Patents by Inventor Zihui Wang
Zihui 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: 10032979Abstract: The present invention is directed to a magnetic memory element including a magnetic free layer structure having a variable magnetization direction perpendicular to a layer plane thereof; an insulating tunnel junction layer formed adjacent to the magnetic free layer structure; a first magnetic reference layer comprising cobalt, iron, and boron formed adjacent to the insulating tunnel junction layer; a second magnetic reference layer comprising cobalt separated from the first magnetic reference layer by a molybdenum layer; an iridium layer formed adjacent to the second magnetic reference layer; and a magnetic fixed layer structure formed adjacent to the iridium layer. The magnetic free layer structure includes a first and a second magnetic free layers with a perpendicular enhancement layer interposed therebetween. The first and second magnetic reference layers have a first invariable magnetization direction perpendicular to layer planes thereof.Type: GrantFiled: November 17, 2017Date of Patent: July 24, 2018Assignee: Avalanche Technology, Inc.Inventors: Huadong Gan, Yiming Huai, Yuchen Zhou, Zihui Wang, Bing K. Yen, Xiaojie Hao, Pengfa Xu
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Patent number: 10008663Abstract: The present invention is directed to an MTJ memory element, which includes a magnetic free layer structure having a variable magnetization direction perpendicular to a layer plane thereof; a tunnel junction layer formed adjacent to the magnetic free layer structure; a magnetic reference layer structure formed adjacent to the tunnel junction layer and having a first invariable magnetization direction perpendicular to a layer plane thereof; an anti-ferromagnetic coupling layer formed adjacent to the magnetic reference layer structure; and a magnetic fixed layer structure formed adjacent to the anti-ferromagnetic coupling layer and having a second invariable magnetization direction that is perpendicular to a layer plane thereof and is opposite to the first invariable magnetization direction. The magnetic fixed layer structure includes multiple stacks of a trilayer unit structure, which includes three layers of different materials with at least one of the three layers of different materials being magnetic.Type: GrantFiled: April 19, 2017Date of Patent: June 26, 2018Assignee: Avalanche Technology, Inc.Inventors: Xiaojie Hao, Zihui Wang, Huadong Gan, Yuchen Zhou, Yiming Huai
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Patent number: 10008540Abstract: The present invention is directed to a spin-orbitronics device including an array of MTJs with each of the MTJs coupled to a respective one of a plurality of selection transistors; a plurality of transverse polarizing lines with each of the transverse polarizing lines coupled to a row of the MTJs along a first direction; a plurality of word lines with each of the word lines coupled to gates of a row of the selection transistors along a second direction; and a plurality of source lines with each of the source lines coupled to a row of the selection transistors along a direction substantially perpendicular to the second direction. Each MTJ includes a magnetic comparison layer structure having a pseudo-invariable magnetization direction, which is configured to switch between two stable states by passing a comparison current through one of the plurality of transverse polarizing lines formed adjacent to the magnetic comparison layer structure.Type: GrantFiled: May 4, 2017Date of Patent: June 26, 2018Assignee: Avalanche Technology, Inc.Inventors: Parviz Keshtbod, Xiaobin Wang, Kimihiro Satoh, Zihui Wang, Huadong Gan
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Publication number: 20180090675Abstract: The present invention is directed to a magnetic memory element including a magnetic free layer and a first magnetic reference layer with an insulating tunnel junction layer interposed therebetween; a second magnetic reference layer made of a material comprising cobalt and formed adjacent to the first magnetic reference layer opposite the insulating tunnel junction layer; an iridium layer formed adjacent to the second magnetic reference layer opposite the first magnetic reference layer; and a magnetic fixed layer formed adjacent to the iridium layer. The magnetic free layer has a variable magnetization direction substantially perpendicular to the layer plane thereof. The first and second magnetic reference layers have a first fixed magnetization direction substantially perpendicular to the layer planes thereof.Type: ApplicationFiled: November 16, 2017Publication date: March 29, 2018Inventors: Huadong Gan, Yiming Huai, Yuchen Zhou, Zihui Wang
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Publication number: 20180076384Abstract: The present invention is directed to a magnetic memory element including a magnetic free layer structure having a variable magnetization direction perpendicular to a layer plane thereof; an insulating tunnel junction layer formed adjacent to the magnetic free layer structure; a first magnetic reference layer comprising cobalt, iron, and boron formed adjacent to the insulating tunnel junction layer; a second magnetic reference layer comprising cobalt separated from the first magnetic reference layer by a molybdenum layer; an iridium layer formed adjacent to the second magnetic reference layer; and a magnetic fixed layer structure formed adjacent to the iridium layer. The magnetic free layer structure includes a first and a second magnetic free layers with a perpendicular enhancement layer interposed therebetween. The first and second magnetic reference layers have a first invariable magnetization direction perpendicular to layer planes thereof.Type: ApplicationFiled: November 17, 2017Publication date: March 15, 2018Inventors: Huadong Gan, Yiming Huai, Yuchen Zhou, Zihui Wang, Bing K. Yen, Xiaojie Hao, Pengfa Xu
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Publication number: 20180075891Abstract: The present invention is directed to a method for sensing the resistance state of a memory cell that includes an MTJ memory element coupled to a two-terminal selector element in series. The method includes the steps of raising a cell voltage across the memory cell above a threshold voltage for the selector element to become conductive; decreasing the cell voltage to a first sensing voltage and measuring a first sensing current passing through the memory cell, the selector element being nominally conductive irrespective of the resistance state of the MTJ memory element at the first sensing voltage; and further decreasing the cell voltage to a second sensing voltage and measuring a second sensing current, the selector element being nominally conductive if the MTJ memory element is in the low resistance state or nominally insulative if the MTJ memory element is in the high resistance state at the second sensing voltage.Type: ApplicationFiled: September 14, 2016Publication date: March 15, 2018Inventors: Hongxin Yang, Xiaobin Wang, Jing Zhang, Xiaojie Hao, Zihui Wang, Kimihiro Satoh
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Patent number: 9871191Abstract: The present invention is directed to an MRAM device comprising a plurality of MTJ memory elements. Each of the memory elements includes a magnetic free layer and a first magnetic reference layer with an insulating tunnel junction layer interposed therebetween; a second magnetic reference layer formed adjacent to the first magnetic reference layer opposite the insulating tunnel junction layer; an anti-ferromagnetic coupling layer formed adjacent to the second magnetic reference layer opposite the first magnetic reference layer; and a magnetic fixed layer formed adjacent to the anti-ferromagnetic coupling layer. The magnetic free layer has a variable magnetization direction substantially perpendicular to the layer plane thereof. The first and second magnetic reference layers have a first fixed magnetization direction substantially perpendicular to the layer planes thereof.Type: GrantFiled: June 3, 2015Date of Patent: January 16, 2018Assignee: Avalanche Technology, Inc.Inventors: Yuchen Zhou, Yiming Huai, Zihui Wang, Xiaojie Hao, Huadong Gan, Xiaobin Wang
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Patent number: 9871190Abstract: The present invention is directed to an MRAM device comprising a plurality of MTJ memory elements. Each of the memory elements includes a magnetic free layer and a first magnetic reference layer with an insulating tunnel junction layer interposed therebetween; a second magnetic reference layer formed adjacent to the first magnetic reference layer opposite the insulating tunnel junction layer; an anti-ferromagnetic coupling layer formed adjacent to the second magnetic reference layer opposite the first magnetic reference layer; and a magnetic fixed layer formed adjacent to the anti-ferromagnetic coupling layer. The magnetic free layer has a variable magnetization direction substantially perpendicular to the layer plane thereof. The first and second magnetic reference layers have a first fixed magnetization direction substantially perpendicular to the layer planes thereof.Type: GrantFiled: April 28, 2014Date of Patent: January 16, 2018Assignee: Avalanche Technology, Inc.Inventors: Huadong Gan, Yiming Huai, Yuchen Zhou, Xiaobin Wang, Zihui Wang
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Patent number: 9831421Abstract: The present invention is directed to an MTJ memory element including a magnetic free layer structure which includes one or more magnetic free layers that have a same variable magnetization direction substantially perpendicular to layer planes thereof; an insulating tunnel junction layer formed adjacent to the magnetic free layer structure; a magnetic reference layer structure comprising a first magnetic reference layer formed adjacent to the insulating tunnel junction layer and a second magnetic reference layer separated therefrom by a perpendicular enhancement layer with the first and second magnetic reference layers having a first fixed magnetization direction substantially perpendicular to layer planes thereof; an anti-ferromagnetic coupling layer formed adjacent to the second magnetic reference layer opposite the perpendicular enhancement layer; and a magnetic fixed layer comprising first and second magnetic fixed sublayers with the second magnetic fixed sublayer formed adjacent to the anti-ferromagneticType: GrantFiled: July 13, 2015Date of Patent: November 28, 2017Assignee: Avalanche Technology, Inc.Inventors: Zihui Wang, Huadong Gan, Yiming Huai, Yuchen Zhou, Xiaobin Wang, Bing K. Yen, Xiaojie Hao
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Publication number: 20170324027Abstract: The present invention is directed to a magnetic tunnel junction (MTJ) memory element including a magnetic free layer structure and a magnetic reference layer structure with an insulating tunnel junction layer interposed therebetween; a magnetic fixed layer exchange coupled to the magnetic reference layer structure through an anti-ferromagnetic coupling layer; a magnesium oxide layer formed adjacent to the magnetic fixed layer; and a metal layer comprising nickel and chromium formed adjacent to the magnesium oxide layer. The magnetic reference layer structure includes a first and a second magnetic reference layers with a first perpendicular enhancement layer (PEL) interposed therebetween. The first and second magnetic reference layers have a first invariable magnetization direction substantially perpendicular to layer planes thereof. The magnetic fixed layer has a second invariable magnetization direction opposite to the first invariable magnetization direction.Type: ApplicationFiled: July 27, 2017Publication date: November 9, 2017Inventors: Yiming Huai, Huadong Gan, Zihui Wang
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Publication number: 20170288137Abstract: The present invention is directed to an MTJ memory element including a magnetic free layer structure which includes one or more magnetic free layers that have a same variable magnetization direction substantially perpendicular to layer planes thereof; an insulating tunnel junction layer formed adjacent to the magnetic free layer structure; a magnetic reference layer structure comprising a first magnetic reference layer formed adjacent to the insulating tunnel junction layer and a second magnetic reference layer separated therefrom by a perpendicular enhancement layer with the first and second magnetic reference layers having a first fixed magnetization direction substantially perpendicular to layer planes thereof; an anti-ferromagnetic coupling layer formed adjacent to the second magnetic reference layer opposite the perpendicular enhancement layer; and a magnetic fixed layer comprising first and second magnetic fixed sublayers with the second magnetic fixed sublayer formed adjacent to the anti-ferromagneticType: ApplicationFiled: July 13, 2015Publication date: October 5, 2017Inventors: Zihui Wang, Huadong Gan, Yiming Huai, Yuchen Zhou, Xiaobin Wang, Bing K. Yen, Xiaojie Hao
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Patent number: 9748471Abstract: The present invention is directed to an STT-MRAM device comprising a plurality of memory elements. Each of the memory elements includes an MTJ structure that comprises a magnetic free layer structure and a magnetic reference layer structure with an insulating tunnel junction layer interposed therebetween; a first perpendicular enhancement layer (PEL) formed adjacent to the magnetic free layer structure; a magnetic dead layer formed adjacent to the first PEL; and a magnetic fixed layer exchange coupled to the magnetic reference layer structure through an anti-ferromagnetic coupling layer. The magnetic reference layer structure includes a first magnetic reference layer formed adjacent to the insulating tunnel junction layer and a second magnetic reference layer separated from the first magnetic reference layer by a second PEL. The first and second magnetic reference layers have a first invariable magnetization direction substantially perpendicular to layer planes thereof.Type: GrantFiled: February 23, 2017Date of Patent: August 29, 2017Assignee: Avalanche Technology, Inc.Inventors: Yuchen Zhou, Zihui Wang, Huadong Gan, Yiming Huai
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Publication number: 20170236868Abstract: The present invention is directed to a spin-orbitronics device including an array of MTJs with each of the MTJs coupled to a respective one of a plurality of selection transistors; a plurality of transverse polarizing lines with each of the transverse polarizing lines coupled to a row of the MTJs along a first direction; a plurality of word lines with each of the word lines coupled to gates of a row of the selection transistors along a second direction; and a plurality of source lines with each of the source lines coupled to a row of the selection transistors along a direction substantially perpendicular to the second direction. Each MTJ includes a magnetic comparison layer structure having a pseudo-invariable magnetization direction, which is configured to switch between two stable states by passing a comparison current through one of the plurality of transverse polarizing lines formed adjacent to the magnetic comparison layer structure.Type: ApplicationFiled: May 4, 2017Publication date: August 17, 2017Inventors: Parviz Keshtbod, Xiaobin Wang, Kimihiro Satoh, Zihui Wang, Huadong Gan
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Perpendicular magnetic tunnel junction (pMTJ) with in-plane magneto-static switching-enhancing layer
Patent number: 9679625Abstract: An STTMRAM element includes a magnetic tunnel junction (MTJ) having a perpendicular magnetic orientation. The MTJ includes a barrier layer, a free layer formed on top of the barrier layer and having a magnetic orientation that is perpendicular and switchable relative to the magnetic orientation of the fixed layer. The magnetic orientation of the free layer switches when electrical current flows through the STTMRAM element. A switching-enhancing layer (SEL), separated from the free layer by a spacer layer, is formed on top of the free layer and has an in-plane magnetic orientation and generates magneto-static fields onto the free layer, causing the magnetic moments of the outer edges of the free layer to tilt with an in-plane component while minimally disturbing the magnetic moment at the center of the free layer to ease the switching of the free layer and to reduce the threshold voltage/current.Type: GrantFiled: November 2, 2015Date of Patent: June 13, 2017Assignee: Avalanche Technology, Inc.Inventors: Jing Zhang, Yiming Huai, Rajiv Yadav Ranjan, Yuchen Zhou, Zihui Wang, Xiaojie Hao -
Publication number: 20170162781Abstract: The present invention is directed to an STT-MRAM device comprising a plurality of memory elements. Each of the memory elements includes an MTJ structure that comprises a magnetic free layer structure and a magnetic reference layer structure with an insulating tunnel junction layer interposed therebetween; a first perpendicular enhancement layer (PEL) formed adjacent to the magnetic free layer structure; a magnetic dead layer formed adjacent to the first PEL; and a magnetic fixed layer exchange coupled to the magnetic reference layer structure through an anti-ferromagnetic coupling layer. The magnetic reference layer structure includes a first magnetic reference layer formed adjacent to the insulating tunnel junction layer and a second magnetic reference layer separated from the first magnetic reference layer by a second PEL. The first and second magnetic reference layers have a first invariable magnetization direction substantially perpendicular to layer planes thereof.Type: ApplicationFiled: February 23, 2017Publication date: June 8, 2017Inventors: Yuchen Zhou, Zihui Wang, Huadong Gan, Yiming Huai
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Patent number: 9647032Abstract: The present invention is directed to a spin-orbitronics device including a magnetic comparison layer structure having a pseudo-invariable magnetization direction; a magnetic free layer structure whose variable magnetization direction can be switched by a switching current passing between the magnetic comparison layer structure and the magnetic free layer structure; an insulating tunnel junction layer interposed between the magnetic comparison layer structure and the magnetic free layer structure; and a non-magnetic transverse polarizing layer formed adjacent to the magnetic comparison layer structure. The pseudo-invariable magnetization direction of the magnetic comparison layer structure may be switched by passing a comparison current through the transverse polarizing layer along a direction that is substantially parallel to a layer plane of the transverse polarizing layer. The pseudo-invariable magnetization direction of the magnetic comparison layer structure is not switched by the switching current.Type: GrantFiled: August 20, 2015Date of Patent: May 9, 2017Assignee: Avalanche Technology, Inc.Inventors: Xiaobin Wang, Parviz Keshtbod, Kimihiro Satoh, Zihui Wang, Huadong Gan
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Patent number: 9647202Abstract: The present invention is directed to an MRAM element comprising a plurality of magnetic tunnel junction (MTJ) memory elements. Each of the memory elements comprises a magnetic reference layer structure, which includes a first and a second magnetic reference layers with a tantalum perpendicular enhancement layer interposed therebetween, an insulating tunnel junction layer formed adjacent to the first magnetic reference layer opposite the tantalum perpendicular enhancement layer, and a magnetic free layer formed adjacent to the insulating tunnel junction layer. The first and second magnetic reference layers have a first fixed magnetization direction substantially perpendicular to the layer planes thereof.Type: GrantFiled: April 18, 2014Date of Patent: May 9, 2017Assignee: Avalanche Technology, Inc.Inventors: Huadong Gan, Yuchen Zhou, Yiming Huai, Zihui Wang, Xiaobin Wang
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Patent number: 9634244Abstract: The present invention is directed to an MRAM element comprising a magnetic free layer structure and a magnetic reference layer structure with an insulating tunnel junction layer interposed therebetween. The magnetic free layer structure has a variable magnetization direction substantially perpendicular to the layer plane thereof. The magnetic reference layer structure includes a first magnetic reference layer formed adjacent to the insulating tunnel junction layer and a second magnetic reference layer separated from the first magnetic reference layer by a first non-magnetic perpendicular enhancement layer. The first and second magnetic reference layers have a first fixed magnetization direction substantially perpendicular to the layer plane thereof.Type: GrantFiled: March 24, 2016Date of Patent: April 25, 2017Assignee: Avalanche Technology, Inc.Inventors: Huadong Gan, Yiming Huai, Zihui Wang, Yuchen Zhou
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Patent number: 9608038Abstract: The present invention is directed to an STT-MRAM device comprising a plurality of memory elements. Each of the memory elements includes an MTJ structure in between a seed layer and a cap layer. The MTJ structure includes a magnetic free layer structure and a magnetic reference layer structure with an insulating tunnel junction layer interposed therebetween; and a magnetic fixed layer separated from the magnetic reference layer structure by an anti-ferromagnetic coupling layer. The magnetic reference layer structure includes a first magnetic reference layer formed adjacent to the insulating tunnel junction layer and a second magnetic reference layer separated from the first magnetic reference layer by an intermediate magnetic reference layer. The first, second, and intermediate magnetic reference layers have a first invariable magnetization direction substantially perpendicular to layer planes thereof.Type: GrantFiled: June 6, 2016Date of Patent: March 28, 2017Assignee: Avalanche Technology, Inc.Inventors: Zihui Wang, Yuchen Zhou, Huadong Gan, Yiming Huai
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Patent number: 9559144Abstract: The present invention is directed to a spin transfer torque (STT) MRAM device having a perpendicular magnetic tunnel junction (MTJ) memory element. The memory element includes a perpendicular MTJ structure in between a non-magnetic seed layer and a non-magnetic cap layer. The MTJ structure comprises a magnetic free layer structure and a magnetic reference layer structure with an insulating tunnel junction layer interposed therebetween, an anti-ferromagnetic coupling layer formed adjacent to the magnetic reference layer structure, and a magnetic fixed layer formed adjacent to the anti-ferromagnetic coupling layer. At least one of the magnetic free and reference layer structures includes a non-magnetic perpendicular enhancement layer, which improves the perpendicular anisotropy of magnetic layers adjacent thereto.Type: GrantFiled: June 3, 2015Date of Patent: January 31, 2017Assignee: Avalanche Technology, Inc.Inventors: Huadong Gan, Yiming Huai, Yuchen Zhou, Zihui Wang, Xiaobin Wang, Bing K. Yen