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: 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
  • Publication number: 20200127192
    Abstract: A plasma enhanced chemical vapor deposition (PECVD) method is disclosed for forming a SiON encapsulation layer on a magnetic tunnel junction (MTJ) sidewall that minimizes attack on the MTJ sidewall during the PECVD or subsequent processes. The PECVD method provides a higher magnetoresistive ratio for the MTJ than conventional methods after a 400° C. anneal. In one embodiment, the SiON encapsulation layer is deposited using a N2O:silane flow rate ratio of at least 1:1 but less than 15:1. A N2O plasma treatment may be performed immediately following the PECVD to ensure there is no residual silane in the SiON encapsulation layer. In another embodiment, a first (lower) SiON sub-layer has a greater Si content than a second (upper) SiON sub-layer. A second encapsulation layer is formed on the SiON encapsulation layer so that the encapsulation layers completely fill the gaps between adjacent MTJs.
    Type: Application
    Filed: December 18, 2019
    Publication date: April 23, 2020
    Inventors: Vignesh Sundar, Yu-Jen Wang, Dongna Shen, Sahil Patel, Ru-Ying Tong
  • Publication number: 20200115788
    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: October 16, 2018
    Publication date: April 16, 2020
    Inventors: Sahil Patel, Guenole Jan, Yu-Jen Wang
  • Publication number: 20200091408
    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: Application
    Filed: September 18, 2018
    Publication date: March 19, 2020
    Inventors: Vignesh Sundar, Yu-Jen Wang, Luc Thomas, Guenole Jan, Sahil Patel, Ru-Ying Tong
  • Publication number: 20200068816
    Abstract: The present disclosure provides peanut maturity grading systems and methods for quickly, efficiently, and objectively determining a peanut maturity grade for a crop of peanuts and determining an optimal harvest time for the crop. Embodiments of systems and methods of the present disclosure can be performed in the field or field-side and do not require assistance of a trained peanut grading specialist.
    Type: Application
    Filed: September 5, 2019
    Publication date: March 5, 2020
    Inventors: Zion Tse, Brian Boland, Donald Leo, Kyle Johnsen, Sahil Patel, Zhuo Zhao
  • Patent number: 10522745
    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 14, 2017
    Date of Patent: December 31, 2019
    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: 10522749
    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: Grant
    Filed: May 15, 2017
    Date of Patent: December 31, 2019
    Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY, LTD.
    Inventors: Dongna Shen, Yu-Jen Wang, Ru-Ying Tong, Vignesh Sundar, Sahil Patel
  • Patent number: 10516100
    Abstract: A plasma enhanced chemical vapor deposition (PECVD) method is disclosed for forming a SiON encapsulation layer on a magnetic tunnel junction (MTJ) sidewall that minimizes attack on the MTJ sidewall during the PECVD or subsequent processes. The PECVD method provides a higher magnetoresistive ratio for the MTJ than conventional methods after a 400° C. anneal. In one embodiment, the SiON encapsulation layer is deposited using a N2O:silane flow rate ratio of at least 1:1 but less than 15:1. A N2O plasma treatment may be performed immediately following the PECVD to ensure there is no residual silane in the SiON encapsulation layer. In another embodiment, a first (lower) SiON sub-layer has a greater Si content than a second (upper) SiON sub-layer. A second encapsulation layer is formed on the SiON encapsulation layer so that the encapsulation layers completely fill the gaps between adjacent MTJs.
    Type: Grant
    Filed: June 12, 2017
    Date of Patent: December 24, 2019
    Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY, LTD.
    Inventors: Vignesh Sundar, Yu-Jen Wang, Dongna Shen, Sahil Patel, Ru-Ying Tong
  • Publication number: 20190280197
    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: May 20, 2019
    Publication date: September 12, 2019
    Inventors: Yu-Jen Wang, Dongna Shen, Vignesh Sundar, Sahil Patel
  • Publication number: 20190189910
    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 14, 2017
    Publication date: June 20, 2019
    Inventors: Sahil Patel, Guenole Jan, Ru-Ying Tong, Vignesh Sundar, Dongna Shen, Yu-Jen Wang, Po-Kang Wang, Huanlong Liu
  • Patent number: 10297746
    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: April 5, 2017
    Date of Patent: May 21, 2019
    Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY, LTD.
    Inventors: Yu-Jen Wang, Dongna Shen, Vignesh Sundar, Sahil Patel
  • Publication number: 20190140168
    Abstract: A seed layer stack with a uniform top surface having a peak to peak roughness of 0.5 nm is formed by sputter depositing an amorphous layer on a smoothing layer such as Mg where the latter has a resputtering rate 2 to 30× that of the amorphous layer. The uppermost seed (template) layer is NiW, NiMo, or one or more of NiCr, NiFeCr, and Hf while the bottommost seed layer is one or more of Ta, TaN, Zr, ZrN, Nb, NbN, Mo, MoN, TiN, W, WN, and Ru. Accordingly, perpendicular magnetic anisotropy in an overlying magnetic layer is substantially maintained during high temperature processing up to 400° C. and is advantageous for magnetic tunnel junctions in embedded MRAMs, spintronic devices, or in read head sensors. The amorphous seed layer is SiN, TaN, or CoFeM where M is B or another element with a content that makes CoFeM amorphous as deposited.
    Type: Application
    Filed: December 17, 2018
    Publication date: May 9, 2019
    Inventors: Jian Zhu, Guenole Jan, Yuan-Jen Lee, Huanlong Liu, Ru-Ying Tong, Jodi Mari Iwata, Vignesh Sundar, Luc Thomas, Yu-Jen Wang, Sahil Patel
  • Publication number: 20190088866
    Abstract: A seed layer stack with a uniform top surface having a peak to peak roughness of 0.5 nm is formed by sputter depositing an amorphous layer on a smoothing layer such as Mg where the latter has a resputtering rate 2 to 30× that of the amorphous layer. The seed layer stack may be repeated to give a laminate of two amorphous layers and two smoothing layers, and is advantageous for enhancing performance in magnetic tunnel junctions in embedded MRAMs, spintronic devices, or in read head sensors. A template layer such as NiCr may be formed on the uppermost smoothing layer to promote and maintain perpendicular magnetic anisotropy in an overlying magnetic layer during high temperature processing up to 400° C. The amorphous seed layer is SiN, TaN, or CoFeM where M is B or another element with a content that makes CoFeM amorphous as deposited.
    Type: Application
    Filed: October 29, 2018
    Publication date: March 21, 2019
    Inventors: Jian Zhu, Guenole Jan, Yuan-Jen Lee, Huanlong Liu, Ru-Ying Tong, Jodi Mari Iwata, Vignesh Sundar, Luc Thomas, Yu-Jen Wang, Sahil Patel
  • Publication number: 20180358545
    Abstract: A plasma enhanced chemical vapor deposition (PECVD) method is disclosed for forming a SiON encapsulation layer on a magnetic tunnel junction (MTJ) sidewall that minimizes attack on the MTJ sidewall during the PECVD or subsequent processes. The PECVD method provides a higher magnetoresistive ratio for the MTJ than conventional methods after a 400° C. anneal. In one embodiment, the SiON encapsulation layer is deposited using a N2O:silane flow rate ratio of at least 1:1 but less than 15:1. A N2O plasma treatment may be performed immediately following the PECVD to ensure there is no residual silane in the SiON encapsulation layer. In another embodiment, a first (lower) SiON sub-layer has a greater Si content than a second (upper) SiON sub-layer. A second encapsulation layer is formed on the SiON encapsulation layer so that the encapsulation layers completely fill the gaps between adjacent MTJs.
    Type: Application
    Filed: June 12, 2017
    Publication date: December 13, 2018
    Inventors: Vignesh Sundar, Yu-Jen Wang, Dongna Shen, Sahil Patel, Ru-Ying Tong
  • Publication number: 20180331279
    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: May 15, 2017
    Publication date: November 15, 2018
    Inventors: Dongna Shen, Yu-Jen Wang, Ru-Ying Tong, Vignesh Sundar, Sahil Patel