Patents by Inventor Jon M. Slaughter
Jon M. Slaughter 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: 20160315252Abstract: A magnetoresistive magnetic tunnel junction (MTJ) stack includes a free magnetic region, a fixed magnetic region, and a dielectric layer positioned between the free magnetic region and the fixed magnetic region. In one aspect, the fixed magnetic region consists essentially of an unpinned, fixed synthetic anti-ferromagnetic (SAF) structure which comprises (i) a first layer of one or more ferromagnetic materials, including cobalt, (ii) a multi-layer region including a plurality of layers of ferromagnetic materials, wherein the plurality of layers of ferromagnetic materials include a layer of one or more ferromagnetic materials including cobalt, and (iii) an anti-ferromagnetic coupling layer disposed between the first layer and the multi-layer region. The free magnetic region may include a circular shape, the one or more ferromagnetic materials of the first layer may include cobalt, iron and boron, and the dielectric layer may be disposed on the first layer.Type: ApplicationFiled: June 30, 2016Publication date: October 27, 2016Inventors: Srinivas V. Pietambaram, Bengt J. Akerman, Renu Whig, Jason A. Janesky, Nicholas D. Rizzo, Jon M. Slaughter
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Patent number: 9391264Abstract: An MRAM bit includes a free magnetic region, a fixed magnetic region comprising an anti-ferromagnetic material, and a dielectric layer positioned between the free magnetic region and the fixed magnetic region. In one aspect, the fixed magnetic region consists essentially of an unpinned, fixed synthetic anti-ferromagnetic (SAF) structure which comprises (i) a first layer of one or more ferromagnetic materials, wherein the one or more ferromagnetic materials includes cobalt, (ii) a second layer of one or more ferromagnetic materials wherein the one or more ferromagnetic materials includes cobalt, (iii) a third layer of one or more ferromagnetic materials, and an anti-ferromagnetic coupling layer, wherein: (a) the anti-ferromagnetic coupling layer is disposed between the first and third layers, and (b) the second layer is disposed between the first layer and the anti-ferromagnetic coupling layer.Type: GrantFiled: June 2, 2015Date of Patent: July 12, 2016Assignee: Everspin Technologies, Inc.Inventors: Srinivas V. Pietambaram, Bengt J. Akerman, Renu Whig, Jason A. Janesky, Nicholas D. Rizzo, Jon M. Slaughter
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Publication number: 20150280110Abstract: An MRAM bit includes a free magnetic region, a fixed magnetic region comprising an anti-ferromagnetic material, and a dielectric layer positioned between the free magnetic region and the fixed magnetic region. In one aspect, the fixed magnetic region consists essentially of an unpinned, fixed synthetic anti-ferromagnetic (SAF) structure which comprises (i) a first layer of one or more ferromagnetic materials, wherein the one or more ferromagnetic materials includes cobalt, (ii) a second layer of one or more ferromagnetic materials wherein the one or more ferromagnetic materials includes cobalt, (iii) a third layer of one or more ferromagnetic materials, and an anti-ferromagnetic coupling layer, wherein: (a) the anti-ferromagnetic coupling layer is disposed between the first and third layers, and (b) the second layer is disposed between the first layer and the anti-ferromagnetic coupling layer.Type: ApplicationFiled: June 2, 2015Publication date: October 1, 2015Inventors: Srinivas V. Pietambaram, Bengt J. Akerman, Renu Whig, Jason A. Janesky, Nicholas D. Rizzo, Jon M. Slaughter
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Patent number: 9093637Abstract: An MRAM bit (10) includes a free magnetic region (15), a fixed magnetic region (17) comprising an antiferromagnetic material, and a tunneling barrier (16) comprising a dielectric layer positioned between the free magnetic region (15) and the fixed magnetic region (17). The MRAM bit (10) avoids a pinning layer by comprising a fixed magnetic region exhibiting a well-defined high Hflop using a combination of high Hk (uniaxial anisotropy), high Hsat (saturation field), and ideal soft magnetic properties exhibiting well-defined easy and hard axes.Type: GrantFiled: June 12, 2014Date of Patent: July 28, 2015Assignee: Everspin Technologies, Inc.Inventors: Srinivas V. Pietambaram, Bengt J. Akerman, Renu Whig, Jason A. Janesky, Nicholas D. Rizzo, Jon M. Slaughter
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Patent number: 8754460Abstract: An MRAM bit (10) includes a free magnetic region (15), a fixed magnetic region (17) comprising an antiferromagnetic material, and a tunneling barrier (16) comprising a dielectric layer positioned between the free magnetic region (15) and the fixed magnetic region (17). The MRAM bit (10) avoids a pinning layer by comprising a fixed magnetic region exhibiting a well-defined high Hflop using a combination of high Hk (uniaxial anisotropy), high Hsat (saturation field), and ideal soft magnetic properties exhibiting well-defined easy and hard axes.Type: GrantFiled: June 24, 2013Date of Patent: June 17, 2014Assignee: EverSpin Technologies, Inc.Inventors: Srinivas V. Pietambaram, Bengt J. Akerman, Renu Whig, Jason A. Janesky, Nicholas D. Rizzo, Jon M. Slaughter
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Publication number: 20140021471Abstract: An MRAM bit (10) includes a free magnetic region (15), a fixed magnetic region (17) comprising an antiferromagnetic material, and a tunneling barrier (16) comprising a dielectric layer positioned between the free magnetic region (15) and the fixed magnetic region (17). The MRAM bit (10) avoids a pinning layer by comprising a fixed magnetic region exhibiting a well-defined high Hflop using a combination of high Hk (uniaxial anisotropy), high Hsat (saturation field), and ideal soft magnetic properties exhibiting well-defined easy and hard axes.Type: ApplicationFiled: June 24, 2013Publication date: January 23, 2014Inventors: Srinivas V. Pietambaram, Bengt J. Akerman, Renu W. Dave, Jason A. Janesky, Nicholas D. Rizzo, Jon M. Slaughter
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Patent number: 8497538Abstract: An MRAM bit (10) includes a free magnetic region (15), a fixed magnetic region (17) comprising an antiferromagnetic material, and a tunneling barrier (16) comprising a dielectric layer positioned between the free magnetic region (15) and the fixed magnetic region (17). The MRAM bit (10) avoids a pinning layer by comprising a fixed magnetic region exhibiting a well-defined high Hflop using a combination of high Hk (uniaxial anisotropy), high Hsat (saturation field), and ideal soft magnetic properties exhibiting well-defined easy and hard axes.Type: GrantFiled: May 31, 2006Date of Patent: July 30, 2013Assignee: Everspin Technologies, Inc.Inventors: Srinivas V. Pietambaram, Bengt J. Akerman, Renu W. Dave, Jason A. Janesky, Nicholas D. Rizzo, Jon M. Slaughter
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Patent number: 8257596Abstract: A fabrication process and apparatus provide a high-performance magnetic field sensor (200) from two differential sensor configurations (201, 211) which require only two distinct pinning axes (206, 216) which are formed from a single reference layer (60) that is etched into high aspect ratio shapes (62, 63) with their long axes drawn with different orientations so that, upon treating the reference layer with a properly aligned orienting field (90) and then removing the orienting field, the high aspect ratio patterns provide a shape anisotropy that forces the magnetization of each patterned shape (62, 63) to relax along its respective desired axis.Type: GrantFiled: April 30, 2009Date of Patent: September 4, 2012Assignee: Everspin Technologies, Inc.Inventors: Phillip G. Mather, Jon M. Slaughter
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Patent number: 8237437Abstract: A fabrication process and apparatus provide a high-performance magnetic field sensor (200) from two differential sensor configurations (201, 211) which require only two distinct pinning axes (206, 216) which are formed from a single reference layer (60) that is etched into high aspect ratio shapes (62, 63) with their long axes drawn with different orientations so that, upon treating the reference layers with a properly aligned saturating field (90) and then removing the saturating field, the high aspect ratio patterns provide a shape anisotropy that forces the magnetization of each patterned shape (62, 63) to relax along its respective desired axis. Upon heating and cooling, the ferromagnetic film is pinned in the different desired directions.Type: GrantFiled: February 8, 2011Date of Patent: August 7, 2012Assignee: Everspin Technologies, Inc.Inventors: Bradley N Engel, Phillip G. Mather, Jon M. Slaughter
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Patent number: 8216703Abstract: A magnetic tunnel junction (MTJ) (10) employing a dielectric tunneling barrier (16), useful in magnetoresistive random access memories (MRAMs) and other devices, has a synthetic antiferromagnet (SAF) structure (14, 16), comprising two ferromagnetic (FM) layers (26, 41; 51, 58; 61, 68) separated by a coupling layer (38, 56, 66). Improved magnetoresistance (MR) ratio is obtained by providing a further layer (44, 46, 46?, 47, 52, 62), e.g. containing Ta, preferably spaced apart from the coupling layer (38, 56, 66) by a FM layer (41, 30-2, 54). The further layer (44, 46, 46?, 47, 52, 62) may be a Ta dusting layer (44) covered by a FM layer (30-2), or a Ta containing FM alloyed layer (46), or a stack (46?) of interleaved FM and N-FM layers, or other combination (47, 62). Furthering these benefits, another FM layer, e.g., CoFe, NiFe, (30, 30-1, 51, 61) is desirably provided between the further layer (44, 46, 46?, 47, 52, 62) and the tunneling barrier (16).Type: GrantFiled: February 21, 2008Date of Patent: July 10, 2012Assignee: Everspin Technologies, Inc.Inventors: Jijun Sun, Jon M. Slaughter
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Patent number: 7977941Abstract: A magnetic field sensing device for determining the strength of a magnetic field, includes four magnetic tunnel junction elements or element arrays (100) configured as a bridge (200). A current source is coupled to a current line (116) disposed near each of the four magnetic tunnel junction elements (100) for selectively supplying temporally spaced first and second currents. Sampling circuitry (412, 414) coupled to the current source samples the bridge output during the first and second currents and determines the value of the magnetic field from the difference of the first and second values. A method for sensing the magnetic field includes supplying a first current to the current line (116), supplying a second current the current line (116), sampling the value at the output for each of the first and second currents, determining the difference between the sampled values during each of the first and second currents, and determining a measured magnetic field based on the determined difference.Type: GrantFiled: February 25, 2009Date of Patent: July 12, 2011Assignee: Everspin Technologies, Inc.Inventors: Phillip G. Mather, Jon M. Slaughter
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Patent number: 7965543Abstract: A method for reducing spin-torque current density needed to switch a magnetoelectronic device (200, 300, 400), includes applying (602) a voltage bias having a predetermined polarity to the magnetoelectronic device (200, 300, 400) that creates a spin-polarized current with spin torque transfer to a synthetic antiferromagnet free layer (206), applying (604) a magnetic field having a predetermined direction to the magnetoelectronic device (200, 300, 400), removing (606) the applied magnetic field; and removing (608) the voltage bias subsequent to removing (606) the applied magnetic field, wherein the polarity of the voltage bias and the direction of the magnetic field leave the synthetic antiferromagnet free layer (206) in a predetermined magnetic state after the voltage bias is removed.Type: GrantFiled: April 30, 2009Date of Patent: June 21, 2011Assignee: Everspin Technologies, Inc.Inventors: Jon M. Slaughter, Nicholas D. Rizzo
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Patent number: 7965077Abstract: A fabrication process and apparatus provide a high-performance magnetic field sensor (200) from two differential sensor configurations (201, 211) which require only two distinct pinning axes (206, 216) which are formed from a single reference layer (60) that is etched into high aspect ratio shapes (62, 63) with their long axes drawn with different orientations so that, upon treating the reference layers with a properly aligned saturating field (90) and then removing the saturating field, the high aspect ratio patterns provide a shape anisotropy that forces the magnetization of each patterned shape (62, 63) to relax along its respective desired axis. Upon heating and cooling, the ferromagnetic film is pinned in the different desired directions.Type: GrantFiled: May 8, 2008Date of Patent: June 21, 2011Assignee: Everspin Technologies, Inc.Inventors: Bradley N. Engel, Phillip G. Mather, Jon M. Slaughter
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Publication number: 20110121826Abstract: A fabrication process and apparatus provide a high-performance magnetic field sensor (200) from two differential sensor configurations (201, 211) which require only two distinct pinning axes (206, 216) which are formed from a single reference layer (60) that is etched into high aspect ratio shapes (62, 63) with their long axes drawn with different orientations so that, upon treating the reference layers with a properly aligned saturating field (90) and then removing the saturating field, the high aspect ratio patterns provide a shape anisotropy that forces the magnetization of each patterned shape (62, 63) to relax along its respective desired axis. Upon heating and cooling, the ferromagnetic film is pinned in the different desired directions.Type: ApplicationFiled: February 8, 2011Publication date: May 26, 2011Applicant: EVERSPIN TECHNOLOGIES, INC.Inventors: Bradley N. ENGEL, Phillip G. MATHER, Jon M. SLAUGHTER
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Publication number: 20100277971Abstract: A method for reducing spin-torque current density needed to switch a magnetoelectronic device (200, 300, 400), includes applying (602) a voltage bias having a predetermined polarity to the magnetoelectronic device (200, 300, 400) that creates a spin-polarized current with spin torque transfer to a synthetic antiferromagnet free layer (206), applying (604) a magnetic field having a predetermined direction to the magnetoelectronic device (200, 300, 400), removing (606) the applied magnetic field; and removing (608) the voltage bias subsequent to removing (606) the applied magnetic field, wherein the polarity of the voltage bias and the direction of the magnetic field leave the synthetic antiferromagnet free layer (206) in a predetermined magnetic state after the voltage bias is removed.Type: ApplicationFiled: April 30, 2009Publication date: November 4, 2010Applicant: EVERSPIN TECHNOLOGIES, INC.Inventors: Jon M. SLAUGHTER, Nicholas D. RIZZO
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Publication number: 20100276389Abstract: A fabrication process and apparatus provide a high-performance magnetic field sensor (200) from two differential sensor configurations (201, 211) which require only two distinct pinning axes (206, 216) which are formed from a single reference layer (60) that is etched into high aspect ratio shapes (62, 63) with their long axes drawn with different orientations so that, upon treating the reference layer with a properly aligned orienting field (90) and then removing the orienting field, the high aspect ratio patterns provide a shape anisotropy that forces the magnetization of each patterned shape (62, 63) to relax along its respective desired axis.Type: ApplicationFiled: April 30, 2009Publication date: November 4, 2010Applicant: EVERSPIN TECHNOLOGIES, INC.Inventors: Phillip G. MATHER, Jon M. SLAUGHTER
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Publication number: 20100213933Abstract: A magnetic field sensing device for determining the strength of a magnetic field, includes four magnetic tunnel junction elements or element arrays (100) configured as a bridge (200). A current source is coupled to a current line (116) disposed near each of the four magnetic tunnel junction elements (100) for selectively supplying temporally spaced first and second currents. Sampling circuitry (412, 414) coupled to the current source samples the bridge output during the first and second currents and determines the value of the magnetic field from the difference of the first and second values. A method for sensing the magnetic field includes supplying a first current to the current line (116), supplying a second current the current line (116), sampling the value at the output for each of the first and second currents, determining the difference between the sampled values during each of the first and second currents, and determining a measured magnetic field based on the determined difference.Type: ApplicationFiled: February 25, 2009Publication date: August 26, 2010Applicant: EVERSPIN TECHNOLOGIES, INC.Inventors: Phillip G. MATHER, Jon M. SLAUGHTER
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Patent number: 7683445Abstract: Low power magnetoelectronic device structures and methods therefore are provided. The magnetoelectronic device structure (100, 150, 450, 451) comprises a programming line (104, 154, 156, 454, 456), a magnetoelectronic device (102, 152, 452) magnetically coupled to the programming line (104, 154, 156, 454, 456), and an enhanced permeability dielectric (EPD) material (106, 108, 110, 158, 160, 162, 458, 460, 462) disposed adjacent the magnetoelectronic device. The EPD material (106, 108, 110, 158, 160, 162, 458, 460, 462) comprises multiple composite layers (408) of magnetic nano-particles (406) embedded in a dielectric matrix (409). The composition of the composite layers is chosen to provide a predetermined permeability profile. A method for making a magnetoelectronic device structure is also provided. The method comprises fabricating the magnetoelectronic device (102, 152, 452) and depositing the programming line (104, 154, 156, 454, 456).Type: GrantFiled: April 25, 2007Date of Patent: March 23, 2010Assignee: Everspin Technologies, Inc.Inventors: Srinivas V. Pietambaram, Nicholas D. Rizzo, Jon M. Slaughter
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Methods and apparatus for a synthetic anti-ferromagnet structure with reduced temperature dependence
Patent number: 7684161Abstract: A synthetic antiferromagnet (SAF) structure includes a first ferromagnetic layer, a first insertion layer, a coupling layer, a second insertion layer, and a second ferromagnetic layer. The insertion layers comprise materials selected such that SAF exhibits reduced temperature dependence of antiferromagnetic coupling strength. The insertion layers may include CoFe or CoFeX alloys. The thickness of the insertion layers is selected such that they do not increase the uniaxial anisotropy or deteriorate any other properties.Type: GrantFiled: April 18, 2006Date of Patent: March 23, 2010Assignee: Everspin Technologies, Inc.Inventors: Srinivas V. Pietambaram, Renu W. Dave, Jon M. Slaughter, JiJun Sun -
Patent number: 7635654Abstract: Methods and apparatus are provided for magnetic tunnel junction (MTJ) devices and arrays, comprising metal-insulator-metal (M-I-M) structures with opposed first and second ferro-magnetic electrodes with alterable relative magnetization direction. The insulator is formed by depositing an oxidizable material (e.g., Al) on the first electrode, naturally oxidizing it, e.g., at about 0.03 to 10 milli-Torr for up to a few thousand seconds at temperatures below about 35° C., then further rapidly (e.g., plasma) oxidizing at a rate much larger than that of the initial natural oxidation. The second electrode of the M-I-M structure is formed on this oxide. More uniform tunneling properties result. A second oxidizable material layer is optionally provided after the initial natural oxidation and before the rapid oxidation step during which it is substantially entirely converted to insulating oxide. A second natural oxidation cycle may be optionally provided before the second layer is rapidly oxidized.Type: GrantFiled: January 27, 2006Date of Patent: December 22, 2009Assignee: Everspin Technologies, Inc.Inventors: JiJun Sun, John T. Martin, Jon M. Slaughter