Patents by Inventor Roger K. Malmhall
Roger K. Malmhall 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: 9793319Abstract: The present invention is directed to a magnetic random access memory element that includes a multilayered seed structure formed by interleaving multiple layers of a first transition metal with multiple layers of a second transition metal; and a first magnetic layer formed on top of the multilayered seed structure. The first magnetic layer has a multilayer structure formed by interleaving layers of the first transition metal with layers of a magnetic material and has a first fixed magnetization direction substantially perpendicular to a layer plane thereof. The first transition metal is platinum or palladium, while the second transition metal is selected from the group consisting of tantalum, titanium, zirconium, hafnium, vanadium, niobium, chromium, molybdenum, and tungsten.Type: GrantFiled: October 17, 2016Date of Patent: October 17, 2017Assignee: Avalanche Technology, Inc.Inventors: Huadong Gan, Yiming Huai, Bing K. Yen, Roger K. Malmhall, Yuchen Zhou
-
Publication number: 20170033156Abstract: The present invention is directed to a magnetic random access memory element that includes a multilayered seed structure formed by interleaving multiple layers of a first transition metal with multiple layers of a second transition metal; and a first magnetic layer formed on top of the multilayered seed structure. The first magnetic layer has a multilayer structure formed by interleaving layers of the first transition metal with layers of a magnetic material and has a first fixed magnetization direction substantially perpendicular to a layer plane thereof The first transition metal is platinum or palladium, while the second transition metal is selected from the group consisting of tantalum, titanium, zirconium, hafnium, vanadium, niobium, chromium, molybdenum, and tungsten.Type: ApplicationFiled: October 17, 2016Publication date: February 2, 2017Inventors: Huadong Gan, Yiming Huai, Bing K. Yen, Roger K. Malmhall, Yuchen Zhou
-
Patent number: 9444038Abstract: The present invention is directed to a magnetic random access memory element that includes a multilayered seed structure formed by interleaving a first type sublayer and a second type sublayer to form one or more repeats of a unit bilayer structure and a first magnetic layer formed on top of the multilayered seed structure. The unit bilayer structure is made of the first and second type sublayers with at least one of the first and second type sublayers including therein one or more ferromagnetic elements. The multilayered seed structure may be amorphous or non-magnetic or both. The unit bilayer structure may be made of CoFeB and Ta sublayers.Type: GrantFiled: June 1, 2015Date of Patent: September 13, 2016Assignee: Avalanche Technology, Inc.Inventors: Yiming Huai, Huadong Gan, Bing K. Yen, Roger K. Malmhall, Yuchen Zhou
-
Publication number: 20150340601Abstract: The present invention is directed to a magnetic random access memory element that includes a multilayered seed structure formed by interleaving a first type sublayer and a second type sublayer to form one or more repeats of a unit bilayer structure and a first magnetic layer formed on top of the multilayered seed structure. The unit bilayer structure is made of the first and second type sublayers with at least one of the first and second type sublayers including therein one or more ferromagnetic elements. The multilayered seed structure may be amorphous or non-magnetic or both. The unit bilayer structure may be made of CoFeB and Ta sublayers.Type: ApplicationFiled: June 1, 2015Publication date: November 26, 2015Inventors: Yiming Huai, Huadong Gan, Bing K. Yen, Roger K. Malmhall, Yuchen Zhou
-
Spin-Transfer Torque Magnetic Random Access Memory (STTMRAM) with Perpendicular Laminated Free Layer
Publication number: 20150137293Abstract: A perpendicular spin-transfer torque magnetic random access memory (STTMRAM) element includes a fixed layer having a magnetization that is substantially fixed in one direction and a barrier layer formed on top of the fixed layer and a free layer. The free layer has a number of alternating laminates, each laminate being made of a magnetic layer and an insulating layer. The magnetic layer is switchable and formed on top of the barrier layer. The free layer is capable of switching its magnetization to a parallel or an anti-parallel state relative to the magnetization of the fixed layer during a write operation when bidirectional electric current is applied across the STTMRAM element. Magnetic layers of the laminates are ferromagnetically coupled to switch together as a single domain during the write operation and the magnetization of the fixed and free layers and the magnetic layers of the laminates have perpendicular anisotropy.Type: ApplicationFiled: January 30, 2015Publication date: May 21, 2015Inventors: Yiming Huai, Rajiv Yadav Ranjan, Roger K. Malmhall -
Spin-transfer torque magnetic random access memory (STTMRAM) with perpendicular laminated free layer
Patent number: 9025371Abstract: A perpendicular spin-transfer torque magnetic random access memory (STTMRAM) element includes a fixed layer having a magnetization that is substantially fixed in one direction and a barrier layer formed on top of the fixed layer and a free layer. The free layer has a number of alternating laminates, each laminate being made of a magnetic layer and an insulating layer. The magnetic layer is switchable and formed on top of the barrier layer. The free layer is capable of switching its magnetization to a parallel or an anti-parallel state relative to the magnetization of the fixed layer during a write operation when bidirectional electric current is applied across the STTMRAM element. Magnetic layers of the laminates are ferromagnetically coupled to switch together as a single domain during the write operation and the magnetization of the fixed and free layers and the magnetic layers of the laminates have perpendicular anisotropy.Type: GrantFiled: January 30, 2015Date of Patent: May 5, 2015Assignee: Avalanche Technology, Inc.Inventors: Yiming Huai, Rajiv Yadav Ranjan, Roger K. Malmhall -
Patent number: 8975088Abstract: Various embodiments of the invention relate to etching processes used in fabrication of MTJ cells in an MRAM device. The various embodiments can be used in combination with each other. The first embodiment adds a hard mask buffer layer between a hard mask and a top electrode. The second embodiment uses a multilayered etching hard mask. The third embodiment uses a multilayered top electrode structure including a first Cu layer under a second layer such as Ta. The fourth embodiment is a two-phase etching process used for the bottom electrode to remove re-deposited material while maintaining a more vertical sidewall etching profile. In the first phase the bottom electrode layer is removed using carbonaceous reactive ion etching until the endpoint. In the second phase an inert gas and/or oxygen plasma is used to remove the polymer that was deposited during the previous etching processes.Type: GrantFiled: July 30, 2013Date of Patent: March 10, 2015Assignee: Avalanche Technology, Inc.Inventors: Kimihiro Satoh, Yiming Huai, Jing Zhang, Rajiv Yadav Ranjan, Parviz Keshtbod, Roger K. Malmhall
-
Patent number: 8885395Abstract: A magnetoresistive logic cell (MRLC) is described that includes two MTJs in series that share a common free layer (CFL). The relative magnetization orientations of the CFL and the switchable reference layer (SRL) in MTJ-1 dominate the overall resistance of the MRLC without regard to the fixed magnetization orientation of the nonswitchable reference layer in MTJ-2. The high resistance state of the MRLC occurs when the switchable reference and common free layers have opposite magnetization orientations. The low resistance state occurs when the orientations are the same. This behavior allows the MRLC to be used as a logical comparator. The CFL is switched by STT effect by application of selected relatively short voltage pulses that do not switch the SRL. The SRL is switched with reference to the CFL by a voltage effect generated by a selected longer voltage pulse that does not switch the CFL.Type: GrantFiled: February 22, 2012Date of Patent: November 11, 2014Assignee: Avalanche Technology, Inc.Inventors: Yuchen Zhou, Zihui Wang, Yiming Huai, Rajiv Yadav Ranjan, Roger K. Malmhall
-
Publication number: 20130337582Abstract: Various embodiments of the invention relate to etching processes used in fabrication of MTJ cells in an MRAM device. The various embodiments can be used in combination with each other. The first embodiment adds a hard mask buffer layer between a hard mask and a top electrode. The second embodiment uses a multilayered etching hard mask. The third embodiment uses a multilayered top electrode structure including a first Cu layer under a second layer such as Ta. The fourth embodiment is a two-phase etching process used for the bottom electrode to remove re-deposited material while maintaining a more vertical sidewall etching profile. In the first phase the bottom electrode layer is removed using carbonaceous reactive ion etching until the endpoint. In the second phase an inert gas and/or oxygen plasma is used to remove the polymer that was deposited during the previous etching processes.Type: ApplicationFiled: July 30, 2013Publication date: December 19, 2013Applicant: Avalanche Technology Inc.Inventors: Kimihiro Satoh, Yiming Huai, Jing Zhang, Yadav Ranjan, Parviz Keshtbod, Roger K. Malmhall
-
Patent number: 8536063Abstract: Various embodiments of the invention relate to etching processes used in fabrication of MTJ cells in an MRAM device. The various embodiments can be used in combination with each other. The first embodiment adds a hard mask buffer layer between a hard mask and a top electrode. The second embodiment uses a multilayered etching hard mask. The third embodiment uses a multilayered top electrode structure including a first Cu layer under a second layer such as Ta. The fourth embodiment is a two-phase etching process used for the bottom electrode to remove re-deposited material while maintaining a more vertical sidewall etching profile. In the first phase the bottom electrode layer is removed using carbonaceous reactive ion etching until the endpoint. In the second phase an inert gas and/or oxygen plasma is used to remove the polymer that was deposited during the previous etching processes.Type: GrantFiled: August 30, 2011Date of Patent: September 17, 2013Assignee: Avalanche Technology Inc.Inventors: Kimihiro Satoh, Yiming Huai, Jing Zhang, Rajiv Yadav Ranjan, Parviz Keshtbod, Roger K. Malmhall
-
Publication number: 20130215672Abstract: A magnetoresistive logic cell (MRLC) is described that includes two MTJs in series that share a common free layer (CFL). The relative magnetization orientations of the CFL and the switchable reference layer (SRL) in MTJ-1 dominate the overall resistance of the MRLC without regard to the fixed magnetization orientation of the nonswitchable reference layer in MTJ-2. The high resistance state of the MRLC occurs when the switchable reference and common free layers have opposite magnetization orientations. The low resistance state occurs when the orientations are the same. This behavior allows the MRLC to be used as a logical comparator. The CFL is switched by STT effect by application of selected relatively short voltage pulses that do not switch the SRL. The SRL is switched with reference to the CFL by a voltage effect generated by a selected longer voltage pulse that does not switch the CFL.Type: ApplicationFiled: February 22, 2012Publication date: August 22, 2013Inventors: Yuchen Zhou, Zihui Wang, Yiming Huai, Yadav Ranjan, Roger K. Malmhall
-
Publication number: 20130052752Abstract: Various embodiments of the invention relate to etching processes used in fabrication of MTJ cells in an MRAM device. The various embodiments can be used in combination with each other. The first embodiment adds a hard mask buffer layer between a hard mask and a top electrode. The second embodiment uses a multilayered etching hard mask. The third embodiment uses a multilayered top electrode structure including a first Cu layer under a second layer such as Ta. The fourth embodiment is a two-phase etching process used for the bottom electrode to remove re-deposited material while maintaining a more vertical sidewall etching profile. In the first phase the bottom electrode layer is removed using carbonaceous reactive ion etching until the endpoint. In the second phase an inert gas and/or oxygen plasma is used to remove the polymer that was deposited during the previous etching processes.Type: ApplicationFiled: August 30, 2011Publication date: February 28, 2013Inventors: Kimihiro Satoh, Yiming Huai, Jing Zhang, Rajiv Yadav Ranjan, Parviz Keshtbod, Roger K. Malmhall
-
Patent number: 7327667Abstract: A single monolithic semiconductor substrate comprises a first side and a second side. The first side includes an air bearing surface. A laser integrates with the first side. The laser has an emission facet substantially co-planer with the air bearing surface. A contact pad on the second side electronically bridges to the laser.Type: GrantFiled: September 23, 2004Date of Patent: February 5, 2008Assignee: Research Investment Network, Inc.Inventors: Robert L. Thornton, Douglas G. Stinson, Roger K. Malmhall, Matthew C. Bashaw
-
Patent number: 7158470Abstract: A near-field optical apparatus having one or more solid state lasers and an aerodynamically shaped slider which comprise a single integrated, monolithic device fabricated from the same base semiconductor material. The monolithic optical head can be quickly and easily attached to the read arm of an optical read/write device without requiring attachment of separate laser elements, and without micropositioning or use of optical microscopy for positioning the lasers. The optical head comprising a single semiconductor substrate including a first region which defines a slider having an air bearing surface, and at least one second, laser region which defines a diode laser, with the diode laser having an emission face which is substantially co-planar with the air bearing surface.Type: GrantFiled: August 23, 2005Date of Patent: January 2, 2007Assignee: Research Investment Network, Inc.Inventors: Robert L. Thornton, Douglas G. Stinson, Roger K. Malmhall, Mathew C. Bashaw
-
Patent number: 7069569Abstract: A near-field optical system having one or more solid state lasers and an aerodynamically shaped slider which comprise a single integrated, monolithic device fabricated from the same base semiconductor material. The monolithic optical head can be quickly and easily attached to the read arm of an optical read/write device without requiring attachment of separate laser elements, and without micropositioning or use of optical microscopy for positioning the lasers. The optical head comprising a single semiconductor substrate including a first region which defines a slider having an air bearing surface, and at least one second, laser region which defines a diode laser, with the diode laser having an emission face which is substantially co-planar with the air bearing surface.Type: GrantFiled: April 23, 2002Date of Patent: June 27, 2006Assignee: Research Investment Network, Inc.Inventors: Robert L. Thornton, Douglas G. Stinson, Roger K. Malmhall, Mathew C. Bashaw
-
Patent number: 6963530Abstract: A near-field optical apparatus having one or more solid state lasers and an aerodynamically shaped slider which comprise a single integrated, monolithic device fabricated from the same base semiconductor material. The monolithic optical head can be quickly and easily attached to the read arm of an optical read/write device without requiring attachment of separate laser elements, and without micropositioning or use of optical microscopy for positioning the lasers. The optical head comprising a single semiconductor substrate including a first region which defines a slider having an air bearing surface, and at least one second, laser region which defines a diode laser, with the diode laser having an emission face which is substantially co-planar with the air bearing surface.Type: GrantFiled: February 1, 2000Date of Patent: November 8, 2005Assignee: Research Investment Network, Inc.Inventors: Robert L. Thornton, Douglas G. Stinson, Roger K. Malmhall, Mathew C. Bashaw
-
Patent number: 6937637Abstract: A near-field optical system having one or more solid state lasers and an aerodynamically shaped slider which comprise a single integrated, monolithic device fabricated from the same base semiconductor material. The monolithic optical head can be quickly and easily attached to the read arm of an optical read/write device without requiring attachment of separate laser elements, and without micropositioning or use of optical microscopy for positioning the lasers. The optical head comprising a single semiconductor substrate including a first region which defines a slider having an air bearing surface, and at least one second, laser region which defines a diode laser, with the diode laser having an emission face which is substantially co-planar with the air bearing surface. A slider region of the semiconductor substrate includes an air bearing surface, adjacent the p-clad layer, which is aerodynamically structured and configured to define a slider.Type: GrantFiled: May 19, 2003Date of Patent: August 30, 2005Assignee: Research Investment Network, Inc.Inventors: Robert L. Thornton, Douglas G. Stinson, Roger K. Malmhall, Matthew C. Bashaw
-
Publication number: 20040008605Abstract: A near-field optical system having one or more solid state lasers and an aerodynamically shaped slider which comprise a single integrated, monolithic device fabricated from the same base semiconductor material. The monolithic optical head can be quickly and easily attached to the read arm of an optical read/write device without requiring attachment of separate laser elements, and without micropositioning or use of optical microscopy for positioning the lasers. The optical head comprising a single semiconductor substrate including a first region which defines a slider having an air bearing surface, and at least one second, laser region which defines a diode laser, with the diode laser having an emission face which is substantially co-planar with the air bearing surface.Type: ApplicationFiled: April 23, 2002Publication date: January 15, 2004Applicant: Siros Technologies, Inc., a California CorporationInventors: Robert L. Thornton, Douglas G. Stinson, Roger K. Malmhall, Mathew C. Bashaw
-
Patent number: 6661592Abstract: A system for transferring information to and from a magnetic disk is disclosed wherein the information may be encoded on a data track in a large number of polarization orientations in comparison to conventional bidirectional recording schemes. In one embodiment of the present invention, it is contemplated that a single segment may be polarized in eight different orientations, each of which being distinguishable from each other by a read/write head. Polarization of a segment in one of eight different orientations significantly increases the amount of information which can be stored in any given segment relative to conventional systems which are polarized in only one of two orientations. Thus, the amount of information which may be stored on a disk may be increased without having to alter the linear or radial density of the disk.Type: GrantFiled: December 19, 2002Date of Patent: December 9, 2003Assignee: Seagate Technology LLCInventors: Hans J. Richter, Roger K. Malmhäll
-
Publication number: 20030090826Abstract: A system for transferring information to and from a magnetic disk is disclosed wherein the information may be encoded on a data track in a large number of polarization orientations in comparison to conventional bidirectional recording schemes. In one embodiment of the present invention, it is contemplated that a single segment may be polarized in eight different orientations, each of which being distinguishable from each other by a read/write head. Polarization of a segment in one of eight different orientations significantly increases the amount of information which can be stored in any given segment relative to conventional systems which are polarized in only one of two orientations. Thus, the amount of information which may be stored on a disk may be increased without having to alter the linear or radial density of the disk.Type: ApplicationFiled: December 19, 2002Publication date: May 15, 2003Applicant: Seagate Technology, Inc.Inventors: Hans J. Richter, Roger K. Malmhall