Patents by Inventor Michael Grobis
Michael Grobis 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: 20220108158Abstract: An MRAM-based vector multiplication device, such as can be used for inferencing in a neural network, is presented that is ultralow power, low cost, and does not require special on-chip programming. A crosspoint array has an MRAM cell at each crosspoint junction and periphery array circuitry capable of supplying independent input voltages to each word line and reading current on each bit line. Vector multiplication is performed as an in-array multiplication of a vector of input voltages with matrix weight values encoded by the MRAM cell states. The MRAM cells can be individually programmed using a combination of input voltages and an external magnetic field. The external magnetic field is chosen so that a write voltage of one polarity reduces the anisotropy sufficiently to align the cell state with the external field, but is insufficient to align the cell if only half of the write voltage is applied.Type: ApplicationFiled: October 2, 2020Publication date: April 7, 2022Applicant: SanDisk Technologies LLCInventors: Michael Grobis, Michael Nicolas Albert Tran
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Publication number: 20220108759Abstract: Non-volatile memory structures for performing compute-in-memory inferencing for neural networks are presented. A memory array is formed according to a crosspoint architecture with a memory cell at each crosspoint junction. The multi-levels memory cells (MLCs) are formed of multiple of ultra-thin dielectric layers separated by metallic layers, where programming of the memory cell is done by selectively breaking down one or more of the dielectric layers by selecting the write voltage level. In an alternate set of embodiments, the memory cells are formed as anti-fuses.Type: ApplicationFiled: October 2, 2020Publication date: April 7, 2022Applicant: SanDisk Technologies LLCInventors: Michael Nicolas Albert Tran, Michael Grobis
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Patent number: 11289171Abstract: Non-volatile memory structures for performing compute-in-memory inferencing for neural networks are presented. A memory array is formed according to a crosspoint architecture with a memory cell at each crosspoint junction. The multi-levels memory cells (MLCs) are formed of multiple of ultra-thin dielectric layers separated by metallic layers, where programming of the memory cell is done by selectively breaking down one or more of the dielectric layers by selecting the write voltage level. In an alternate set of embodiments, the memory cells are formed as anti-fuses.Type: GrantFiled: October 2, 2020Date of Patent: March 29, 2022Assignee: SanDisk Technologies LLCInventors: Michael Nicolas Albert Tran, Michael Grobis
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Patent number: 11271040Abstract: A memory cell includes an ovonic threshold switch (OTS) selector containing a first electrode, a second electrode, an OTS located between the first electrode and the second electrode, and a current focusing layer containing discrete electrically conductive current focusing regions having a width of 30 nm or less located between the first electrode and the OTS, and a memory device located in electrical series with the OTS selector.Type: GrantFiled: October 21, 2020Date of Patent: March 8, 2022Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.Inventors: Derek Stewart, John Read, Michael Grobis
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Patent number: 11031435Abstract: A memory device includes a plurality of memory cells, and an isolation material portion located between the memory cells. The isolation material portion includes at least one ovonic threshold switch material portion.Type: GrantFiled: June 17, 2019Date of Patent: June 8, 2021Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.Inventors: Michael Grobis, Joyeeta Nag, Derek Stewart
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Patent number: 11004489Abstract: A perpendicular spin transfer torque MRAM memory cell includes a magnetic tunnel junction stack comprising a pinned layer having a fixed direction of magnetization, a free layer having a direction of magnetization that can be switched, a tunnel barrier between the pinned layer and the free layer, a cap layer above the free layer and one or more in-stack multi-layer thermal barrier layers having multiple internal interfaces between materials. The thermal barrier layers have high enough thermal resistivity to maintain the heat generated in the memory cell and low enough electrical resistivity to not materially change the electrical resistance of the memory cell. One embodiment further includes a thermal barrier liner surrounding the free layer, pinned layer, tunnel barrier and cap layer.Type: GrantFiled: July 1, 2019Date of Patent: May 11, 2021Assignee: Western Digital Technologies, Inc.Inventors: Goran Mihajlovic, Tiffany Santos, Michael Grobis
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Patent number: 10891999Abstract: A MRAM memory cell comprises a SHE layer, a magnetic bit layer with perpendicular anisotropy and an Oersted layer. The magnetic bit layer has a switchable direction of magnetization in order to store data. Data is written to the MRAM memory cell using the Spin Hall Effect so that spin current generated in the SHE layer exerts a torque on the magnetic bit layer while the Oersted layer provides heat and an Oersted field to enable deterministic switching. Data is read form the MRAM memory cell using the Anomalous Hall Effect and sensing voltage at the Oersted layer.Type: GrantFiled: July 1, 2019Date of Patent: January 12, 2021Assignee: Western Digital Technologies, Inc.Inventors: Goran Mihajlovic, Michael Grobis
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Publication number: 20200402559Abstract: A perpendicular spin transfer torque MRAM memory cell includes a magnetic tunnel junction stack comprising a pinned layer having a fixed direction of magnetization, a free layer having a direction of magnetization that can be switched, a tunnel barrier between the pinned layer and the free layer, a cap layer above the free layer and one or more in-stack multi-layer thermal barrier layers having multiple internal interfaces between materials. The thermal barrier layers have high enough thermal resistivity to maintain the heat generated in the memory cell and low enough electrical resistivity to not materially change the electrical resistance of the memory cell. One embodiment further includes a thermal barrier liner surrounding the free layer, pinned layer, tunnel barrier and cap layer.Type: ApplicationFiled: July 1, 2019Publication date: December 24, 2020Applicant: WESTERN DIGITAL TECHNOLOGIES, INC.Inventors: Goran Mihajlovic, Tiffany Santos, Michael Grobis
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Publication number: 20200402561Abstract: A MRAM memory cell comprises a SHE layer, a magnetic bit layer with perpendicular anisotropy and an Oersted layer. The magnetic bit layer has a switchable direction of magnetization in order to store data. Data is written to the MRAM memory cell using the Spin Hall Effect so that spin current generated in the SHE layer exerts a torque on the magnetic bit layer while the Oersted layer provides heat and an Oersted field to enable deterministic switching. Data is read form the MRAM memory cell using the Anomalous Hall Effect and sensing voltage at the Oersted layer.Type: ApplicationFiled: July 1, 2019Publication date: December 24, 2020Applicant: WESTERN DIGITAL TECHNOLOGIES, INC.Inventors: Goran Mihajlovic, Michael Grobis
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Publication number: 20200395410Abstract: A memory device includes a plurality of memory cells, and an isolation material portion located between the memory cells. The isolation material portion includes at least one ovonic threshold switch material portion.Type: ApplicationFiled: June 17, 2019Publication date: December 17, 2020Inventors: Michael GROBIS, Joyeeta NAG, Derek STEWART
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Patent number: 10868245Abstract: A phase change memory device includes a phase change material portion located between a first electrode and a second electrode, and a crystallization template material portion located between the first electrode and the second electrode in contact with the phase change material portion. The crystallization template material portion and the phase change material portion belong to a same crystal system and have matching lattice spacing, or the crystallization template material portion and the phase change material portion do not belong to the same crystal system, but have a matching translational symmetry along at least one paired lattice plane with a matching lattice spacing.Type: GrantFiled: June 5, 2019Date of Patent: December 15, 2020Assignee: SANDISK TECHNOLOGIES LLCInventors: Zhaoqiang Bai, Mac Apodaca, Michael Grobis, Michael Nicolas Albert Tran, Neil Leslie Robertson, Gerardo Bertero
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Publication number: 20200388752Abstract: A phase change memory device includes a phase change material portion located between a first electrode and a second electrode, and a crystallization template material portion located between the first electrode and the second electrode in contact with the phase change material portion. The crystallization template material portion and the phase change material portion belong to a same crystal system and have matching lattice spacing, or the crystallization template material portion and the phase change material portion do not belong to the same crystal system, but have a matching translational symmetry along at least one paired lattice plane with a matching lattice spacing.Type: ApplicationFiled: June 5, 2019Publication date: December 10, 2020Inventors: Zhaoqiang BAI, Mac APODACA, Michael GROBIS, Michael Nicolas Albert TRAN, Neil Leslie ROBERTSON, Gerardo BERTERO
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Patent number: 10777248Abstract: A magnetoresistive random access memory (MRAM) memory cell comprises a pinned layer having fixed direction of magnetization that is perpendicular to a plane of the pinned layer, a first free layer having a direction of magnetization that can be switched and is perpendicular to a plane of the first free layer, a tunnel barrier positioned between the pinned layer and the first free layer, a second free layer having a direction of magnetization that can be switched, and a spacer layer positioned between the first free layer and the second free layer. Temperature dependence of coercivity of the second free layer is greater than temperature dependence of coercivity of the first free layer.Type: GrantFiled: July 1, 2019Date of Patent: September 15, 2020Assignee: Western Digital Technologies, Inc.Inventors: Goran Mihajlovic, Neil Smith, Michael Grobis, Michael Tran
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Patent number: 10622063Abstract: A method of operating a phase change memory device includes flowing a write current of a first polarity through a phase change memory element of a selected phase change memory cell, and flowing a read current of a second polarity opposite to the first polarity through the phase change memory element of the selected phase change memory cell. A first junction between the phase change memory element and a first electrode and a second junction between the phase change memory element and a second electrode exhibit asymmetric thermoelectric heat generation during the step of flowing the write current.Type: GrantFiled: June 27, 2018Date of Patent: April 14, 2020Assignee: SANDISK TECHNOLOGIES LLCInventors: Michael Grobis, Zhaoqiang Bai, Ward Parkinson
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Publication number: 20200005863Abstract: A method of operating a phase change memory device includes flowing a write current of a first polarity through a phase change memory element of a selected phase change memory cell, and flowing a read current of a second polarity opposite to the first polarity through the phase change memory element of the selected phase change memory cell. A first junction between the phase change memory element and a first electrode and a second junction between the phase change memory element and a second electrode exhibit asymmetric thermoelectric heat generation during the step of flowing the write current.Type: ApplicationFiled: June 27, 2018Publication date: January 2, 2020Inventors: Michael GROBIS, Zhaoqiang BAI, Ward PARKINSON
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Patent number: 10388646Abstract: A surge protection device contains a first electrode, a second electrode electrically connected to electrical ground, and a field-induced switching component electrically contacting the first electrode and the second electrode. The field-induced switching component can include a correlated-electron material or a volatile conductive bridge.Type: GrantFiled: June 4, 2018Date of Patent: August 20, 2019Assignee: SANDISK TECHNOLOGIES LLCInventors: Derek Stewart, Daniel Bedau, Michael Grobis, Christopher J. Petti
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Patent number: 9190093Abstract: The present disclosure relates to a magnetic medium that includes a substrate and a bit patterned magnetic layer applied to the substrate. The bit-patterned magnetic layer includes islands and each island includes a first magnetic material having a first magnetic anisotropy and that has a top surface, a bottom surface, and a peripheral surface. Each island also includes a second magnetic material covering the peripheral surface of the first magnetic material and having a second magnetic anisotropy that is higher than the first magnetic anisotropy. In one embodiment, the first magnetic material may comprise a nucleation domain in a centrally located surface portion of the magnetic islands and/or the second magnetic material may comprise an outer shell on the peripheral surface of the islands.Type: GrantFiled: February 6, 2013Date of Patent: November 17, 2015Assignee: HGST NETHERLANDS, B.V.Inventors: Michael Grobis, Dan S. Kercher, Kurt A. Rubin
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Publication number: 20140218824Abstract: The present disclosure relates to a magnetic medium that includes a substrate and a bit patterned magnetic layer applied to the substrate. The bit-patterned magnetic layer includes islands and each island includes a first magnetic material having a first magnetic anisotropy and that has a top surface, a bottom surface, and a peripheral surface. Each island also includes a second magnetic material covering the peripheral surface of the first magnetic material and having a second magnetic anisotropy that is higher than the first magnetic anisotropy. In one embodiment, the first magnetic material may comprise a nucleation domain in a centrally located surface portion of the magnetic islands and/or the second magnetic material may comprise an outer shell on the peripheral surface of the islands.Type: ApplicationFiled: February 6, 2013Publication date: August 7, 2014Applicant: HGST NETHERLANDS B.V.Inventors: Michael Grobis, Dan S. Kercher, Kurt A. Rubin