the angle of the taper 112 is opposite to the angle of the peg gap layer 108. Figure 1B shows an exemplary main pole 109 with a taper 112.

[0057] In some embodiments, the trailing edge 111 of the main magnetic pole 109 has a sloped structure. Figure 1E shows the main magnetic pole 109 having a sloped structure with a slope angle. The slope angle may be any angle effective for generating the desired magnetic field. In some embodiments, the taper angle is in the opposite direction to the taper angle present in the layer of the optical component. In some embodiments, the slope angle is about -15 to about -45 degrees. In some embodiments, the slope angle is about -20 degrees. In some embodiments, the surface of the heat sink layer 107 in contact with the main magnetic pole 109 has a sloped edge, and the slope angle of the trailing edge 111 of the main magnetic pole 109 is the same angle as that sloped edge.

[0058] In some embodiments, the surface of the main magnetic pole 109 in contact with the heat sink layer 107 may have a notch 113. In some embodiments, the notch 113 may include a recess into the surface of the main magnetic pole 109. In some embodiments, the notch 113 may be filled with the heat sink layer 107. The notch 113 may start at a predetermined distance from the air bearing surface 110. In some embodiments, the notch 113 may start at a distance of about 100 nm to about 400 nm. In some embodiments, the notch 113 may start at a distance of about 250 nm from the air bearing surface 110.

[0059] In some embodiments, the main magnetic pole 109 comprises a second magnetic layer 201 positioned on the surface of the main magnetic pole 109 adjacent to the heat sink layer 107. Figures 2A to 2E show exemplary optical components in which the main magnetic pole 109 comprises the second magnetic layer 201. In some embodiments, the second magnetic layer 201 comprises a material having a lower magnetic moment than the rest of the main magnetic pole 109. In some embodiments, the second magnetic layer 201 comprises one or more of CoFe, NiFe, or CoFeNi. In some embodiments, the second magnetic layer 201 is doped with a dopant containing a transition metal. In some embodiments, the dopant comprises one or more of palladium or rhenium. In some embodiments, the second magnetic layer 201 has a thickness of about 10 nm to about 100 nm. In some embodiments, the second magnetic layer 201 has a thickness of about 20 nm.

[0060] In some embodiments, the thickness of the second magnetic layer 201 is expressed as a ratio of the thickness of the second magnetic layer 201 to the average particle size of the recording medium. In some embodiments, the ratio of the thickness of the second magnetic layer 201 to the average particle size of the recording medium is about 1.4 to about 14.

[0061] Figures 3A to 3J show exemplary writer heads for HAMR devices. In some embodiments, the writer head includes an optical component 301. The optical component may be any of the optical components 301 described above. The optical component 301 may be positioned adjacent to the main pole 302. In some embodiments, the optical component 301 is positioned at the bottom of the main pole 302. The main pole 302 may be the main pole 109 described above. In some embodiments, the optical component 301 and the main pole 302 extend to the air bearing surface 311. In some embodiments, the writer head includes a first return pole 303 configured to allow the magnetic flux from the main pole 302 to complete a loop. In some embodiments, the first return pole 303 extends to the air bearing surface 311.

[0062] The distance between the principal pole 302 and the first return pole 303 can be selected to maximize the magnetic field at the recording point on the recording medium. In some embodiments, the first return pole 303 is positioned on the opposite side of the optical component 301 from the principal pole 302. In such embodiments, the distance between the first return pole 303 and the principal pole 302 is not limited by the optical component 301. In some embodiments, the distance between the principal pole 302 and the first return pole 303 is about 50 nm to about 1,000 nm. In some embodiments, the distance between the principal pole 302 and the first return pole 303 is about 500 nm.

[0063] The first return pole 303 may have any thickness 313 that is effective in allowing the magnetic flux from the main pole 302 to complete the loop. In some embodiments, the first return pole 303 has a thickness of about 500 nm to about 1,500 nm. In some embodiments, the first return pole 303 comprises a magnetic material having a saturation magnetization lower than the saturation magnetization of the main pole 302. In some embodiments, the first return pole 303 has a saturation magnetization of about 10 kG to about 22 kG. In some embodiments, the first return pole 303 has a saturation magnetization of about 19 kG.

[0064] In some embodiments, the first return pole 303 comprises a first pedestal 305 configured to determine the distance between the first return pole 303 and the main pole 302. In some embodiments, the first pedestal 305 is positioned adjacent to the air bearing surface 311. In some embodiments, the first pedestal 305 has a thickness 212 of about 1.5 μm to about 2.5 μm. In some embodiments, the first pedestal 305 has a thickness 212 of about 1 μm. In some embodiments, the first pedestal 305 has a height 316 of about 200 nm to about 1,000 nm. In some embodiments, the first pedestal 305 has a height 316 of about 300 nm. In some embodiments, the first pedestal 305 comprises a magnetic material having a saturation magnetization lower than the saturation magnetization of the main pole 302. In some embodiments, the first pedestal 305 has a saturation magnetization of about 10 kG to about 22 kG. In some embodiments, the first pedestal 305 has a saturation magnetization of about 19 kG.

[0065] In some embodiments, the first return pole 303 comprises a magnetic reading shield (MLS) 309 positioned adjacent to the air bearing surface 311. In some embodiments, the magnetic reading shield 309 has a thickness 212 of about 0.1 μm to about 1 μm. In some embodiments, the magnetic reading shield 309 has a thickness 212 of about 0.5 μm. In some embodiments, the magnetic reading shield 309 has a height 316 of about 500 nm to about 2,000 nm. In some embodiments, the magnetic reading shield 309 has a height 316 of about 800 nm.

[0066] In some embodiments, the first return pole 303 may be operably connected to the main pole 302 by a first connector 304. In some embodiments, the first connector 304 includes a magnetic material having a saturation magnetization lower than the saturation magnetization of the main pole 302. In some embodiments, the first connector 304 has a saturation magnetization of about 10 kG to about 22 kG. In some embodiments, the first connector 304 has a saturation magnetization of about 19 kG.

[0067] Figures 3E to 3G show that the magnetic pole 302 does not extend to the first connector 304. In such embodiments, the main magnetic pole 302 may have a length of about 0.5 μm to about 4.0 μm. In such embodiments, the main magnetic pole 302 may have a length of about 2 μm. In such embodiments, the main magnetic pole 302 further comprises an upper yoke 310 configured to help control the magnetic flux concentration on the rear of the main magnetic pole 302. In some embodiments, the upper yoke 310 is recessed from the air bearing surface 311. In some embodiments, the upper yoke 310 contains a magnetic material having a saturation magnetization lower than the saturation magnetization of the main magnetic pole 302. In some embodiments, the upper yoke 310 has a saturation magnetization of about 10 kG to about 22 kG. In some embodiments, the upper yoke 310 has a saturation magnetization of about 19 kG. In some embodiments, the first return magnetic pole 303 is operably connected to the upper yoke 310 by the first connector 304.

[0068] In some embodiments, the main pole 302 has a sloping trailing edge. In such embodiments, the upper yoke 310 may have a sloping trailing edge. Figures 3H to 3J show exemplary main poles 302 having a sloping trailing edge. In such embodiments, the main pole 302 may have a sloping portion having a length of about 0.5 μm to about 3.0 μm. In such embodiments, the main pole 302 may have a sloping portion having a length of about 1.5 μm. In some embodiments, the sloping trailing edge may have an angle of about -15 degrees to about -45 degrees. In some embodiments, the sloping trailing edge may have an angle of about -20 degrees.

[0069] In some embodiments, the writer head further comprises at least one coil 317 configured to conduct current and provide a magnetomotive force to the writer head. In some embodiments, the at least one coil 317 is positioned between the optical component 301 and the first return pole 303. The at least one coil may comprise any number of loops effective in providing a magnetomotive force to the writer head. In some embodiments, the at least one coil 317 comprises 1 to 6 loops.

[0070] In some embodiments, the writer head includes a second return pole 306 configured to allow the magnetic flux from the main pole 302 to complete a loop. In some embodiments, the second return pole 306 extends to the air bearing surface 311. The distance between the main pole 302 and the second return pole 306 can be selected to maximize the magnetic field at the recording point on the recording medium. In some embodiments, the second return pole 306 is positioned on the same side of the main pole 302 as the optical component 301. In such embodiments, the distance between the second return pole 306 and the main pole 302 is limited by the optical component 301. In some embodiments, the distance between the main pole 302 and the second return pole 306 is about 100 nm to about 1000 nm. In some embodiments, the distance between the main pole 302 and the second return pole 306 is about 800 nm.

[0071] The second return pole 306 may have any thickness 313 that is effective in allowing the magnetic flux from the main pole 302 to complete the loop. In some embodiments, the thickness of the second return pole 306 is limited by the position of the optical component 301. In some embodiments, the second return pole 306 has a thickness of about 100 nm to about 1,500 nm. In some embodiments, the second return pole 306 has a thickness of about 500 nm. In some embodiments, the second return pole 306 comprises a magnetic material having a saturation magnetization lower than the saturation magnetization of the main pole 302. In some embodiments, the second return pole 306 has a saturation magnetization of about 10 kG to about 22 kG. In some embodiments, the second return pole 306 has a saturation magnetization of about 19 kG.

[0072] In some embodiments, the second return pole 306 comprises a second pedestal 208 configured to determine the distance between the second return pole 306 and the main pole 302. In some embodiments, the second pedestal 208 is positioned adjacent to the air bearing surface 311. In some embodiments, the second pedestal 208 has a thickness 212 of about 1.5 μm to about 2.5 μm. In some embodiments, the second pedestal 208 has a thickness 212 of about 2 μm. In some embodiments, the second pedestal 208 has a height 316 of about 200 nm to about 1,000 nm. In some embodiments, the second pedestal 208 comprises a magnetic material having a saturation magnetization lower than the saturation magnetization of the main pole 302. In some embodiments, the second pedestal 208 has a saturation magnetization of about 10 kG to about 22 kG. In some embodiments, the second pedestal 208 has a saturation magnetization of about 19 kG.

[0073] In some embodiments, the second return pole 306 comprises a magnetic reading shield (MLS) 309 positioned adjacent to the air bearing surface 311. In some embodiments, the magnetic reading shield 309 has a thickness 212 of about 0.1 μm to about 0.8 μm. In some embodiments, the magnetic reading shield 309 has a thickness 212 of about 0.5 μm. In some embodiments, the magnetic reading shield 309 has a height 316 of about 500 nm to about 1,000 nm. In some embodiments, the magnetic reading shield 309 has a height 316 of about 800 nm.

[0074] In some embodiments, the second return pole 306 may be operably connected to the main pole 302 by a second connector 307. In some embodiments, the second connector 307 includes a magnetic material having a saturation magnetization lower than the saturation magnetization of the main pole 302. In some embodiments, the second connector 307 has a saturation magnetization of about 10 kG to about 22 kG. In some embodiments, the second connector 307 has a saturation magnetization of about 19 kG.

[0075] In embodiments where the writer head includes a first return pole 303 and a second return pole 306, the writer head may include at least one coil 317 positioned between the first return pole 303 and the main pole 302, and at least one coil 317 positioned between the second return pole 306 and the main pole 302. In some embodiments, the total number of loops between the first return pole 303 and the main pole 302, and between the second return pole 306 and the main pole 302, is the same. In some embodiments, the writer head has a total of 1 to 6 loops.

[0076] method A method for manufacturing the above optical components for a HAMR writer head can be employed. A method for manufacturing optical components for a HAMR writer head includes preparing a substrate, depositing a triangular layer on the surface of the substrate, and depositing each subsequent layer of the optical component. Each layer may be deposited by any method known to those skilled in the art. In some embodiments, the method includes depositing each layer by one of sputter deposition, physical vapor deposition, plating, chemical vapor deposition, or electron beam deposition. Each layer may be deposited to a thickness greater than or equal to the desired thickness of the corresponding layer.

[0077] The method may further include surface treatment of each layer before depositing the next layer. In some embodiments, the surface of each layer is treated to achieve a desired thickness and shape. In some embodiments, the surface treatment includes etching, polishing, milling, laser ablation, or one or more of the above. In some embodiments, the surface treatment includes creating a smooth surface. In some embodiments, one or more surfaces of the layers are treated to create a tapered portion with a tapered edge. In some embodiments, the tapered edge has an angle of about 20 to about 70 degrees. In some embodiments, the tapered edge has an angle of about 45 degrees. In some embodiments, the surface may be treated to control the position of the layer relative to the air bearing surface.

[0078] The method may further include operably connecting the principal poles to an optical component. In some embodiments, the principal poles are deposited on the optical component. The principal poles may be deposited by any method known to those skilled in the art. In some embodiments, the principal poles are deposited by one of sputter deposition, physical vapor deposition, plating, chemical vapor deposition, or electron beam deposition. In some embodiments, the principal poles are deposited by first depositing a first material having a first magnetic moment, and then depositing a second material having a second magnetic moment on the surface of the first material. The principal poles may be deposited to a thickness greater than or equal to the desired thickness of the final product. In some embodiments, the method further includes surface treatment of the surface of the principal pole opposite the optical component to create a tapered edge. In some embodiments, the tapered edge has an angle of about -15 to about -45 degrees. In some embodiments, the tapered edge has an angle of about -20 degrees. In some embodiments, the method further includes surface treatment of the surface of the magnetic principal pole opposite the optical component to create a flat surface. [Examples]

[0079] Example 1: Magnetic field test The magnetic properties of the HAMR writer heads described herein were compared with existing HAMR writer head designs. The HAMR writer head structures included optical components and main magnetic poles having the following parameters: (1) a writer head having the structure of Figure 1A, (2) a writer head having the structure of Figure 1B, (3) a writer head having the structure of Figure 1C, (4) a writer head having the structure of Figure 1D, (5) a writer head having the structure of Figure 1E, (6) a writer head having the structure of Figure 2A, and (7) a writer head having the structure of Figure 2B. The characteristics were tested by calculating the magnetic field and magnetic field angle during recording using finite element method modeling and simulation. Graphs of the test results are provided in Figures 4-5. Each of the sample HAMR writer heads performed better than existing HAMR writer heads in both the magnetic field and magnetic field angle during recording. Test cases 1, 2, and 5 each had a magnetic field at the recording position that was more than 40% stronger than existing HAMR writer heads. Furthermore, each HMAR writer head sample had a magnetic field angle at the recording position that was at least 10% lower than that of existing HAMR writer heads, with test case 5 having a magnetic field angle approximately 19% lower. These improvements demonstrate that tapered principal poles result in a significant increase in the surface density capacitance of HAMR.

[0080] As used herein, the term "about" when preceding a number means a range of ±10% of that number. For example, "about 50" means 45 to 55, and "about 25,000" means 22,500 to 27,500. However, this does not apply if otherwise indicated in the context of this disclosure or if such interpretation is inconsistent.

[0081] This disclosure is not limited to the specific embodiments described herein, which are intended to illustrate various aspects. As will be apparent to those skilled in the art, many modifications and changes can be made without departing from the idea and scope. Functionally equivalent methods and apparatus included within the scope of this disclosure, as well as those enumerated herein, will be apparent to those skilled in the art from this specification. Such modifications and changes are intended to be included within the scope of the appended claims. This disclosure is limited only by the language of the appended claims and the full extent of the equivalents that such claims may enjoy. Furthermore, this disclosure is not limited to specific methods, reagents, compounds, compositions or biological systems, which can, of course, be modified. It should also be understood that the terms used herein are merely descriptive of specific embodiments and are not intended to be limiting.

[0082] In this document, a singular "a," "an," and "the" are considered to include the plural unless otherwise specified in the context. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art. Nothing in this disclosure should be construed as acknowledging that the embodiments described herein do not have any retroactive rights to such disclosures due to prior inventions. In this document, "comprising" means "including, but not limited to."

[0083] Various compositions, methods, and apparatuses are described as “comprising” (meaning “including, but not limited to) various components or processes. However, such compositions, methods, and apparatuses may also “consist essentially of” or “consist of” these components and processes, and such terms should be interpreted as defining a substantially closed set of components.

[0084] In this specification, a person skilled in the art can appropriately substitute plural for singular and singular, depending on the context and application, for the use of substantially all singular and plural terms. For clarity, various singular / plural substitutions may also be explicitly listed herein.

[0085] Those skilled in the art will understand that the terms used herein, particularly those used in the appended claims (e.g., the claim text), are generally intended to be "open" terms (for example, the term "including" should be interpreted as "including, but not limited to," the term "having" should be interpreted as "having at least," and the term "includes" should be interpreted as "including, but not limited to"). Furthermore, if a specific number of constituent elements is intended to be included in a claim, that intention is explicitly stated in the claim, and those skilled in the art will understand that such intention does not exist unless it is explicitly stated. For example, to aid understanding, the following appended claims may use "at least one" or "one or more" as constituent elements of a claim. However, the use of such expressions should not be interpreted as meaning that, when a constituent element of a claim is included by the indefinite article "a" or "an," the claim containing that constituent element is limited to embodiments containing only one of that constituent element. The same applies even if one or more "one or more," at least one "at least one," or the indefinite articles "a" or "an" are used in the same claim (for example, "a" and "an" should be interpreted as meaning "at least one" or "one or more"). The same applies to the definite articles used to include the constituent elements of a claim. Furthermore, even if a specific number of constituent elements of a claim is explicitly stated, a person skilled in the art will recognize that the statement should be interpreted as meaning at least that number (for example, if it is simply stated as "two constituent elements" without other modifiers, it means at least two, i.e., two or more constituent elements).Furthermore, when expressions similar to "at least one of A, B, and C" are used, the construction is generally intended to have the meaning understood by those skilled in the art from its conventional expression (for example, "a system having at least one of A, B, and C" includes, but is not limited to, a system having only A, a system having only B, a system having only C, a system having A and B, a system having A and C, a system having B and C, and a system having all of A, B, and C). Similarly, when expressions similar to "at least one of A, B, or C" are used, they are generally intended to have the conventional meaning understood by those skilled in the art (for example, "a system having at least one of A, B, or C" includes, but is not limited to, a system having only A, only B, only C, A and B, A and C, B and C, and a system having all of A, B, and C). Furthermore, a person skilled in the art will understand that virtually any disjunctive phrase presenting two or more alternative terms in this specification, claims, or drawings should be understood to encompass the possibility of including only one of the terms, either one, or both. For example, the phrase "A or B" should be understood to encompass the possibility of including "A only," "B only," or "A and B."

[0086] Furthermore, even if the features or aspects of the present disclosure are described in the form of Markush groups, a person skilled in the art will recognize that the present disclosure describes any individual component or subgroup of such Markush groups.

[0087] As will be understood by those skilled in the art, for purposes such as satisfying disclosure requirements, all numerical ranges disclosed herein also encompass all possible subranges of such ranges and combinations thereof. Any listed range can be readily understood as sufficiently describing and enabling that the range is divisible into at least equal halves, thirds, quarters, fifths, tenths, etc., etc., of which the range is divisible into lower thirds, middle thirds, upper thirds, etc., as an example without limitation. Also, as will be understood by those skilled in the art, all expressions such as "up to" and "at least" include the numerical value itself and refer to a range that is divisible into subranges as described above. Finally, as will be understood by those skilled in the art, a range includes each individual numerical value within that range. Thus, for example, a group having 1 to 3 cells means a group having 1, 2, or 3 cells. Similarly, a group having 1 to 5 cells means a group having 1, 2, 3, 4, or 5 cells.

Claims

1. A writer head for a heat-assisted magnetic recording (HAMR) device, It is an optical component, A triangular layer having a tapered edge, A first cladding layer positioned adjacent to the triangular layer, A waveguide (WG) layer positioned adjacent to the first cladding layer, A second cladding layer positioned adjacent to the WG layer, A near-field transducer (NFT) layer positioned adjacent to the cladding layer, A heat sink layer positioned adjacent to the NFT layer, An optical component comprising a triangular peg gap layer positioned adjacent to the heat sink layer and including a taper angle of approximately 20 to 70 degrees, A main magnetic pole positioned adjacent to the triangular peg gap layer and the heat sink layer, and having a saturation magnetization of approximately 24 kG or more. A writer's head equipped with this feature.

2. In the writer head described in claim 1, A writer head in which the surface of the main magnetic pole includes a taper angle equal to the taper angle of the triangular peg gap layer.

3. In the writer head described in claim 1, A writer head in which the surface of the main magnetic pole opposite the tapered peg gap layer includes a flat surface.

4. In the writer head described in claim 1, A writer head in which the surface of the principal magnetic pole opposite the tapered peg gap layer includes a taper that is equal to and opposite to the angle of the triangular peg gap layer.

5. In the writer head described in claim 1, A writer head in which the surface of the main magnetic pole opposite the tapered peg gap layer includes a slope with an angle of approximately -15 to -45 degrees.

6. In the writer head described in claim 1, A writer head in which the surface of the main magnetic pole opposite the tapered peg gap layer includes a slope with an angle of approximately -15 to approximately -45 degrees, and the surface of the heat sink layer in contact with the main magnetic pole includes a taper with an angle of approximately -15 to approximately -45 degrees.

7. In the writer head described in claim 1, A writer head in which the main magnetic poles include a first layer adjacent to the peg gap layer and a second layer adjacent to the first layer, wherein the first layer has a lower magnetic moment than the second layer.

8. In the writer head according to claim 7, The first layer is a writer head with a thickness of approximately 10 nm to 50 nm.

9. In the writer head according to claim 7, A writer head in which the first layer comprises one or more of CoFe, NiFe, and CoFeNi, and a dopant containing a transition metal.

10. In the writer head according to claim 9, A lighter head in which the dopant contains one or more of palladium or rhenium.

11. In the writer head described in claim 1, A writer head with a triangular layer containing a waveguide cutoff layer with ruthenium.

12. In the writer head described in claim 1, A lighter head in which a triangular layer contains one or more of alumina or silica.

13. In the writer head described in claim 1, The NFT layer comprises a first NFT layer containing a first metal and a second NFT layer containing a transition metal. The first NFT layer contains one or more of gold, silver, copper, their alloys, graphene, and metal oxides. A writer head in which the second NFT layer includes one of Rh or Ir.

14. In the writer head described in claim 1, A lighter head in which the heat sink layer contains one or more of gold, ruthenium, aluminum nitride, or silicon carbide.

15. In the writer head described in claim 1, A writer head, further comprising an optical component, a laser diode configured to generate a light beam.

16. In the writer head described in claim 1, A writer head in which a magnetic component includes a first return pole operably connected to a main magnetic pole by a first connector and positioned on the opposite side of the optical component from the main magnetic pole.

17. In the writer head according to claim 16, A writer head in which the magnetic component further includes a coil containing 0 to 6 loops, the coil positioned between a first return pole and a main pole.

18. In the writer head according to claim 16, A writer head in which the distance between the first return pole and the principal pole is approximately 50 nm to approximately 1,000 nm.

19. In the writer head according to claim 16, A writer head in which the first return magnetic pole has a thickness of approximately 500 nm to approximately 1,500 nm.

20. In the writer head according to claim 16, A writer head comprising a first return pole, which includes a first pedestal having a thickness of approximately 1.5 μm to approximately 2.5 μm and a height of approximately 200 nm to approximately 1,000 nm.

21. In the writer head according to claim 16, A writer head further comprising a first magnetic reading shield (MLS) having a thickness of approximately 100 nm to approximately 1,000 nm and a height of approximately 500 nm to approximately 2,000 nm, wherein the first return pole is a first magnetic reading shield (MLS).

22. In the writer head according to claim 16, A writer head in which the magnetic components include a first yoke positioned between a first connector and a main magnetic pole.

23. In the writer head according to claim 16, A writer head in which the main magnetic poles include a sloping trailing edge having an angle of approximately 15 degrees to approximately -75 degrees.

24. In the writer head according to claim 16, A writer head in which a magnetic component includes a second return pole, which is operably connected to a main pole by a second connector and positioned opposite to the first return pole relative to the main pole.

25. In the writer head according to claim 24, A writer head in which the distance between the second return pole and the main pole is approximately 100 nm to approximately 1,000 nm.

26. In the writer head according to claim 24, A writer head in which the second return magnetic pole has a thickness of approximately 100 nm to 1,500 nm.

27. In the writer head according to claim 24, A writer head comprising a second return pole, which includes a second pedestal having a thickness of approximately 1.5 μm to approximately 2.5 μm and a height of approximately 200 nm to approximately 1,000 nm.

28. In the writer head according to claim 24, A writer head further comprising a second magnetic reading shield (MLS) having a thickness of approximately 100 nm to approximately 800 nm and a height of approximately 500 nm to approximately 1,000 nm, wherein the second return pole is a second magnetic reading shield (MLS).

29. In the writer head according to claim 24, A writer head comprising a magnetic component further including a first coil and a second coil, the first coil and the second coil combined to form 0 to 6 loops, the first coil positioned between a first return pole and a main pole, the second coil positioned between a second return pole and a main pole, and the first coil and the second coil each containing the same number of loops.

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