Patents by Inventor Donald G. Allen
Donald G. Allen has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20240027892Abstract: A write pole of a write head of a hard disk drive can be manufactured by forming a photoresist layer over a magnetic material layer located over a substrate, disposing a tri-tone lithographic mask over the photoresist layer, lithographically exposing the photoresist layer through the lithographic mask, developing the photoresist layer to form a patterned photoresist layer, and patterning the magnetic material layer into the write pole by removing portions of the magnetic material layer that are not covered by the photoresist layer. The tri-tone lithographic mask includes a patterned opaque material layer and a patterned partially-transparent material layer located over a transparent substrate. The patterned opaque material layer includes a uniform width region and a flare region. The patterned partially-transparent material layer includes a pair of partially-transparent strips extending adjacent to a respective edge of the patterned opaque material layer, and partially-transparent assist bars.Type: ApplicationFiled: July 22, 2022Publication date: January 25, 2024Inventors: Xianzhong Zeng, Yi Zheng, Ming Jiang, Donald G. Allen
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Patent number: 9412398Abstract: Depositing a seed layer for a high-moment shield onto a write pole may have a deleterious effect on the magnetic response of the write pole. Instead, an amorphous separation layer may be deposited between the write pole and the seed layer. In one embodiment, the seed layer is formed directly on the amorphous layer. In addition to separating the seed layer from the write pole, the amorphous separation layer permits the seed layer to dictate the crystallographic orientation of the shield which is subsequently deposited on the magnetic head. That is, the amorphous layer provides a substrate that allows the seed layer to have a crystalline structure independent of the layers that were deposited previously. The amorphous separation layer may comprise an amorphous metal—e.g., NiNb or NiTa—or an insulative material—e.g., alumina or silicon dioxide.Type: GrantFiled: August 21, 2013Date of Patent: August 9, 2016Assignee: HGST Netherlands B.V.Inventors: Donald G. Allen, Wen-Chien D. Hsiao, Quan-chiu H. Lam, Ning Shi
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Publication number: 20150056473Abstract: Depositing a seed layer for a high-moment shield onto a write pole may have a deleterious effect on the magnetic response of the write pole. Instead, an amorphous separation layer may be deposited between the write pole and the seed layer. In one embodiment, the seed layer is formed directly on the amorphous layer. In addition to separating the seed layer from the write pole, the amorphous separation layer permits the seed layer to dictate the crystallographic orientation of the shield which is subsequently deposited on the magnetic head. That is, the amorphous layer provides a substrate that allows the seed layer to have a crystalline structure independent of the layers that were deposited previously. The amorphous separation layer may comprise an amorphous metal—e.g., NiNb or NiTa—or an insulative material—e.g., alumina or silicon dioxide.Type: ApplicationFiled: August 21, 2013Publication date: February 26, 2015Applicant: HGST Netherlands B.V.Inventors: Donald G. Allen, Wen-Chien D. Hsiao, Quan-chiu H. Lam, Ning Shi
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Patent number: 8547660Abstract: A magnetic write head having a tapered trailing edge and having a magnetic layer formed over a trailing edge of the write pole at a location recessed from the ABS, the magnetic layer being separated from the trailing edge of the write pole by a thin non-magnetic layer. The thin non-magnetic layer is preferably sufficiently thin that the magnetic layer can function as a portion of the write pole in a region removed from the ABS. A trailing magnetic shield is formed over the write pole and is separated from the write pole by a non-magnetic trailing gap layer. A non-magnetic spacer layer can be formed over the magnetic layer to provide additional separation between the magnetic layer and the trailing magnetic shield.Type: GrantFiled: December 17, 2009Date of Patent: October 1, 2013Assignee: HGST Netherlands B.V.Inventors: Donald G. Allen, Amanda Baer, Yingjian Chen, Andrew Chiu, Liubo Hong, Wen-Chien D. Hsiao, Edward H. P. Lee, Fenglin Liu, Aron Pentek, Katalin Pentek, Kyusik Shin, Yi Zheng, Qiping Zhong, Honglin Zhu
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Patent number: 8498078Abstract: Methods for fabrication of tapered magnetic poles with a non-magnetic front bump layer. A magnetic pole may have a plurality of tapered surfaces at or near an air bearing surface (ABS), wherein a thickness of the write pole increases in a direction away from the ABS. A non-magnetic front bump layer may be formed on one or more of the tapered surfaces of the magnetic pole at a distance from the ABS. The front bump layer may increase the separation distance between a shield layer and the magnetic pole near the tapered surface, thereby improving the performance of the write head.Type: GrantFiled: December 9, 2009Date of Patent: July 30, 2013Assignee: HGST Netherlands B.V.Inventors: Donald G. Allen, Liubo Hong, Aron Pentek, Thomas J. A. Roucoux, Sue S. Zhang, Yi Zheng
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Publication number: 20130082027Abstract: A method for manufacturing a magnetic write head for magnetic data recording. The method includes forming a depositing a magnetic write pole material and forming a mask structure over the write pole material that includes a polymer mask under-layer, a dielectric hard mask formed over the polymer mask under-layer and a photoresist mask formed over the dielectric hard mask. The image of the photoresist mask is transferred onto the underlying dielectric hard mask and then a reactive ion etching is performed to transfer the image of the dielectric hard mask onto the polymer mask under-layer. This reactive ion etching is performed in an atmosphere chemistry that includes both an oxygen containing gas and a nitrogen containing gas.Type: ApplicationFiled: September 30, 2011Publication date: April 4, 2013Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Guomin Mao, Donald G. Allen, Aron Pentek, Thomas J. A. Roucoux, Yi Zheng
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Publication number: 20130020204Abstract: A method for manufacturing a magnetic write head having a tapered leading edge. The method includes depositing a sacrificial non-magnetic layer to a thickness that is at least as great as the thickness of the write pole to be formed. The sacrificial non-magnetic layer is then masked and ion milled so as to form a tapered edge on the sacrificial non-magnetic layer that extends through the thickness of the non-magnetic fill layer. A magnetic material is then deposited and planarized by chemical mechanical polishing. The remaining magnetic material forms the entirety of the magnetic write pole so that there is no need to deposit additional magnetic layers further construct the write pole.Type: ApplicationFiled: July 20, 2011Publication date: January 24, 2013Inventors: Donald G. Allen, Liubo Hong, Aron Pentek, Thomas J. A. Roucoux, Junsheng Yang, Yi Zheng, Qiping Zhong, Honglin Zhu
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Patent number: 8218263Abstract: According to one embodiment, a system comprises an upper yoke having a first length defined between a pole tip thereof and a back gap thereof. In addition, the system includes a lower yoke having a second length defined between a pole tip thereof and a back gap thereof, the second length being greater than the first length. Also, the system includes coil turns in the upper and lower yokes. Additional systems and methods are also presented.Type: GrantFiled: December 22, 2008Date of Patent: July 10, 2012Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Donald G. Allen, Wen-Chien David Hsiao, Edward Hin Pong Lee, Jennifer Leung, Vladimir Nikitin
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Publication number: 20120162821Abstract: The present disclosure describes various ways to achieve a rotational write field using a single coil. For example, a rotational write field can be achieved with a single coil by using different yoke lengths for different poles of a write element. Also described are ways to achieve a rotational write field with a single coil by varying the resistivity, saturation flux density, or pole width of the different poles of the write element of the present invention. The present disclosure also describes various ways to achieve a rotational write field using varied windings of a single coil.Type: ApplicationFiled: December 27, 2010Publication date: June 28, 2012Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Quan-Chiu Harry Lam, Donald G. Allen, Yansheng Luo
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Patent number: 8201320Abstract: A method for manufacturing a magnetic write head having a leading magnetic shield and a trailing magnetic shield that are arranged to prevent the lost of magnetic write field to the trailing magnetic shield. The write head includes a non-magnetic step layer that provides additional spacing between the trailing magnetic shield and the write pole at a region removed from the air bearing surface.Type: GrantFiled: December 17, 2009Date of Patent: June 19, 2012Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Donald G. Allen, Yingjian Chen, Andrew Chiu, Liubo Hong, Wen-Chien D. Hsiao, Edward H. P. Lee, Fenglin Liu, Katalin Pentek, Kyusik Shin, Yi Zheng, Qiping Zhong, Honglin Zhu
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Publication number: 20110151279Abstract: A magnetic write head having a tapered trailing edge and having a magnetic layer formed over a trailing edge of the write pole at a location recessed from the ABS, the magnetic layer being separated from the trailing edge of the write pole by a thin non-magnetic layer. The thin non-magnetic layer is preferably sufficiently thin that the magnetic layer can function as a portion of the write pole in a region removed from the ABS. A trailing magnetic shield is formed over the write pole and is separated from the write pole by a non-magnetic trailing gap layer. A non-magnetic spacer layer can be formed over the magnetic layer to provide additional separation between the magnetic layer and the trailing magnetic shield.Type: ApplicationFiled: December 17, 2009Publication date: June 23, 2011Inventors: Donald G. Allen, Amanda Baer, Yingjian Chen, Andrew Chiu, Liubo Hong, Wen-Chien D. Hsiao, Edward H.P. Lee, Fenglin Liu, Aron Pentek, Katalin Pentek, Kyusik Shin, Yi Zheng, Qiping Zhong, Honglin Zhu
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Publication number: 20110146062Abstract: A method for manufacturing a magnetic write head having a leading magnetic shield and a trailing magnetic shield that are arranged to prevent the lost of magnetic write field to the trailing magnetic shield. The write head includes a non-magnetic step layer that provides additional spacing between the trailing magnetic shield and the write pole at a region removed from the air bearing surface.Type: ApplicationFiled: December 17, 2009Publication date: June 23, 2011Inventors: Donald G. Allen, Yingjian Chen, Andrew Chiu, Liubo Hong, Wen-Chien D. Hsiao, Edward H.P. Lee, Fenglin Liu, Katalin Pentek, Kyusik Shin, Yi Zheng, Qiping Zhong, Honglin Zhu
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Publication number: 20110134569Abstract: Methods for fabrication of tapered magnetic poles with a non-magnetic front bump layer. A magnetic pole may have a plurality of tapered surfaces at or near and air bearing surface (ABS), wherein a thickness of the write pole increases in a direction away from the ABS. A non-magnetic front bump layer may be formed on one or more of the tapered surfaces of the magnetic pole at a distance from the ABS. The front bump layer may increase the separation distance between a shield layer and the magnetic pole near the tapered surface, thereby improving the performance of the write head.Type: ApplicationFiled: December 9, 2009Publication date: June 9, 2011Inventors: Donald G. Allen, Liubo Hong, Aron Pentek, Thomas J. A. Roucoux, Sue S. Zhang, Yi Zheng
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Patent number: 7933096Abstract: Methods and structures for the fabrication of both thin film longitudinal and perpendicular write heads are disclosed. A unique feature of these write heads is the inclusion of layered return poles, which comprise alternating layers of 22/78 and 80/20 NiFe alloys. The alternating layers also vary in thickness, the 22/78 NiFe layers having a nominal thickness of 1500 angstroms and the 80/20 NiFe layers having a nominal thickness of about 75 angstroms. Head efficiency and signal to noise ratios are significantly improved in heads having layered return pole construction.Type: GrantFiled: December 26, 2007Date of Patent: April 26, 2011Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Donald G. Allen, Hieu Lam, Terence Tin-Lok Lam, Steve C. Puga
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Patent number: 7748103Abstract: A perpendicular magnetic recording write head has a write pole, a trapezoidal-shaped trailing shield notch, and a metal gap layer between the write pole and notch. The write pole has a trailing edge that has a width substantially defining the track width and that faces the front edge of the notch but is spaced from it by the gap layer. The write head is fabricated by reactive ion beam etching of a thin mask film above the write pole to remove the mask film and widen the opening at the edges of the write pole. The gap layer and notch are deposited into the widened opening above the write pole. The write pole has nonmagnetic filler material, such as alumina, surrounding it except at its trailing edge, where it is in contact with the gap layer, which is formed of a different material than the surrounding filler material.Type: GrantFiled: April 24, 2006Date of Patent: July 6, 2010Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Donald G. Allen, Amanda Baer, Michael Feldbaum, Wen-Chien David Hsiao, Vladimir Nikitin, Aron Pentek, Katalin Pentek
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Publication number: 20100157471Abstract: According to one embodiment, a system comprises an upper yoke having a first length defined between a pole tip thereof and a back gap thereof. In addition, the system includes a lower yoke having a second length defined between a pole tip thereof and a back gap thereof, the second length being greater than the first length. Also, the system includes coil turns in the upper and lower yokes. Additional systems and methods are also presented.Type: ApplicationFiled: December 22, 2008Publication date: June 24, 2010Inventors: Donald G. Allen, Wen-Chien David Hsiao, Edward Hin Pong Lee, Jennifer Leung, Vladimir Nikitin
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Patent number: 7612963Abstract: A magnetic recording head for use in perpendicular magnetic recording having a design that allows the write coil to be manufactured by a damascene process for increased coil pitch and reduced coil resistance. The magnetic write head includes a photoresist dam structure that allows a hard baked photoresist to be formed that does not extend to the air bearing surface (ABS). Since the photoresist dam prevents the hard baked photoresist from reaching the ABS, the damascene process, in which the hard baked photoresist remains in the finished write head, can be used to produce the write head. The use of such a damascene process advantageously allows the space between the coil turns to be reduced, which maximizes the number of turns that can be used and also maximizes the number width to which the coil turns can be constructed, thereby minimizing the electrical resistance of the write coil.Type: GrantFiled: June 30, 2006Date of Patent: November 3, 2009Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Donald G. Allen, Edward Hin Pong Lee, Jennifer Ai-Ming Leung
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Patent number: 7576951Abstract: A magnetic write head for perpendicular magnetic recording having a write pole with a concave trailing edge. The magnetic write pole can have a trapezoidal shape with first and second laterally opposed sides that are further apart at the trailing edge than at the leading edge. The write head may or may not include a magnetic trailing shield, and if a trailing shield is included it is separated from the trailing edge by a non-magnetic write gap layer. The concave trailing edge improves magnetic performance such as by improving the transition curvature. A method for constructing the write head includes forming a magnetic write pole by forming a mask structure over a deposited write pole material, the mask structure having an alumina hard mask and an image transfer layer such as DURAMIDE®. An alumina fill layer is then deposited and a chemical mechanical polish is performed to open up the image transfer layer.Type: GrantFiled: April 25, 2006Date of Patent: August 18, 2009Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Donald G. Allen, Amanda Baer, Michael Feldbaum, Hung-Chin Guthrie, Wen-Chien David Hsiao, Yimin Hsu, Ming Jiang, Yinshi Liu, Aaron Neuhaus, Vladimir Nikitin, Aron Pentek, Katalin Pentek, Yi Zheng
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Publication number: 20090168260Abstract: Methods and structures for the fabrication of both thin film longitudinal and perpendicular write heads are disclosed. A unique feature of these write heads is the inclusion of layered return poles, which comprise alternating layers of 22/78 and 80/20 NiFe alloys. The alternating layers also vary in thickness, the 22/78 NiFe layers having a nominal thickness of 1500 angstroms and the 80/20 NiFe layers having a nominal thickness of about 75 angstroms. Head efficiency and signal to noise ratios are significantly improved in heads having layered return pole construction.Type: ApplicationFiled: December 26, 2007Publication date: July 2, 2009Inventors: Donald G. Allen, Hieu Lam, Terence Tin-Lok Lam, Steve C. Puga
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Patent number: 7509729Abstract: A method for making a write pole in a perpendicular magnetic recording write head uses a metal mask to pattern the primary resist and only ion milling during the subsequent patterning steps. A layer of primary resist is deposited over the magnetic write pole material and a metal mask layer is deposited on the primary resist layer. An imaging resist layer is formed on the metal mask layer and lithographically patterned generally in the desired shape of the write pole. Ion milling without a reactive gas is then performed over the imaging resist pattern to pattern the underlying metal mask layer, which is then used as the mask to define the shape of the primary resist pattern. Ion milling with oxygen is then performed over the metal mask pattern to pattern the underlying primary resist. Ion milling without a reactive gas is then performed over the primary resist pattern to form the underlying write pole.Type: GrantFiled: April 25, 2006Date of Patent: March 31, 2009Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Donald G. Allen, Amanda Baer, Michael Feldbaum, Hung-Chin Guthrie, Aron Pentek