Patents by Inventor Matthias G. Gottwald

Matthias G. Gottwald 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: 11487508
    Abstract: A true random number generator (TRNG) device having a magnetic tunnel junction (MTJ) structure coupled to a domain wall wire. The MTJ structure is formed of a free layer (FL) and a reference layer (RL) that sandwiches a tunnel barrier layer. The free layer has anisotropy energy sufficiently low to provide stochastic fluctuation in the orientation of the magnetic state of the free layer via thermal energy. The domain wall wire is coupled to the MTJ structure. The domain wall wire has a domain wall. Movement of the domain wall tunes a probability distribution of the fluctuation in the orientation of the magnetic state of the free layer. The domain wall can be moved by application of a suitable current through the wire to tune the probability distribution of 1's and 0's generated by a readout circuit of the TRNG device.
    Type: Grant
    Filed: April 15, 2019
    Date of Patent: November 1, 2022
    Assignee: International Business Machines Corporation
    Inventors: Rasit O. Topaloglu, Jonathan Z. Sun, Matthias G. Gottwald, Chandrasekharan Kothandaraman
  • Publication number: 20200326911
    Abstract: A true random number generator (TRNG) device having a magnetic tunnel junction (MTJ) structure coupled to a domain wall wire. The MTJ structure is formed of a free layer (FL) and a reference layer (RL) that sandwiches a tunnel barrier layer. The free layer has anisotropy energy sufficiently low to provide stochastic fluctuation in the orientation of the magnetic state of the free layer via thermal energy. The domain wall wire is coupled to the MTJ structure. The domain wall wire has a domain wall. Movement of the domain wall tunes a probability distribution of the fluctuation in the orientation of the magnetic state of the free layer. The domain wall can be moved by application of a suitable current through the wire to tune the probability distribution of 1's and 0's generated by a readout circuit the TRNG device.
    Type: Application
    Filed: April 15, 2019
    Publication date: October 15, 2020
    Inventors: Rasit O. Topaloglu, Jonathan Z. Sun, Matthias G. Gottwald, Chandrasekharan Kothandaraman
  • Patent number: 10804319
    Abstract: A top pinned magnetic tunnel junction (MTJ) stack for use in spin-transfer torque magnetoresistive random access memory (STT MRAM) is provided. The top pinned MTJ stack contains a synthetic anti-ferromagnetic magnetic free layer stack that is formed on an insulating aluminum nitride (AlN) seed layer having hexagonal symmetry. For such a top pinned MTJ stack, the symmetry requirements for the tunnel barrier layer do not conflict anymore with the symmetry requirements for strong anti-ferromagnetic exchange. Further, and compared to using only a metallic seed, the insulating AlN seed layer limits spin pumping from the magnetic free layer into the metallic seed layer and therefore lowers the switching current, while only making a small contribution to the resistance of a STT MRAM.
    Type: Grant
    Filed: February 15, 2019
    Date of Patent: October 13, 2020
    Assignee: International Business Machines Corporation
    Inventor: Matthias G. Gottwald
  • Publication number: 20200266236
    Abstract: A top pinned magnetic tunnel junction (MTJ) stack for use in spin-transfer torque magnetoresistive random access memory (STT MRAM) is provided. The top pinned MTJ stack contains a synthetic anti-ferromagnetic magnetic free layer stack that is formed on an insulating aluminum nitride (AlN) seed layer having hexagonal symmetry. For such a top pinned MTJ stack, the symmetry requirements for the tunnel barrier layer do not conflict anymore with the symmetry requirements for strong anti-ferromagnetic exchange. Further, and compared to using only a metallic seed, the insulating AlN seed layer limits spin pumping from the magnetic free layer into the metallic seed layer and therefore lowers the switching current, while only making a small contribution to the resistance of a STT MRAM.
    Type: Application
    Filed: February 15, 2019
    Publication date: August 20, 2020
    Inventor: Matthias G. Gottwald
  • Patent number: 10692927
    Abstract: A double magnetic tunnel junction (MTJ) stack for use in spin-transfer torque magnetoresistive random access memory (STT MRAM) is provided. The double MTJ stack includes a bottom tunnel barrier layer having hexagonal symmetry and composed of AlN, a magnetic free layer stack containing a synthetic anti-ferromagnetic coupling layer, and a top tunnel barrier layer having cubic symmetry. For such a double MTJ stack, the symmetry requirements for the tunnel barrier layers do not conflict anymore with the symmetry requirements for strong anti-ferromagnetic exchange. Thus, such a double MTJ stack can be used to provide performance enhancement such as faster switching times and lower write errors to a STT MRAM.
    Type: Grant
    Filed: February 15, 2019
    Date of Patent: June 23, 2020
    Assignee: International Business Machines Corporation
    Inventor: Matthias G. Gottwald
  • Patent number: 10079337
    Abstract: A double magnetic tunnel junction (DMTJ) device includes a fixed reference layer of a first magnetic material having a perpendicular magnetic anisotropy with a magnetic moment that is fixed. The device also includes a free layer of a second magnetic material having a perpendicular magnetic anisotropy with a magnetic moment that is changeable based on a current. A dynamic reference layer of a third magnetic material has an in-plane magnetic anisotropy and a changeable magnetic moment. The free layer is disposed between the fixed reference layer and the dynamic reference layer.
    Type: Grant
    Filed: January 11, 2017
    Date of Patent: September 18, 2018
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Matthias G. Gottwald, Guohan Hu
  • Publication number: 20180198058
    Abstract: A double magnetic tunnel junction (DMTJ) device includes a fixed reference layer of a first magnetic material having a perpendicular magnetic anisotropy with a magnetic moment that is fixed. The device also includes a free layer of a second magnetic material having a perpendicular magnetic anisotropy with a magnetic moment that is changeable based on a current. A dynamic reference layer of a third magnetic material has an in-plane magnetic anisotropy and a changeable magnetic moment. The free layer is disposed between the fixed reference layer and the dynamic reference layer.
    Type: Application
    Filed: January 11, 2017
    Publication date: July 12, 2018
    Inventors: Matthias G. Gottwald, Guohan Hu