Patents by Inventor Yu-Hsia Chen

Yu-Hsia Chen 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: 7646568
    Abstract: Improved magnetic devices have been fabricated by replacing the conventional seed layer (typically Ta) with a bilayer of Ru on Ta. Although both Ru and Ta layers are ultra thin (between 5 and 20 Angstroms), good exchange bias between the seed and the AFM layer (IrMn about 70 Angstroms thick) is retained. This arrangement facilitates minimum shield-to-shield spacing and gives excellent performance in CPP, CCP-CPP, or TMR configurations.
    Type: Grant
    Filed: December 23, 2005
    Date of Patent: January 12, 2010
    Assignee: Headway Technologies, Inc.
    Inventors: Kunliang Zhang, Hui-Chuan Wang, Tong Zhao, Yu-Hsia Chen, Min Li, Cherng-Chyi Han
  • Publication number: 20090314632
    Abstract: A method of forming a CPP-GMR spin valve having a pinned layer with an AP2/coupling/AP1 configuration is disclosed wherein the AP2 portion is a FCC-like trilayer having a composition represented by CoZFe(100-Z)/Fe(100-X)TaX/CoZFe(100-Z) or CoZFe(100-Z)/FeYCo(100-Y)/CoZFe(100-Z) where x is 3 to 30 atomic %, y is 40 to 100 atomic %, and z is 75 to 100 atomic %. Preferably, z is 90 to provide a face centered cubic structure that minimizes electromigration. Optionally, the middle layer is comprised of an Fe rich alloy such as FeCr, FeV, FeW, FeZr, FeNb, FeHf, or FeMo. EM performance is improved significantly compared to a spin valve with a conventional AP2 Co50Fe50 or Co75Fe25 single layer. MR ratio is also increased and RA is maintained at an acceptable level. The coupling layer is preferably Ru and the AP1 layer may be comprised of a lamination of CoFe and Cu layers as in [CoFe/Cu]2/CoFe.
    Type: Application
    Filed: August 25, 2009
    Publication date: December 24, 2009
    Inventors: Kunliang Zhang, Dan Abels, Min Li, Chyu-Jiuh Torng, Chen-Jung Chien, Yu-Hsia Chen
  • Patent number: 7610674
    Abstract: Concerns about inadequate electromigration robustness in CCP CPP GMR devices have been overcome by adding magnesium to the current confining structures that are presently in use. In one embodiment the alumina layer, in which the current carrying copper regions are embedded, is fully replaced by a magnesia layer. In other embodiments, alumina is still used but a layer of magnesium is included within the structure before it is subjected to ion assisted oxidation.
    Type: Grant
    Filed: February 13, 2006
    Date of Patent: November 3, 2009
    Assignee: Headway Technologies, Inc.
    Inventors: Kunliang Zhang, Daniel G Abels, Min Li, Yu-Hsia Chen
  • Patent number: 7602033
    Abstract: A high performance TMR sensor is fabricated by employing a composite inner pinned (AP1) layer in an AP2/Ru/AP1 pinned layer configuration. In one embodiment, there is a 10 to 80 Angstrom thick lower CoFeB or CoFeB alloy layer on the Ru coupling layer, a and 5 to 50 Angstrom thick Fe or Fe alloy layer on the CoFeB or CoFeB alloy, and a 5 to 30 Angstrom thick Co or Co rich alloy layer formed on the Fe or Fe alloy. A MR ratio of about 48% with a RA of <2 ohm-um2 is achieved when a CoFe AP2 layer, MgO (NOX) tunnel barrier, and CoFe/NiFe free layer are used in the TMR stack. Improved RA uniformity and less head noise are observed. Optionally, a CoFe layer may be inserted between the coupling layer and CoFeB or CoFeB alloy layer to improve pinning strength and enhance crystallization.
    Type: Grant
    Filed: May 29, 2007
    Date of Patent: October 13, 2009
    Assignee: Headway Technologies, Inc.
    Inventors: Tong Zhao, Hui-Chuan Wang, Kunliang Zhang, Yu-Hsia Chen, Min Li
  • Patent number: 7583481
    Abstract: A CPP-GMR spin valve having a pinned layer with an AP2/coupling/AP1 configuration is disclosed wherein the AP2 portion is a FCC-like trilayer having a composition represented by CoZFe(100-Z)/Fe(100-X)TaX/CoZFe(100-Z) or CoZFe(100-Z)/FeYCo(100-Y)/CoZFe(100-Z) where x is 3 to 30 atomic %, y is 40 to 100 atomic %, and z is 75 to 100 atomic %. Preferably, z is 90 to provide a face centered cubic structure that minimizes electromigration. Optionally, the middle layer is comprised of an Fe rich alloy such as FeCr, FeV, FeW, FeZr, FeNb, FeHf, or FeMo. EM performance is improved significantly compared to a spin valve with a conventional AP2 Co50Fe5 or Co75Fe25 single layer. The MR ratio of the spin valve is also increased and the RA is maintained at an acceptable level. The coupling layer is preferably Ru and the AP1 layer may be comprised of a lamination of CoFe and Cu layers as in [CoFe/Cu]2/CoFe.
    Type: Grant
    Filed: September 23, 2005
    Date of Patent: September 1, 2009
    Assignee: Headway Technologies, Inc.
    Inventors: Kunliang Zhang, Dan Abels, Min Li, Chyu-Jiuh Torng, Chen-Jung Chien, Yu-Hsia Chen
  • Publication number: 20080299679
    Abstract: A high performance TMR sensor is fabricated by employing a composite inner pinned (AP1) layer in an AP2/Ru/AP1 pinned layer configuration. In one embodiment, there is a 10 to 80 Angstrom thick lower CoFeB or CoFeB alloy layer on the Ru coupling layer, a and 5 to 50 Angstrom thick Fe or Fe alloy layer on the CoFeB or CoFeB alloy, and a 5 to 30 Angstrom thick Co or Co rich alloy layer formed on the Fe or Fe alloy. A MR ratio of about 48% with a RA of <2 ohm-um2 is achieved when a CoFe AP2 layer, MgO (NOX) tunnel barrier, and CoFe/NiFe free layer are used in the TMR stack. Improved RA uniformity and less head noise are observed. Optionally, a CoFe layer may be inserted between the coupling layer and CoFeB or CoFeB alloy layer to improve pinning strength and enhance crystallization.
    Type: Application
    Filed: May 29, 2007
    Publication date: December 4, 2008
    Inventors: Tong Zhao, Hui-Chuan Wang, Kunliang Zhang, Yu-Hsia Chen, Min Li
  • Publication number: 20080209741
    Abstract: A blade structure of an electric hair trimmer is a blade set, comprising a fixed blade, a movable blade and a vibration seat which is driven by a motor. A front end of both fixed and movable blades is provided with a plurality of teeth to cut the hair by an alternate movement. The lower sections of edge parts at two sides of a tooth of the movable blade are extended outward from top to bottom to form with externally expanded surfaces with sharp transection angles. Accordingly, when hair is cut, a contact area of the edge parts between the hair is decreased, to largely reduce resistance to cutting, such that the hair can be cut off well with improved speed and efficiency and can be prevented from being damaged. Besides, lifetime of usage of blade structure in the electric hair trimmer can be extended.
    Type: Application
    Filed: March 2, 2007
    Publication date: September 4, 2008
    Inventors: Chin-Chuan Chen, Yu-Hsia Chen Yang, Cheng-I Chen, Cheng-Hsiang Chen
  • Publication number: 20080192388
    Abstract: Improved performance uniformity among CPP magnetic read devices that include an oxide barrier has been achieved by fabricating the oxide layer from at least two separately formed CCP layers. Each CCP layer is given its own PIT and IAO treatment which is of shorter duration than the PIT/IAO treatment that is used when only a single CCP layer is formed.
    Type: Application
    Filed: February 9, 2007
    Publication date: August 14, 2008
    Inventors: Kunliang Zhang, Min Li, Yu-Hsia Chen
  • Publication number: 20080168658
    Abstract: A reciprocative electric hair trimmer is constituted by a seat, a blade body, and a mesh. An interior of the seat is provided with a reciprocative vibration mechanism; the blade body is fixed on the reciprocative vibration mechanism, and is formed into a piece of continuous bending surfaces. Lower concave surfaces of the continuous bending surfaces are fixed on the reciprocative vibration mechanism, and top surfaces of the continuous bending surfaces are formed with a plurality of blades. The mesh is mutually assembled with the seat, and conforms to an outline of the blade body. Accordingly, the present invention is provided with a great hair trimming effect and function, and can be also used to trim temples.
    Type: Application
    Filed: January 12, 2007
    Publication date: July 17, 2008
    Inventors: Chin-Chuan Chen, Yu-Hsia Chen Yang, Cheng-Hsiang Chen, Hung-Chieh Chen, Cheng-I Chen
  • Patent number: 7390529
    Abstract: By using a free layer that includes a NiFe layer containing between 65 and 72 atomic percent iron, an improved CPP GMR device has been created. The resulting structure yields a higher CPP GMR ratio than prior art devices, while maintaining free layer softness and acceptable magnetostriction. A process for manufacturing the device is also described.
    Type: Grant
    Filed: May 26, 2004
    Date of Patent: June 24, 2008
    Assignee: Headway Technologies, Inc.
    Inventors: Min Li, Cheng T. Horng, Cherng Chyi Han, Yu-Hsia Chen, Ru-Ying Tong
  • Publication number: 20080112089
    Abstract: Improved CPP GMR devices have been fabricated by replacing the conventional seed layer (typically Ta) with a bilayer of NiCr on Ta, said seed being deposited on the NiFe layer that constitutes a magnetic shield. Additional improvement was also obtained by replacing the conventional non-magnetic spacer layer of copper with a sandwich structure of two copper layers with an NOL (nano-oxide layer) between them. A process for manufacturing the devices is also described.
    Type: Application
    Filed: January 9, 2008
    Publication date: May 15, 2008
    Inventors: Min Li, Cheng Horng, Cherng Han, Yue Liu, Yu-Hsia Chen, Ru-Ying Tong
  • Patent number: 7355823
    Abstract: The effectiveness of an IrMn pinning layer in a CPP GMR device at high switching fields has been improved by replacing the conventional single layer seed by a layer of tantalum and either ruthenium or copper. The tantalum serves to cancel out the crystallographic influence of underlying layers while the ruthenium or copper provide a suitable base on which to grow the IrMn layer.
    Type: Grant
    Filed: January 26, 2005
    Date of Patent: April 8, 2008
    Assignee: Head Way Technologies, Inc.
    Inventors: Min Li, Kunliang Zhang, Chyu-Jiuh Torng, Yu-Hsia Chen
  • Patent number: 7352543
    Abstract: The effectiveness of an IrMn pinning layer in a CPP GMR device at high switching fields has been improved by replacing the conventional single layer seed by a layer of tantalum and either ruthenium or copper. The tantalum serves to cancel out the crystallographic influence of underlying layers while the ruthenium or copper provide a suitable base on which to grow the IrMn layer.
    Type: Grant
    Filed: January 26, 2005
    Date of Patent: April 1, 2008
    Assignee: Headway Technologies, Inc.
    Inventors: Min Li, Kunliang Zhang, Chyu-Jiuh Torng, Yu-Hsia Chen
  • Patent number: 7333306
    Abstract: A TMR sensor, a CPP GMR sensor and a CCP CPP GMR sensor all include a tri-layered free layer that is of the form CoFe/CoFeB/NiFe, where the atom percentage of Fe can vary between 5% and 90% and the atom percentage of B can vary between 5% and 30%. The sensors also include SyAP pinned layers which, in the case of the GMR sensors include at least one layer of CoFe laminated onto a thin layer of Cu. In the CCP CPP sensor, a layer of oxidized aluminum containing segregated particles of copper is formed between the spacer layer and the free layer. All three configurations exhibit extremely good values of coercivity, areal resistance, GMR ratio and magnetostriction.
    Type: Grant
    Filed: August 23, 2005
    Date of Patent: February 19, 2008
    Assignee: Headway Technologies, Inc.
    Inventors: Tong Zhao, Kunliang Zhang, Hui-Chuan Wang, Yu-Hsia Chen, Min Li
  • Patent number: 7331100
    Abstract: An improved seed/AFM structure is formed by first depositing a layer of tantalum on the lower shield. A NiCr layer is then deposited on the Ta followed by a layer of IrMn. The latter functions effectively as an AFM for thicknesses in the 40-80 Angstrom range, enabling a reduced shield-to-shield spacing.
    Type: Grant
    Filed: July 7, 2004
    Date of Patent: February 19, 2008
    Assignee: Headway Technologies, Inc.
    Inventors: Min Li, Cheng T. Horng, Cherng Chyi Han, Yue Liu, Yu-Hsia Chen, Ru-Ying Tong
  • Publication number: 20070297103
    Abstract: A spin valve structure is disclosed in which an AP1 layer and/or free layer are made of a laminated Heusler alloy having Al or FeCo insertion layers. The ordering temperature of a Heusler alloy such as Co2MnSi is thereby lowered from about 350° C. to 280° C. which becomes practical for spintronics device applications. The insertion layer is 0.5 to 5 Angstroms thick and may also be Sn, Ge, Ga, Sb, or Cr. The AP1 layer or free layer can contain one or two additional FeCo layers to give a configuration represented by FeCo/[HA/IL]nHA, [HA/IL]nHA/FeCo, or FeCo/[HA/IL]nHA/FeCo where n is an integer?1, HA is a Heusler alloy layer, and IL is an insertion layer. Optionally, a Heusler alloy insertion scheme is possible by doping Al or FeCo in the HA layer. For example, Co2MnSi may be co-sputtered with an Al or FeCo target or with a Co2MnAl or Co2FeSi target.
    Type: Application
    Filed: June 21, 2006
    Publication date: December 27, 2007
    Inventors: Kunliang Zhang, Min Li, Yu-Hsia Chen, Hui-Chuan Wang, Tong Zhao
  • Patent number: 7288281
    Abstract: Fe rich CoFe can be used in AP1 to enhance CPP GMR. However, this is found to degrade the electro-migration performance of the device. This problem has been solved by using an AP1 that is a laminate of several CoFe(25%) layers, separated from one another by copper layers. Ultra-thin layers of iron-rich CoFe are then inserted at all the copper-CoFe interfaces.
    Type: Grant
    Filed: September 2, 2004
    Date of Patent: October 30, 2007
    Assignee: Headway Technologies, Inc.
    Inventors: Min Li, Kunliang Zhang, Cheng T. Horng, Chyu Jiuh Torng, Yu-Hsia Chen, Ru-Ying Tong
  • Publication number: 20070188936
    Abstract: Concerns about inadequate electromigration robustness in CCP CPP GMR devices have been overcome by adding magnesium to the current confining structures that are presently in use. In one embodiment the alumina layer, in which the current carrying copper regions are embedded, is fully replaced by a magnesia layer. In other embodiments, alumina is still used but a layer of magnesium is included within the structure before it is subjected to ion assisted oxidation.
    Type: Application
    Filed: February 13, 2006
    Publication date: August 16, 2007
    Inventors: Kunliang Zhang, Daniel Abels, Min Li, Yu-Hsia Chen
  • Patent number: 7238979
    Abstract: An MTJ (magnetic tunneling junction) device particularly suitable for use as an MRAM (magnetic random access memory) or a tunneling magnetoresistive (TMR) read sensor, is formed on a seed layer which allows the tunneling barrier layer to be ultra-thin, smooth, and to have a high breakdown voltage. The seed layer is a layer of NiCr which is formed on a sputter-etched layer of Ta. The tunneling barrier layer for the MRAM is formed from a thin layer of Al which is radically oxidized (ROX), in-situ, to form the layer with characteristics described above. The tunneling barrier layer for the read sensor formed from a thin layer of Al or a HfAl bilayer which is naturally oxidized (NOX), in-situ, to form the barrier layer. The resulting device has generally improved performance characteristics in terms of GMR ratio and junction resistance.
    Type: Grant
    Filed: September 26, 2005
    Date of Patent: July 3, 2007
    Assignees: Headway Technologies, Inc., Applied Spintronics, Inc.
    Inventors: Cheng T. Horng, Liubo Hong, Ru-Ying Tong, Yu-Hsia Chen
  • Publication number: 20070146928
    Abstract: Improved magnetic devices have been fabricated by replacing the conventional seed layer (typically Ta) with a bilayer of Ru on Ta. Although both Ru and Ta layers are ultra thin (between 5 and 20 Angstroms), good exchange bias between the seed and the AFM layer (IrMn about 70 Angstroms thick) is retained. This arrangement facilitates minimum shield-to-shield spacing and gives excellent performance in CPP, CCP-CPP, or TMR configurations.
    Type: Application
    Filed: December 23, 2005
    Publication date: June 28, 2007
    Inventors: Kunliang Zhang, Hui-Chuan Wang, Tong Zhao, Yu-Hsia Chen, Min Li, Cherng-Chyi Han