Patents by Inventor John C. Read
John C. Read 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).
-
Patent number: 10290338Abstract: Embodiments disclosed herein generally relate to a multilayer magnetic device, and specifically to a spin-torque transfer magnetoresistive random access memory (STT-MRAM) device which provides for a reduction in the amount of current required for switching individual bits. As such, a polarizing reference layer consisting of a synthetic antiferromagnet (SAF) structure with an in-plane magnetized ferromagnet film indirectly exchange coupled to a magnetic film with perpendicular magnetic anisotropy (PMA) is disclosed. By tuning the exchange coupling strength and the PMA, the layers of the SAF may both be canted such that either may be used as a tilted polarizer for either an in-plane free layer or a free layer with PMA.Type: GrantFiled: December 18, 2017Date of Patent: May 14, 2019Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.Inventors: Patrick M. Braganca, John C. Read
-
Patent number: 10269400Abstract: Embodiments disclosed herein generally relate to a multilayer magnetic device, and specifically to a spin-torque transfer magnetoresistive random access memory (STT-MRAM) device which provides for a reduction in the amount of current required for switching individual bits. As such, a polarizing reference layer consisting of a synthetic antiferromagnet (SAF) structure with an in-plane magnetized ferromagnet film indirectly exchange coupled to a magnetic film with perpendicular magnetic anisotropy (PMA) is disclosed. By tuning the exchange coupling strength and the PMA, the layers of the SAF may both be canted such that either may be used as a tilted polarizer for either an in-plane free layer or a free layer with PMA.Type: GrantFiled: September 6, 2017Date of Patent: April 23, 2019Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.Inventors: Patrick M. Braganca, John C. Read
-
Publication number: 20180108391Abstract: Embodiments disclosed herein generally relate to a multilayer magnetic device, and specifically to a spin-torque transfer magnetoresistive random access memory (STT-MRAM) device which provides for a reduction in the amount of current required for switching individual bits. As such, a polarizing reference layer consisting of a synthetic antiferromagnet (SAF) structure with an in-plane magnetized ferromagnet film indirectly exchange coupled to a magnetic film with perpendicular magnetic anisotropy (PMA) is disclosed. By tuning the exchange coupling strength and the PMA, the layers of the SAF may both be canted such that either may be used as a tilted polarizer for either an in-plane free layer or a free layer with PMA.Type: ApplicationFiled: December 18, 2017Publication date: April 19, 2018Inventors: Patrick M. BRAGANCA, John C. READ
-
Patent number: 9929213Abstract: The present disclosure generally relates to a nano-particle matrix in a 3D NVM RRAM device. The RRAM device utilizes a material that may be deposited into high aspect ratio channels, has good cycle ability, short erase and write times, and write/erase voltages that are compatible with CMOS. The RRAM material is disposed between two electrodes of the device and includes conductive nano-particles that are distributed within an insulating matrix. The particles are distributed below the percolation threshold.Type: GrantFiled: January 27, 2016Date of Patent: March 27, 2018Assignee: Western Digital Technologies, Inc.Inventors: John C. Read, Kurt Allan Rubin
-
Publication number: 20170372763Abstract: Embodiments disclosed herein generally relate to a multilayer magnetic device, and specifically to a spin-torque transfer magnetoresistive random access memory (STT-MRAM) device which provides for a reduction in the amount of current required for switching individual bits. As such, a polarizing reference layer consisting of a synthetic antiferromagnet (SAF) structure with an in-plane magnetized ferromagnet film indirectly exchange coupled to a magnetic film with perpendicular magnetic anisotropy (PMA) is disclosed. By tuning the exchange coupling strength and the PMA, the layers of the SAF may both be canted such that either may be used as a tilted polarizer for either an in-plane free layer or a free layer with PMA.Type: ApplicationFiled: September 6, 2017Publication date: December 28, 2017Inventors: Patrick M. BRAGANCA, John C. READ
-
Patent number: 9852782Abstract: Embodiments disclosed herein generally relate to a multilayer magnetic device, and specifically to a spin-torque transfer magnetoresistive random access memory (STT-MRAM) device which provides for a reduction in the amount of current required for switching individual bits. As such, a polarizing reference layer consisting of a synthetic antiferromagnet (SAF) structure with an in-plane magnetized ferromagnet film indirectly exchange coupled to a magnetic film with perpendicular magnetic anisotropy (PMA) is disclosed. By tuning the exchange coupling strength and the PMA, the layers of the SAF may both be canted such that either may be used as a tilted polarizer for either an in-plane free layer or a free layer with PMA.Type: GrantFiled: August 31, 2015Date of Patent: December 26, 2017Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.Inventors: Patrick M. Braganca, John C. Read
-
Publication number: 20170213869Abstract: The present disclosure generally relates to a nano-particle matrix in a 3D NVM RRAM device. The RRAM device utilizes a material that may be deposited into high aspect ratio channels, has good cycle ability, short erase and write times, and write/erase voltages that are compatible with CMOS. The RRAM material is disposed between two electrodes of the device and includes conductive nano-particles that are distributed within an insulating matrix. The particles are distributed below the percolation threshold.Type: ApplicationFiled: January 27, 2016Publication date: July 27, 2017Inventors: John C. READ, Kurt Allan RUBIN
-
Publication number: 20170133588Abstract: Embodiments disclosed herein generally relate to an electrode structure for a resistive random access memory (ReRAM) device cell which focuses the electric field at a center of the cell and methods for making the same. As such, a non-uniform metallic electrode may be deposited onto the ReRAM device which is subsequently exposed to an oxidation or nitrogenation process during cell fabrication. The electrode structure may be conical or pyramid shaped, and comprise at least one layer comprising a first material and a second material, wherein the concentration of the first material and the second material are varied based on location within the electrode. A metal electrode profile is formed which favors the center of the cell as the location with the greatest electric field. As such, size scaling and reliability of the non-volatile memory component are each increased.Type: ApplicationFiled: November 6, 2015Publication date: May 11, 2017Inventors: Daniel BEDAU, Jeffrey Robinson CHILDRESS, Oleksandr MOSENDZ, John C. READ, Derek STEWART
-
Publication number: 20170062700Abstract: Embodiments disclosed herein generally relate to a multilayer magnetic device, and specifically to a spin-torque transfer magnetoresistive random access memory (STT-MRAM) device which provides for a reduction in the amount of current required for switching individual bits. As such, a polarizing reference layer consisting of a synthetic antiferromagnet (SAF) structure with an in-plane magnetized ferromagnet film indirectly exchange coupled to a magnetic film with perpendicular magnetic anisotropy (PMA) is disclosed. By tuning the exchange coupling strength and the PMA, the layers of the SAF may both be canted such that either may be used as a tilted polarizer for either an in-plane free layer or a free layer with PMA.Type: ApplicationFiled: August 31, 2015Publication date: March 2, 2017Inventors: Patrick M. BRAGANCA, John C. READ
-
Publication number: 20160307587Abstract: Embodiments disclosed herein generally relate to a magnetic head having an amorphous ferromagnetic reference layer. The ferromagnetic reference layer may have amorphous structure as a result of an amorphous ferromagnetic underlayer that the ferromagnetic reference layer is deposited thereon. The amorphous ferromagnetic reference layer enhances magnetoresistance, leading to an improved magnetic head.Type: ApplicationFiled: June 30, 2016Publication date: October 20, 2016Inventors: Jeffrey Robinson CHILDRESS, Young-Suk CHOI, Tomoya NAKATANI, John C. READ
-
Patent number: 9130055Abstract: In one embodiment, a device includes a reference layer, a free layer positioned above the reference layer, and a spacer layer positioned between the reference layer and the free layer, the spacer layer providing a gap between the reference layer and the free layer, wherein the reference layer extends beyond a rear extent of the free layer in an element height direction perpendicular to a media-facing surface of the device, and wherein a rear portion of the spacer layer that extends beyond the rear extent of the free layer has an increased resistivity in comparison with a resistivity of a rest of the spacer layer. In other embodiments, a method for forming the device is presented, along with other device structures having an extended pinned layer (EPL).Type: GrantFiled: May 7, 2014Date of Patent: September 8, 2015Assignee: HGST Netherlands B.V.Inventors: Patrick M. Braganca, Matthew J. Carey, Jeffrey R. Childress, Young-suk Choi, Jordan A. Katine, Yang Li, John C. Read, Neil L. Robertson
-
Patent number: 9099115Abstract: A magnetic head according to one embodiment includes an underlayer, a first nonmagnetic spacer layer above the underlayer, a free layer above the first nonmagnetic spacer layer, a second nonmagnetic spacer layer above the free layer, and a cap layer above the second nonmagnetic spacer layer. At least one of the cap layer and the underlayer comprises a soft ferromagnetic material and a high spin orbit coupling material. Other embodiments are also described.Type: GrantFiled: November 12, 2013Date of Patent: August 4, 2015Assignee: HGST Netherlands B.V.Inventors: Patrick M. Braganca, Jeffrey R. Childress, John C. Read
-
Publication number: 20150131179Abstract: A magnetic head according to one embodiment includes an underlayer, a first nonmagnetic spacer layer above the underlayer, a free layer above the first nonmagnetic spacer layer, a second nonmagnetic spacer layer above the free layer, and a cap layer above the second nonmagnetic spacer layer. At least one of the cap layer and the underlayer comprises a soft ferromagnetic material and a high spin orbit coupling material. Other embodiments are also described.Type: ApplicationFiled: November 12, 2013Publication date: May 14, 2015Applicant: HGST Netherlands B.V.Inventors: Patrick M. Braganca, Jeffrey R. Childress, John C. Read
-
Patent number: 8743511Abstract: A method and apparatus for increasing the electrical resistivity and corrosion resistance of the material forming a spacer layer in current-perpendicular-to-the-plane (CPP) giant magnetoresistive (GMR) sensors. The increased resistivity of the spacer layer, and thus, the CPP-GMR sensor permits a larger voltage across the sensor and a higher signal-to-noise ratio. The increased corrosion resistance of the spacer layer minimizes the effects of exposing the spacer layer to corrosive materials during fabrication. For example, adding tin to silver to form a metallic alloy spacer layer increases the corrosion resistance of the spacer layer and the electrical resisitivity of the CPP-GMR sensor relative to a spacer layer consisting solely of silver. The Ag—Sn alloy permits a larger current to flow through the sensor, which increases the signal-to-noise ratio.Type: GrantFiled: August 31, 2011Date of Patent: June 3, 2014Assignee: HGST Netherlands B.V.Inventors: Jeffrey R. Childress, John C. Read, Neil Smith
-
Publication number: 20130052484Abstract: A method and apparatus for increasing the electrical resistivity and corrosion resistance of the material forming a spacer layer in current-perpendicular-to-the-plane (CPP) giant magnetoresistive (GMR) sensors. The increased resistivity of the spacer layer, and thus, the CPP-GMR sensor permits a larger voltage across the sensor and a higher signal-to-noise ratio. The increased corrosion resistance of the spacer layer minimizes the effects of exposing the spacer layer to corrosive materials during fabrication. For example, adding tin to silver to form a metallic alloy spacer layer increases the corrosion resistance of the spacer layer and the electrical resisitivity of the CPP-GMR sensor relative to a spacer layer consisting solely of silver. The Ag—Sn alloy permits a larger current to flow through the sensor, which increases the signal-to-noise ratio.Type: ApplicationFiled: August 31, 2011Publication date: February 28, 2013Inventors: Jeffrey R. Childress, John C. Read, Neil Smith
-
Patent number: 7537218Abstract: A jaw for the chuck of a turning device such as a lathe generally comprises a base, a tooth adjustable relative to the base in the radial direction and a cam for adjusting the tooth position. The base may be held on the chuck and driven in a conventional manner. The tooth has a face for engaging a workpiece and is attached to the base such that the face is radially movable relative to the base. The cam includes a surface bearing against the base and a surface bearing against the tooth. The cam varies in thickness such that movement of the cam changes the radial distance between the base and the tooth. In exemplary embodiments, the cam is an eccentric cylinder that rotates to adjust the tooth or is wedge shaped and one or both of the bearing surfaces of the tooth and base are ramps.Type: GrantFiled: July 24, 2006Date of Patent: May 26, 2009Inventors: William R. Wachtler, John C. Read
-
Publication number: 20080018062Abstract: A jaw for the chuck of a turning device such as a lathe generally comprises a base, a tooth adjustable relative to the base in the radial direction and a cam for adjusting the tooth position. The base may be held on the chuck and driven in a conventional manner. The tooth has a face for engaging a workpiece and is attached to the base such that the face is radially movable relative to the base. The cam includes a surface bearing against the base and a surface bearing against the tooth. The cam varies in thickness such that movement of the cam changes the radial distance between the base and the tooth. In exemplary embodiments, the cam is an eccentric cylinder that rotates to adjust the tooth or is wedge shaped and one or both of the bearing surfaces of the tooth and base are ramps.Type: ApplicationFiled: July 24, 2006Publication date: January 24, 2008Inventors: William R. Wachtler, John C. Read
-
Patent number: 5549012Abstract: A rotary drive for swinging a heavy member between two extreme positions. The drive transmits a rotary force provided by a motor or similar device through a first rotatable shaft to a second rotatable shaft perpendicular to the first shaft and connected to the heavy member. The second shaft rotates in an oscillatory manner between the extreme positions in response to rotation of the first shaft. The member may thus be positioned at any suitable location in its travel by operating the motor unidirectionally. The first shaft rotates about a first axis of rotation and rotates an arm about a second axis of rotation that intersects the first axis at an angle between zero and 90 degrees non-inclusive. The arm is connected to a universal joint having three mutually perpendicular axes. The universal joint transmits forces from the arm to the second shaft.Type: GrantFiled: December 27, 1994Date of Patent: August 27, 1996Inventor: John C. Read
-
Patent number: 4559489Abstract: A multi-port power controller uses remote-controllable variable reactive elements to set the amount of power delivered to the ports.Type: GrantFiled: September 30, 1983Date of Patent: December 17, 1985Assignee: The Boeing CompanyInventors: David C. Vacanti, John C. Read, Jimmy S. Takeuchi