Patents by Inventor Po-Kang Wang

Po-Kang Wang 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: 10978124
    Abstract: Circuits and methods for programming a MTJ stack of an MRAM cell minimizes a ferromagnetic free layer or pinned layer polarization reversal due to back-hopping. The programming begins by applying a first segment of the segment of the write pulse at a first write voltage level for a first time period to program the MTJ stack. A second segment of the segment of the write pulse at a second write voltage level that is less than the first write voltage level is applied to the magnetic tunnel junction stack for a second time period to correct the polarization of the MTJ when the MTJ stack has reversed polarization during the first time period. The second segment of the segment of the write pulse may be a ramp, or multiple ramps, or have a quiescent period between it and the first segment of the write pulse.
    Type: Grant
    Filed: June 29, 2020
    Date of Patent: April 13, 2021
    Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY, LTD.
    Inventors: Huanlong Liu, Guenole Jan, Yuan-Jen Lee, Jian Zhu, Po-Kang Wang
  • 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: 20200395534
    Abstract: A magnetic tunnel junction is disclosed wherein the reference layer and free layer each comprise one layer having a boron content from 25 to 50 atomic %, and an adjoining second layer with a boron content from 1 to 20 atomic %. One of the first and second layers in each of the free layer and reference layer contacts the tunnel barrier. Each boron containing layer has a thickness of 1 to 10 Angstroms and may include one or more B layers and one or more Co, Fe, CoFe, or CoFeB layers. As a result, migration of non-magnetic metals along crystalline boundaries to the tunnel barrier is prevented, and the MTJ has a low defect count of around 10 ppm while maintaining an acceptable TMR ratio following annealing to temperatures of about 400° C. The boron containing layers are selected from CoB, FeB, CoFeB and alloys thereof including CoFeNiB.
    Type: Application
    Filed: August 31, 2020
    Publication date: December 17, 2020
    Inventors: Huanlong Liu, Yuan-Jen Lee, Jian Zhu, Guenole Jan, Po-Kang Wang
  • Publication number: 20200327918
    Abstract: Circuits and methods for programming a MTJ stack of an MRAM cell minimizes a ferromagnetic free layer or pinned layer polarization reversal due to back-hopping. The programming begins by applying a first segment of the segment of the write pulse at a first write voltage level for a first time period to program the MTJ stack. A second segment of the segment of the write pulse at a second write voltage level that is less than the first write voltage level is applied to the magnetic tunnel junction stack for a second time period to correct the polarization of the MTJ when the MTJ stack has reversed polarization during the first time period. The second segment of the segment of the write pulse may be a ramp, or multiple ramps, or have a quiescent period between it and the first segment of the write pulse.
    Type: Application
    Filed: June 29, 2020
    Publication date: October 15, 2020
    Inventors: Huanlong Liu, Guenole Jan, Yuan-Jen Lee, Jian Zhu, Po-Kang Wang
  • 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
  • Publication number: 20200279995
    Abstract: A magnetic tunnel junction with perpendicular magnetic anisotropy (PMA MTJ) is disclosed wherein a free layer interfaces with a tunnel barrier and has a second interface with an oxide layer. A lattice-matching layer adjoins an opposite side of the oxide layer with respect to the free layer and is comprised of CoXFeYNiZLWMV or an oxide or nitride of Ru, Ta, Ti, or Si, wherein L is one of B, Zr, Nb, Hf, Mo, Cu, Cr, Mg, Ta, Ti, Au, Ag, or P, and M is one of Mo, Mg, Ta, Cr, W, or V, (x+y+z+w+v)=100 atomic %, x+y>0, and each of v and w are >0. The lattice-matching layer grows a BCC structure during annealing thereby promoting BCC structure growth in the oxide layer that results in enhanced free layer PMA and improved thermal stability.
    Type: Application
    Filed: May 18, 2020
    Publication date: September 3, 2020
    Inventors: Huanlong Liu, Yuan-Jen Lee, Jian Zhu, Guenole Jan, Luc Thomas, Po-Kang Wang, Ru-Ying Tong, Jodi Iwata
  • Patent number: 10763428
    Abstract: A magnetic tunnel junction is disclosed wherein the reference layer and free layer each comprise one layer having a boron content from 25 to 50 atomic %, and an adjoining second layer with a boron content from 1 to 20 atomic %. One of the first and second layers in each of the free layer and reference layer contacts the tunnel barrier. Each boron containing layer has a thickness of 1 to 10 Angstroms and may include one or more B layers and one or more Co, Fe, CoFe, or CoFeB layers. As a result, migration of non-magnetic metals along crystalline boundaries to the tunnel barrier is prevented, and the MTJ has a low defect count of around 10 ppm while maintaining an acceptable TMR ratio following annealing to temperatures of about 400° C. The boron containing layers are selected from CoB, FeB, CoFeB and alloys thereof including CoFeNiB.
    Type: Grant
    Filed: December 8, 2017
    Date of Patent: September 1, 2020
    Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY, LTD.
    Inventors: Huanlong Liu, Yuan-Jen Lee, Jian Zhu, Guenole Jan, Po-Kang Wang
  • Patent number: 10699765
    Abstract: Circuits and methods for programming a MTJ stack of an MRAM cell minimizes a ferromagnetic free layer or pinned layer polarization reversal due to back-hopping. The programming begins by applying a first segment of the segment of the write pulse at a first write voltage level for a first time period to program the MTJ stack. A second segment of the segment of the write pulse at a second write voltage level that is less than the first write voltage level is applied to the magnetic tunnel junction stack for a second time period to correct the polarization of the MTJ when the MTJ stack has reversed polarization during the first time period. The second segment of the segment of the write pulse may be a ramp, or multiple ramps, or have a quiescent period between it and the first segment of the write pulse.
    Type: Grant
    Filed: June 7, 2017
    Date of Patent: June 30, 2020
    Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY, LTD.
    Inventors: Huanlong Liu, Guenole Jan, Yuan-Jen Lee, Jian Zhu, Po-Kang Wang
  • Publication number: 20200200520
    Abstract: A flatness sensing device includes a pressure sensing unit and a controller. The pressure sensing unit includes a plate portion, and a pressure sensor fixed and exposed at an edge of the plate portion. A sensing surface of the pressure sensor is flush with the bottom surface of the plate portion. The pressure sensor senses a pressure or lack of pressure of an object to be tested when it touches the object to be tested. The controller receives the pressure value output from the pressure sensor and determines a flatness of the object to be tested, the controller can issue an alarm on finding non-flatness and cause the degree of flatness to be displayed to a user.
    Type: Application
    Filed: March 11, 2019
    Publication date: June 25, 2020
    Inventors: EDDY LIU, XI-HANG LI, JUN-KANG FANG, PO-LIN SU, WEI WU, XUE-WEI WANG, YI-LUNG CHEN, GUO-YI CUI
  • Patent number: 10658577
    Abstract: A magnetic tunnel junction with perpendicular magnetic anisotropy (PMA MTJ) is disclosed wherein a free layer interfaces with a tunnel barrier and has a second interface with an oxide layer. A lattice-matching layer adjoins an opposite side of the oxide layer with respect to the free layer and is comprised of CoXFeYNiZLWMV or an oxide or nitride of Ru, Ta, Ti, or Si, wherein L is one of B, Zr, Nb, Hf, Mo, Cu, Cr, Mg, Ta, Ti, Au, Ag, or P, and M is one of Mo, Mg, Ta, Cr, W, or V, (x+y+z+w+v)=100 atomic %, x+y>0, and each of v and w are >0. The lattice-matching layer grows a BCC structure during annealing thereby promoting BCC structure growth in the oxide layer that results in enhanced free layer PMA and improved thermal stability.
    Type: Grant
    Filed: September 30, 2019
    Date of Patent: May 19, 2020
    Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY, LTD.
    Inventors: Huanlong Liu, Yuan-Jen Lee, Jian Zhu, Guenole Jan, Luc Thomas, Po-Kang Wang, Ru-Ying Tong, Jodi Iwata
  • Publication number: 20200144487
    Abstract: A laminated seed layer stack with a smooth top surface having a peak to peak roughness of 0.5 nm is formed by sequentially sputter depositing a first seed layer, a first amorphous layer, a second seed layer, and a second amorphous layer where each seed layer may be Mg and has a resputtering rate 2 to 30X that of the amorphous layers that are TaN, SiN, or a CoFeM alloy. A template layer that is NiCr or NiFeCr is formed on the second amorphous layer. As a result, perpendicular magnetic anisotropy in an overlying magnetic layer that is a reference layer, free layer, or dipole 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 laminated seed layer stack may include a bottommost Ta or TaN buffer layer.
    Type: Application
    Filed: December 27, 2019
    Publication date: May 7, 2020
    Inventors: Jian Zhu, Guenole Jan, Yuan-Jen Lee, Huanlong Liu, Ru-Ying Tong, Po-Kang Wang
  • 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: 20200116790
    Abstract: A method includes receiving tester configuration data, test pattern data, and tester operation data; configuring a circuit for performing a designated test evaluation; generating a stimulus waveform; converting the stimulus waveform to an analog stimulus signal; transferring the analog stimulus signal to a first terminal of a MTJ DUT at reception of a trigger timing signal; generating time traces based on the trigger timing signal; generating a response signal at a second terminal of the MTJ DUT and across a termination resistor as the analog stimulus signal is transferred through the MTJ DUT; converting the response signal to a digitized response signal indicating its voltage amplitude; and performing the designated test evaluation and analysis function in the configurable circuit based on voltage amplitudes and time values of the stimulus waveform, the digitized response signal, and the timing traces.
    Type: Application
    Filed: December 16, 2019
    Publication date: April 16, 2020
    Inventors: Guenole Jan, Huanlong Liu, Jian Zhu, Yuan-Jen Lee, Po-Kang Wang
  • Publication number: 20200028073
    Abstract: A magnetic tunnel junction with perpendicular magnetic anisotropy (PMA MTJ) is disclosed wherein a free layer interfaces with a tunnel barrier and has a second interface with an oxide layer. A lattice-matching layer adjoins an opposite side of the oxide layer with respect to the free layer and is comprised of CoXFeYNiZLWMV or an oxide or nitride of Ru, Ta, Ti, or Si, wherein L is one of B, Zr, Nb, Hf, Mo, Cu, Cr, Mg, Ta, Ti, Au, Ag, or P, and M is one of Mo, Mg, Ta, Cr, W, or V, (x+y+z+w+v)=100 atomic %, x+y>0, and each of v and w are >0. The lattice-matching layer grows a BCC structure during annealing thereby promoting BCC structure growth in the oxide layer that results in enhanced free layer PMA and improved thermal stability.
    Type: Application
    Filed: September 30, 2019
    Publication date: January 23, 2020
    Inventors: Huanlong Liu, Yuan-Jen Lee, Jian Zhu, Guenole Jan, Luc Thomas, Po-Kang Wang, Ru-Ying Tong, Jodi Iwata
  • 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: 10522747
    Abstract: A laminated seed layer stack with a smooth top surface having a peak to peak roughness of 0.5 nm is formed by sequentially sputter depositing a first seed layer, a first amorphous layer, a second seed layer, and a second amorphous layer where each seed layer may be Mg and has a resputtering rate 2 to 30X that of the amorphous layers that are TaN, SiN, or a CoFeM alloy. A template layer that is NiCr or NiFeCr is formed on the second amorphous layer. As a result, perpendicular magnetic anisotropy in an overlying magnetic layer that is a reference layer, free layer, or dipole 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 laminated seed layer stack may include a bottommost Ta or TaN buffer layer.
    Type: Grant
    Filed: February 19, 2019
    Date of Patent: December 31, 2019
    Assignee: TAIWAN SEMICONDUCTOR MANUFACUTING COMPANY, LTD.
    Inventors: Jian Zhu, Guenole Jan, Yuan-Jen Lee, Huanlong Liu, Ru-Ying Tong, Po-Kang Wang
  • Patent number: 10509074
    Abstract: A stimulus/response controller within a magnetic electrical test apparatus is configured for generating and transmitting stimulus waveforms to a high-speed DAC for application to a MTJ DUT. The response signal from the MTJ DUT is applied to an ADC that digitizes and transfers the response signal to the stimulus/response controller. The stimulus/response controller has a configurable function circuit that is selectively configured for performing evaluation and analysis of the digitized stimulus and response signals. The configurable functions are structured for performing any evaluation and analysis function for determining the characteristics of the MTJ DUT(s). Examples of the evaluation and analysis operations include averaging the stimulus and/or response signals, determining the differential resistance, the degradation times, failure counts, or the bit error rate of the MTJ DUT(s).
    Type: Grant
    Filed: February 22, 2018
    Date of Patent: December 17, 2019
    Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY, LTD.
    Inventors: Guenole Jan, Huanlong Liu, Jian Zhu, Yuan-Jen Lee, Po-Kang Wang
  • Patent number: 10431736
    Abstract: A magnetic tunnel junction with perpendicular magnetic anisotropy (PMA MTJ) is disclosed wherein a free layer interfaces with a tunnel barrier and has a second interface with an oxide layer. A lattice-matching layer adjoins an opposite side of the oxide layer with respect to the free layer and is comprised of CoXFeYNiZLWMV or an oxide or nitride of Ru, Ta, Ti, or Si, wherein L is one of B, Zr, Nb, Hf, Mo, Cu, Cr, Mg, Ta, Ti, Au, Ag, or P, and M is one of Mo, Mg, Ta, Cr, W, or V, (x+y+z+w+v)=100 atomic %, x+y>0, and each of v and w are >0. The lattice-matching layer grows a BCC structure during annealing thereby promoting BCC structure growth in the oxide layer that results in enhanced free layer PMA and improved thermal stability.
    Type: Grant
    Filed: June 29, 2018
    Date of Patent: October 1, 2019
    Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY, LTD.
    Inventors: Huanlong Liu, Yuan-Jen Lee, Jian Zhu, Guenole Jan, Luc Thomas, Po-Kang Wang, Ru-Ying Tong, Jodi Mari Iwata
  • Publication number: 20190257881
    Abstract: A stimulus/response controller within a magnetic electrical test apparatus is configured for generating and transmitting stimulus waveforms to a high-speed DAC for application to a MTJ DUT. The response signal from the MTJ DUT is applied to an ADC that digitizes and transfers the response signal to the stimulus/response controller. The stimulus/response controller has a configurable function circuit that is selectively configured for performing evaluation and analysis of the digitized stimulus and response signals. The configurable functions are structured for performing any evaluation and analysis function for determining the characteristics of the MTJ DUT(s). Examples of the evaluation and analysis operations include averaging the stimulus and/or response signals, determining the differential resistance, the degradation times, failure counts, or the bit error rate of the MTJ DUT(s).
    Type: Application
    Filed: February 22, 2018
    Publication date: August 22, 2019
    Inventors: Guenole Jan, Huanlong Liu, Jian Zhu, Yuan-Jen Lee, Po-Kang Wang
  • Publication number: 20190189911
    Abstract: A laminated seed layer stack with a smooth top surface having a peak to peak roughness of 0.5 nm is formed by sequentially sputter depositing a first seed layer, a first amorphous layer, a second seed layer, and a second amorphous layer where each seed layer may be Mg and has a resputtering rate 2 to 30X that of the amorphous layers that are TaN, SiN, or a CoFeM alloy. A template layer that is NiCr or NiFeCr is formed on the second amorphous layer. As a result, perpendicular magnetic anisotropy in an overlying magnetic layer that is a reference layer, free layer, or dipole 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 laminated seed layer stack may include a bottommost Ta or TaN buffer layer.
    Type: Application
    Filed: February 19, 2019
    Publication date: June 20, 2019
    Inventors: Jian Zhu, Guenole Jan, Yuan-Jen Lee, Huanlong Liu, Ru-Ying Tong, Po-Kang Wang