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: 8557407
    Abstract: A high performance TMR sensor is fabricated by incorporating a tunnel barrier having a Mg/MgO/Mg configuration. The 4 to 14 Angstroms thick lower Mg layer and 2 to 8 Angstroms thick upper Mg layer are deposited by a DC sputtering method while the MgO layer is formed by a NOX process involving oxygen pressure from 0.1 mTorr to 1 Torr for 15 to 300 seconds. NOX time and pressure may be varied to achieve a MR ratio of at least 34% and a RA value of 2.1 ohm-um2. The NOX process provides a more uniform MgO layer than sputtering methods. The second Mg layer is employed to prevent oxidation of an adjacent ferromagnetic layer. In a bottom spin valve configuration, a Ta/Ru seed layer, IrMn AFM layer, CoFe/Ru/CoFeB pinned layer, Mg/MgO/Mg barrier, CoFe/NiFe free layer, and a cap layer are sequentially formed on a bottom shield in a read head.
    Type: Grant
    Filed: August 6, 2010
    Date of Patent: October 15, 2013
    Assignee: Headway Technologies, Inc.
    Inventors: Tong Zhao, Kunliang Zhang, Hui Chuan Wang, Yu-Hsia Chen, Min Li
  • Patent number: 8484830
    Abstract: A CPP-GMR spin valve having a CoFe/NiFe composite free layer is disclosed in which Fe content of the CoFe layer ranges from 20 to 70 atomic % and Ni content in the NiFe layer varies, from 85 to 100 atomic % to maintain low Hc and ?s values. A small positive magnetostriction value in a Co75Fe25 layer is used to offset a negative magnetostriction value in a Ni90Fe10layer. The CoFe layer is deposited on a sensor stack in which a seed layer, AFM layer, pinned layer, and non-magnetic spacer layer are sequentially formed on a substrate. After a NiFe layer and capping layer are sequentially deposited on the CoFe layer, the sensor stack is patterned to give a sensor element with top and bottom surfaces and a sidewall connecting the top and bottom surfaces. Thereafter, a dielectric layer is formed adjacent to the sidewalls.
    Type: Grant
    Filed: April 4, 2011
    Date of Patent: July 16, 2013
    Assignee: Headway Technologies, Inc.
    Inventors: Kunliang Zhang, Min Li, Yu-Hsia Chen, Chyu-Jiuh Torng
  • Patent number: 8337676
    Abstract: A high performance TMR sensor is fabricated by incorporating a tunnel barrier having a Mg/MgO/Mg configuration. The 4 to 14 Angstroms thick lower Mg layer and 2 to 8 Angstroms thick upper Mg layer are deposited by a DC sputtering method while the MgO layer is formed by a NOX process involving oxygen pressure from 0.1 mTorr to 1 Torr for 15 to 300 seconds. NOX time and pressure may be varied to achieve a MR ratio of at least 34% and a RA value of 2.1 ohm-um2. The NOX process provides a more uniform MgO layer than sputtering methods. The second Mg layer is employed to prevent oxidation of an adjacent ferromagnetic layer. In a bottom spin valve configuration, a Ta/Ru seed layer, IrMn AFM layer, CoFe/Ru/CoFeB pinned layer, Mg/MgO/Mg barrier, CoFe/NiFe free layer, and a cap layer are sequentially formed on a bottom shield in a read head.
    Type: Grant
    Filed: August 5, 2010
    Date of Patent: December 25, 2012
    Assignee: Headway Technologies, Inc.
    Inventors: Tong Zhao, Kunliang Zhang, Hui Chuan Wang, Yu-Hsia Chen, Min Li
  • Patent number: 8289661
    Abstract: A CPP-GMR spin valve having a CoFe/NiFe composite free layer is disclosed in which Fe content of the CoFe layer ranges from 20 to 70 atomic % and Ni content in the NiFe layer varies from 85 to 100 atomic % to maintain low Hc and ?S values. A higher than normal Fe content in the CoFe layer improves the MR ratio by ?16% compared with conventional CoFe/NiFe free layers in which the Fe content in CoFe is typically <20 atomic % and the Ni content in NiFe is <85 atomic %. The CPP-GMR performance may also be optimized by incorporating a confining current path layer in the copper spacer between the pinned layer and free layer. For a pinned layer with an AP2/Ru/AP1 configuration, the spin valve performance is further improved by an AP1 layer comprised of a lamination of CoFe and Cu layers as in [CoFe/Cu]2/CoFe.
    Type: Grant
    Filed: April 4, 2011
    Date of Patent: October 16, 2012
    Assignee: Headway Technologies, Inc.
    Inventors: Kunliang Zhang, Min Li, Yu-Hsia Chen, Chyu-Jiuh Torng
  • Publication number: 20110302789
    Abstract: A hair trimmer includes a fixture having an upper and a lower tie plates, with an elastic element between the upper and lower tie plates; at least two cutting units at an end of the upper and lower tie plates, with each cutting unit having a corresponding cutting part, and an end of each cutting part having notches of different depths; and at least two combing units assembled with the upper and lower tie plates and corresponding to an exterior side of each cutting unit, with each combing unit including a teeth part which corresponds to each other and is parallel to the cutting part, and an end of each teeth part having comb slots of different depths. Therefore, a multiedged thinning can be carried out while trimming and it allows the hair to have more different levels of edge and a sense of beauty.
    Type: Application
    Filed: November 23, 2008
    Publication date: December 15, 2011
    Inventors: Chin-Chuan CHEN, Yu-Hsia Chen Yang, Hung-Chieh Chen, Cheng-I Chen, Cheng-Hsiang Chen
  • Patent number: 8012316
    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: Grant
    Filed: August 25, 2009
    Date of Patent: September 6, 2011
    Assignee: Headway Technologies, Inc.
    Inventors: Kunliang Zhang, Dan Abels, Min Li, Chyu-Jiuh Torng, Chen-Jung Chien, Yu-Hsia Chen
  • Patent number: 8008740
    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: September 23, 2009
    Date of Patent: August 30, 2011
    Assignee: Headway Technologies, Inc.
    Inventors: Tong Zhao, Hui-Chuan Wang, Kunliang Zhang, Yu-Hsia Chen, Min Li
  • Patent number: 7990660
    Abstract: An improved CPP magnetic read device whose oxide barrier comprises at least two separate CCP layers is disclosed. These two CCP layers differ in the PIT and IAO treatments that they received relative to the PIT/IAO treatment that would be used when only a single CCP layer is formed.
    Type: Grant
    Filed: January 14, 2011
    Date of Patent: August 2, 2011
    Assignee: Headway Technologies, Inc.
    Inventors: Kunliang Zhang, Min Li, Yu-Hsia Chen
  • Publication number: 20110183158
    Abstract: A CPP-GMR spin valve having a CoFe/NiFe composite free layer is disclosed in which Fe content of the CoFe layer ranges from 20 to 70 atomic % and Ni content in the NiFe layer varies from 85 to 100 atomic % to maintain low Hc and ?S values. A higher than normal Fe content in the CoFe layer improves the MR ratio by ?16% compared with conventional CoFe/NiFe free layers in which the Fe content in CoFe is typically <20 atomic % and the Ni content in NiFe is <85 atomic %. The CPP-GMR performance may also be optimized by incorporating a confining current path layer in the copper spacer between the pinned layer and free layer. For a pinned layer with an AP2/Ru/AP1 configuration, the spin valve performance is further improved by an AP1 layer comprised of a lamination of CoFe and Cu layers as in [CoFe/Cu]2/CoFe.
    Type: Application
    Filed: April 4, 2011
    Publication date: July 28, 2011
    Inventors: Kunliang Zhang, Min Li, Yu-Hsia Chen, Chyu-Jiuh Torng
  • Publication number: 20110179635
    Abstract: A CPP-GMR spin valve having a CoFe/NiFe composite free layer is disclosed in which Fe content of the CoFe layer ranges from 20 to 70 atomic % and Ni content in the NiFe layer varies from 85 to 100 atomic % to maintain low Hc and ?s values. A higher than normal Fe content in the CoFe layer improves the MR ratio by ?16% compared with conventional CoFe/NiFe free layers in which the Fe content in CoFe is typically <20 atomic % and the Ni content in NiFe is <85 atomic %. The CPP-GMR performance may also be optimized by incorporating a confining current path layer in the copper spacer between the pinned layer and free layer. For a pinned layer with an AP2/Ru/AP1 configuration, the spin valve performance is further improved by an AP1 layer comprised of a lamination of CoFe and Cu layers as in [CoFe/Cu]2/CoFe.
    Type: Application
    Filed: April 4, 2011
    Publication date: July 28, 2011
    Inventors: Kunliang Zhang, Min Li, Yu-Hsia Chen, Chyu-Jiuh Torng
  • Patent number: 7978440
    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: Grant
    Filed: January 9, 2008
    Date of Patent: July 12, 2011
    Assignee: Headway Technologies, Inc.
    Inventors: Min Li, Cheng T. Horng, Cherng Chyi Han, Yue Liu, Yu-Hsia Chen, Ru-Ying Tong
  • Publication number: 20110117388
    Abstract: An improved CPP magnetic read device whose oxide barrier comprises at least two separate CCP layers is disclosed. These two CCP layers differ in the PIT and IAO treatments that they received relative to the PIT/IAO treatment that would be used when only a single CCP layer is formed.
    Type: Application
    Filed: January 14, 2011
    Publication date: May 19, 2011
    Inventors: Kunliang Zhang, Min Li, Yu-Hsia Chen
  • Patent number: 7918014
    Abstract: A CPP-GMR spin valve having a CoFe/NiFe composite free layer is disclosed in which Fe content of the CoFe layer ranges from 20 to 70 atomic % and Ni content in the NiFe layer varies from 85 to 100 atomic % to maintain low Hc and ?S values. A small positive magnetostriction value in a Co75Fe25 layer is used to offset a negative magnetostriction value in a Ni90Fe10 layer. The CoFe layer is deposited on a sensor stack in which a seed layer, AFM layer, pinned layer, and non-magnetic spacer layer are sequentially formed on a substrate. After a NiFe layer and capping layer are sequentially deposited on the CoFe layer, the sensor stack is patterned to give a sensor element with top and bottom surfaces and a sidewall connecting the top and bottom surfaces. Thereafter, a dielectric layer is formed adjacent to the sidewalls.
    Type: Grant
    Filed: July 13, 2005
    Date of Patent: April 5, 2011
    Assignee: Headway Technologies, Inc.
    Inventors: Kunliang Zhang, Min Li, Yu-Hsia Chen, Chyu-Jiuh Torng
  • Patent number: 7872838
    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: Grant
    Filed: February 9, 2007
    Date of Patent: January 18, 2011
    Assignee: Headway Technologies, Inc.
    Inventors: Kunliang Zhang, Min Li, Yu-Hsia Chen
  • Publication number: 20100320076
    Abstract: A high performance TMR sensor is fabricated by incorporating a tunnel barrier having a Mg/MgO/Mg configuration. The 4 to 14 Angstroms thick lower Mg layer and 2 to 8 Angstroms thick upper Mg layer are deposited by a DC sputtering method while the MgO layer is formed by a NOX process involving oxygen pressure from 0.1 mTorr to 1 Torr for 15 to 300 seconds. NOX time and pressure may be varied to achieve a MR ratio of at least 34% and a RA value of 2.1 ohm-um2. The NOX process provides a more uniform MgO layer than sputtering methods. The second Mg layer is employed to prevent oxidation of an adjacent ferromagnetic layer. In a bottom spin valve configuration, a Ta/Ru seed layer, IrMn AFM layer, CoFe/Ru/CoFeB pinned layer, Mg/MgO/Mg barrier, CoFe/NiFe free layer, and a cap layer are sequentially formed on a bottom shield in a read head.
    Type: Application
    Filed: August 5, 2010
    Publication date: December 23, 2010
    Inventors: Tong Zhao, Kunliang Zhang, Hui Chuan Wang, Yu-Hsia Chen, Min Li
  • Publication number: 20100304185
    Abstract: A high performance TMR sensor is fabricated by incorporating a tunnel barrier having a Mg/MgO/Mg configuration. The 4 to 14 Angstroms thick lower Mg layer and 2 to 8 Angstroms thick upper Mg layer are deposited by a DC sputtering method while the MgO layer is formed by a NOX process involving oxygen pressure from 0.1 mTorr to 1 Torr for 15 to 300 seconds. NOX time and pressure may be varied to achieve a MR ratio of at least 34% and a RA value of 2.1 ohm-um2. The NOX process provides a more uniform MgO layer than sputtering methods. The second Mg layer is employed to prevent oxidation of an adjacent ferromagnetic layer. In a bottom spin valve configuration, a Ta/Ru seed layer, IrMn AFM layer, CoFe/Ru/CoFeB pinned layer, Mg/MgO/Mg barrier, CoFe/NiFe free layer, and a cap layer are sequentially formed on a bottom shield in a read head.
    Type: Application
    Filed: August 6, 2010
    Publication date: December 2, 2010
    Inventors: Tong Zhao, Kunliang Zhang, Hui Chuan Wang, Yu-Hsia Chen, Min Li
  • Patent number: 7780820
    Abstract: A high performance TMR sensor is fabricated by incorporating a tunnel barrier having a Mg/MgO/Mg configuration. The 4 to 14 Angstroms thick lower Mg layer and 2 to 8 Angstroms thick upper Mg layer are deposited by a DC sputtering method while the MgO layer is formed by a NOX process involving oxygen pressure from 0.1 mTorr to 1 Torr for 15 to 300 seconds. NOX time and pressure may be varied to achieve a MR ratio of at least 34% and a RA value of 2.1 ohm-um2. The NOX process provides a more uniform MgO layer than sputtering methods. The second Mg layer is employed to prevent oxidation of an adjacent ferromagnetic layer. In a bottom spin valve configuration, a Ta/Ru seed layer, IrMn AFM layer, CoFe/Ru/CoFeB pinned layer, Mg/MgO/Mg barrier, CoFe/NiFe free layer, and a cap layer are sequentially formed on a bottom shield in a read head.
    Type: Grant
    Filed: November 16, 2005
    Date of Patent: August 24, 2010
    Assignee: Headway Technologies, Inc.
    Inventors: Tong Zhao, Kunliang Zhang, Hui-Chuan Wang, Yu-Hsia Chen, Min Li
  • Patent number: 7672088
    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: Grant
    Filed: June 21, 2006
    Date of Patent: March 2, 2010
    Assignee: Headway Technologies, Inc.
    Inventors: Kunliang Zhang, Min Li, Yu-Hsia Chen, Hui-Chuan Wang, Tong Zhao
  • Publication number: 20100037453
    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: October 20, 2009
    Publication date: February 18, 2010
    Inventors: Kunliang Zhang, Daniel Gabels, Min Li, Yu-Hsia Chen
  • Publication number: 20100019333
    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: September 23, 2009
    Publication date: January 28, 2010
    Inventors: Tong Zhao, Hui-Chuan Wang, Kunliang Zhang, Yu-Hsia Chen, Min Li