Patents by Inventor Sahil Patel

Sahil Patel 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: 20210262078
    Abstract: A MgO layer is formed using a process flow wherein a Mg layer is deposited at a temperature <200° C. on a substrate, and then an anneal between 200° C. and 900° C., and preferably from 200° C. and 400° C., is performed so that a Mg vapor pressure >10?6 Torr is reached and a substantial portion of the Mg layer sublimes and leaves a Mg monolayer. After an oxidation between ?223° C. and 900° C., a MgO monolayer is produced where the Mg:O ratio is exactly 1:1 thereby avoiding underoxidized or overoxidized states associated with film defects. The process flow may be repeated one or more times to yield a desired thickness and resistance×area value when the MgO is a tunnel barrier or Hk enhancing layer. Moreover, a doping element (M) may be added during Mg deposition to modify the conductivity and band structure in the resulting MgMO layer.
    Type: Application
    Filed: May 10, 2021
    Publication date: August 26, 2021
    Inventors: Sahil Patel, Guenole Jan, Yu-Jen Wang
  • Patent number: 11031548
    Abstract: A method for fabricating a magnetic tunneling junction (MTJ) structure is described. A MTJ film stack is deposited on a bottom electrode on a substrate. The MTJ film stack is first ion beam etched (IBE) using a first angle and a first energy to form a MTJ device wherein conductive re-deposition forms on sidewalls of the MTJ device. Thereafter, the conductive re-deposition is oxidized. Thereafter, the MTJ device is second ion beam etched (IBE) at a second angle and a second energy to remove oxidized re-deposition.
    Type: Grant
    Filed: November 4, 2019
    Date of Patent: June 8, 2021
    Assignee: Headway Technologies, Inc.
    Inventors: Dongna Shen, Yi Yang, Sahil Patel, Vignesh Sundar, Yu-Jen Wang
  • Publication number: 20210143322
    Abstract: A plurality of conductive via connections are fabricated on a substrate located at positions where MTJ devices are to be fabricated, wherein a width of each of the conductive via connections is smaller than or equivalent to a width of the MTJ devices. The conductive via connections are surrounded with a dielectric layer having a height sufficient to ensure that at the end of a main MTJ etch, an etch front remains in the dielectric layer surrounding the conductive via connections. Thereafter, a MTJ film stack is deposited on the plurality of conductive via connections surrounded by the dielectric layer. The MTJ film stack is etched using an ion beam etch process (IBE), etching through the MTJ film stack and into the dielectric layer surrounding the conductive via connections to form the MTJ devices wherein by etching into the dielectric layer, re-deposition on sidewalls of the MTJ devices is insulating.
    Type: Application
    Filed: November 7, 2019
    Publication date: May 13, 2021
    Inventors: Vignesh Sundar, Yi Yang, Dongna Shen, Zhongjian Teng, Jesmin Haq, Sahil Patel, Yu-Jen Wang, Tom Zhong
  • Patent number: 11001919
    Abstract: A MgO layer is formed using a process flow wherein a Mg layer is deposited at a temperature <200° C. on a substrate, and then an anneal between 200° C. and 900° C., and preferably from 200° C. and 400° C., is performed so that a Mg vapor pressure >10?6 Torr is reached and a substantial portion of the Mg layer sublimes and leaves a Mg monolayer. After an oxidation between ?223° C. and 900° C., a MgO monolayer is produced where the Mg:O ratio is exactly 1:1 thereby avoiding underoxidized or overoxidized states associated with film defects. The process flow may be repeated one or more times to yield a desired thickness and resistance x area value when the MgO is a tunnel barrier or Hk enhancing layer. Moreover, a doping element (M) may be added during Mg deposition to modify the conductivity and band structure in the resulting MgMO layer.
    Type: Grant
    Filed: May 11, 2020
    Date of Patent: May 11, 2021
    Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY, LTD.
    Inventors: Sahil Patel, Guenole Jan, Yu-Jen Wang
  • Publication number: 20210135097
    Abstract: A method for fabricating a magnetic tunneling junction (MTJ) structure is described. A MTJ film stack is deposited on a bottom electrode on a substrate. The MTJ film stack is first ion beam etched (IBE) using a first angle and a first energy to form a MTJ device wherein conductive re-deposition forms on sidewalls of the MTJ device. Thereafter, the conductive re-deposition is oxidized. Thereafter, the MTJ device is second ion beam etched (IBE) at a second angle and a second energy to remove oxidized re-deposition.
    Type: Application
    Filed: November 4, 2019
    Publication date: May 6, 2021
    Inventors: Dongna Shen, Yi Yang, Sahil Patel, Vignesh Sundar, Yu-Jen Wang
  • Publication number: 20210111338
    Abstract: A film stack for a magnetic tunnel comprises a substrate, a magnetic reference layer disposed over the substrate, and a tunnel barrier layer disposed over the magnetic reference layer. The film stack further comprises a magnetic storage layer disposed over the tunnel barrier layer, and a capping layer disposed over the magnetic storage layer. Further, the film stack comprises at least one protection layer disposed between the magnetic reference layer and the tunnel barrier layer and disposed between the magnetic storage layer and the capping layer. Additionally, a material forming the at least one protection layer differs from at least one of a material forming the magnetic reference layer and a material forming the magnetic storage layer.
    Type: Application
    Filed: October 14, 2019
    Publication date: April 15, 2021
    Inventors: Lin XUE, Jaesoo Ahn, Sahil Patel, Chando Park, Mahendra Pakala
  • Publication number: 20210020831
    Abstract: A magnetic tunnel junction (MTJ) is disclosed wherein a free layer (FL) interfaces with a first metal oxide (Mox) layer and second metal oxide (tunnel barrier) to produce perpendicular magnetic anisotropy (PMA) in the FL. In some embodiments, conductive metal channels made of a noble metal are formed in the Mox that is MgO to reduce parasitic resistance. In a second embodiment, a discontinuous MgO layer with a plurality of islands is formed as the Mox layer and a non-magnetic hard mask layer is deposited to fill spaces between adjacent islands and form shorting pathways through the Mox. In another embodiment, end portions between the sides of a center Mox portion and the MTJ sidewall are reduced to form shorting pathways by depositing a reducing metal layer on Mox sidewalls, or performing a reduction process with forming gas, H2, or a reducing species.
    Type: Application
    Filed: October 5, 2020
    Publication date: January 21, 2021
    Inventors: Sahil Patel, Guenole Jan, Ru-Ying Tong, Vignesh Sundar, Dongna Shen, Yu-Jen Wang, Po-Kang Wang, Huanlong Liu
  • Publication number: 20210020830
    Abstract: A dual magnetic tunnel junction (DMTJ) is disclosed with a PL1/TB1/free layer/TB2/PL2/capping layer configuration wherein a first tunnel barrier (TB1) has a substantially lower resistance x area (RA1) product than RA2 for an overlying second tunnel barrier (TB2) to provide an acceptable net magnetoresistive ratio (DRR). Moreover, magnetizations in first and second pinned layers, PL1 and PL2, respectively, are aligned antiparallel to enable a lower critical switching current than when in a parallel alignment. An oxide capping layer having a RACAP is formed on PL2 to provide higher PL2 stability. The condition RA1<RA2 and RACAP<RA2 is achieved when TB1 and the oxide capping layer have one or both of a smaller thickness and a lower oxidation state than TB2, are comprised of conductive (metal) channels in a metal oxide or metal oxynitride matrix, or are comprised of a doped metal oxide or doped metal oxynitride layer.
    Type: Application
    Filed: October 5, 2020
    Publication date: January 21, 2021
    Inventors: Vignesh Sundar, Yu-Jen Wang, Luc Thomas, Guenole Jan, Sahil Patel, Ru-Ying Tong
  • Publication number: 20210013260
    Abstract: A fabrication process for an STT MTJ MRAM device includes steps of cooling the device at individual or at multiple stages in its fabrication. The cooling process, which may be equally well applied during the fabrication of other multi-layered devices, is demonstrated to produce an operational device that is more resistant to adverse thermal effects during operation that would normally cause a similar device not so fabricated to lose stored data and otherwise fail to operate properly.
    Type: Application
    Filed: September 21, 2020
    Publication date: January 14, 2021
    Inventors: Huanlong Liu, Guenole Jan, Ru-Ying Tong, Jian Zhu, Yuan-Jen Lee, Jodi Mari Iwata, Sahil Patel, Vignesh Sundar
  • Publication number: 20200328345
    Abstract: A method for etching a magnetic tunneling junction (MTJ) structure is described. A stack of MTJ layers is provided on a bottom electrode. A top electrode is provided on the MTJ stack. The top electrode is patterned. Thereafter, the MTJ stack not covered by the patterned top electrode is oxidized or nitridized. Then, the MTJ stack is patterned to form a MTJ device wherein any sidewall re-deposition formed on sidewalls of the MTJ device is non-conductive and wherein some of the dielectric layer remains on horizontal surfaces of the bottom electrode.
    Type: Application
    Filed: June 29, 2020
    Publication date: October 15, 2020
    Inventors: Yu-Jen Wang, Dongna Shen, Vignesh Sundar, Sahil Patel
  • Patent number: 10797225
    Abstract: A dual magnetic tunnel junction (DMTJ) is disclosed with a PL1/TB1/free layer/TB2/PL2/capping layer configuration wherein a first tunnel barrier (TB1) has a substantially lower resistance×area (RA1) product than RA2 for an overlying second tunnel barrier (TB2) to provide an acceptable net magnetoresistive ratio (DRR). Moreover, magnetizations in first and second pinned layers, PL1 and PL2, respectively, are aligned antiparallel to enable a lower critical switching current than when in a parallel alignment. An oxide capping layer having a RACAP is formed on PL2 to provide higher PL2 stability. The condition RA1<RA2 and RACAP<RA2 is achieved when TB1 and the oxide capping layer have one or both of a smaller thickness and a lower oxidation state than TB2, are comprised of conductive (metal) channels in a metal oxide or metal oxynitride matrix, or are comprised of a doped metal oxide or doped metal oxynitride layer.
    Type: Grant
    Filed: September 18, 2018
    Date of Patent: October 6, 2020
    Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY, LTD.
    Inventors: Vignesh Sundar, Yu-Jen Wang, Luc Thomas, Guenole Jan, Sahil Patel, Ru-Ying Tong
  • Patent number: 10797232
    Abstract: A magnetic tunnel junction (MTJ) is disclosed wherein a free layer (FL) interfaces with a first metal oxide (Mox) layer and second metal oxide (tunnel barrier) to produce perpendicular magnetic anisotropy (PMA) in the FL. In some embodiments, conductive metal channels made of a noble metal are formed in the Mox that is MgO to reduce parasitic resistance. In a second embodiment, a discontinuous MgO layer with a plurality of islands is formed as the Mox layer and a non-magnetic hard mask layer is deposited to fill spaces between adjacent islands and form shorting pathways through the Mox. In another embodiment, end portions between the sides of a center Mox portion and the MTJ sidewall are reduced to form shorting pathways by depositing a reducing metal layer on Mox sidewalls, or performing a reduction process with forming gas, H2, or a reducing species.
    Type: Grant
    Filed: December 27, 2019
    Date of Patent: October 6, 2020
    Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY, LTD.
    Inventors: Sahil Patel, Guenole Jan, Ru-Ying Tong, Vignesh Sundar, Dongna Shen, Yu-Jen Wang, Po-Kang Wang, Huanlong Liu
  • Patent number: 10784310
    Abstract: A fabrication process for an STT MTJ MRAM device includes steps of cooling the device at individual or at multiple stages in its fabrication. The cooling process, which may be equally well applied during the fabrication of other multi-layered devices, is demonstrated to produce an operational device that is more resistant to adverse thermal effects during operation that would normally cause a similar device not so fabricated to lose stored data and otherwise fail to operate properly.
    Type: Grant
    Filed: November 8, 2018
    Date of Patent: September 22, 2020
    Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY, LTD.
    Inventors: Huanlong Liu, Guenole Jan, Ru-Ying Tong, Jian Zhu, Yuan-Jen Lee, Jodi Mari Iwata, Sahil Patel, Vignesh Sundar
  • Publication number: 20200270737
    Abstract: A MgO layer is formed using a process flow wherein a Mg layer is deposited at a temperature <200° C. on a substrate, and then an anneal between 200° C. and 900° C., and preferably from 200° C. and 400° C., is performed so that a Mg vapor pressure >10?6 Torr is reached and a substantial portion of the Mg layer sublimes and leaves a Mg monolayer. After an oxidation between ?223° C. and 900° C., a MgO monolayer is produced where the Mg:O ratio is exactly 1:1 thereby avoiding underoxidized or overoxidized states associated with film defects. The process flow may be repeated one or more times to yield a desired thickness and resistance x area value when the MgO is a tunnel barrier or Hk enhancing layer. Moreover, a doping element (M) may be added during Mg deposition to modify the conductivity and band structure in the resulting MgMO layer.
    Type: Application
    Filed: May 11, 2020
    Publication date: August 27, 2020
    Inventors: Sahil Patel, Guenole Jan, Yu-Jen Wang
  • Publication number: 20200212297
    Abstract: A complementary metal oxide semiconductor (CMOS) device comprises a first metal line, a first metal via on the first metal line, a magnetic tunneling junction (MTJ) device on the first metal via wherein the first metal via acts as a bottom electrode for the MTJ device, a second metal via on the MTJ device, and a second metal line on the second metal via.
    Type: Application
    Filed: December 31, 2018
    Publication date: July 2, 2020
    Inventors: Yi Yang, Vignesh Sundar, Dongna Shen, Sahil Patel, Ru-Ying Tong, Yu-Jen Wang
  • Patent number: 10700269
    Abstract: A method for etching a magnetic tunneling junction (MTJ) structure is described. A stack of MTJ layers is provided on a bottom electrode. A top electrode is provided on the MTJ stack. The top electrode is patterned. Thereafter, the MTJ stack not covered by the patterned top electrode is oxidized or nitridized. Then, the MTJ stack is patterned to form a MTJ device wherein any sidewall re-deposition formed on sidewalls of the MTJ device is non-conductive and wherein some of the dielectric layer remains on horizontal surfaces of the bottom electrode.
    Type: Grant
    Filed: May 20, 2019
    Date of Patent: June 30, 2020
    Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY, LTD.
    Inventors: Yu-Jen Wang, Dongna Shen, Vignesh Sundar, Sahil Patel
  • Publication number: 20200152698
    Abstract: A fabrication process for an STT MTJ MRAM device includes steps of cooling the device at individual or at multiple stages in its fabrication. The cooling process, which may be equally well applied during the fabrication of other multi-layered devices, is demonstrated to produce an operational device that is more resistant to adverse thermal effects during operation that would normally cause a similar device not so fabricated to lose stored data and otherwise fail to operate properly.
    Type: Application
    Filed: November 8, 2018
    Publication date: May 14, 2020
    Inventors: Huanlong Liu, Guenole Jan, Ru-Ying Tong, Jian Zhu, Yuan-Jen Lee, Jodi Mari Iwata, Sahil Patel, Vignesh Sundar
  • Patent number: 10648069
    Abstract: A MgO layer is formed using a process flow wherein a Mg layer is deposited at a temperature <200° C. on a substrate, and then an anneal between 200° C. and 900° C., and preferably from 200° C. and 400° C., is performed so that a Mg vapor pressure >100.6 Torr is reached and a substantial portion of the Mg layer sublimes and leaves a Mg monolayer. After an oxidation between ?223° C. and 900° C., a MgO monolayer is produced where the Mg:O ratio is exactly 1:1 thereby avoiding underoxidized or overoxidized states associated with film defects. The process flow may be repeated one or more times to yield a desired thickness and resistance x area value when the MgO is a tunnel barrier or Hk enhancing layer. Moreover, a doping element (M) may be added during Mg deposition to modify the conductivity and band structure in the resulting MgMO layer.
    Type: Grant
    Filed: October 16, 2018
    Date of Patent: May 12, 2020
    Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY, LTD.
    Inventors: Sahil Patel, Guenole Jan, Yu-Jen Wang
  • Publication number: 20200144492
    Abstract: A process flow for forming magnetic tunnel junction (MTJ) nanopillars with minimal sidewall residue and minimal sidewall damage is disclosed wherein a pattern is first formed in a hard mask that is an uppermost MTJ layer. Thereafter, the hard mask sidewall is etch transferred through the remaining MTJ layers including a reference layer, free layer, and tunnel barrier between the free layer and reference layer. The etch transfer may be completed in a single RIE step that features a physical component involving inert gas ions or plasma, and a chemical component comprised of ions or plasma generated from one or more of methanol, ethanol, ammonia, and CO. In other embodiments, a chemical treatment with one of the aforementioned chemicals, and a volatilization at 50° C. to 450° C. may follow an etch transfer through the MTJ stack with an ion beam etch or plasma etch involving inert gas ions.
    Type: Application
    Filed: December 27, 2019
    Publication date: May 7, 2020
    Inventors: Dongna Shen, Yu-Jen Wang, Ru-Ying Tong, Vignesh Sundar, Sahil Patel
  • Publication number: 20200136025
    Abstract: A magnetic tunnel junction (MTJ) is disclosed wherein a free layer (FL) interfaces with a first metal oxide (Mox) layer and second metal oxide (tunnel barrier) to produce perpendicular magnetic anisotropy (PMA) in the FL. In some embodiments, conductive metal channels made of a noble metal are formed in the Mox that is MgO to reduce parasitic resistance. In a second embodiment, a discontinuous MgO layer with a plurality of islands is formed as the Mox layer and a non-magnetic hard mask layer is deposited to fill spaces between adjacent islands and form shorting pathways through the Mox. In another embodiment, end portions between the sides of a center Mox portion and the MTJ sidewall are reduced to form shorting pathways by depositing a reducing metal layer on Mox sidewalls, or performing a reduction process with forming gas, H2, or a reducing species.
    Type: Application
    Filed: December 27, 2019
    Publication date: April 30, 2020
    Inventors: Sahil Patel, Guenole Jan, Ru-Ying Tong, Vignesh Sundar, Dongna Shen, Yu-Jen Wang, Po-Kang Wang, Huanlong Liu