Patents by Inventor You Feng Zheng
You Feng Zheng 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: 7184248Abstract: A patterned, synthetic, longitudinally exchange biased GMR sensor is provided which has a narrow effective trackwidth and reduced side reading. The advantageous properties of the sensor are obtained by satisfying a novel relationship between the magnetizations (M) of the ferromagnetic free layer (F1) and the ferromagnetic biasing layer (F2) which enables the optimal thicknesses of those layers to be determined for a wide range of ferromagnetic materials and exchange coupling materials. The relationship to be satisfied is MF2/MF1=(Js+Jex)/Js, where Js is the synthetic coupling energy between F1 and F2 and Jex is the exchange energy between F2 and an overlaying antiferromagnetic pinning layer. An alternative embodiment omits the overlaying antiferromagnetic pinning layer which causes the relationship to become MF2/MF1=1.Type: GrantFiled: November 1, 2005Date of Patent: February 27, 2007Assignee: Headway Technologies, Inc.Inventors: Min Li, You Feng Zheng, Simon Liao, Kochan Ju
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Patent number: 7106558Abstract: A magnetic read head with reduced side reading characteristics is described. This design combines use of a current channeling layer (CCL) with stabilizing longitudinal bias layers whose magnetization direction is canted relative to that of the free layer easy axis and that of the pinned layer (of the GMR). This provides several advantages: First, the canting of the free layer at the side region results in a reduction of side reading by reducing magnetic sensitivity in that region. Second, the CCL leads to a narrow current flow profile at the side region, therefore producing a narrow track width definition. A process for making this device is described. Said process allows some of the requirements for interface cleaning associated with prior art processes to be relaxed.Type: GrantFiled: June 15, 2004Date of Patent: September 12, 2006Assignee: Headway Technologies, Inc.Inventors: Kochan Ju, You Feng Zheng, Mao-Min Chen, Cherng-Chyi Han, Charles Lin
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Patent number: 7010848Abstract: A patterned, synthetic, longitudinally exchange biased GMR sensor is provided which has a narrow effective trackwidth and reduced side reading. The advantageous properties of the sensor are obtained by satisfying a novel relationship between the magnetizations (M) of the ferromagnetic free layer (F1) and the ferromagnetic biasing layer (F2) which enables the optimal thicknesses of those layers to be determined for a wide range of ferromagnetic materials and exchange coupling materials. The relationship to be satisfied is MF2/MF1=(Js+Jex)/Js, where Js is the synthetic coupling energy between F1 and F2 and Jex is the exchange energy between F2 and an overlaying antiferromagnetic pinning layer. An alternative embodiment omits the overlaying antiferromagnetic pinning layer which causes the relationship to become MF2/MF1=1.Type: GrantFiled: February 15, 2002Date of Patent: March 14, 2006Assignee: Headway Technologies, Inc.Inventors: Min Li, You Feng Zheng, Simon Liao, Kochan Ju
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Patent number: 6857180Abstract: Patterned, longitudinally and transversely antiferromagnetically exchange biased GMR sensors are provided which have narrow effective trackwidths and reduced side reading. The exchange biasing significantly reduces signals produced by the portion of the ferromagnetic free layer that is underneath the conducting leads while still providing a strong pinning field to maintain sensor stability. In the case of the transversely biased sensor, the magnetization of the free and biasing layers in the same direction as the pinned layer simplifies the fabrication process and permits the formation of thinner leads by eliminating the necessity for current shunting.Type: GrantFiled: March 22, 2002Date of Patent: February 22, 2005Assignee: Headway Technologies, Inc.Inventors: Cheng T. Horng, Min Li, Ru-Ying Tong, Yun-Fei Li, You Feng Zheng, Simon Liao, Kochan Ju, Cherng Chyi Han
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Publication number: 20040246633Abstract: A magnetic read head with reduced side reading characteristics is described. This design combines use of a current channeling layer (CCL) with stabilizing longitudinal bias layers whose magnetization direction is canted relative to that of the free layer easy axis and that of the pinned layer (of the GMR). This provides several advantages: First, the canting of the free layer at the side region results in a reduction of side reading by reducing magnetic sensitivity in that region. Second, the CCL leads to a narrow current flow profile at the side region, therefore producing a narrow track width definition. A process for making this device is described. Said process allows some of the requirements for interface cleaning associated with prior art processes to be relaxed.Type: ApplicationFiled: June 15, 2004Publication date: December 9, 2004Applicant: HEADWAY TECHNOLOGIES, INC.Inventors: Kochan Ju, You Feng Zheng, Mao-Min Chen, Cherng-Chyi Han, Charles Lin
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Patent number: 6816346Abstract: As the dimensions of spin valve heads continue to be reduced, a number of difficulties are being encountered. One such is with the longitudinal bias when an external magnetic field can cause reversal of the hard magnet, thereby causing a hysteric response by the head. This coercivity reduction becomes more severe as the hard magnet becomes thinner. This problem has been overcome by inserting a decoupling layer between the antiferromagnetic layer that is used to stabilize the pinned layer of the spin valve itself and the soft ferromagnetic layer that is used for longitudinal biasing. This soft ferromagnetic layer is pinned by a second antiferromagnetic layer deposited on it on its far side away from the first antiferromagnetic layer. The presence of the decoupling layer ensures that the magnetization of the soft layer is determined only by the second antiferromagnetic layer. The inclusion of said decoupling layer allows more latitude in etch depth control during manufacturing.Type: GrantFiled: March 2, 2004Date of Patent: November 9, 2004Assignee: Headway Technologies, Inc.Inventors: You Feng Zheng, Kochan Ju, Cheng T. Horng, Simon Liao, Ru Ying Tong
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Publication number: 20040169962Abstract: As the dimensions of spin valve heads continue to be reduced, a number of difficulties are being encountered. One such is with the longitudinal bias when an external magnetic field can cause reversal of the hard magnet, thereby causing a hysteric response by the head. This coercivity reduction becomes more severe as the hard magnet becomes thinner. This problem has been overcome by inserting a decoupling layer between the antiferromagnetic layer that is used to stabilize the pinned layer of the spin valve itself and the soft ferromagnetic layer that is used for longitudinal biasing. This soft ferromagnetic layer is pinned by a second antiferromagnetic layer deposited on it on its far side away from the first antiferromagnetic layer. The presence of the decoupling layer ensures that the magnetization of the soft layer is determined only by the second antiferromagnetic layer. The inclusion of said decoupling layer allows more latitude in etch depth control during manufacturing.Type: ApplicationFiled: March 2, 2004Publication date: September 2, 2004Applicant: HEADWAY TECHNOLOGIES, INC.Inventors: You Feng Zheng, Kochan Ju, Cheng T. Horng, Simon Liao, Ru Ying Tong
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Patent number: 6776883Abstract: A magnetic read head with reduced side reading characteristics is described. This design combines use of a current channeling layer (CCL) with stabilizing longitudinal bias layers whose magnetization direction is canted relative to that of the free layer easy axis and that of the pinned layer (of the GMR). This provides several advantages: First, the canting of the free layer at the side region results in a reduction of side reading by reducing magnetic sensitivity in that region. Second, the CCL leads to a narrow current flow profile at the side region, therefore producing a narrow track width definition. A process for making this device is described. Said process allows some of the requirements for interface cleaning associated with prior art processes to be relaxed.Type: GrantFiled: March 19, 2002Date of Patent: August 17, 2004Assignee: Headway Technologies, Inc.Inventors: Kochan Ju, You Feng Zheng, Mao-Min Chen, Cherng-Chyi Han, Charles Lin
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Patent number: 6721143Abstract: As the dimensions of spin valve heads continue to be reduced, a number of difficulties are being encountered. One such is with the longitudinal bias when an external magnetic field can cause reversal of the hard magnet, thereby causing a hysteric response by the head. This coercivity reduction becomes more severe as the hard magnet becomes thinner. This problem has been overcome by inserting a decoupling layer between the antiferromagnetic layer that is used to stabilize the pinned layer of the spin valve itself and the soft ferromagnetic layer that is used for longitudinal biasing. This soft ferromagnetic layer is pinned by a second antiferromagnetic layer deposited on it on its far side away from the first antiferromagnetic layer. The presence of the decoupling layer ensures that the magnetization of the soft layer is determined only by the second antiferromagnetic layer. The inclusion of the decoupling layer allows more latitude in etch depth control during manufacturing.Type: GrantFiled: August 22, 2001Date of Patent: April 13, 2004Assignee: Headway Technologies, Inc.Inventors: You Feng Zheng, Kochan Ju, Cheng T. Horng, Simon Liao, Ru Ying Tong
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Patent number: 6665154Abstract: Spin valve heads with overlaid leads have several advantages over butted contiguous junction designs, including larger signal output and better head stability. However, in any overlaid design there is always present at least one high resistance layer between the GMR layer and the conductive leads. This leads to an effective read width that is greater than the actual physical width. This problem has been overcome by inserting a highly conductive channeling layer between the GMR stack and the conducting lead laminate. This arrangement ensures that, at the intersection between the leads and the GMR stack, virtually all the current moves out of the free layer into the leads thereby providing an effective read width for the device that is very close to the physical read width defined by the spacing between the two leads. A process for manufacturing the device is also described.Type: GrantFiled: August 17, 2001Date of Patent: December 16, 2003Assignee: Headway Technologies, Inc.Inventors: Kochan Ju, You Feng Zheng, Rod Lee
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Publication number: 20030179517Abstract: Patterned, longitudinally and transversely antiferromagnetically exchange biased GMR sensors are provided which have narrow effective trackwidths and reduced side reading. The exchange biasing significantly reduces signals produced by the portion of the ferromagnetic free layer that is underneath the conducting leads while still providing a strong pinning field to maintain sensor stability. In the case of the transversely biased sensor, the magnetization of the free and biasing layers in the same direction as the pinned layer simplifies the fabrication process and permits the formation of thinner leads by eliminating the necessity for current shunting.Type: ApplicationFiled: March 22, 2002Publication date: September 25, 2003Applicant: Headway Technologies, Inc.Inventors: Cheng T. Horng, Min Li, Ru-Ying Tong, Yun-Fei Li, You Feng Zheng, Simon Liao, Kochan Ju, Cherng Chyi Han
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Publication number: 20030156361Abstract: A patterned, synthetic, longitudinally exchange biased GMR sensor is provided which has a narrow effective trackwidth and reduced side reading. The advantageous properties of the sensor are obtained by satisfying a novel relationship between the magnetizations (M) of the ferromagnetic free layer (F1) and the ferromagnetic biasing layer (F2) which enables the optimal thicknesses of those layers to be determined for a wide range of ferromagnetic materials and exchange coupling materials. The relationship to be satisfied is MF2/MF1=(Js+Jex)/Js, where Js is the synthetic coupling energy between F1 and F2 and Jex is the exchange energy between F2 and an overlaying antiferromagnetic pinning layer. An alternative embodiment omits the overlaying antiferromagnetic pinning layer which causes the relationship to become MF2/MF1=1.Type: ApplicationFiled: February 15, 2002Publication date: August 21, 2003Inventors: Min Li, You Feng Zheng, Simon Liao, Kochan Ju
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Patent number: 6594124Abstract: An improved stabilization scheme for a GMR read head is described. Two important changes relative to prior art designs have been introduced. Instead of biasing by means of a permanent magnet or through exchange coupling with an antiferromagnetic layer, the magnetostatic field emanating from a nearby, but not contiguous, layer is used. Additionally, to obtain optimum stability with this scheme the bias, instead of running parallel to the easy axis of the free layer, is canted away from it towards the direction of the demagnetizing field of the pinned layer. A process for the manufacture of the structure is also described.Type: GrantFiled: November 6, 2001Date of Patent: July 15, 2003Assignee: Headway Technologies, Inc.Inventors: You Feng Zheng, Kochan Ju, Simon Liao
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Publication number: 20030087133Abstract: An improved stabilization scheme for a GMR read head is described. Two important changes relative to prior art designs have been introduced. Instead of biasing by means of a permanent magnet or through exchange coupling with an antiferromagnetic layer, the magnetostatic field emanating from a nearby, but not contiguous, layer is used. Additionally, to obtain optimum stability with this scheme the bias, instead of running parallel to the easy axis of the free layer, is canted away from it towards the direction of the demagnetizing field of the pinned layer. A process for the manufacture of the structure is also described.Type: ApplicationFiled: November 6, 2001Publication date: May 8, 2003Applicant: Headway Technologies, Inc.Inventors: You Feng Zheng, Kochan Ju, Simon Liao
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Publication number: 20030039079Abstract: As the dimensions of spin valve heads continue to be reduced, a number of difficulties are being encountered. One such is with the longitudinal bias when an external magnetic field can cause reversal of the hard magnet, thereby causing a hysteric response by the head. This coercivity reduction becomes more severe as the hard magnet becomes thinner. This problem has been overcome by inserting a decoupling layer between the antiferromagnetic layer that is used to stabilize the pinned layer of the spin valve itself and the soft ferromagnetic layer that is used for longitudinal biasing. This soft ferromagnetic layer is pinned by a second antiferromagnetic layer deposited on it on its far side away from the first antiferromagnetic layer. The presence of the decoupling layer ensures that the magnetization of the soft layer is determined only by the second antiferromagnetic layer. The inclusion of said decoupling layer allows more latitude in etch depth control during manufacturing.Type: ApplicationFiled: August 22, 2001Publication date: February 27, 2003Applicant: Headway Technologies, Inc.Inventors: You Feng Zheng, Kochan Ju, Cheng T. Horng, Simon Liao, Ru Ying Tong
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Publication number: 20030035250Abstract: Spin valve heads with overlaid leads have several advantages over butted contiguous junction designs, including larger signal output and better head stability. However, in any overlaid design there is always present at least one high resistance layer between the GMR layer and the conductive leads. This leads to an effective read width that is greater than the actual physical width. This problem has been overcome by inserting a highly conductive channeling layer between the GMR stack and the conducting lead laminate. This arrangement ensures that, at the intersection between the leads and the GMR stack, virtually all the current moves out of the free layer into the leads thereby providing an effective read width for the device that is very close to the physical read width defined by the spacing between the two leads. A process for manufacturing the device is also described.Type: ApplicationFiled: August 17, 2001Publication date: February 20, 2003Applicant: Headway Technologies, Inc.Inventors: Kochan Ju, You Feng Zheng, Rod Lee