Patents by Inventor Yimin Guo

Yimin Guo 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).

  • Publication number: 20240331334
    Abstract: An optical synapse device which can be used in a neuromorphic machine vision system to enable broadband sensing and fast data processing in applications where machine vision is used, such as for example in real-time video analysis, autonomous vehicles and medical diagnosis. The novel optical synapse device enables image sensing, convolutional processing, and computing. Multiple synaptic plasticity triggered by photons can implement photonic computing and information transmission. Convolutional processing is realized by ultra-low energy kernel generators fully controlled by photons. The optical synapse device shows the ability of conductance modulations under electronic stimulations that implement neuromorphic computing. The novel two-terminal broadband optoelectronic synapse device enables front-end retinomorphic image sensing, convolutional processing, and back-end neuromorphic computing.
    Type: Application
    Filed: March 27, 2024
    Publication date: October 3, 2024
    Inventors: Yimin WU, Tao GUO, Baizhou ZHANG, Y. Norman ZHOU
  • Patent number: 11957063
    Abstract: A magnetoresistive element comprises a nonmagnetic nano-current-channel (NCC) structure provided on a surface of the magnetic recording layer, which is opposite to a surface of the magnetic recording layer where the tunnel barrier layer is provided, and comprising a spatial distribution of perpendicular conducting channels throughout the NCC structure thickness and surrounded by an insulating medium, making the magnetic recording layer a magnetically soft-hard composite structure. Correspondingly, the critical write current and write power are reduced with reversal modes of exchange-spring magnets of the magnetically soft-hard composite structure.
    Type: Grant
    Filed: August 28, 2021
    Date of Patent: April 9, 2024
    Inventors: Yimin Guo, Rongfu Xiao, Jun Chen
  • Patent number: 11910721
    Abstract: The invention comprises a method of forming a novel magnetic pinning structure having a (100) textured or cube-textured reference layer through a non-epitaxial texturing approach so that an excellent coherent tunneling effect is achieved in a pMTJ element due to its texture structure of CoFe BCC (100)/MgO rocksalt (100)/CoFe BCC (100). Correspondingly, a high MR ratio and a high pinning strength on the reference layer can be achieved for perpendicular spin-transfer-torque magnetic-random-access memory (pSTT-MRAM) using perpendicular magnetoresistive elements as basic memory cells which potentially replace the conventional semiconductor memory used in electronic chips, especially mobile chips for power saving and non-volatility.
    Type: Grant
    Filed: July 12, 2021
    Date of Patent: February 20, 2024
    Inventors: Yimin Guo, Rongfu Xiao, Jun Chen
  • Patent number: 11854589
    Abstract: A magnetoresistive element comprises a nonmagnetic sidewall-current-channel (SCC) structure provided on a surface of the SOT material layer that exhibits the Spin Hall Effect, which is opposite to a surface of the SOT material layer where the magnetic recording layer is provided, and comprising an insulating medium in a central region of the SCC structure, and a conductive medium being a sidewall of the SCC structure and surrounding the insulating medium, making an electric current crowding inside the SOT material layer and the magnetic recording layer to achieve a spin-orbit torque and a higher spin-polarization degree for an applied electric current.
    Type: Grant
    Filed: October 24, 2021
    Date of Patent: December 26, 2023
    Inventors: Yimin Guo, Rongfu Xiao, Jun Chen
  • Patent number: 11805702
    Abstract: A perpendicular magnetoresistive element comprises (counting from the element bottom): a reference layer having magnetic anisotropy in a direction perpendicular to a film surface and having an invariable magnetization direction; a tunnel barrier layer; a crystalline recording layer having magnetic anisotropy in a direction perpendicular to a film surface and having a variable magnetization direction; an oxide buffer layer; and a cap layer, wherein the crystalline recording layer consists of a CoFe alloy that is substantially free of boron and has BCC (body-centered cubic) CoFe grains having epitaxial growth with (100) plane parallel to a film surface.
    Type: Grant
    Filed: May 6, 2021
    Date of Patent: October 31, 2023
    Inventors: Yimin Guo, Rongfu Xiao, Jun Chen
  • Patent number: 11600660
    Abstract: An ultra-fast magnetic random access memory (MRAM) comprises a three terminal bottom-pinned composite SOT magnetic tunneling junction (bCSOT-MTJ) element including (counting from top to bottom) a magnetic flux guide (MFG) having a very high magnetic permeability, a spin Hall channel (SHC) having a large positive spin Hall angle, an in-plane magnetic memory (MM) layer, a tunnel barrier (TB) layer, and a magnetic pinning stack (MPS) having a synthetic antiparallel coupling pinned by an antiferromagnetic material. The magnetic writing is significantly boosted by a combined effort of enhanced spin orbit torque (SOT) and Lorentz force generated by current-flowing wire (CFW) in the SHC layer and spin transfer torque (STT) by a current flowing through the MTJ stack, and further enhanced by a magnetic close loop formed at the cross section of MFG/SHC/MM tri-layer.
    Type: Grant
    Filed: April 15, 2020
    Date of Patent: March 7, 2023
    Inventors: Rongfu Xiao, Yimin Guo, Jun Chen
  • Publication number: 20230067295
    Abstract: A magnetoresistive element comprises a nonmagnetic nano-current-channel (NCC) structure provided on a surface of the magnetic recording layer, which is opposite to a surface of the magnetic recording layer where the tunnel barrier layer is provided, and comprising a spatial distribution of perpendicular conducting channels throughout the NCC structure thickness and surrounded by an insulating medium, making the magnetic recording layer a magnetically soft-hard composite structure. Correspondingly, the critical write current and write power are reduced with reversal modes of exchange-spring magnets of the magnetically soft-hard composite structure.
    Type: Application
    Filed: August 28, 2021
    Publication date: March 2, 2023
    Inventors: YIMIN GUO, RONGFU XIAO, JUN CHEN
  • Publication number: 20230039108
    Abstract: The invention comprises a method of forming a magnetic free layer having a (100) texture and a novel magnetic pinning structure having a (100) textured or cube-textured reference layer through a non-epitaxial texturing approach so that an excellent coherent tunneling effect is achieved in a pMTJ element due to its texture structure of Fe or CoFe BCC (100)/MgO rocksalt (100)/Fe or CoFe BCC (100). The invention also discloses a pMTJ element comprising a soft-magnetic adjacent layer having at least one high-permeability material layer having a near-zero magnetostriction. Correspondingly, a high MR ratio and a coherent domain reversal of the magnetic free layer can be achieved for perpendicular spin-transfer-torque magnetic-random-access memory (pSTT-MRAM) using perpendicular magnetoresistive elements as basic memory cells which potentially replace the conventional semiconductor memory used in electronic chips, especially mobile chips for power saving and non-volatility.
    Type: Application
    Filed: August 3, 2021
    Publication date: February 9, 2023
    Inventors: Yimin GUO, Rongfu XIAO, Jun CHEN
  • Patent number: 11569440
    Abstract: The invention disclosed a method to make an implanted hard mask with ultra-small dimensions for fabricating integrated nonvolatile random access memory. Instead of directly depositing hard mask material on top of the memory film stack element, we first make ultra-small VIA holes on a pattern transfer molding (PTM) layer using a reverse memory mask, then fill in the hard mask material into the VIA holes within the PTM material. Ultra-small hard mask pillars are formed after removing the PTM material. To improve the adhesion of the hard mask pillars with the underneath memory stack element, a hard mask sustaining element (HMSE) is added below PTM. Due to a better materials adhesion between HMSE and the hard mask, a stronger hard mask array can be formed.
    Type: Grant
    Filed: January 23, 2017
    Date of Patent: January 31, 2023
    Inventors: Yimin Guo, Rongfu Xiao, Jun Chen
  • Publication number: 20230012255
    Abstract: The invention comprises a method of forming a novel magnetic pinning structure having a (100) textured or cube-textured reference layer through a non-epitaxial texturing approach so that an excellent coherent tunneling effect is achieved in a pMTJ element due to its texture structure of CoFe BCC (100)/MgO rocksalt (100)/CoFe BCC (100). Correspondingly, a high MR ratio and a high pinning strength on the reference layer can be achieved for perpendicular spin-transfer-torque magnetic-random-access memory (pSTT-MRAM) using perpendicular magnetoresistive elements as basic memory cells which potentially replace the conventional semiconductor memory used in electronic chips, especially mobile chips for power saving and non-volatility.
    Type: Application
    Filed: July 12, 2021
    Publication date: January 12, 2023
    Inventors: YIMIN GUO, Rongfu Xiao, Jun Chen
  • Patent number: 11545290
    Abstract: A magnetoresistive element comprises a novel iPMA cap layer on a surface of a ferromagnetic recording layer. The iPMA cap layer introduces giant interfacial magnetic anisotropy energies (G-iMAE) on the interface between the recording layer and the iPMA cap layer, yielding a giant interfacial perpendicular magnetic anisotropy (G-iPMA) of the recording layer.
    Type: Grant
    Filed: November 12, 2020
    Date of Patent: January 3, 2023
    Inventors: Yimin Guo, Rongfu Xiao, Jun Chen
  • Patent number: 11527708
    Abstract: An ultra-fast magnetic random access memory (MRAM) comprises a three terminal composite SOT magnetic tunneling junction (CSOT-MTJ) element including a magnetic flux guide (MFG) having a very high magnetic permeability, a spin Hall channel (SHC) having a large positive spin Hall angle, an in-plane magnetic memory (MM) layer, a tunnel barrier (TB) layer, and a magnetic pinning stack (MPS) having a synthetic antiparallel coupling pinned by an antiferromagnetic material. The magnetic writing is significantly boosted by a combined effort of enhanced spin orbit torque (SOT) and Lorentz force generated by current-flowing wire (CFW) in the SHC layer and spin transfer torque (STT) by a current flowing through the MTJ stack, and further enhanced by a magnetic close loop formed at the cross section of MFG/SHC/MM tri-layer.
    Type: Grant
    Filed: April 15, 2020
    Date of Patent: December 13, 2022
    Inventors: Yimin Guo, Rongfu Xiao, Jun Chen
  • Publication number: 20220359818
    Abstract: A perpendicular magnetoresistive element comprises (counting from the element bottom): a reference layer having magnetic anisotropy in a direction perpendicular to a film surface and having an invariable magnetization direction; a tunnel barrier layer; a crystalline recording layer having magnetic anisotropy in a direction perpendicular to a film surface and having a variable magnetization direction; an oxide buffer layer; and a cap layer, wherein the crystalline recording layer consists of a CoFe alloy that is substantially free of boron and has BCC (body-centered cubic) CoFe grains having epitaxial growth with (100) plane parallel to a film surface.
    Type: Application
    Filed: May 6, 2021
    Publication date: November 10, 2022
    Inventors: YIMIN GUO, RONGFU XIAO, JUN CHEN
  • Patent number: 11450467
    Abstract: A magnetoresistive element comprises a novel iPMA cap layer on a surface of a recording layer to induce a giant interfacial perpendicular magnetic anisotropy (G-iPMA) of the recording layer and a method of making the same. The recording layer comprises a first free layer immediately contacting to the tunnel barrier layer and having a body-centered cubic structure with a (100) texture, and a second free layer having a body-centered cubic structure with a (110) texture or a face-centered cubic structure with a (111) texture, and a crystal-breaking layer inserted between the first free layer and the second free layer.
    Type: Grant
    Filed: November 25, 2020
    Date of Patent: September 20, 2022
    Inventors: Yimin Guo, Rongfu Xiao, Jun Chen
  • Patent number: 11450466
    Abstract: The invention comprises a novel composite seed structure (CSS) having lattice constant matched crystalline structure with the Co layer in above perpendicular magnetic pinning layer (pMPL) so that an excellent epitaxial growth of magnetic super lattice pinning layer [Co/(Pt, Pd or Ni)]n along its FCC (111) orientation can be achieved, resulting in a significant enhancement of perpendicular magnetic anisotropy (PMA) for perpendicular spin-transfer-torque magnetic-random-access memory (pSTT-MRAM) using perpendicular magnetoresistive elements as basic memory cells which potentially replace the conventional semiconductor memory used in electronic chips, especially mobile chips for power saving and non-volatility.
    Type: Grant
    Filed: August 19, 2020
    Date of Patent: September 20, 2022
    Inventors: Yimin Guo, Rongfu Xiao, Jun Chen
  • Patent number: 11444239
    Abstract: A magnetoresistive element using combined spin-transfer-torque controlled magnetic bias and VCMA effects comprising a free layer and an adjacent-bias layer separated by a nonmagnetic spacing layer, wherein the free layer has an interfacial perpendicular magnetic anisotropy and a variable magnetization direction substantially perpendicular to a film surface, the adjacent-bias layer has a perpendicular magnetic anisotropy and a variable magnetization direction substantially perpendicular to a film surface, and the perpendicular anisotropy of the free layer is sufficiently higher than that of the adjacent-bias layer such that the critical switching current to reverse the free layer magnetization direction is at least 3 times as high as the critical switching current to reverse the adjacent-bias layer magnetization direction.
    Type: Grant
    Filed: February 28, 2021
    Date of Patent: September 13, 2022
    Inventors: Yimin Guo, Rongfu Xiao, Jun Chen
  • Publication number: 20220278270
    Abstract: A magnetoresistive element using combined spin-transfer-torque controlled magnetic bias and VCMA effects comprising a free layer and an adjacent-bias layer separated by a nonmagnetic spacing layer, wherein the free layer has an interfacial perpendicular magnetic anisotropy and a variable magnetization direction substantially perpendicular to a film surface, the adjacent-bias layer has a perpendicular magnetic anisotropy and a variable magnetization direction substantially perpendicular to a film surface, and the perpendicular anisotropy of the free layer is sufficiently higher than that of the adjacent-bias layer such that the critical switching current to reverse the free layer magnetization direction is at least 3 times as high as the critical switching current to reverse the adjacent-bias layer magnetization direction.
    Type: Application
    Filed: February 28, 2021
    Publication date: September 1, 2022
    Inventors: Yimin Guo, Rongfu Xiao, Jun Chen
  • Publication number: 20220246836
    Abstract: A composite recording structure comprising a first magnetic free layer comprising an amorphous magnetic material sub-layer, a Boron-absorbing material sub-layer atop the amorphous magnetic material sub-layer and a Co/Ni superlattice sub-layer atop the Boron-absorbing material sub-layer; one or many repeats of a substructure including a nonmagnetic spacing layer and a Co/Ni superlattice free layer, atop the first magnetic free layer, wherein said first magnetic free layer has a perpendicular magnetic anisotropy and a variable magnetization direction substantially perpendicular to a film surface, said each Co/Ni superlattice free layer has a perpendicular magnetic anisotropy and a variable magnetization direction substantially perpendicular to a film surface.
    Type: Application
    Filed: February 2, 2021
    Publication date: August 4, 2022
    Inventors: YIMIN GUO, RONGFU XIAO, JUN CHEN
  • Publication number: 20220238799
    Abstract: A method of forming a bottom-pinned magnetoresistive element comprising a composite recording structure that includes a first magnetic free layer and a second magnetic free layer containing Ni atoms, separated by an oxide spacing layer. The first magnetic free layer is Ni-free and the first magnetic free layer and the second magnetic free layer are magnetically parallel-coupled. A magnetic STT-enhancing structure is further provided atop the cap layer, wherein the magnetic STT-enhancing structure comprises a first magnetic material layer atop the cap layer and having a perpendicular magnetic anisotropy and an invariable magnetization anti-parallel to the magnetization direction of the reference layer, a second anti-ferromagnetic coupling (AFC) layer atop the first magnetic material layer, and a second magnetic material layer atop the second AFC layer.
    Type: Application
    Filed: January 27, 2021
    Publication date: July 28, 2022
    Inventors: Yimin Guo, Rongfu Xiao, Jun Chen
  • Publication number: 20220165470
    Abstract: A magnetoresistive element comprises a novel iPMA cap layer on a surface of a recording layer to induce a giant interfacial perpendicular magnetic anisotropy (G-iPMA) of the recording layer and a method of making the same. The recording layer comprises a first free layer immediately contacting to the tunnel barrier layer and having a body-centered cubic structure with a (100) texture, and a second free layer having a body-centered cubic structure with a (110) texture or a face-centered cubic structure with a (111) texture, and a crystal-breaking layer inserted between the first free layer and the second free layer.
    Type: Application
    Filed: November 25, 2020
    Publication date: May 26, 2022
    Inventors: Yimin Guo, Rongfu Xiao, Jun Chen