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).
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Patent number: 11696511Abstract: 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: GrantFiled: October 5, 2020Date of Patent: July 4, 2023Assignee: 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
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Patent number: 11573270Abstract: 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: GrantFiled: July 1, 2021Date of Patent: February 7, 2023Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY, LTD.Inventors: Guenole Jan, Huanlong Liu, Jian Zhu, Yuan-Jen Lee, Po-Kang Wang
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Patent number: 11569441Abstract: 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: GrantFiled: May 18, 2020Date of Patent: January 31, 2023Assignee: 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
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Patent number: 11563170Abstract: 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: GrantFiled: December 27, 2019Date of Patent: January 24, 2023Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY, LTD.Inventors: Jian Zhu, Guenole Jan, Yuan-Jen Lee, Huanlong Liu, Ru-Ying Tong, Po-Kang Wang
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Publication number: 20220238798Abstract: 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: ApplicationFiled: April 18, 2022Publication date: July 28, 2022Inventors: Huanlong Liu, Yuan-Jen Lee, Jian Zhu, Guenole Jan, Po-Kang Wang
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Patent number: 11309489Abstract: 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: GrantFiled: August 31, 2020Date of Patent: April 19, 2022Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY, LTD.Inventors: Huanlong Liu, Yuan-Jen Lee, Jian Zhu, Guenole Jan, Po-Kang Wang
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Publication number: 20210325460Abstract: 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: ApplicationFiled: July 1, 2021Publication date: October 21, 2021Inventors: Guenole Jan, Huanlong Liu, Jian Zhu, Yuan-Jen Lee, Po-Kang Wang
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Patent number: 11054471Abstract: 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: GrantFiled: December 16, 2019Date of Patent: July 6, 2021Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY, LTD.Inventors: Guenole Jan, Huanlong Liu, Jian Zhu, Yuan-Jen Lee, Po-Kang Wang
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Patent number: 10978124Abstract: 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: GrantFiled: June 29, 2020Date of Patent: April 13, 2021Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY, LTD.Inventors: Huanlong Liu, Guenole Jan, Yuan-Jen Lee, Jian Zhu, Po-Kang Wang
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Publication number: 20210020831Abstract: 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: ApplicationFiled: October 5, 2020Publication date: January 21, 2021Inventors: Sahil Patel, Guenole Jan, Ru-Ying Tong, Vignesh Sundar, Dongna Shen, Yu-Jen Wang, Po-Kang Wang, Huanlong Liu
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Publication number: 20200395534Abstract: 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: ApplicationFiled: August 31, 2020Publication date: December 17, 2020Inventors: Huanlong Liu, Yuan-Jen Lee, Jian Zhu, Guenole Jan, Po-Kang Wang
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Publication number: 20200327918Abstract: 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: ApplicationFiled: June 29, 2020Publication date: October 15, 2020Inventors: Huanlong Liu, Guenole Jan, Yuan-Jen Lee, Jian Zhu, Po-Kang Wang
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Patent number: 10797232Abstract: 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: GrantFiled: December 27, 2019Date of Patent: October 6, 2020Assignee: 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
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Publication number: 20200279995Abstract: 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: ApplicationFiled: May 18, 2020Publication date: September 3, 2020Inventors: Huanlong Liu, Yuan-Jen Lee, Jian Zhu, Guenole Jan, Luc Thomas, Po-Kang Wang, Ru-Ying Tong, Jodi Iwata
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Patent number: 10763428Abstract: 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: GrantFiled: December 8, 2017Date of Patent: September 1, 2020Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY, LTD.Inventors: Huanlong Liu, Yuan-Jen Lee, Jian Zhu, Guenole Jan, Po-Kang Wang
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Patent number: 10699765Abstract: 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: GrantFiled: June 7, 2017Date of Patent: June 30, 2020Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY, LTD.Inventors: Huanlong Liu, Guenole Jan, Yuan-Jen Lee, Jian Zhu, Po-Kang Wang
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Patent number: 10658577Abstract: 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: GrantFiled: September 30, 2019Date of Patent: May 19, 2020Assignee: 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
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Publication number: 20200144487Abstract: 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: ApplicationFiled: December 27, 2019Publication date: May 7, 2020Inventors: Jian Zhu, Guenole Jan, Yuan-Jen Lee, Huanlong Liu, Ru-Ying Tong, Po-Kang Wang
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Publication number: 20200136025Abstract: 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: ApplicationFiled: December 27, 2019Publication date: April 30, 2020Inventors: Sahil Patel, Guenole Jan, Ru-Ying Tong, Vignesh Sundar, Dongna Shen, Yu-Jen Wang, Po-Kang Wang, Huanlong Liu
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Publication number: 20200116790Abstract: 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: ApplicationFiled: December 16, 2019Publication date: April 16, 2020Inventors: Guenole Jan, Huanlong Liu, Jian Zhu, Yuan-Jen Lee, Po-Kang Wang